Microstructural and mechanical characterization of powder-pack boronized Incoloy A286 superalloy

摘要

In this study, Incoloy A286 superalloy were boronized successfully by powder-pack boronizing process at 850℃, 900℃ and 950℃ for 4 h by using a boronizing powder mixture containing H_3BO_3 as boron source. The thickness and morphology of the boride layer was identified by microstructural examinations. The boride layer with complex, compact and smooth morphology was formed on the surface of the samples. As a result of XRD analyses, it was determined that the compact boride layer was formed many phases such as FeB, Fe_2B, Fe_3B, CrB and Ni_4B_3 etc. It was specified that the average hardness value of the boride layer was approximately between 2400 and 3000 HV by microhardness tests. Also the graphs of friction coefficient and values of the specific wear rate were obtained by performing ball on disk wear tests. It was identified that the specific wear rate of boronized samples was approximately 9.5 times lower than that of unboronized samples.