Negative creep during compressive creep of as-cast ZA27 alloy

摘要

The negative creep during compressive creep deformation of as cast ZA27 alloy was investigated at the temperature range of 20160 ℃ and at compressive stress levels from 50137.5 MPa with special apparatus. Results show that the negative creep in the alloy occurred respectively at 20 ℃ (50 MPa, 87.5 MPa and 100 MPa), 60 ℃(50 MPa and 87.5 MPa) and 100 ℃(50 MPa). According to the phase transformation and theoretical analysis, the negative creep resulted from volume expansion caused by four phase transformation α+ε→T′+η in the alloy. The theoretical analysis is consistent with the experiment results. And the values of negative creep depended on the difference between the compressive creep deformation and the volume expansion.