Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. Zinc oxide as a low expansion, secondary flux improves the elasticity of glazes by reducing the change in viscosity as a function of temperature and helps prevent crazing and shivering. By substituting ZnO for BaO and PbO, the heat capacity is decreased and the thermal conductivity is increased.
Ceramic industry
Zinc oxide
Zinc oxide | Ceramic industry
It is used in ceramic glaze and frit compositions. Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics. Ceramic glaze and frit compositions and used in small amounts improves the development of glossy and brilliant surfaces. Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics.
describe in general terms the structure of ionic solids such as nacl
user
Ions typically pack into extremely regular crystalline structures, in an arrangement that minimizes the lattice energy.
assistant
what can you tell me about their boiling point?
user
Boiling points exhibit similar trends to melting points in terms of the size of ions and strength of other interactions. When vapourized, the ions are still not freed of one another.
assistant
can you name any compounds?
user
Ammonium acetate, zinc oxide, aluminum hydroxide,  aluminium oxide and lead(II) oxide.
assistant
what are the uses of the aforesaid initial one?
user
It is also used as a diuretic.
assistant
what can you tell me about its production?
user
Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia.
assistant
what are the applications of the second one?
user
It is used for making plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
assistant
how is it used in the ceramic industry?
user
Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coefficient of expansion are desirable properties in the production of ceramics. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. Zinc oxide as a low expansion, secondary flux improves the elasticity of glazes by reducing the change in viscosity as a function of temperature and helps prevent crazing and shivering. By substituting ZnO for BaO and PbO, the heat capacity is decreased and the thermal conductivity is increased.
Zinc oxide | Ceramic industry
Zinc in small amounts improves the development of glossy and brilliant surfaces. However, in moderate to high amounts, it produces matte and crystalline surfaces. With regard to color, zinc has a complicated influence.
Zinc oxide | Ceramic industry
Roughly one quarter of all zinc output in the United States in 2009 was consumed in zinc compounds; a variety of which are used industrially. Zinc oxide is widely used as a white pigment in paints and as a catalyst in the manufacture of rubber to disperse heat. Zinc oxide is used to protect rubber polymers and plastics from ultraviolet radiation (UV). The semiconductor properties of zinc oxide make it useful in varistors and photocopying products. The zinc zinc-oxide cycle is a two step thermochemical process based on zinc and zinc oxide for hydrogen production. Zinc chloride is often added to lumber as a fire retardant and sometimes as a wood preservative.
Zinc | Other industrial uses
Between 50% and 60% of ZnO use is in the rubber industry. Zinc oxide along with stearic acid is used in the vulcanization of rubber ZnO additive also protect rubber from fungi (see medical applications) and UV light.
Zinc oxide | Rubber manufacture
One of the advantages of computerized dentistry (CAD/CAM technologies) involves the use of machinable ceramics which are sold in a partially sintered, machinable state that is fired again after machining to form a hard ceramic. Some of the materials used are glass-bonded porcelain (Viablock), lithium disilicate glass-ceramic (a ceramic crystallizing from a glass by special heat treatment), and phase stabilized zirconia (zirconium dioxide, ZrO). Previous attempts to utilize high-performance ceramics such as zirconium-oxide were thwarted by the fact that this material could not be processed using the traditional methods used in dentistry. Because of its high strength and comparatively much higher fracture toughness, sintered zirconium oxide can be used in posterior crowns and bridges, implant abutments, and root dowel pins.
Dental restoration | Porcelain (ceramics)
Yttrium oxide is used to stabilize the Zirconia in late-generation porcelain-free metal-free dental ceramics. This is a very hard ceramic used as a strong base material in some full ceramic restorations. The zirconia used in dentistry is zirconium oxide which has been stabilized with the addition of yttrium oxide. The full name of zirconia used in dentistry is "yttria-stabilized zirconia" or YSZ.
Yttrium(III) oxide | Dental ceramics
Some ceramics are semiconductors. Most of these are transition metal oxides that are II-VI semiconductors, such as zinc oxide. While there are prospects of mass-producing blue LEDs from zinc oxide, ceramicists are most interested in the electrical properties that show grain boundary effects. One of the most widely used of these is the varistor. These are devices that exhibit the property that resistance drops sharply at a certain threshold voltage. Once the voltage across the device reaches the threshold, there is a breakdown of the electrical structure in the vicinity of the grain boundaries, which results in its electrical resistance dropping from several megohms down to a few hundred ohms.
Ceramic | Semiconductors
Ceramic manufacturers primarily use lead(II) oxide (PbO) as a flux for its low melting range, wide firing range, low surface tension, high index of refraction, and resistance to devitrification. Lead used in the manufacture of commercial glazes are molecularly bound to silica in a 1:1 ratio, or included in frit form, to ensure stabilization and reduce the risk of leaching. In polluted environments, nitrogen dioxide reacts with water () to produce nitrous acid () and nitric acid (). Soluble Lead(II) nitrate () forms when lead(II) oxide (PbO) of leaded glazes is exposed to nitric acid ()
Ceramic glaze | Lead(II) oxide
The applications of zinc oxide powder are numerous, and the principal ones are summarized below. Most applications exploit the reactivity of the oxide as a precursor to other zinc compounds. For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties. Consequently, it is added into materials and products including plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
Zinc oxide | Applications
The very low thermal conductivity of cubic phase of zirconia also has led to its use as a thermal barrier coating, or TBC, in jet and diesel engines to allow operation at higher temperatures. Thermodynamically, the higher the operation temperature of an engine, the greater the possible efficiency. Another low thermal conductivity use is a ceramic fiber insulation for crystal growth furnaces, fuel cell stack insulation and infrared heating systems. This material is also used in dentistry in the manufacture of 1) subframes for the construction of dental restorations such as crowns and bridges, which are then veneered with a conventional feldspathic porcelain for aesthetic reasons, or of 2) strong, extremely durable dental prostheses constructed entirely from monolithic zirconia, with limited but constantly improving aesthetics.
