(上海交通大学 材料与科学与工程学院 金属基复合材料国家重点实验室,上海 200240)
摘 要: 对不同烧结温度下制备出的Ti、Al、Nb混合粉烧结坯的显微结构进行研究。结果表明,高Nb含量TiAl金属间化合物制备过程中,铝熔化后包裹在Ti与Nb颗粒表面,Ti原子与Al原子相互扩散,Ti-Al反应随着温度的升高,反应程度不断升高。同一温度下的Ti-Al反应并不是单一反应,而是多种Ti-Al系反应共存。在1 200 ℃反应中,Ti基本反应完全,但是单相Nb依然存在。在1 000 ℃反应后,依然有单相α-Ti存在,从而有望提高固结后材料的可加工性能。
关键字: TiAl金属间化合物;粉末冶金;元素粉末反应;反应机理
(The State Key Laboratory of Metal Matrix Composites,
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
Abstract:Compacts of Ti, Al, Nb elemental powder blend sintered at temperatures of 800-1 200 ℃ were characterized and analyzed. The results show that molten Al liquid first coats the Ti and Nb powder particles, and then inter-diffusion happens between Ti and Al phases during the preparation of high Nb containing TiAl intermetallic. The extent of the reaction becomes lager at a higher temperature. Multiple reactions happen during sintering. Ti particles are consumed by the reactions at 1 200 ℃, but the Nb phase still exist. The α-Ti phase still exist after sintering at 1 000 ℃, showing the sintered powder compact may have excellent workability.
Key words: TiAl intermetallics; powder metallurgy; elemental powder reactions; reaction mechanism