Ti-C-Al-Fe_2O_3体系原位合成钢基复合材料组织与形貌研究

Study on Structure and Properties of Steel Matrix Composites in Situ by Ti-C-Al-Fe_2O_3 System

采用Ti-C-Al-Fe2O3反应体系,结合铸造和自蔓延高温合成(SHS)两种工艺,在湿砂型中浇注高温熔融的钢水,引燃SHS压块,从而发生自蔓延高温合成反应,生成了高硬度的陶瓷相TiC、Al2O3.通过改变Ti-C-Al-Fe2O3体系组分配比,探讨了体系在金属液内SHS反应对原位内生TiC、Al2O3尺寸与分布的影响.结果表明,随着过量Al元素的增加,陶瓷增强颗粒尺寸逐渐减小且分布更均匀;稀土CeO2加入量的增加,增强区更加致密,稀土CeO2添加剂含量为0.8%时制备的复合材料中原位形成的Al2O3、TiC颗粒尺寸较小,分布均匀.

The material system,Ti-C-Al-Fe2O3,was selected in this paper to prepare a steel casting with a layer of ceramic reinforced surface by a casting process combined with SHS.During the process,high temperature molten steel was poured into a sand mould where a preformed SHS block was preset and ignited by the high temperature molten steel.As a result,a SHS reaction happened and ceramic reinforcements TiC and Al2O3 were synthesized inside the mould.The influence of TiC and Al2O3 on the size and distribution in the Ti-C-Al-Fe2O3 system inside the SHS reaction situ in the liquid metal was studied.With the excessive Al element increasing,ceramic particle size decreased gradually and distributed more evenly.With the total mass of CeO2 addition increasing from 0wt% to 1.2wt%,the density in the reinforced region increased.When the CeO2 additive content is 0.8% of the composite materials prepared by in situ formation of Al2O3 and TiC,the particles were the finest and distributed evenly.