Zirconium dioxide | Niche uses
Zinc oxide is an inorganic compound with the formula . ZnO is a white powder that is insoluble in water. It is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically. ZnO is a wide-band gap semiconductor of the II-VI semiconductor group. The native doping of the semiconductor due to oxygen vacancies or zinc interstitials is n-type. Other favorable properties include good transparency, high electron mobility, wide band gap, and strong room-temperature luminescence.
Zinc oxide | Introduction
In halogen-free system, zinc borate can be used together with alumina trihydrate, magnesium hydroxide, red phosphorus, or ammonium polyphosphate. During burning the plastics, a porous borate ceramics is formed that protects the underlying layers. In presence of silica, borosilicate glass can be formed at plastic burning temperatures.
Zinc borate | Uses
Industrial applications include wood preservation, manufacturing other zinc salts, polymers, manufacture of ethyl acetate, as a dye mordant, and analytical reagent. It is used in commercial nuclear power plants as a plating inhibitor on primary water piping.
Zinc acetate | Industrial applications
In the indirect or French process, metallic zinc is melted in a graphite crucible and vaporized at temperatures above 907 °C (typically around 1000 °C). Zinc vapor reacts with the oxygen in the air to give ZnO, accompanied by a drop in its temperature and bright luminescence. Zinc oxide particles are transported into a cooling duct and collected in a bag house. This indirect method was popularized by LeClaire (France) in 1844 and therefore is commonly known as the French process. Its product normally consists of agglomerated zinc oxide particles with an average size of 0.1 to a few micrometers.
Zinc oxide | Indirect process
Coke is now widely used to produce carbide ceramics. Potter Josiah Wedgwood opened the first modern ceramics factory in Stoke-on-Trent, England, in 1759. Austrian chemist Carl Josef Bayer, working for the textile industry in Russia, developed a process to separate alumina from bauxite ore in 1888. The Bayer process is still used to purify alumina for the ceramic and aluminium industries. Brothers Pierre and Jacques Curie discovered piezoelectricity in Rochelle salt circa 1880. Piezoelectricity is one of the key properties of electroceramics. E.G. Acheson heated a mixture of coke and clay in 1893, and invented carborundum, or synthetic silicon carbide.
Ceramic engineering | History
A small amount of industrial production involves wet chemical processes, which start with aqueous solutions of zinc salts, from which zinc carbonate or zinc hydroxide is precipitated. The solid precipitate is then calcined at temperatures around 800 °C.
Zinc oxide | Wet chemical process
The whiteness resulting from the use of zirconia has been described as more "clinical" than that from tin oxide and is preferred in some applications. Nevertheless, tin oxide still finds use in ceramic manufacture and has been widely used as the opacifier in sanitaryware, with up to 6% used in glazes. Otherwise, tin oxide in glazes, often in conjunction with zircon compounds, is generally restricted to specialist low temperature applications and use by studio potters.
Tin-glazed pottery | Current use
The special character of ceramic materials gives rise to many applications in materials engineering, electrical engineering, chemical engineering and mechanical engineering. As ceramics are heat resistant, they can be used for many tasks for which materials like metal and polymers are unsuitable. Ceramic materials are used in a wide range of industries, including mining, aerospace, medicine, refinery, food and chemical industries, packaging science, electronics, industrial and transmission electricity, and guided lightwave transmission.
Ceramic engineering | Introduction
Metals used in ceramic glazes are typically in the form of metal oxides.
Ceramic glaze | Metal oxide chemistry
This produces zinc sulfide, together with large amounts of hot gas, heat, and light.
Zinc | Other industrial uses
The company's largest source of revenue comes from the production of over 300 billion coin blanks annually. The company also supplies zinc strips used in various cathodic protection, building, automotive, architectural, and specialty products. Such products include zinc galvanic anodes, LifeJacket, and LifeDowel automotive blade fuses, metal flashing, guttering systems, plumbing hardware, wall cladding, braille, organ pipes, counter tops, signs, and medals among other niche items.
Jarden Zinc Products | Products
A further example is an oxide CMC lifting gate for a sintering furnace, which has survived more than 260,000 opening cycles.
Ceramic matrix composite | Application of oxide CMC in burner and hot gas ducts
It is used in the manufacture of other chemicals. Zinc methyl () is used in a number of organic syntheses. Zinc sulfide (ZnS) is used in luminescent pigments such as on the hands of clocks, X-ray and television screens, and luminous paints. Crystals of ZnS are used in lasers that operate in the mid-infrared part of the spectrum. Zinc sulfate is a chemical in dyes and pigments. Zinc pyrithione is used in antifouling paints. Zinc powder is sometimes used as a propellant in model rockets. When a compressed mixture of 70% zinc and 30% sulfur powder is ignited there is a violent chemical reaction.
Zinc | Other industrial uses
These characteristics limit the use of alumina. For molten metals, alumina is used only with gold and platinum. These fibers demonstrate corrosion properties similar to alumina, but commercially available fibers are not very pure and therefore less resistant. Because of creep at temperatures above 1000 °C, there are only a few applications for oxide CMCs.
Ceramic matrix composite | Corrosion properties
ZOE cements were introduced in the 1890s. Zinc oxide eugenol is also used as an impression material during construction of complete dentures and is used in the mucostatic technique of taking impressions, usually in a special tray, (acrylic) produced after primary alginate impressions. However, ZOE is not usually used if the patient has large undercuts or tuberosities, whereby silicone impression materials would be better suited. Zinc oxide eugenol is also used as an antimicrobial additive in paint.
