深冷处理对铜合金组织与性能影响

Effect of cryogenic treatment on microstructure and properties of copper alloy

对经挤压后的Cu-6%Al铜合金进行-196℃的深冷处理,研究深冷处理时间对其组织和性能的影响。结果表明：Cu-6%Al铜合金经深冷处理后组织中剪切带细化,孪晶形成。随着深冷时间的延长,Cu-6%Al铜合金的布氏硬度变化呈现先增大再减小,后趋于平稳的趋势,在12 h处达到峰值,为181.6 HBS,并建立了布氏硬度与深冷时间的关系方程。随着深冷处理的进行,Cu-6%Al铜合金的抗拉强度和屈服强度得到提升,而均匀伸长率的变化并不明显。研究发现,挤压变形后的Cu-6%Al铜合金经过深冷处理,其微观组织更为均匀,力学性能更加优异。

Effect of soaking time on the microstructure and properties of extruded Cu-6%Al copper alloy when cryogenic treated at-196 ℃was studied. The results show that after cryogenic treatment,shear bands are refined and twins form. With the prolongation of the soaking time,the Brinell hardness of Cu-6%Al copper alloy increases first and then decreases,then tends to be stable. It reaches the peak value of181. 6 HBS when soaked for 12 h. The equation between Brinell hardness and cryogenic soaking time is established. With the cryogenic treatment,the tensile strength and yield strength of Cu-6%Al copper alloy increase,but the change of uniform elongation is not obvious. It is found that the microstructure of extruded Cu-6% Al copper alloy is more uniform and mechanical properties are better after cryogenic treatment.