Patent ID: 7608797

Claim:
A thermal spray apparatus comprising: a heating module for providing a stream of heated gas; a forming module coupled to said stream of heated gas, said forming module comprising a first zone having an entrance coupled to said stream of heated gas and an exit coupled to a throat having a constant cross-sectional area, and a second zone having an entrance coupled to said throat and an exit; a barrel coupled to said exit of said forming module; a powder injection module comprising at least one powder injector for introducing powder material into said stream of gas; and a shockwave generator; where the ratio between the cross-sectional area of the exit of the second zone and the cross-sectional area of the throat =(0.5 to 0.8) 2 −(1.7+0.1 Pcc/Pa) 2 , wherein Pcc is absolute pressure in the heating module, and Pa is atmospheric pressure.