Zinc oxide eugenol | Introduction
ZnO is a relatively soft material with approximate hardness of 4.5 on the Mohs scale. Its elastic constants are smaller than those of relevant III-V semiconductors, such as GaN. The high heat capacity and heat conductivity, low thermal expansion and high melting temperature of ZnO are beneficial for ceramics. The E2 optical phonon in ZnO exhibits an unusually long lifetime of 133 ps at 10 K. Among the tetrahedrally bonded semiconductors, it has been stated that ZnO has the highest piezoelectric tensor, or at least one comparable to that of GaN and AlN. This property makes it a technologically important material for many piezoelectrical applications, which require a large electromechanical coupling.
Zinc oxide | Mechanical properties
The direct or American process starts with diverse contaminated zinc composites, such as zinc ores or smelter by-products. The zinc precursors are reduced (carbothermal reduction) by heating with a source of carbon such as anthracite to produce zinc vapor, which is then oxidized as in the indirect process. Because of the lower purity of the source material, the final product is also of lower quality in the direct process as compared to the indirect one.
Zinc oxide | Direct process
It then quickly fell back to a routine 80 cents by July 2010. Zinc is popular in manufacturing and building; its ability to create corrosion-resistant zinc plating of steel (hot-dip galvanizing) is the major application for zinc. Other applications are in batteries and alloys, such as brass. A variety of zinc compounds are commonly used, such as zinc carbonate and zinc gluconate (as dietary supplements), zinc chloride (in deodorants), zinc pyrithione (anti-dandruff shampoos), zinc sulfide (in luminescent paints), and zinc methyl or zinc diethyl in the organic laboratory.
2000s commodities boom | Zinc
The products of technical ceramics include tiles used in the Space Shuttle program, gas burner nozzles, ballistic protection, nuclear fuel uranium oxide pellets, bio-medical implants, jet engine turbine blades, and missile nose cones. Its products are often made from materials other than clay, chosen for their particular physical properties. These may be classified as follows: Ceramics can be used in many technological industries. One application is the ceramic tiles on NASA's Space Shuttle, used to protect it and the future supersonic space planes from the searing heat of re-entry into the Earth's atmosphere. They are also used widely in electronics and optics.
Ceramic engineering | Applications
Other additives such as AlO and YO have also been used during the hot pressing of ZrB-SiC composites at 1800 °C. These additives react with impurities to form a transient liquid phase and promote sintering of the diboride composites. The addition of rare earth oxides such as YO, YbO, LaO and NdO can lower densification temperatures and can react with surface oxides to promote densification. Hot pressing may result in improved densities for UHTCs, but it is an expensive technique that relies on high temperatures and pressures to provide useful materials. Pressureless sintering is another method for processing and densifying UHTCs.
Ultra-high-temperature ceramics | Processing of UHTCs and the addition of SiC
The New Jersey Zinc process is no longer used to produce primary zinc in the U.S., in Europe and Japan, however it still is used to treat secondary operations. This process peaked in 1960, when it accounted for 5% of world zinc production. A modified version of this process is still used at Huludao, China, which produced 65,000 metric tons per year. This process begins by roasting concentrates that are mixed with coal and briquetted in two stages. The briquettes are then heated in an autogenous coker at and then charged into the retort. There are three reasons to briquette the calcine: to ensure free downward movement of the charge; to permit heat transfer across a practical size cross-section; to allow adequate porosity for the passage of reduced zinc vapour to the top of the retort.
Zinc smelting | New Jersey Zinc continuous vertical retort
Oxygen-containing gas at temperatures above is rather corrosive for metal and silicon carbide components. Such components, which are not exposed to high mechanical stress, can be made of oxide CMCs, which can withstand temperatures up to . The gallery below shows the flame holder of a crispbread bakery as tested after for 15,000 hours, which subsequently operated for a total of more than 20,000 hours. Flaps and ventilators circulating hot, oxygen-containing gases can be fabricated in the same shape as their metal equivalents. The lifetime for these oxide CMC components is several times longer than for metals, which often deform.
Ceramic matrix composite | Application of oxide CMC in burner and hot gas ducts
Dielectric materials used for construction of ceramic capacitors include: Lead Zirconate titanate (PZT), Barium titanate(BT), strontium titanate (ST), calcium titanate (CT), magnesium titanate (MT), calcium magnesium titanate (CMT), zinc titanate (ZT), lanthanum titanate (LT), and neodymium titanate (NT), barium zirconate (BZ), calcium zirconate (CZ), lead magnesium niobate (PMN), lead zinc niobate (PZN), lithium niobate (LN), barium stannate (BS), calcium stannate (CS), magnesium aluminium silicate, magnesium silicate, barium tantalate, titanium dioxide, niobium oxide, zirconia, silica, sapphire, beryllium oxide, and zirconium tin titanate Some piezoelectric materials can be used as well; the EIA Class 2 dielectrics are based on mixtures rich on barium titanate.
Electroceramics | Dielectric ceramics
Tin oxide has been widely used as the opacifier in sanitaryware glazes. In this application, additions of up to 6% are reported to be in then-current use. The cost of tin oxide rose considerably during the 1914-1918 war, and resulted in a search for cheaper alternatives. The first successful replacement was zirconia and later zircon. Whilst zirconium compounds are not as effective their low price led to a gradual increase in popularity with an associated reduction in use of tin oxide. Today, tin oxide usage in glazes finds limited use in conjunction with zircon compounds, although it is generally restricted to specialist low temperature applications and use by studio potters.
Tin-glazing | Current use and alternatives
Materials fabricated from zirconium metal and ZrO are used in space vehicles where resistance to heat is needed. High temperature parts such as combustors, blades, and vanes in jet engines and stationary gas turbines are increasingly being protected by thin ceramic layers, usually composed of a mixture of zirconia and yttria.
