According to properties of the free-jet field, an annular nozzle with six holes was designed. The common oxy-fuel sprayed coatings were improved evidently. Thermal sprayed coatings which were adapted to sinter were gained. The test method was used to evaluate the bond strength of high-strength coatings. In this test, symmetrical cuts were done along the interface of the coating by wire cutting exactly,and then the two sides of the samples were adhered and undrawed by tensile force along the interface of the coating. The bond strength of thermal sprayed coatings with various processing paramet...