Microtwinning in Ni-base supalloy Mar-M247 at intermediate temperature and low stress

After creep deformation at 760 degrees C and 470 MPa, approximately half of the yield strength, for 7075 h, the deformation microstructures of Mar-M247 are investigated using transmission electron microscope. Experimental results reveal that pairs of a/2 (1 1 0) dislocations, superlattice stacking faults and microtwins are produced in the deformed specimens, suggesting anti-phase boundary shearing, stacking fault shearing and microtwinning operate simultaneously during creep deformation. This study provides new insights into understanding the creep deformation mechanisms in Ni-base superalloy. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study found that during creep deformation of Ni-base superalloy at high temperatures and pressures, a/2 (1 1 0) dislocations, superlattice stacking faults, and microtwins are produced, indicating that multiple deformation mechanisms occur during creep. This helps to provide new insights into the creep deformation process of Ni-base superalloy.