Zirconium | Space and aeronautic industries
Unfortunately above a certain temperature (it depends on environmental conditions of oxygen partial pressure) starts the active oxidation of silicon carbide matrix to gaseous silicon monoxide (SiO), consequently loss of protection from further oxidation, which leads the material to an uncontrolled and fast erosion. For this reason C/SiC and SiC/SiC are used in the range of temperature between 1200° - 1400 °C. On the one hand CMCs are lightweight materials with high strength-to-weight ratio even at high temperature, high thermal shock resistance and toughness but suffer of erosion during service. On the other side bulk ceramics made of UHTCs (e.g.
Ultra high temperature ceramic matrix composite | Introduction
Zinc borate is primarily used as a flame retardant in plastics and cellulose fibers, paper, rubbers and textiles. It is also used in paints, adhesives, and pigments. As a flame retardant, it can replace antimony(III) oxide as a synergist in both halogen-based and halogen-free systems. It is an anti-dripping and char-promoting agent, and suppresses the afterglow. In electrical insulator plastics it suppresses arcing and tracking. In halogen-containing systems, zinc borate is used together with antimony trioxide and alumina trihydrate. It catalyzes formation of char and creates a protective layer of glass. Zinc catalyzes the release of halogens by forming zinc halides and zinc oxyhalides.
Zinc borate | Uses
For industrial use, ZnO is produced at levels of 10 tons per year by three main processes:
Zinc oxide | Production
Zirconium nitride is a hard ceramic material similar to titanium nitride and is a cement-like refractory material. Thus it is used in refractories, cermets and laboratory crucibles. When applied using the physical vapor deposition coating process it is commonly used for coating medical devices, industrial parts (notably drill bits), automotive and aerospace components and other parts subject to high wear and corrosive environments. When alloyed with Al, the electronic structure develops from local octahedral bond symmetry of cubic ZrN that distorts for increasing Al content into more complex bonding and higher hardness. Zirconium nitride was suggested as a hydrogen peroxide fuel tank liner for rockets and aircraft.
Zirconium nitride | Uses
With this method, one material located between the fibers reacts with a second material to form the ceramic matrix. Some conventional ceramics are also manufactured by chemical reactions. For example, reaction-bonded silicon nitride (RBSN) is produced through the reaction of silicon powder with nitrogen, and porous carbon reacts with silicon to form reaction bonded silicon carbide, a silicon carbide which contains inclusions of a silicon phase. An example of CMC manufacture, which was introduced for the production of ceramic brake discs, is the reaction of silicon with a porous preform of C/C. The process temperature is above , that is above the melting point of silicon, and the process conditions are controlled such that the carbon fibers of the C/C-preform almost completely retain their mechanical properties.
Ceramic matrix composite | Matrix forming via chemical reaction
Zirconia stabilized with yttria (yttrium oxide), known as yttria-stabilized zirconia, can be used as a strong base material in some full ceramic crown restorations. Transformation toughened zirconia is used to make ceramic knives. Because of the hardness, ceramic-edged cutlery stays sharp longer than steel edged products.
Zirconium dioxide | Niche uses
Calcium fluoride was also used, especially in China. For dental ceramics, several approaches are in use. Spodumene or mica crystals can be precipitated. Fluorides of aluminium, calcium, barium, and magnesium can be used with suitable heat treatment. Tin oxide can be used, but zirconia and titania give better results; for titania, the appropriate resulting particle size is between submicron to 20 µm. Another desirable opacifier is zinc oxide. Opacifiers must also form small particles in the system. Opacifiers are generally inert.
Opacifier | Glasses
Traditional ceramic raw materials include clay minerals such as kaolinite, whereas more recent materials include aluminium oxide, more commonly known as alumina. The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide and tungsten carbide. Both are valued for their abrasion resistance and hence find use in applications such as the wear plates of crushing equipment in mining operations. Advanced ceramics are also used in the medicine, electrical, electronics industries and body armor.
Ceramic | Materials
Commercially used piezoceramic is primarily lead zirconate titanate (PZT). Barium titanate (BT), strontium titanate (ST), quartz, and others are also used. See .
Electroceramics | Piezoelectric and ferroelectric ceramics
"Chrome is a rather versatile and fickle colorant," (Chappell). Chrome oxide (CrO) is commonly used for achieving greens. However, in the presence of zinc, chrome can produce brown. Glazes with tin oxide present will often blush to pink if fumed with chrome or if chrome is present in the glaze with the tin, often intense pinks occur. If fired above cone 6, chrome will fume and become a gas in the kiln. Common saturation percentages for chrome at low saturation range from (.25 to .5%) and at higher percentages from (1 to 2%). Chrome is a refractory.
Ceramic colorants | Chrome
By weight, most of the world's zinc oxide is manufactured via French process.
Zinc oxide | Indirect process
Copper(II) hydroxide is also occasionally used as ceramic colorant.
Copper(II) hydroxide | Uses
This process is used to manufacture oxide fiber/oxide matrix CMC materials. Since most ceramic fibers cannot withstand the normal sintering temperatures of above , special precursor liquids are used to infiltrate the preform of oxide fibers. These precursors allow sintering, that is ceramic-forming processes, at temperatures of 1000–1200 °C. They are, for example, based on mixtures of alumina powder with the liquids tetra-ethyl-orthosilicate (as Si donor) and aluminium-butylate (as Al donor), which yield a mullite matrix. Other techniques, such as sol–gel process chemistry, are also used. CMCs obtained with this process usually have a high porosity of about 20%.
