热变形对烧结Cu-10%WC复合材料组织及性能的影响

Effects of Thermal Deformation on Microstructure and Properties of Sintered Cu-10%WC Composites

采用还原法制备Cu-10%WC复合粉末(质量分数),热压烧结得到Cu-10%WC复合材料,并进行热轧处理。采用扫描电子显微镜、X射线衍射仪、透射电子显微镜、拉伸试验等研究了热轧对Cu-10%WC复合材料组织和性能的影响及机理。结果表明,经热轧:复合材料中WC颗粒尺寸无变化但沿轧制方向重新排列;Cu晶粒尺寸减小,发生再结晶时沿(220)晶面择优生长,降低了与WC颗粒结合界面的错配度。轧制后,复合材料抗拉强度从426 MPa提高至492MPa,硬度HV0.2从1467.1 MPa提高至1634.6 MPa,导电、导热性能不变。热轧使WC颗粒重新排列调节了位错的分布、Cu晶粒择优取向提高与WC颗粒界面结合强度以及细晶强化的作用,提高了复合材料综合性能。

The Cu-10wt%WC composite powder was prepared by reduction,and the Cu-10wt%WC composite material was obtained by hot-pressing sintering followed by hot rolling.Scanning electron microscope,X-ray diffractometer,transmission electron microscope and tensile test were used to study the effect and mechanism of hot rolling on the microstructure and properties of Cu-10wt%WC composites.The results show that after hot rolling,the WC particle does not change in size but rearranges along the rolling direction in composites.The grain size of Cu decreases,and when the copper matrix recrystallizes,it grows preferentially along the(220)crystal plane,which reduces the misfit of the interface with the WC particles.After rolling,the tensile strength of the composites increases from 426 MPa to 492 MPa,the hardness HV0.2 increases from 1467.1 MPa to 1634.6 MPa,and the electrical and thermal conductivity remain unchanged.Hot rolling can adjust the distribution of dislocations by rearranging WC particles,improve the bonding strength of Cu grains interface with WC particles,and strengthen the grain refinement,thus improving the comprehensive properties of composites.