Microstructure And Properties Of Directional Solidification CuCrZr Alloy C-ECAP

With the rapid development of integrated circuits,communication transmission,ship transportation,aerospace and other fields,new requirements have been put forward for high-performance conductive copper alloy materials.However,maintaining high conductivity while increasing strength still faces many difficulties and challenges.In this study,Directional solidification CuCrZr alloy was used to conduct Continuous ECAP(C-ECAP)deformation,and the effects of different paths of continuous ECAP+rolling and aging treatment on the microstructure and properties of the material were studied.The microstructure of the material was tested using OM,SEM,XRD,and EBSD techniques,and various properties of the material were tested.The results indicate that:(1)The alloy undergoes C-ECAP deformation,and under the action of shear stress,the material structure is rapidly refined.The strength and hardness of the alloy increase and the elongation and conductivity decrease after different passes of deformation in two different paths.Overall,path A exhibits the best overall performance after deformation.The strength,hardness,elongation,and conductivity of the alloy after three passes of deformation in path A reach 435.71 MPa,130.5HV,14.3%,and 45.5% IACS,respectively.Compared with before deformation,the tensile strength and hardness increased by 53.0% and 44.2%,while the elongation and conductivity decreased by 70.5% and 17.6%.(2)As the rolling strain increases,the alloy grains elongate and break along the rolling direction,the grain size further decreases,the dislocation density increases,and a fibrous structure is formed.During the rolling process,the preferred orientation of the alloy changes with the increase of deformation.After rolling at 75%deformation at C-ECAP + room temperature,the {110}<001> Goss texture and{110}<112> brass texture are mainly formed,with higher texture strength.After 75%deformation during cryo rolling,there is mainly a {110}<001>Gaussian texture with uniform distribution.The strength,hardness,and conductivity of the material reached541.71 MPa,159.8HV,and 47.4% IACS,respectively,after 75% cryo rolling through path C-ECAP.(3)After C-ECAP+room temperature/cryo rolling and aging treatment,with the increase of aging temperature and time,the number of second phase precipitates in the alloy increases,and the precipitated phase is mainly Cr elemental.After rolling,the alloy reaches a better aging state at 450 ℃.After 3 hours of room temperature rolling aging,the strength,hardness,and conductivity of the A-path alloy were 494.27 MPa,155.6HV,and 80.6% IACS,respectively.After 2 hours of cryo rolling aging,the tensile strength,hardness,and conductivity of the A-path alloy were 537.4 MPa,167.9HV,and 79.6% IACS,respectively.The preferred orientation of the alloy after aging for different times is consistent with the rolled state.(4)C-ECAP+rolling+aging can quickly prepare high-performance micro nano structured materials,significantly improving the structure and properties of the materials.Along with the refinement of the material structure and the regulation of grain boundaries,various properties of the material have been improved.The formation of recrystallization texture after alloy deformation and aging is more conducive to the improvement of material conductivity.