Ceramic matrix composite | Matrix forming via sintering
During World War II, the company again manufactured primarily for the US military. However, the company was declared a non-essential factory and was not permitted to replace employees who left to serve in the military. Having lost some of its best skilled labor and with competitors not subject to similar regulation, the company turned to automation, with new equipment funded by the sale of several buildings. In 1946, Robert E. Gould (1900–1979), known in the ceramics industry as the "master potter," was named president. By this time, economic efficiency had forced the company to drop customization in favor of mass production of a limited catalog of designs.
Buffalo China | Intermediate years
Zirconium oxide is used due to its polymorphism. It exists in three phases: monoclinic, tetragonal and cubic. Cooling to the monoclinic phase after sintering causes a large volume change, which often causes stress fractures in pure zirconia. Additives such as magnesia, calcia and yttria are used in manufacturing the knife material to stabilize the high-temperature phases and minimize this volume change. The highest strength and toughness is produced by the addition of 3 mol% yttrium oxide yielding partially stabilized zirconia. This material consists of a mixture of tetragonal and cubic phases with a bending strength of nearly 1,200 MPa. Small cracks allow phase transformations to occur, which essentially close the cracks and prevent catastrophic failure, resulting in a relatively tough ceramic material, sometimes known as TTZ (transformation-toughened zirconia).
Ceramic knife | Zirconium oxide
Since the 1930s zinc peroxide has been applied in a variety of settings, from medicine to aesthetics and even fireworks.
Zinc peroxide | Applications
Chromium oxidation during manufacturing processes can be reduced with the introduction of compounds that bind to calcium. Ceramic industries are reluctant to use lead alternatives since leaded glazes provide products with a brilliant shine and smooth surface. The United States Environmental Protection Agency has experimented with a dual glaze, barium alternative to lead, but they were unsuccessful in achieving the same optical effect as leaded glazes.
Ceramic glaze | Prevention
• 2013 F. Cai, "The Hazards of Polishing Waste Residue which Used in the Cement Admixtures," Foshan Ceramic, no. 2, p. 63, 2013. (in Chinese) • 2011 F. Cai, "The application of chromium-containing products in the ceramic industry and relevant pollution prevention measures," Foshan Ceramic, no. 9, p. 56, 2011. (in Chinese) • 2010 F. Cai, "Discussion on the problem of super white washed mud which used in polishing bricks," Foshan Ceramic, no. 6, p. 50, 2010. (in Chinese) F. Cai, "The basic principles and production control of spray drying technology," Foshan Ceramic, no. 1, pp. 18–27, 2010. (in Chinese)
Cai Feihu | Main Published Articles
Ceramic solids are composed of inorganic compounds, usually oxides of chemical elements. They are chemically inert, and often are capable of withstanding chemical erosion that occurs in an acidic or caustic environment. Ceramics generally can withstand high temperatures ranging from 1000 to 1600 °C (1800 to 3000 °F). Exceptions include non-oxide inorganic materials, such as nitrides, borides and carbides. Traditional ceramic raw materials include clay minerals such as kaolinite, more recent materials include aluminium oxide (alumina). The modern ceramic materials, which are classified as advanced ceramics, include silicon carbide and tungsten carbide. Both are valued for their abrasion resistance, and hence find use in such applications as the wear plates of crushing equipment in mining operations.
Solid | Ceramics
Although dependent on the other constituents the solubility of tin oxide in glaze melts is generally low. Its solubility is increased by NaO, KO and BO, and reduced by CaO, BaO, ZnO, AlO, and to a limited extent PbO. SnO has been used as pigment in the manufacture of glasses, enamels and ceramic glazes. Pure SnO gives a milky white colour; other colours are achieved when mixed with other metallic oxides e.g. VO yellow; CrO pink; and SbO grey blue.
Tin(IV) oxide | Ceramic glazes
Other less dominant applications include the vulcanization of rubber and the production of certain pigments and paints. PbO is used in cathode ray tube glass to block X-ray emission, but mainly in the neck and funnel because it can cause discoloration when used in the faceplate. Strontium oxide is preferred for the faceplate. The consumption of lead, and hence the processing of PbO, correlates with the number of automobiles, because it remains the key component of automotive lead-acid batteries.
Lead(II) oxide | Applications
During WWI, zinc was used for ammunition, weapons, sheet metal, and boiler plates. After WWI, zinc was used for auto parts, brass, linoleum, batteries, semiconductors, pharmaceuticals, and rubber tires.
Matthiessen and Hegeler Zinc Company | Zinc uses
Zirconium dioxide is one of the most studied ceramic materials. ZrO adopts a monoclinic crystal structure at room temperature and transitions to tetragonal and cubic at higher temperatures. The change of volume caused by the structure transitions from tetragonal to monoclinic to cubic induces large stresses, causing it to crack upon cooling from high temperatures. When the zirconia is blended with some other oxides, the tetragonal and/or cubic phases are stabilized. Effective dopants include magnesium oxide (MgO), yttrium oxide (YO, yttria), calcium oxide (CaO), and cerium(III) oxide (CeO). Zirconia is often more useful in its phase 'stabilized' state. Upon heating, zirconia undergoes disruptive phase changes.
Zirconium dioxide | Engineering properties
Two more competitors—Research Instrument Co. of Norman, OK, and Alumina Ceramics Inc. of Benton, AR—were acquired in 1975 and ‘76, resp. Coors opened its first foreign factory in Glenrothes, Scotland, in 1981. Two more foreign subsidiaries were acquired in the early 1980s, an electronic ceramics plant in Singapore and a paper-tooling plant in Brazil. Coors began making silicon carbide, silicon nitride, spinel, zirconia and several other ceramic products by the mid-1980s.
