Effects of compression parameters on deformation behaviors of semi-solid ZA27 alloys

Abstract

An investigation was performed on the effects of semi-solid compression parameters, such as strain rate, compression temperature and heating time at these temperatures on deformation behaviors of two kinds of ZA27 alloys, one was modified by Zr and the other was unmodified. The results indicate that with the increasing of the strain, the stress of the modified composite first sharply increases to a peak value, then dramatically decreases to a peakeau value, and again increases till the end of deformation. But for the unmodified, after being up to a peak value, the stress only decreases slowly. As the compression temperature or the heating time decreases, or the strain rate increases, the stress level and the cracking degree of these two kinds of alloys increase. Under the same deformation conditions, the stress level and the cracking degree of the unmodified alloy are higher than those of the modified one. But there is an exception that the stress level of the unmodified alloy is minimum and smaller than that of them modified one when deformed at the low temperature of 450°C. These phenomena were mainly discussed through analyzing the microstructures under different conditions and the deformation mechanisms at different deformation stages.

Keywords

ZA27 alloy / semi-solid state / compressive deformation / microstructure / thixoforming

References

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