The Al-4Ti master alloy was fabricated via combining the titanium particle method with the reaction of halide salt in resistance furnace at different cooling rates.This study aims to investigate the effect of cooling rate and the proportion of fluorides on morphology evolution of TiAl3 in Al-4Ti master alloy.Results show that cooling rate and the proportion of fluorides had no effect on the kind of second phase and various morphologies of TiAl3 particles in Al-4Ti master alloy could be acquired by adopting different cooling rate.The three kinds of TiAl3 particles confirmed in Al-4Ti master alloy were as follow: petal-like, blocky and flake-like, which corresponded to the cooing rate of 3.36, 2.57 and 0.31 K/s respectively.It could also be found that the morphology of TiAl3 particles in the prepared master alloy changed from petal-like to blocky, and finally to flake-like with the decrease of cooling rate.Moreover, the type of the phase in Al-4Ti master alloys could hardly change whatever the proportion of fluorides is.Finally, the introduction of K2TiF6 would promote the formation of petal-like TiAl3 particles.%研究了Al-4Ti中间合金生产过程中冷却速度和氟盐比例对TiAl3相的形貌演变影响规律.结果表明,冷却速度和氟盐比例不影响Al-4Ti铸锭组织中第二相的种类且Al-4Ti合金中不同形貌的TiAl3相可通过改变铝熔体冷却速度而获得;一般情况下,随冷却速度由3.36 ℃/s降低到0.31 ℃/s,Al-4Ti中间合金中TiAl3颗粒的形貌由花瓣状逐渐向块状过渡,最后转变为细长片状形貌;特别的,当Al-4Ti中间合金中来自海绵钛和来自氟钛酸钾中的钛的比例为3∶2时,TiAl3相的三维形貌对冷却速度不敏感,都为块状.此外,氟盐的加入与否会在一定程度上影响花瓣状TiAl3颗粒的形成.
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