Local Mechanical Properties at the Dendrite Scale of Ni-Based Superalloys Studied by Advanced High Temperature Indentation Creep and Micropillar Compression Tests

摘要: Chemical inhomogenities due to dendritic solidification of Ni-based superalloys result in different local microstructures with varying mechanical properties. New indentation creep test methods allow probing the properties at dendrite scale high temperatures. The as-cast single crystalline superalloy ERBO1A (a derivative alloy CMSX–4) was investigated and electron-probe microanalysis (EPMA) measurements revealed strong segregation of, e.g., Re W region and, Ta interdendritic region. Indentation experiments 750 °C micropillar compression tests 785 were conducted both regions, a higher strength found compared Theoretical models for solid solution hardening as well γ′ precipitation confirm these results, since they predict than Compared fully heat treated state, smaller difference or even reverse ratio can be expected.