Microstructural Characterization of the New Tool Ni-Based Alloy with High Carbon and Chromium Content

The concept of new tool materials, based on Ni alloys strengthened by intermetallic compounds, intended for applications at high temperatures is presented in the paper. The chemical composition of this new material was designed in such a way as to obtain the matrix strengthening by means of the precipitation of intermetallic compounds rich in Ni and to have the carbide fraction above 25%. Carbides should remain stable in the microstructure, regardless of the heat treatment, since they favourably influence an abrasion resistance. The results of microstructure investigations in the as-cast condition, are given. The type of phases appearing in the microstructure was determined and their morphology described. The main microstructure components of the investigated Ni-based alloy with high carbon and chromium content are: the γ phase, which constitutes a matrix, the γ' phase, which occurs as fine globular precipitates and the primary Ta and Cr carbides (of MC and M7C3 type - respectively).