合成过程对Al-Ti-B合金中TiB_2粒子三维形貌的影响(英文)

Influence of forming process on three-dimensional morphology of TiB_2 particles in Al-Ti-B alloys

通过不同工艺制备出一系列Al-Ti-B中间合金,并利用相提取工艺对合金中的TiB2粒子进行提取和分析。研究表明:合成过程对TiB2粒子的三维形貌有显著的影响,不同的制备工艺会导致不同的反应路径,并最终影响TiB2粒子的形貌。利用氟盐法制备的Al-Ti-B中间合金中的TiB2粒子呈现相互独立的六角板块状形貌,且反应温度不会对TiB2粒子的形貌产生影响。然而,利用Al-3B中间合金和海绵Ti制备Al-Ti-B中间合金时,TiB2粒子的形貌随着反应温度的升高而发生明显变化。当反应温度为850℃时,Al-Ti-B中间合金中的TiB2粒子以大的聚集团形式存在,而当反应温度升高到1200℃时,TiB2粒子的形貌转变为复杂的层片状和枝晶状。

A series of Al-Ti-B master alloys were prepared by different preparation routes,and the TiB2 particles in the master alloys were extracted and analyzed.It is found that the forming process has significant influence on the three-dimensional morphology of TiB2 particles.Different preparation routes result in different reaction forms,which accounts for the morphology variation of TiB2 particles.When the Al-Ti-B master alloy is prepared using ＂halide salt＂ route,TiB2 particles exhibit hexagonal platelet morphology and are independent with each other.In addition,the reaction temperature almost does not have influence on the morphology of TiB2 particles.However,TiB2 particles exhibit different morphologies at different reaction temperatures when the master alloys are prepared with Al-3B and Ti sponge.When the master alloy is prepared at 850 ℃,a kind of TiB2 particle agglomeration forms with a size larger than 5 μm.The TiB2 particles change to layered stacking morphology even dendritic morphology with the reaction temperature reaching up to 1200 ℃.