TiC_P/Ti复合材料的熔铸法制备及微观组织研究

Fabrication and Microstructure of TiC_P/Ti Composites in Melting-Casting

用熔铸法制备了原位自生钛合金基复合材料。为减少复合材料的成分波动 ,熔炼前先用混合均匀的TiC粉和铝粉制备TiC Al中间合金 ,然后用中间合金制取复合材料。研究了复合材料中TiC的形貌。结果表明所制备的复合材料的成分易控制 ,波动小。对其TEM的研究表明 ,其TiC形态为初生树枝晶和短棒状共晶 ,此外还发现有 0 3～ 0 6 μm的规则块状TiC颗粒析出 ,多分布在晶界上 ,与基体界面干净 ,无反应层 ,HRTEM也证明不存在反应层。基体中存在较多位错 ,且位错线上有阻碍位错运动的TiC析出物 ,。

In situ titanium alloy matrix composites were fabricated by melting casting.To reduce the fluctuation of composition,a master TiC Al alloy was made using the mixing powders of TiC and Al,then the in situ composite was molten and cast by the master alloy.A study on morphology of TiC in composites indicated that with this process the accurate composition of composites could be attained and controlled easily.Morphology of TiC was primary dendrite and short bar eutectic.TEM and HRTEM demonstrated that there was also a large number of regular TiC particles with size of 0 3～0 6μm at boundary and without contamination and reaction zone on its interface.In the matrix,there was a lot of dislocations,and on dislocation lines there were TiC precipitates hampering the motion of dislocations.