CoorsTek | Ceramic technology and company growth after WW2
3. Ceramic industry make to double turnover by 2021
RAK Ceramics | References
Lithium oxide is used as a flux in ceramic glazes; and creates blues with copper and pinks with cobalt. Lithium oxide reacts with water and steam, forming lithium hydroxide and should be isolated from them. Its usage is also being investigated for non-destructive emission spectroscopy evaluation and degradation monitoring within thermal barrier coating systems. It can be added as a co-dopant with yttria in the zirconia ceramic top coat, without a large decrease in expected service life of the coating. At high heat, lithium oxide emits a very detectable spectral pattern, which increases in intensity along with degradation of the coating.
Lithium oxide | Uses
ZnO has also been considered for spintronics applications: if doped with 1–10% of magnetic ions (Mn, Fe, Co, V, etc.), ZnO could become ferromagnetic, even at room temperature. Such room temperature ferromagnetism in ZnO:Mn has been observed, but it is not clear yet whether it originates from the matrix itself or from secondary oxide phases.
Zinc oxide | Spintronics
Calcium oxide is used in the following reaction: Copper sulphate and powdered zinc can also be used, but this process is less efficient:
Self-heating food packaging | Chemistry
The increasing use and diversity of speciality forms of ceramics adds to the diversity of process technologies to be used. Thus, reinforcing fibres and filaments are mainly made by polymer, sol-gel, or CVD processes, but melt processing also has applicability. The most widely used speciality form is layered structures, with tape casting for electronic substrates and packages being pre-eminent. Photo-lithography is of increasing interest for precise patterning of conductors and other components for such packaging. Tape casting or forming processes are also of increasing interest for other applications, ranging from open structures such as fuel cells to ceramic composites.
Ceramic engineering | Forming methods
The Inorganics Sector consists of the Ceramics Division, Carbons Division and Fine Carbon Department. SDK's Ceramics products are used in a wide range of fields, including chemical products, refractory products, ceramics, paper manufacture, plastics and electronics. Key products include alumina hydroxide, alumina, and high-purity alumina. SDK also produces fused alumina abrasive grains, silicon carbide and boron nitride. SDK produces artificial graphite electrodes, an indispensable material for the recycling of steel. Other products include fine carbulizing agents for iron casting.
Showa Denko | Inorganics Sector
Typical materials used are: wood, metal, water, plaster, epoxy and STLs, silica, and zirconia. This production operation is well known for providing tools with dimensional stability, surface quality, density and uniformity. For instance, on the slip casting process the cast part is of high concentration of raw materials with little additive, this improves uniformity. But also, the plaster mould draws water from the poured slip to compact and form the casting at the mould surface. This forms a dense cast.
Ceramic forming techniques | Introduction
Calcium oxalate is used in the manufacture of ceramic glazes.
Calcium oxalate | Industrial applications
Zirconium silicate is used for manufacturing refractory materials for applications where resistance to corrosion by alkali materials is required. It is also used in production of some ceramics, enamels, and ceramic glazes. In enamels and glazes it serves as an opacifier. It can be also present in some cements. Another use of zirconium silicate is as beads for milling and grinding. Thin films of zirconium silicate and hafnium silicate produced by chemical vapor deposition, most often MOCVD, can be used as a high-k dielectric as a replacement for silicon dioxide in semiconductors. Zirconium silicates have also been studied for potential use in medical applications.
Zirconium(IV) silicate | Uses
As a significant product of copper mining, copper(II) oxide is the starting point for the production of other copper salts. For example, many wood preservatives are produced from copper oxide. Cupric oxide is used as a pigment in ceramics to produce blue, red, and green, and sometimes gray, pink, or black glazes. It is also incorrectly used as a dietary supplement in animal feed. Due to low bioactivity, negligible copper is absorbed.
Copper(II) oxide | Uses
Zircotec manufactures a number of different industrial ceramic components. Some examples are as follows:
Zircotec | Ceramic Fabrications
Ceramic mixing technology is used to mix and blend ceramics to create end products such as: ceramic powder blends, injection molding feedstock, electronics, decorative finishes, refractory linings, batteries and fuel cells, thermally conductive pastes, investment casting slurries, dental ceramics and advanced composites. A wide range of equipment is available for these requirements.
Ceramic mixing technology | Introduction
Zinc nitrate has no large scale application but is used on a laboratory scale for the synthesis of coordination polymers. Its controlled decomposition to zinc oxide has also been used for the generation of various ZnO based structures, including nanowires. It can be used as a mordant in dyeing. An example reaction gives a precipitate of zinc carbonate:
Zinc nitrate | Applications
Flash typically requires nine masks. This makes possible for example, the integration of FeRAM onto microcontrollers, where a simplified process would reduce costs. However, the materials used to make FeRAMs are not commonly used in CMOS integrated circuit manufacturing. Both the PZT ferroelectric layer and the noble metals used for electrodes raise CMOS process compatibility and contamination issues. Texas Instruments has incorporated an amount of FRAM memory into its MSP430 microcontrollers in its new FRAM series.
Ferroelectric RAM | Overall
Plastics, such as polyethylene naphthalate (PEN), can be protected by applying zinc oxide coating. The coating reduces the diffusion of oxygen with PEN. Zinc oxide layers can also be used on polycarbonate in outdoor applications. The coating protects polycarbonate from solar radiation, and decreases its oxidation rate and photo-yellowing.
Zinc oxide | Coatings
There are also severe risks of damage to the hot, brittle ceramics from differential thermal cracking. The magnets are usually near absolute zero, while the channel is several thousand degrees. For MHDs, both alumina (AlO) and magnesium peroxide (MgO) were reported to work for the insulating walls. Magnesium peroxide degrades near moisture. Alumina is water-resistant and can be fabricated to be quite strong, so in practice most MHDs have used alumina for the insulating walls.
