To investigate the complex relationship between rolling process parameters and mechanical properties of AZ31 magnesium alloy rolled sheets,the Leave-One-Out Cross-Validation(LOOCV)and parameter tuning were applied to ...To investigate the complex relationship between rolling process parameters and mechanical properties of AZ31 magnesium alloy rolled sheets,the Leave-One-Out Cross-Validation(LOOCV)and parameter tuning were applied to optimizing hyper-parameters for the four(BPNN,SVR,RF,and KNN)machine learning models.An interpretable prediction model based on machine learning and SHapley Additive exPlanations(SHAP),as well as an analytical method combining the SHAP model and the Pearson Correlation Coefficient(PCC),were proposed.The results showed that among the four models,the SVR model was able to simultaneously and accurately predict the ultimate tensile strength(UTS)and elongation(EL).According to the combination analysis of PCC and the magnesium alloy rolling forming mechanism,it was found that strain rate and reduction displayed a negative and positive correlation with UTS,respectively,while rolling temperature and reduction illustrated a positive and negative correlation with EL,respectively.Through the SHAP method,which could interpret the output results of the SVR machine learning model,it was deduced that reduction and strain rate played an important role in the SVR model of the outputs of the UTS and EL,respectively.Combining SHAP with PCC,it was found that strain rate and reduction had a greater influence on the UTS than rolling temperature,whereas strain rate and rolling temperature had more influence on the EL compared to reduction.展开更多
To investigate the evolution of grain orientation and slip modes in magnesium alloys with multiple texture components,an AZ31 gradient-structured magnesium alloy sheet was fabricated using hard plate rolling(HPR).The ...To investigate the evolution of grain orientation and slip modes in magnesium alloys with multiple texture components,an AZ31 gradient-structured magnesium alloy sheet was fabricated using hard plate rolling(HPR).The changes in texture and slip modes under different reductions were examined.The results demonstrate that the AZ31 magnesium alloy sheets display a self-epitaxial gradient structure,with the best mechanical properties observed at rolling temperature of 673 K and reduction of 50%.Significant changes in texture type and strength are observed along the normal direction(ND)of the sheet.The coarse-grain region exhibits a bimodal texture aligned with the rolling direction.These texture variations enhance the stress distribution at the fine grain-coarse grain interface,influencing the grain orientation and the activation of different slip modes,thus improving the mechanical properties of gradient-structured magnesium alloy sheets.This approach offers a new strategy for the fabrication of high-performance magnesium alloy sheets.展开更多
通过向AZ91镁合金基体(采用镁合金铸锭)复合添加不同成分的碱土元素Ca、Sr,Ca和Sr元素是以Mg-30%Ca(质量分数)的镁钙中间合金和Mg-30%Sr(质量分数)的镁锶中间合金的形式添加,采用JVAM-1C型高真空电弧熔炼炉对添加后的合金在自制熔剂的...通过向AZ91镁合金基体(采用镁合金铸锭)复合添加不同成分的碱土元素Ca、Sr,Ca和Sr元素是以Mg-30%Ca(质量分数)的镁钙中间合金和Mg-30%Sr(质量分数)的镁锶中间合金的形式添加,采用JVAM-1C型高真空电弧熔炼炉对添加后的合金在自制熔剂的覆盖和氩气保护下熔炼,获得不同成分的AZ91镁合金试样。运用DM2700M型徕卡研究级材料显微镜、JSM-6360LV型扫描电镜(Scanning Electron Microscope,SEM)对合金铸态以及均匀化退火后固溶时效态的显微组织展开观察,利用XD98型X射线衍射仪开展合金相结构分析,同时对其抗拉强度、延伸率和断面收缩率进行测试分析。结果表明:在AZ91镁合金中复合添加碱土元素Ca、Sr后,铸态中晶粒细化机理、晶界高熔点化合物对力学性能作用;证实了AZ91镁合金通过碱土Ca、Sr的复合作用后在高温状态下的力学性能提高机理、强韧性改善机理。展开更多
基金supported by the National Natural Science Foundation of China(Nos.52471132,52475356,52071139,U21A20130)the National Social Science Fund of China(No.21BJL075)+1 种基金the Natural Science Foundation of Fujian Province for Distinguished Young Scholars,China(No.2024J010031)the Natural Science Foundation of Chongqing,China(No.CSTB2023NSCQ-MSX0886)。
文摘To investigate the complex relationship between rolling process parameters and mechanical properties of AZ31 magnesium alloy rolled sheets,the Leave-One-Out Cross-Validation(LOOCV)and parameter tuning were applied to optimizing hyper-parameters for the four(BPNN,SVR,RF,and KNN)machine learning models.An interpretable prediction model based on machine learning and SHapley Additive exPlanations(SHAP),as well as an analytical method combining the SHAP model and the Pearson Correlation Coefficient(PCC),were proposed.The results showed that among the four models,the SVR model was able to simultaneously and accurately predict the ultimate tensile strength(UTS)and elongation(EL).According to the combination analysis of PCC and the magnesium alloy rolling forming mechanism,it was found that strain rate and reduction displayed a negative and positive correlation with UTS,respectively,while rolling temperature and reduction illustrated a positive and negative correlation with EL,respectively.Through the SHAP method,which could interpret the output results of the SVR machine learning model,it was deduced that reduction and strain rate played an important role in the SVR model of the outputs of the UTS and EL,respectively.Combining SHAP with PCC,it was found that strain rate and reduction had a greater influence on the UTS than rolling temperature,whereas strain rate and rolling temperature had more influence on the EL compared to reduction.
基金supported by the Natural Science Foundation of Heilongjiang Province,China(No.JQ2022E004)。
文摘To investigate the evolution of grain orientation and slip modes in magnesium alloys with multiple texture components,an AZ31 gradient-structured magnesium alloy sheet was fabricated using hard plate rolling(HPR).The changes in texture and slip modes under different reductions were examined.The results demonstrate that the AZ31 magnesium alloy sheets display a self-epitaxial gradient structure,with the best mechanical properties observed at rolling temperature of 673 K and reduction of 50%.Significant changes in texture type and strength are observed along the normal direction(ND)of the sheet.The coarse-grain region exhibits a bimodal texture aligned with the rolling direction.These texture variations enhance the stress distribution at the fine grain-coarse grain interface,influencing the grain orientation and the activation of different slip modes,thus improving the mechanical properties of gradient-structured magnesium alloy sheets.This approach offers a new strategy for the fabrication of high-performance magnesium alloy sheets.
文摘通过向AZ91镁合金基体(采用镁合金铸锭)复合添加不同成分的碱土元素Ca、Sr,Ca和Sr元素是以Mg-30%Ca(质量分数)的镁钙中间合金和Mg-30%Sr(质量分数)的镁锶中间合金的形式添加,采用JVAM-1C型高真空电弧熔炼炉对添加后的合金在自制熔剂的覆盖和氩气保护下熔炼,获得不同成分的AZ91镁合金试样。运用DM2700M型徕卡研究级材料显微镜、JSM-6360LV型扫描电镜(Scanning Electron Microscope,SEM)对合金铸态以及均匀化退火后固溶时效态的显微组织展开观察,利用XD98型X射线衍射仪开展合金相结构分析,同时对其抗拉强度、延伸率和断面收缩率进行测试分析。结果表明:在AZ91镁合金中复合添加碱土元素Ca、Sr后,铸态中晶粒细化机理、晶界高熔点化合物对力学性能作用;证实了AZ91镁合金通过碱土Ca、Sr的复合作用后在高温状态下的力学性能提高机理、强韧性改善机理。
