Abstract: LF refining slag contains iron oxide, calcium oxide, silicon dioxide, aluminum oxide, magnesium oxide, iron and so on. However, it is always piled up as solid waste, which not only pollutes the environment but also results in the waste of alloying elements. Some of the alloying oxide can be reduced by Al during thermite reaction, which can reduce waste of alloying elements in LF slag. Calcium oxide can react with aluminum oxide formed by thermite reaction, which can reduce melting point of aluminum oxide and make it easy to float. In addition, mixture of LF refining slag and CaF2 can be added as coolant, which will solve the problems of evaporation of reaction raw materials and low density of Fe-Cr based ceramic composites caused by high heat release of combustion synthesis reaction system, to absorb reaction heat and reduce the temperature of reaction system to reduce the evaporation of raw materials. However, the wear-resistant layer could not connect with the steel plate as too many LF refining slag were added. In this work, in order to explore the appropriate amount of LF refining slag, 2, 4, 6, 8, 10 g LF refining slag and 2.39, 2.50, 2.60, 2.71, 2.81 g CaF2 were designed to study the welding area of steel plate and wear-resistant layer, the density, hardness, and wear resistance of samples fabricated by combustion synthesis. The results showed that the density of wear-resistant layer was the best as added 8 g LF refining slag; abrasion loss per unit area of wear-resistant layer was the least as added 8 g LF refining slag; the hardness of the wear layer was the highest as added 10 g LF refining slag; the welding area of wear-resistant layer and steel plate was the largest as added 10 g LF refining slag. Both density and hardness had positive effect on the wear resistance of the composite, which would be increased with increase of each of them as difference of the other property was not large. In summary, in order to obtain high wear resistance while ensuring the uniformity of other properties of Fe-Cr based ceramic composites, the optimal addition amount of LF refining slag is 8 g.

Key words: combustion synthesis, LF refining slag, composite material, wear resistance

摘要： LF精炼渣作为固体废弃物，大量堆放污染环境，渣中含有合金元素，通过Al可以将渣中合金元素置换出来，对LF精炼渣进行二次利用。为解决燃烧合成反应体系热量高造成反应原料蒸发、Fe-Cr基陶瓷复合材料致密度低等问题，通过添加LF精炼渣和CaF2作为冷却剂吸收反应放热，降低反应体系温度、减少原料蒸发。但是，冷却剂加入量过多，体系温度下降过快会导致熔体熔化钢板的能力下降，出现耐磨层与钢板无法冶金结合的情况。因此，本研究设计添加2, 4, 6, 8, 10 g的LF精炼渣和2.39, 2.50, 2.60, 2.71, 2.81 g的CaF2，利用燃烧合成反应在钢板上制备Fe-Cr基陶瓷复合材料，并对燃烧合成产物耐磨层和钢板的焊接面积及耐磨层的致密度、硬度、耐磨性能进行研究，进而探究合适的LF精炼渣添加量。结果表明，LF精炼渣加入量为8 g时，耐磨层的致密度最高并且耐磨层的单位面积磨损量最少；LF精炼渣加入量为10 g时，耐磨层的硬度最高、钢板和耐磨层的焊接面积最大。材料的耐磨性能受致密度和硬度影响，当硬度差异较小时，耐磨层的耐磨性能随着致密度提高而提高；当致密度差异较小时，耐磨层的耐磨性能随着硬度提高而提高。综上所述，为了获得高耐磨性能的同时保证Fe-Cr基陶瓷复合材料其他性能的均匀性，最佳的LF精炼渣加入量为8 g。

关键词: 燃烧合成, LF精炼渣, 复合材料, 耐磨性能