原位自生A356/TiB_2复合材料的组织与性能

The Microstructure and Properties of in situ TiB_2 Particulates Reinforced A356 Composites

通过混合盐法制备了原位自生TiB2颗粒增强A356复合材料.扫描电镜观察结果表明,制备的原位自生TiB2颗粒分布均匀,其最大尺寸在500nm左右,平均尺寸在200nm左右.高分辨透射电子显微镜观察结果表明,颗粒与基体之间界面结合良好、干净,无任何杂质相的存在.复合材料的抗拉强度和屈服强度较基体都有了明显提高;复合材料的阻尼性能明显高于基体合金的阻尼性能,其室温时的数值为0.018.该研究成功地实现了材料力学性能和阻尼性能的同时提高.

Mix-salts method was employed to fabricate in situ TiB2 particulates reinforced A356 composites. Scanning electron microscope （SEM） observation shows that TiB2 particulates are well distributed within matrix alloy and their average size is about 200 nm in diameter. High resolution transmission electron microscope （HRTM） verifies that there is a cleaner and well bonded interface between particulate and matrix. Improvement of A356 composite in mechanical properties and damping capacity was obtained simultaneously. The experimental results indicate that the tensile strength, yield strength and damping capacity increases by 35 MPa,42 MPa, 10 × 10^-3 respectively.