粉末半固态触变挤压SiC_p/2024复合材料的组织与性能

Microstructures and Mechanical Properties of SiC_p/2024 Matrix Composites Prepared by Powder Semi-solid Thixoextruding Forming

采用粉末半固态触变挤压工艺制备SiC含量为5%、10%和15%的2024铝基复合材料棒材,研究了真空烧结工艺和SiC颗粒含量对复合材料组织及性能的影响。结果表明,孔洞的存在对复合材料性能影响较大。经过真空处理的复合材料孔隙率比未经处理的减小65.3%,抗拉强度提高了9.7%。随着SiC含量的提高,复合材料的强度、硬度增加,塑性降低,SiC含量为15%的复合材料抗拉强度相比SiC含量为5%的复合材料提高了14.1%,伸长率则降低了51.9%,而且随着SiC含量的增加,脆性断裂趋势更加明显。

SiCp/2024 composite bars with SiC particle volume fraction oi 5%, 10%, 15%, respecuveiy, were prepared by powder mixing and semi-solid thixoextruding forming technology. Influenees of vacu- um treatment process and SiC particle volume fraction on mierostrueture and properties of the compos- ites prepared were investigated. The result indicates that porosity rate is decreased approximately 65. 3% in the composites prepared by vacuum treatment than that one without vacuum treatment, and the tensile strength is increased by 9.7 %. With increasing in SiC particles volume fraction, tensile strength and hardness of the composites are increased, while the plasticity is decreased. The composites with 15% SiCp are increased by 14.1% in tensile strength and decreased by 51.9% in elongation , compared with those of the composites with 5 % SiCp. And with the increase of SiC volume fraction, brittle frac- ture exhibits more obvious.