Abstract
Hall-Petch slope(k),an important parameter in Hall-Petch relation,describes the efficiency of strength-ening effect by grain boundaries.Previously,a highly texture dependent k for Mg alloys is frequently reported,but,in the present study,we report a weak texture dependence of k in a rare-earth containing Mg-2Zn-1Gd plate with two peaks of(0002)poles inclining approximately±30 ° away from the ND to-ward the TD.Although there is a strong mechanical anisotropy between tension along the TD and RD,the k for TD-tension(280 MPa μm1/2)is quite similar to that for RD-tension(276 MPa μm1/2).Here,RD,TD and ND refer to the rolling direction,transverse direction and normal direction of the plate,respectively.The weak texture dependence of k is well predicted by the compound use of the activation stress dif-ference between neighboring grains(△Stress)and the geometric compatibility factor(m').By analyzing how the texture affects the values for △Stress and m',the mechanism for this texture independence of k is ascribed to the activation of a high fraction of additional deformation mode,besides the predominant one for both RD-tension and TD-tension,namely,prismatic slip accompanied by a high fraction of basal slip for RD-tension and basal slip accompanied by a high fraction of prismatic slip for TD-tension.This will lead to multiple deformation transfer modes and,consequently,the effect of texture on the ease of deformation transfer across grain boundaries is weakened.As a result,there is a similar k for TD-tension and RD-tension.
基金项目
National Natu-ral Science Foundation of China(52071039)
National Natu-ral Science Foundation of China(51871032)
National Natu-ral Science Foundation of China(51671040)
Natural Science Foundation of Jiangsu Province(BK20202010)
Graduate Scientific Research and Innovation Foundation of Chongqing,China(CYB20001)
NETL
NSTL
万方数据