Influence of coatings deposition parameters on microstructure of aluminide coatings deposited by CVD method on Ni-superalloys

摘要

The paper presents the preliminary results of technological tests of aluminizing using a new BPX Pro 325 S CVD equipment. Nickel based cast superalloys: IN 738 and MAR M200+Hf were used as a substrate material. The aluminizing processes with different parameters - pressure, HCl flow and time - were conducted. Microstructure analysis showed coatings whose thickness didn't exceed 20 μm. The authors showed that the changes of parameters values in the analyzed range weakly influenced the coating thickness (about 1-2 μm). It was proven, that it was necessary to decrease the flow of hydrogen chloride and perform the thermodynamic analysis.