【摘要】 研究了不同球磨时间内Ti-Al复合粉末显微结构及成分的演变。随着球磨时间的延长,原始粉末的形貌发生了一系列变化,从球磨2h的扁平状变为球磨6h的细小的等轴状。球磨8h后粉末的晶粒尺寸达到纳米级,平均约为17nm。对钛铝复合粉末的演化机理进行了分析。在球磨过程中,铝逐渐融入钛晶格形成钛的固溶体。球磨不同时间的粉末中钛铝反应的起始温度的差热分析表明,机械合金化细化了复合粉末,显著降低了钛、铝反应的起始温度。更多还原

【Abstract】 The evolution in microstructure and composition of the milled Ti-Al composite powder with different milling time were investigated. It shows that with the milling time increasing, the initial powder underwent a successive change in its morphology from a flattened shape (2 h) to a fine, equiaxed and uniform one (above 6 h). The milled Ti-Al composite powder was nanocrystalline with the average crystallite size of about 17 nm after milling for 8 h. The evolution mechanism of Ti-Al composite powder was elucidated. The Ti(Al) solid solution is formed through a gradual and progressive solution of Al into Ti lattice. By differential thermal analysis on the ignition temperature of the reaction between Ti and Al as a function of milling time, it indicates that mechanical milling of the powders significantly lowered the ignition temperature of the reaction by refining its Ti-Al composite structure.更多还原