(山东大学 材料液态结构及其遗传性教育部重点实验室,济南 250061)
摘 要: 结合LSM法和MCR法原位反应生成TiB2粒子增强Al-Si-Mg复合材料。研究发现:原位生成TiB2粒子呈等轴状且尺寸<1μm,大都均匀分布在共晶组织中,与共晶Si交织在一起,在α(Al)中只有少量的TiB2粒子;原位TiB2粒子可明显强化Al-Si-Mg复合材料,且随着TiB2粒子数量的增加,强化效果也随之提高,而且延伸率也略有升高,如6%TiB2/ZL104复合材料室温拉伸强度可达296MPa,延伸率为5.5%;热处理(T6 )可将共晶Si由原先的连续棒状变为孤立的颗粒状,大幅度提高材料抗拉强度,使6%TiB2/ZL104复合材料室温拉伸强度达386MPa,而材料仍属于韧性材料。
关键字: TiB2/Al-Si-Mg复合材料; 原位反应; 显微组织; 力学性能
of in-situ TiB2/Al-Si-Mg composites
(The Key Laboratory of Liquid Structure and Heredity of Materials,
Ministry of Education,Shandong University, Jinan 250061, P.R.China)
Abstract: In-situ TiB2 particulate reinforced Al-Si-Mg composites were fabricated by combining LSM method with MCR method. It is found that the shape of the in situ TiB2 particles is equaxed, their size is less than 1μm, most of them uniformly distribute in eutectic structures and are interlaced with eutectic Si, and there is a few of TiB2 particles in α(Al). It is also found that TiB2 particles can enhance the tensile strength of the composites, and with TiB2 particles increasing the degree of enhancement is increased and the ductility is also raised slightly. For example, the tensile strength of 6%TiB2/ZL104 composites is as high as 296MPa, and its ductility is 5.5%. Heat treatment can change the eutectic Si from continuous rod-like to isolated particle-like and increase the tensile strength of the composites considerably. The tensile strength of 6%TiB2/ZL104 composites after heat treatment can be enhanced to 386MPa, however the composites after heat treatment also belong to plastic material.
Key words: TiB2/Al-Si-Mg composites; in-situ reaction; microstructure; mechanical properties