Magnetohydrodynamic generator | Material and design issues
Zinc coatings prevent oxidation of the protected metal by forming a barrier and by acting as a sacrificial anode if this barrier is damaged. Zinc oxide is a fine white dust that (in contrast to iron oxide) does not cause a breakdown of the substrate's surface integrity as it is formed. Indeed, the zinc oxide, if undisturbed, can act as a barrier to further oxidation, in a way similar to the protection afforded to aluminum and stainless steels by their oxide layers. The majority of hardware parts are zinc-plated, rather than cadmium-plated.
Plating | Zinc plating
The material can be used in inner ear ossicles, ocular prostheses, electrical insulation for pacemakers, catheter orifices and in numerous prototypes of implantable systems such as cardiac pumps. Aluminosilicates are commonly used in dental prostheses, pure or in ceramic-polymer composites. The ceramic-polymer composites are a potential way to filling of cavities replacing amalgams suspected to have toxic effects. The aluminosilicates also have a glassy structure. Contrary to artificial teeth in resin, the colour of tooth ceramic remains stable Zirconia doped with yttrium oxide has been proposed as a substitute for alumina for osteoarticular prostheses. The main advantages are a greater failure strength, and a good resistance to fatigue.
Bioceramic | Mechanical properties and composition
However, because of its high price, h-BN was soon abandoned for this application. Its use was revitalized in the late 1990s with the optimization h-BN production processes, and currently h-BN is used by nearly all leading producers of cosmetic products for foundations, make-up, eye shadows, blushers, kohl pencils, lipsticks and other skincare products. Because of its excellent thermal and chemical stability, boron nitride ceramics are traditionally used as parts of high-temperature equipment. h-BN can be included in ceramics, alloys, resins, plastics, rubbers, and other materials, giving them self-lubricating properties. Such materials are suitable for construction of e.g. bearings and in steelmaking.
Boron nitride | Hexagonal BN
One major use is as an absorbent in surgical dressings. It is also used to find zinc salts by mixing sodium hydroxide with the suspect salt.
Zinc hydroxide | Applications
At this present time there is a ceramic industry for construction purposes, but the use of ceramic for artistic purposes is more relevant.
Jun, Granada | Culture
Ceramic materials began being used in restorative dentistry in the 1900s. Ceramic offers a more aesthetically pleasing restoration colour than previous gold and amalgam restorations. It is aesthetic and has high wear resistance. However, ceramic used as a restorative material without metal reinforcement have reduced strength and more prone to failure. This is because conventional ceramics have a higher fracture risk and fractures can propagate easily under cyclical loading causing marginal ridge or bulk fracture. To compensate for this, ceramic is placed in a thicker cross-section of at least 2mm for stress bearing areas. This reduces flexure under loading and prevents crack formation.
Inlays and onlays | Ceramic
Using polymer derived ceramics (PDCs), new application areas can be opened, especially in the area of high performance materials. The most important pre-ceramic polymers are polysilanes [R^1R^2Si-R^1R^2Si]_\mathit{n}, polycarbosilanes [R^1R^2Si-CH2]_\mathit{n}, polysiloxanes [R^1R^2Si-O]_\mathit{n} and polysilazanes [R^1R^2Si-NR^3]_\mathit{n}.
Polysilazane | History
Raw materials are sourced locally (sand, quartz and feldspar) as well as from all over the world (kaolin, ball clay and feldspar). A wide range of technologies are used at the company’s plants some of which include digital printing technology, continua+, chroma, slim, anti-microbial, glow in the dark, double charge, roll feed and other technologies.
RAK Ceramics | Materials and technology
Zinc chromate's main use is in industrial painting as a coating over iron or aluminum materials. It was used extensively on aircraft by the US military, especially during the 1930s and 1940s. It is also used in a variety of paint coatings for the aerospace and automotive industries. Its use as a corrosion-resistant agent was applied to aluminium alloy parts first in commercial aircraft, and then in military ones. During the 1940 and 1950s it was typically found as the "paint" in the wheel wells of retractable landing gear on US military aircraft to protect the aluminium from corrosion. This compound was a useful coating because it is an anti-corrosive and anti-rust primer.
Zinc chromate | Uses
Black oxide for zinc is also known by the trade name "Ebonol Z". Another product is Ultra-Blak 460, which blackens zinc-plated and galvanized surfaces without using any chrome and zinc die-casts.
Black oxide | Zinc
Chromium(III) oxide () is used as a colorant in ceramic glazes. Chromium(III) oxide can undergo a reaction with calcium oxide (CaO) and atmospheric oxygen in temperatures reached by a kiln to produce calcium chromate (). The oxidation reaction changes chromium from its +3 oxidation state to its +6 oxidation state. Chromium(VI) is very soluble and the most mobile out of all the other stable forms of chromium. Chromium may enter water systems via industrial discharge. Chromium(VI) can enter the environment directly or oxidants present in soils can react with chromium(III) to produce chromium(VI). Plants have reduced amounts of chlorophyll when grown in the presence of chromium(VI).
Ceramic glaze | Chromium(III) oxide
In addition to the applications listed here, ceramics are also used as a coating in various engineering cases. An example would be a ceramic bearing coating over a titanium frame used for an aircraft. Recently the field has come to include the studies of single crystals or glass fibres, in addition to traditional polycrystalline materials, and the applications of these have been overlapping and changing rapidly.
Ceramic engineering | Applications
Cobalt(II,III) oxide is used as a blue coloring agent for pottery enamel and glass, as an alternative to cobalt(II) oxide. Cobalt(II,III) oxide is used as an electrode in some lithium-ion batteries, possibly in the form of cobalt oxide nanoparticles.
Cobalt(II,III) oxide | Applications
Other applications are in electrical batteries, small non-structural castings, and alloys such as brass. A variety of zinc compounds are commonly used, such as zinc carbonate and zinc gluconate (as dietary supplements), zinc chloride (in deodorants), zinc pyrithione (anti-dandruff shampoos), zinc sulfide (in luminescent paints), and dimethylzinc or diethylzinc in the organic laboratory.
