(1. 上海交通大学 材料科学与工程学院，凝固科学与技术研究所，上海 200240；
2. 上海市先进高温材料及其精密成型重点实验室，上海 200240)
摘 要: 利用高能球磨结合放电等离子体烧结和热挤压工艺，制备出TiB2/Al-3.8Zn-1.85Mg-1.32Cu复合材料。通过X射线衍射、扫描电镜和透射电镜表征以及拉伸力学性能测试，研究TiB2颗粒添加量对复合材料微观组织和力学性能的影响。结果表明：高能球磨诱导TiB2陶瓷颗粒形貌从多边形转变为近球形；随着TiB2含量从2%增加到10%(体积分数)，铝基体晶粒逐渐细化，析出相含量减少，复合材料抗拉强度、屈服强度和弹性模量分别由381 MPa、231 MPa和78 GPa增加到679 MPa、645 MPa和96 GPa，伸长率从5.2%下降到1.0%；细晶强化和弥散颗粒强化为复合材料的主要强化机制。
关键字: 铝基复合材料；TiB2增强相；粉末冶金；微观组织；力学性能
（1. Institute of Solidification Science and Technology, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;
2. Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai 200240, China）
Abstract:TiB2/Al-3.8Zn-1.85Mg-1.32Cu composites were prepared by high energy ball milling in combination with spark plasma sintering and hot extrusion. The materials were analyzed by X-ray diffraction, scanning electron microscope, transmission electron microscope and tensile testing machine to investigate the effects of TiB2content on microstructure and mechanical properties. The results show that the morphology of TiB2 particles changes from polygon to nearly spherical as a result of high energy ball milling. With increasing TiB2 content from 2% to 10% (volume fraction), the grain size of aluminum matrix gradually is refined and the precipitates density decreases; the tensile strength, yield strength and elastic modulus of the composites increase from 381 MPa, 231 MPa and 78 GPa to 679 MPa, 645 MPa and 96 GPa, respectively, and the elongation to fracture decreases from 5.2% to 1.0%. Fine grain strengthening and dispersion strengthening are the main strengthening mechanisms.
Key words: Al-based composites; TiB2 particles; powder metallurgy; microstructure; mechanical property
