  Bismaleimide (BMI) resins are a new breed of thermosetting resins used mainly
for high temperature applications and have major usage in aerospace. FTIR
studies have shown the signatures of imide, CNC stretching, malemide and N-H
stretching. These BMI polymer coatings were deposited on aluminum and mild
steel substrates by sprinkling powers followed by baking. Thermo gravimetric
analysis and Differential scanning calorimetric studies showed the degradation
temperature of these polymers around 370oC. Aluminum coatings were deposited on
BMI previously deposited on Al and mild steel to make a metal-BMI-metal
trilayer. These trilayers can solve the problem charging of the aircraft bodies
at high altitudes. Atomic force microscopy was done to determine the morphology
of the surface. Roughness and thickness measurements of the BMI coatings were
carried out by surface profilometer. Vickers microhardness tests showed an
increase in hardness of the metal-BMI-metal trilayer. FTIR spectrum showed
signature of imides, CNC stretching, maleimide and N-H stretching in BMI. We
observed that peak broadens at which shows the release of the stress during
thermal treatment of the coating. The coating is subject to variable APPJ
conditions which improve the properties at high temperature.
