半固态触变反挤压锡青铜的组织演变和力学性能

Microstructure evolution and mechanical properties of semi-solid thixotropic back-extrusion tin bronze

摘要:

本文将CuSn10P1铜合金进行半固态触变反挤压成形实验。研究冷轧变形量、等温温度及等温时间对CuSn10P1铜合金的微观组织演变和力学性能的影响规律。结果表明：半固态触变反挤压能够有效地改善铜合金半固态成形件中的液相偏聚现象，冷轧变形量及等温处理工艺对半固态触变反挤压锡青铜微观组织和力学性能影响较大。随冷轧变形量增加，平均晶粒尺寸先减小后增大，成形件抗拉强度先升高后降低。随等温温度的升高和等温时间的延长，晶粒尺寸逐渐增大，成形件抗拉强度先升高后降低。当冷轧变形量30%、等温温度900℃、等温时间20min时，半固态触变反挤压CuSn10P1铜合金成形件的组织和性能较好且各部位均匀。成形件纵向各位置组织的液相率分别为14.41%、14.37%、14.33%、14.30%，晶粒尺寸为60.60 μm、60.28 μm、59.51 μm、61.10 μm，形状因子分别为1.29、1.24、1.26、1.27，成形件抗拉强度为407 MPa，延伸率为7.6%。

Abstract:

In this paper, CuSn10P1 copper alloy was formed by semi-solid thixotropic reverse extrusion. The effects of cold rolling deformation, isothermal temperature and isothermal time on microstructure evolution and mechanical properties of CuSn10P1 copper alloy were studied. The results show that the liquid phase segregation phenomenon in semi-solid copper alloy can be effectively improved by thixotropic reverse extrusion, and the cold rolling deformation and isothermal treatment process have a great influence on the microstructure and mechanical properties of semi-solid thixotropic reverse extrusion tin bronze. With the increase of cold rolling deformation, the average grain size decreases first and then increases, and the tensile strength increases first and then decreases. With the increase of isothermal temperature and the extension of isothermal time, the grain size increases gradually, and the tensile strength of the formed parts increases first and then decreases. Under the conditions of cold rolling deformation of 30%, isothermal temperature of 900℃ and isothermal time of 20min, the microstructure and properties of CuSn10P1 copper alloy formed by semi-solid thixotropic reverse extrusion are better and all parts are uniform. The liquid phase fraction of the forming parts were 14.41%, 14.37%, 14.33%, 14.30%, the grain size was 60.60 μm, 60.28 μm, 59.51 μm, 61.10 μm, the shape factor was 1.29, 1.24, 1.26, 1.27, the tensile strength was 407 MPa, the elongation was 7.6%, respectively.