Strength Improvement in ZK60 Magnesium Alloy Induced by Pre-deformation and Heat Treatment  

作　　者：陈先华 LIU Lizi PAN Fusheng 

机构地区：[1]College of Materials Science and Engineering, Chongqing University, Chongqing 400045, China [2]National Engineering ResearchCenter for Magnesium Alloys, Chongqing University, Chongqing 400045, China [3]Chongqing Academy of Science and Technology, Chongqing 401123, China

出　　处：《Journal of Wuhan University of Technology(Materials Science)》2016年第2期393-398,共6页武汉理工大学学报（材料科学英文版）

基　　金：Funded by the National Natural Science Foundation of China(No.51571043);the International Science&Technology Cooperation Program of China(No.2014DFG52810);the Fundamental Research Funds for the Central Universities(No.106112015CDJZR135515)

摘　　要：The influence of pre-deformation and heat treatment on mechanicalproperties of as-extruded ZK60 alloy was investigated.The experimentalresults indicated that the solid solution,pre-cold rolling and artificialaging treatments remarkably improved the mechanicalstrength of alloys compared with the asextruded condition.Especially,pre-cold rolling in 5% reduction combined with artificialaging at 150 ℃ for 20 h was determined as the optimum heat treatment condition,which resulted in a yield strength of 333 MPa with an increment of 87 MPa and ultimate tensile strength of 373 MPa.High density of nanoscale precipitates in α-Mg matrix observed in this sample was beneficialto enhancing the strength.The as-extruded sample showed a typicalbrittle fracture while the solution treated sample exhibited ductile-fragile failure characterized by cleavage fractures,river patterns,and tear ridges.And the sample after pre-cold rolling combined with aging presented more equiaxialdimples with a great amount of cracked particles in them.The above-mentioned observations were analyzed in terms of microstructure and possible strengthening mechanism in the extruded ZK60 alloy.The influence of pre-deformation and heat treatment on mechanicalproperties of as-extruded ZK60 alloy was investigated.The experimentalresults indicated that the solid solution,pre-cold rolling and artificialaging treatments remarkably improved the mechanicalstrength of alloys compared with the asextruded condition.Especially,pre-cold rolling in 5% reduction combined with artificialaging at 150 ℃ for 20 h was determined as the optimum heat treatment condition,which resulted in a yield strength of 333 MPa with an increment of 87 MPa and ultimate tensile strength of 373 MPa.High density of nanoscale precipitates in α-Mg matrix observed in this sample was beneficialto enhancing the strength.The as-extruded sample showed a typicalbrittle fracture while the solution treated sample exhibited ductile-fragile failure characterized by cleavage fractures,river patterns,and tear ridges.And the sample after pre-cold rolling combined with aging presented more equiaxialdimples with a great amount of cracked particles in them.The above-mentioned observations were analyzed in terms of microstructure and possible strengthening mechanism in the extruded ZK60 alloy.

关 键 词：ZK60 alloy strength solid solution pre-cold rolling aging 

分 类 号：TG166.4[金属学及工艺—热处理] TG339[金属学及工艺—金属学]