高钛渣自蔓延铝热还原制备钛基合金

Preparation of titanium-based alloy by self-propagating aluminothermic reduction of high titanium slag

摘要:

本文通过研究不同配铝比对高钛渣铝热还原制备钛基合金的影响，采用高钛渣、铝粉、KClO?和CaO为原料，成功通过自蔓延铝热还原法制备出钛基合金。本文对高钛渣铝热还原过程的热力学和动力学进行了计算，分析结果显示，高钛渣可通过铝热还原制备钛基合金，其中主要反应为Al还原TiO?，该反应活化能为274.4 kJ/mol，反应级数为1.04。随着配铝比的增加，钛铝合金中Ti元素的质量分数逐渐降低，Al元素的质量分数逐渐上升，同时钛铝合金中存在少量Fe、Mn和Si等合金元素。物相分析显示，在低铝配比条件下，主要物相为Ti?Al；而在高铝配比条件下，主要物相转变为TiAl。化学成分分析结果显示，在配铝量为1.0的实验条件下，制备出的钛基合金成分为51.6 wt% Ti、40.6 wt% Al、7.6 wt% Fe、3.4 wt% Mn和1.3 wt% Si。微观形貌分析表明，所制备的钛合金由基体相区、富铁相区和富硅相区构成。本研究为高钛渣在铝热还原过程中实现钛合金的高值化利用提供了新的技术路径。

Abstract:

In this paper, the effects of different aluminum ratios on the preparation of titanium-based alloys by aluminothermic reduction of high titanium slag were studied. Titanium-based alloys were successfully prepared by self-propagating aluminothermic reduction using high titanium slag, aluminum powder, KClO₃ and CaO as raw materials. The thermodynamics and kinetics of the aluminothermic reduction process of high titanium slag were calculated. The results show that high titanium slag can be used to prepare titanium-based alloys by aluminothermic reduction. The main reaction is the reduction of TiO₂ by Al. The activation energy of the reaction is 274.4 kJ/mol, and the reaction order is 1.04. With the increase of the aluminum ratio, the mass fraction of Ti element in the titanium-based alloy gradually decreases, and the mass fraction of Al element gradually increases. At the same time, there are a small amount of alloying elements such as Fe, Mn and Si in the titanium-based alloy. Phase analysis shows that under the condition of low aluminum ratio, the main phase is Ti₃Al, under the condition of high aluminum ratio, the main phase is transformed into TiAl. The results of chemical composition analysis showed that the composition of the prepared titanium-based alloy was 51.6 wt.% Ti, 40.6 wt.% Al, 7.6 wt.% Fe, 3.4 wt..% Mn and 1.3 wt.% Si under the experimental conditions of 1.0 aluminum ratio. The microstructure analysis shows that the prepared titanium alloy is composed of base phase region, iron-rich phase region and silicon-rich phase region. This study provides a new technical path for the high value utilization of high titanium slag.