摘要
Enhanced tensile ductilities in coarse grained Al-Mg-Zn and Al-Mg-Fe materials were studied.The materials were Al-2Mg-5Zn,Al-3Mg-5Zn,Al-4Mg-5Zn,Al-3Mg-0.11Fe,Al-3Mg-0.27Fe,and Al-3Mg-0.40Fe.Tensile elongation-to-failure tests were conducted at constant cross-head speed and constant temperatures from 300 to 450℃.Strain rate change tests were conducted at a constant temperature from 300 to 450℃and in strain-rate range from 4.31×10-5to 1.97×10-2s-1.Experimental results show that over 100%ductilities are consistently achieved in these materials.This superplasticity-like behavior is rate-controlled by solute-drag creep.Although ternary Zn and Fe additions do not have an adverse effect on solute-drag creep and ductility,they increase stress exponent and its sensitivity to Mg content during solute-drag creep.
Enhanced tensile ductilities in coarse grained Al-Mg-Zn and Al-Mg-Fe materials were studied.The materials were Al-2Mg-5Zn,Al-3Mg-5Zn,Al-4Mg-5Zn,Al-3Mg-0.11Fe,Al-3Mg-0.27Fe,and Al-3Mg-0.40Fe.Tensile elongation-to-failure tests were conducted at constant cross-head speed and constant temperatures from 300 to 450℃.Strain rate change tests were conducted at a constant temperature from 300 to 450℃and in strain-rate range from 4.31×10-5to 1.97×10-2s-1.Experimental results show that over 100%ductilities are consistently achieved in these materials.This superplasticity-like behavior is rate-controlled by solute-drag creep.Although ternary Zn and Fe additions do not have an adverse effect on solute-drag creep and ductility,they increase stress exponent and its sensitivity to Mg content during solute-drag creep.
基金
Project(DMR-9702156)supported by the National Science Foundation of USA
Project(50801034)supported by the National Natural Science Foundation of China
Project(20060425)supported by the Scientific and Technological Research Key Lab Foundation of Liaoning Education Department
