Effect of heat treatment and long-term age on microstructure of a Ni3Al-based single crystal superalloy

摘要

A new Re-containing Ni3Al-based single crystal superalloy was recently developed by our group. In order to obtain uniform microstructure and further improve mechanical properties of superalloy, the heat treatment regime (i.e. solution treatment and age treatment) was investigated by experimental analysis and dynamics calculation (by JMatPro), and the optimal heat treatment regime was 1335-1355 degrees C/16 h, air cooling (AC)+ 1140 degrees C/2 h, AC+870 degrees C/32 h, AC. Meanwhile, completely heat-treated experimental alloy was long-term aged at 1150 degrees C for 25-1000 h, which showed very good microstructural stability and the coarsening behaviour of gamma' phases agreed well with the typical Lifshitz-Slyozov-Wagner (LSW) theory.