Effects of Spray Parameters on Microstructure of High Velocity Arc Sprayed Al/1Cr13 Composite Coatings

Al/1Cr13 composite coatings were fabricated by high velocity arc spray process.The effects of spray parameters(arc current,arc voltage and spray distance) on the microstructure,porosity and oxygen content of the coatings were investigated by an orthogonal experiment design method with 3 factors and 3 levels.The microstructure and porosity were measured by scanning electron microscope(SEM) and the oxygen content was examined by an oxygen-nitrogen analyzer.The results show that the densest Al/1Cr13 composite coatings are achieved under the 9th set spray parameters,arc current of 240 A,arc voltage of 32 V and spray distance of 150 mm.The minimum porosity of Al coating and 1Cr13 coating is 1.6% and 2.2%,respectively.The oxygen content of Al coating is significantly lower than that of 1Cr13 coating,and the minimum is about 2%.