The microstructure and hardness of a 2024 aluminum alloy subjected tomulti-pass upsetting extrusion at ambient temperature were studied. Experimental results indicatedthat with the number of upsetting extrusion passes...The microstructure and hardness of a 2024 aluminum alloy subjected tomulti-pass upsetting extrusion at ambient temperature were studied. Experimental results indicatedthat with the number of upsetting extrusion passes increasing, the grains of the alloy are graduallyrefined and the hardness increases correspondingly. After ten passes of upsetting extrusionprocessing, the grain size decreases to less than 200 nm in diameter and the sample maintains itsoriginal shape, while the hardness is double owing to equal-axial ultrafine grains and workhardening effect caused by large plastic deformation.展开更多
The isothermal repetitive upsetting extrusion(RUE)was implemented to process ZK60 magnesium alloy at 380℃.Then,the relationship between the microstructural characters,including grain refinement and texture evolution,...The isothermal repetitive upsetting extrusion(RUE)was implemented to process ZK60 magnesium alloy at 380℃.Then,the relationship between the microstructural characters,including grain refinement and texture evolution,and the mechanical performance of the alloy was investigated.Results showed that after 3 passes of RUE,the average grain size was refined from 115.0 to 26.5μm,which was mainly caused by the continuous dynamic recrystallization and discontinuous dynamic recrystallization.Meanwhile,the elongation of the alloy increased from 13.8 to 21.6%,and the superplasticity(142%)of the alloy has been achieved in the following high temperature tensile test,which is very beneficial for the further processing of the alloy into components.In particular,the alloy formed a distinctive texture distributed between<2-1-11>and<2-1-14>,which was greatly related to the Schmid factor of extrusion direction(ED)and transverse direction(TD).This texture changed the initiation ability of basal and prismatic slip in both directions and inhibited the initiation of partial tensile twinning in TD;thus,the anisotropy in both directions was weakened.As expected,the tensile yield strength difference decreased from25.9 to 3.4 MPa,but it was used as the cost of tensile yield strength in ED.展开更多
基金This project is financially supported by the Natural Science Foundation (No. E5305293) of South China University of Technology.
文摘The microstructure and hardness of a 2024 aluminum alloy subjected tomulti-pass upsetting extrusion at ambient temperature were studied. Experimental results indicatedthat with the number of upsetting extrusion passes increasing, the grains of the alloy are graduallyrefined and the hardness increases correspondingly. After ten passes of upsetting extrusionprocessing, the grain size decreases to less than 200 nm in diameter and the sample maintains itsoriginal shape, while the hardness is double owing to equal-axial ultrafine grains and workhardening effect caused by large plastic deformation.
基金financially supported by the Program for the Supported by Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxithe‘HIGH-GRADE CNC machine tools and basic manufacturing equipment’Major National Science and Technology Projects(No.2019ZX04022001-004)。
文摘The isothermal repetitive upsetting extrusion(RUE)was implemented to process ZK60 magnesium alloy at 380℃.Then,the relationship between the microstructural characters,including grain refinement and texture evolution,and the mechanical performance of the alloy was investigated.Results showed that after 3 passes of RUE,the average grain size was refined from 115.0 to 26.5μm,which was mainly caused by the continuous dynamic recrystallization and discontinuous dynamic recrystallization.Meanwhile,the elongation of the alloy increased from 13.8 to 21.6%,and the superplasticity(142%)of the alloy has been achieved in the following high temperature tensile test,which is very beneficial for the further processing of the alloy into components.In particular,the alloy formed a distinctive texture distributed between<2-1-11>and<2-1-14>,which was greatly related to the Schmid factor of extrusion direction(ED)and transverse direction(TD).This texture changed the initiation ability of basal and prismatic slip in both directions and inhibited the initiation of partial tensile twinning in TD;thus,the anisotropy in both directions was weakened.As expected,the tensile yield strength difference decreased from25.9 to 3.4 MPa,but it was used as the cost of tensile yield strength in ED.
