复合铝热剂超重力燃烧合成熔渗及快速凝固机制研究

This research focuses on the needs of W-Cu gradient materials prepared by combustion synthesis under high-gravity infiltration. The reactions characteristics and melt infiltration and solidification mechanism of the Al/CuO/WO3 aluminum thermal system under high-gravity field will be studied. The relationship between the characteristic of thermite and the combustion temperature, wave velocity, thermite composition and particle size will be established base on the experimental results and the theoretical simulations. The mechanism and kinetics of the melt infiltration and rapid solidification in the porous media under high-gravity will be clarified. Base on the above research result, W-Cu gradient materials with W volume fraction from 0-80% could be obtained. This study could provide theoretical guidance for the progress of W-Cu gradient materials and other new materials prepared by high-gravity infiltration. This study will promote the development of the research and application of high gravity infiltration method and related materials.

本课题针对超重力熔渗制备W-Cu梯度材料的实际需求，对超重力场作用下Al/CuO/WO3复合铝热体系的燃烧反应特征与熔体渗透机理及凝固机制展开深入研究。根据实验结果并结合理论模拟，研究得出铝热剂配方、粒度等参数对铝热燃烧反应温度和燃烧波蔓延速率之间的关系规律，阐明超重力场作用下高温熔体在多孔介质中的渗透机理及快速凝固机制。基于以上研究，通过优化铝热剂配方和工艺参数，最终制备出W体积分数从0至80%可调的W-Cu梯度材料。通过本课题研究，不仅为超重力熔渗制备W-Cu材料提供理论指导，而且为超重力熔渗制备其他新材料提供有益参考，从而对超重力熔渗技术以及相关材料的研究与应用起到实质性推动作用。

在研究超重力场辅助燃烧合成用铜基铝热剂过程中，首先通过热力学计算获得了Al/CuO反应体系的基本反映参数，结合静态燃烧反应实验，详细研究了以Cu粉作为稀释剂、以B2O3造渣剂的实验，获得了添加量对Al/CuO反应体系燃烧温度、燃烧速率和反应喷溅率的影响规律，确定了最优铜基铝热剂配方各组分的摩尔比为Al:CuO:Cu:B2O3=20%:30%:45%:5%，实现了铝热反应的稳定可控燃烧。结合超重力燃烧合成反应，制备了W/Cu梯度材料的相对密度约为98.2%， W体积分数分别为从0-80%可调、热导率从 170~320 W/m/K梯度变化。