真空热压烧结Al_2O_3/Cu-Cr复合材料的组织与性能

Microstructure and Properties of Al_2O_3/Cu-Cr Composites Prepared by Vacuum Hot-pressed Sintering

采用简化内氧化真空热压烧结工艺制备了不同Cu2O加入量(4%、5%、6%)的Al2O3/Cu-Cr复合材料。分析研究了其微观组织与性能,并研究了冷变形对材料性能的影响。结果表明,在铜基体上弥散分布着细小粒状Al2O3颗粒,其粒径为5～20nm,颗粒间距为20～150nm;Al2O3/Cu-Cr复合材料经80%变形后,其硬度和抗拉强度明显提高,而电导率则随变形量的增大先升高后降低;随着Cu2O加入量的增加,材料的抗软化性能逐渐提高;当Cu2O加入量为5%时,真空热压烧结(950℃,2h,22MPa)后全部完成内氧化,且变形后综合性能最优,此时Cu2O含量为最佳的添加量。

Al_2O_3/Cu-Cr composites with different oxygen resource(Cu2O)contents of 4%,5% and 6% were prepared by vacuum-pressed sintering with a simplified internal oxidation method.The microstructure and effects of cold deformation on properties of the composites were described.It is found that fine Al_2O_3 particles with diameters of 5～20nm and 20～150nm in particle interval were uniformly distributed into the Cu matrix.The hardness and tensile strength of the 80% deformed composites can be remarkably increased,while the electric conductivity of the composites is firstly increased and then decreased with increasing in deformation rate.With oxygen resource content increases,the soft resistance of the composites is strengthened.After hot-pressed sintering at 950℃ for 4 h in case of 22MPa,the internal oxidation of compressed Cu-Al alloy powder is totally completed with 5% oxygen resource content,resulting in the desirable comprehensive properties of deformed composites.