高能球磨工艺对Cu-10Cr-0.5Al_2O_3组织与性能的影响

Influence of high-energy ball milling on structure and performance of Cu-10Cr-0.5Al_2O_3

利用高能球磨方法对Cu-10Cr-0.5Al2O3(质量分数,%)混合粉末进行预处理,采用电场活化烧结技术对球磨粉末进行烧结,运用XRD、SEM、硬度、断裂强度和电导率等测试方法研究球磨时间对Cu-10Cr-0.5Al2O3复合粉末烧结前后组织和性能的影响。结果表明:随着球磨时间的增加,Cu晶粒更加细化,第二相分布更加弥散,以致烧结材料的强度和硬度逐渐增大,球磨20 h后,烧结样品的强度和硬度分别达到952 MPa和285 HV;由于晶粒细化、高度弥散的第二相以及铜相的晶格畸变加强对电子的散射作用,烧结试样的电导率也随球磨时间的延长而逐渐下降,球磨20 h后,烧结样品的电导率下降到51%(IACS)。

Cu-10Cr-0.5Al2O3（mass fraction,%） powder mixtures were pretreated by high-energy ball milling and subsequently sintered by electric field activated sintering technique.The influence of milling time on the structure and performance of Cu-10Cr-0.5Al2O3 before and after sintering was studied by XRD,SEM,hardness,rupture strength and conductivity test.The results show that,with increasing the milling time,the Cu grain size decreases and the distribution of the second phase becomes more uniform,consequently the strength and hardness of the sintered samples increase and reach 952 MPa and 285 HV,respectively,after powders milled for 20 h.Because of the grain refinement,the uniform distribution of second phase and the lattice distortion of Cu phase,the electron scattering in the sintered samples is enhanced,causing a decrease of conductivity.After 20 h milling,the conductivity of sintered samples decreases to 51%（IACS）.