Structure and properties of NiAl-Cr(Co,Hf) alloys prepared by centrifugal SHS casting followed by vacuum induction remelting. Part 2 Evolution of the structure and mechanical behavior at high temperature

The structure and mechanical properties of the Ni41Al41Cr12Co6 intermetallic alloy prepared by vacuum induction remelting (VIR) of the SHS semi-product are studied. The evolution of the microstructure of the Ni41Al41Cr12Co6 alloy heated in the temperature range of 20-850 degrees C was investigated. Noticeable dissolution of Cr inclusions at temperatures above 550 degrees C is observed; the dissolution stage is preceded by fragmentation of dispersed Cr inclusions into nanocrystallites. The thermomechanical properties of the Ni41Al41Cr12Co6 alloy were determined in the temperature range of 400-1100 degrees C. VIR is found to increase high-temperature creep resistance and thermal stability of the Ni41Al41Cr12Co6 alloy to a certain extent.