拉拔形变率对Al2O3颗粒增强Cu基复合材料组织和硬度的影响

Effect of drawing deformation rate on microstructure and hardness of Al2O3 particle reinforced Cu matrix composites

研究了拉拔形变率对Al2O3颗粒增强Cu基复合材料组织和硬度演变规律的影响。结果表明：基体中弥散分布着高体积分数的球状纳米级Al2O3强化相粒子,尺寸为30-60 nm;经拉拔处理后组织形变量增加,晶粒中生成了位错缠结界面以及带状组织。随着拉拔形变率增加,平行于拉拔方向的晶粒发生明显拉长,晶粒的长宽比也明显增大。Al2O3颗粒增强Cu基复合材料在拉拔过程中会产生加工硬化现象,基体中产生大量位错,弥散态Al2O3强化相颗粒会对这些位错产生显著钉扎效果,进而抑制了基体位错的运动。

The influence of drawing deformation rate on microstructure and hardness evolution of Al2O3particle reinforced Cu matrix composite was studied.The results show that spherical nano-sized Al2O3strengthening phase particles with a size of 30-60 nm are dispersed in the matrix.After drawing treatment,the deformation of the composites increases,and dislocation tangled interfaces and banded structures are formed in the grains.With the increase of drawing deformation rate,the grain parallel to the drawing direction is obviously elongated,and the aspect ratio of the alloy grain is also obviously increased.Al2O3particle-reinforced Cu matrix composite has work hardening phenomenon during drawing.A large number of dislocations occur in the matrix.Dispersed Al2O3particles produce significant pinning effect on these dislocations,thus inhibiting the movement of matrix dislocations.