热轧+电脉冲处理对超导用Cu-14Sn-0.3Ti合金组织及性能的影响

Effect of Hot Rolling+Electric Pulse on Microstructure and Properties of Cu-14Sn-0.3Ti Alloy for Superconducting

摘要:

本研究采用热轧+电脉冲处理的方式实现了Cu-14Sn-0.3Ti合金强度与延伸率的协同提升，Cu-14Sn-0.3Ti合金在经过70%热轧+10 min电脉冲处理后，延伸率由4.7%提升至40%，强度由298 MPa提升至530 MPa。通过调控热轧及电脉冲处理工艺，研究了形变储能，脉冲电流对减少层错，促进孪晶生长的影响。结果表明，Cu-14Sn-0.3Ti合金的强度与密度随着形变储能的增加而提升。在焦耳热和电子分风力的共同作用下，Cu-14Sn-0.3Ti合金组织中的δ相发生溶解，层错减少。电脉冲处理后孪晶的形成为位错的运动提供了额外的滑移系，提升了Cu-14Sn-0.3Ti合金的延伸率。一方面孪晶的出现对晶粒进行了分割，细化了晶粒，另一方面，孪晶界的产生阻碍了Cu-14Sn-0.3Ti合金形变时位错的运动，使得Cu-14Sn-0.3Ti合金的强度得到提升。

Abstract:

The strength and elongation of Cu-14Sn-0.3Ti alloy were improved synergistically in this investigation by hot rolling+electric pulse treatment. The elongation of Cu-15Sn-0.3Ti alloy increased from 4.7% to 40%, and the strength increase from 298 MPa to 530 MPa after 70% hot rolling+10 min electric pulse treatment. The influence of deformation energy storage and pulse current on reduction of stacking faults and twin growth was investigated by adjusting hot rolling and electric pulse processing. The results show that the strength and density of Cu-14Sn-0.3Ti alloy increase with the increase of deformation energy storage. The δ phase dissolves, and the deformation-induced stacking faults reduced because of the synergetic effect of Joule heat and electron wind. After electric pulse treatment, the formation of twins provides additional slip systems for the movement of dislocations and improves the elongation of Cu-14Sn-0.3Ti alloy. On the one hand, the appearance of twins has divided and refined the grains. On the other hand, the formation of twin boundaries hinders the movement of dislocations during the deformation of Cu-14Sn-0.3Ti alloy, making the strength of Cu-14Sn-0.3Ti alloy improve.