COMBINATION STRENTHENING PROCESS OF Ni-W-Ti-SiC COMPOSITE COATING AND NITROCARBURIZATION

ＣＯＭＢＩＮＡＴＩＯＮＳＴＲＥＮＴＨＥＮＩＮＧＰＲＯＣＥＳＳＯＦＮｉＷＴｉＳｉＣＣＯＭＰＯＳＩＴＥＣＯＡＴＩＮＧＡＮＤＮＩＴＲＯＣＡＲＢＵＲＩＺＡＴＩＯＮ①ＭａＫｅｙｉ，ＧｕｏＺｈｏｎｇｃｈｅｎｇ，ＷｅｎＭｉｎｇｆｅｎ，ＹａｎｇＸｉａｎｗａｎＤ...

The significance and theoretical basis of the combination strengthening process of electro plating Ni W Ti SiC composite coating and nitrocarburization were expounded briefly with the emphasis on the technical conditions of the process and the structure and properties of the coating. The results showed that satisfactory Ni W Ti SiC composite coating can be obtained on the steel when some appropriate complex reagent and additive were selected and the process parameters were controlled. The hardness and wear resistance of the nitrocarburized composite coating are much higher than those of the composite coating without nitrocarburization. Scanning electron microscope investigation indicated that Fe in the matrix diffuses into the coating during nitrocarburization to produce the “nailing up effect” and to increase the joining force between the coating and the matrix remarkably.