Ti-Al合金板材
( 中南大学 粉末冶金国家重点实验室， 长沙 410083)
摘 要: 以Ti、 Al元素粉末为原料， 在粉末轧机上无包套冷轧成尺寸为500 mm×230 mm×1.5 mm的板坯， 其相对密度达85.9%。 研究了不同工艺参数对Ti、 Al元素粉末轧制板材的影响。 取小样在不同温度下进行真空无压烧结， 研究了板坯的真空烧结行为。 结果表明： Ti、 Al元素粉末冷轧过程要求适中的粉末流动性、 低的轧制速度以及一定大小且较稳定的轧制压力。 真空烧结后， Ti-Al合金由Ti-Al和Ti3Al两相组成， Ti3Al相含量随烧结温度升高而增加。 烧结坯孔隙度大幅度增加， 增加量为21%~32%。 原板坯中的孔隙及偏扩散是造成烧结坯孔隙的主要原因。 低压（<10 kPa）真空烧结过程中， 外压仅有效作用于短暂的液相阶段， 粉末粒度越粗， 烧结温度越高， 烧结坯孔隙度受这种低压强的影响程度越大。
关键字: Ti-Al合金；元素粉末； 轧制； 真空烧结； 板材
（ State Key Laboratory of Powder Metallurgy,
Central South University, Changsha 410083, China）
Abstract: Ti-Al alloy sheets were fabricated successfully by element powder cold roll forming and reactive synthesis. The size and relative density of sheet bars were 500 mm×230 mm×1.5 mm, 85.9% respectively. The effects of process parameters on the fabrication of sheet bars and the vacuum sintering behavior of sheets at different temperatures were investigated. The results show that the moderate flowability of element powders, low rolling velocity and stable rolling pressure are needed for the process of Ti, Al element powder cold rolling. After the sintering, microstructure of Ti-Al alloy sheet consists of Ti-Al and Ti3Al phases, and the content of Ti3Al phase increases with the sintering temperature. The increment of Ti-Al sheets porosity is 21%-32%, and the prime reasons are considered to be the existence of the porosity in sheet bars and Al self-diffusion in the process of reactive synthesis. During the low pressure(＜10 kPa) vacuum sintering process, the external pressure works effectively in the transient liquid phase stage. The effect of the low external pressure on porosity of sintered sheets increases with the increment of the size of the element powder particles and the sintering temperature.
Key words: Ti-Al alloy; element powder; cold roll; vacuum sinter; sheet
