  Despite recent advances in suspension-based thermal spray techniques, there
is still a need to widen the capability of available thermal spray setups to
handle suspension to explore new compositions and improve the properties and
performance of existing ones. In this work, a novel setup for injecting
liquid-based feedstock in a liquid-fuelled high velocity oxy-fuel (HVOLF)
thermal spray torch is proposed, involving a new hardware ("Hybrid Nozzle")
capable of injecting suspension radially and protecting the thermal spray flame
from the environmental oxygen by inert gas shrouding. The new setup was used to
deposit SiC/YAG composite coatings with 85 wt. % SiC content, and their wear
performance was evaluated. An oxygen deficient environment was provided to the
HVOLF flame, ensuring no or minimal (<2 wt. %) SiO_2 was formed in the coating
during the spray, as confirmed by XRD. A good wear performance was observed at
low load below 20 N, with a specific wear rate < 5 x 10^-5 mm^3/Nm, with the
onset of wear mechanisms characteristic of ceramic wear in the brittle regime
between 20 and 30 N. The future applicability of this novel setup to a range of
oxidation- and heat-sensitive materials and composites offers the opportunity
for new coating materials to be explored with suspension and solution
precursor-based HVOLF thermal spray.