Zinc | Introduction
High-alumina (85 to 99.9% AlO) ceramics replaced porcelain (mixed-oxide ceramics, e.g., mullite) in many thermomechanical, electrical and chemical applications. Coors engineers Vlad Wolkodoff and Bob Weaver invented fully dense, glass-free 99.5+% AlO ceramics in 1964, useful for many applications where porcelain is deficient. Growth in the 1970s enabled Coors to build the 150,000 ft electronic ceramics Clear Creek Valley Plant east of Golden in 1970, and its first facility outside of Golden, an electronic substrate plant in Grand Junction, CO, in 1975. Coors made its first purchase of a competitor when it bought Wilbanks Inc. of Hillsboro, OR, in 1973.
CoorsTek | Ceramic technology and company growth after WW2
However, the extremely rapid heating rates can result in incomplete reactions between Zr and B, the formation of stable oxides of Zr, and the retention of porosity. Stoichiometric reactions have also been carried out by reaction of attrition milled (wearing materials by grinding) Zr and B powder (and then hot pressing at 600 °C for 6 h), and nanoscale particles have been obtained by reacting attrition milled Zr and B precursor crystallites (10 nm in size). Unfortunately, all of the stoichiometric reaction methods for synthesizing UHTCs employ expensive charge materials, and therefore these methods are not useful for large-scale or industrial applications.
Ultra-high-temperature ceramics | Synthesis of diboride (Zr, Hf, Ti) UHTCs
Tin(IV) oxide has long been used as an opacifier and as a white colorant in ceramic glazes. This has probably led to the discovery of the pigment lead-tin-yellow, which was produced using tin(IV) oxide as a compound. The use of tin(IV) oxide has been particularly common in glazes for earthenware, sanitaryware and wall tiles; see the articles tin-glazing and Tin-glazed pottery. Tin oxide remains in suspension in vitreous matrix of the fired glazes, and, with its high refractive index being sufficiently different from the matrix, light is scattered, and hence increases the opacity of the glaze. The degree of dissolution increases with the firing temperature, and hence the extent of opacity diminishes.
Tin(IV) oxide | Ceramic glazes
Pre-ceramic polymers can replace these organic binders. After compounding, casting and curing, the thermoset material can be pyrolyzed in one step to give a ceramic component in high yield. However, this application is still in its infancy in the civilian area.
Polysilazane | Applications
Depleted zinc oxide (DZO) is a zinc oxide depleted in the zinc isotope with the atomic mass 64, and used as a corrosion inhibitor in nuclear pressurized water reactors. The depletion of Zn is necessary, because this isotope is transformed into Zn by neutron capture. Zn with a half-life of 244.26 days emits gamma radiation with 1.115 MeV. Zn has a natural abundance of 48.6%, but in DZO it is reduced below 1%. Adding zinc oxide to the primary water loop of a boiling water reactor or pressurized water nuclear reactor reduces corrosion and therefore minimizes the amount of dissolved materials, especially Co.
Depleted zinc oxide | Introduction
Micronized and nano-scale zinc oxide and titanium dioxide provide strong protection against UVA and UVB ultraviolet radiation, and are used in suntan lotion, and also in UV-blocking sunglasses for use in space and for protection when welding, following research by scientists at Jet Propulsion Laboratory (JPL).
Zinc oxide | UV absorber
The predominant application of is as a component of dry cell batteries: alkaline batteries and so called Leclanché cell, or zinc–carbon batteries. Approximately 500,000 tonnes are consumed for this application annually. Other industrial applications include the use of as an inorganic pigment in ceramics and in glassmaking.
Manganese dioxide | Applications
The bonding of atoms together is much stronger in covalent and ionic bonding than in metallic. That is why, generally speaking, metals are ductile and ceramics are brittle. Due to ceramic materials wide range of properties, they are used for a multitude of applications. In general, most ceramics are: High-strain-rate superplasticity has been observed in aluminium-based and magnesium-based alloys. But for ceramic materials, superplastic deformation has been restricted to low strain rates for most oxides, and nitrides with the presence of cavities leading to premature failure. Here we show that a composite ceramic material consisting of tetragonal zirconium oxide, magnesium aluminates spinal and alpha-alumina phase exhibit superplasticity at strain rates up to 1.0 s.
Superplasticity | The properties of ceramics
A secondary flux is a ceramic flux (such as calcium, barium, magnesium or zinc oxide) which does not act as a good flux (i.e., lower the melting point of the mixture) alone, but is effective when used in combination with other fluxes. They also tend to act as "anti-fluxes" at lower temperatures, and may produce matt or opaque glazes under those conditions. For example, calcium oxide is generally used with sodium or potassium and by itself has little fluxing effect at pyrometric cone 6 but does act as a flux at cone 8.. When use calcium with lead it gives low melting temperature to glaz.
Secondary flux | Introduction
There is also substantial interest in dispersion of hard, non-oxide phases such as SiC, TiB, TiC, boron, carbon and especially oxide matrices like alumina and mullite. There is also interest too incorporating other ceramic particulates, especially those of highly anisotropic thermal expansion. Examples include AlO, TiO, graphite, and boron nitride. In processing particulate composites, the issue is not only homogeneity of the size and spatial distribution of the dispersed and matrix phases, but also control of the matrix grain size. However, there is some built-in self-control due to inhibition of matrix grain growth by the dispersed phase. Particulate composites, though generally offer increased resistance to damage, failure, or both, are still quite sensitive to inhomogeneities of composition as well as other processing defects such as pores.
Ceramic engineering | Ceramic composites
Due to its physical strength, chemical inertness, tailorability, and relatively low manufacture costs, it is one of the most commonly used piezo ceramics.
Lead zirconate titanate | Introduction