Microstructural evolution of Mg-15Gd-1Zn-0.4Zr(GZ151K,wt%)alloys,cast under 0 MPa(gravity cast)and 6 MPa(squeeze cast),were comparatively studied.It is found that the grain size of squeeze cast GZ151K alloy with appli...Microstructural evolution of Mg-15Gd-1Zn-0.4Zr(GZ151K,wt%)alloys,cast under 0 MPa(gravity cast)and 6 MPa(squeeze cast),were comparatively studied.It is found that the grain size of squeeze cast GZ151K alloy with applied stress 6 MPa is much smaller than that of the gravity cast counterpart.Moreover,the squeezing pressure hinders the transition fromβ’precipitates toβ1 precipitates during subsequent aging process,leading to reduced volume fraction ofβ1 precipitates in the squeeze cast alloy.Thus,the relatively lower volume fraction ofβ1 precipitates in the squeeze cast GZ151K results in higher hardness increment and stronger precipitation hardening effect.展开更多
基金supported by the National Key Research and Development Program of China(No.2016YFB0701201)Na-tional Natural Science Foundation of China(No.51771113,51671128,51605288)+1 种基金the United Fund of National De-partment of Education and Equipment Development(No.6141A02033213)the 111 Project(Grant No.B16032).
文摘Microstructural evolution of Mg-15Gd-1Zn-0.4Zr(GZ151K,wt%)alloys,cast under 0 MPa(gravity cast)and 6 MPa(squeeze cast),were comparatively studied.It is found that the grain size of squeeze cast GZ151K alloy with applied stress 6 MPa is much smaller than that of the gravity cast counterpart.Moreover,the squeezing pressure hinders the transition fromβ’precipitates toβ1 precipitates during subsequent aging process,leading to reduced volume fraction ofβ1 precipitates in the squeeze cast alloy.Thus,the relatively lower volume fraction ofβ1 precipitates in the squeeze cast GZ151K results in higher hardness increment and stronger precipitation hardening effect.
