烧结温度对SiC_(p)/2024Al复合材料组织与性能的影响

Effect of Sintering Temperature on Microstructure and Mechanical Properties of SiC_(p)/2024Al Matrix Composites

以高纯度碳化硅(SiC)颗粒和2024铝合金粉末为原材料,采用高速球磨+热压粉末冶金工艺制备了不同烧结温度下的SiC_(p)/2024Al复合材料,研究了不同烧结温度对该材料显微组织及力学性能的影响。结果表明:烧结温度较低时该材料孔隙率较高,孔隙在断裂失效中起主导作用;随烧结温度升高,该材料孔隙率降低;材料断裂失效呈SiC颗粒脆性断裂、基体合金撕裂、界面结合失效开裂三种失效方式共存特点;当烧结温度为590℃时,该材料组织致密,抗拉强度、硬度和伸长率分别达到最大值364 MPa、106 HV和7.6%。

SiC_(p)/2024Al composite at different sintering temperatures was prepared by high speed ball milling+hot-press powder metallurgy technology with high-purity SiC particles and 2024 aluminium alloy powders as raw materials.The effects of different sintering temperatures on the microstructure and mechanical properties of the composites were investigated.The results show that the porosity of the composites is higher when the sintering temperature is lower,which is the main factor of the fracture failure of the composites.As the sintering temperature increases,the porosity of the composites decreases,the fracture failure of the composite is characterized by SiC particle brittle fracture,matrix alloy tearing and interface bonding failure and cracking.When the sintering temperature is 590℃,the microstructure of the composite is dense,and the tensile strength,hardness and elongation reach the maximum values of 364 MPa,106 HV and 7.6%,respectirely.