论文部分内容阅读
以Ti、Si元素粉末为原料,采用燃烧合成技术制备了Ti:Si原子配比分别为1:1、5:4、5:3、3:1的4种多孔材料,对其燃烧合成特征、相组成、孔结构以及微观形貌进行了分析。结果表明:随着Ti含量的增加,Ti-Si体系反应程度先加剧后减弱,燃烧温度表现为先升高后降低的变化趋势,最高燃烧温度达2075 K;燃烧产物分别以TiSi、Ti5Si4、Ti5Si3、Ti5Si3相为主。多孔材料开孔率为42.43%~49.42%,体积中值孔径处于64.10~18.11μm;抗压强度最高达到23.15MPa。造孔机制主要包括粉末压坯颗粒间的原始孔隙;燃烧合成反应过程中先熔化的硅颗粒在毛细作用下发生流动形成的原位孔隙;原位孔隙和颗粒间原始孔隙结合形成的大孔隙;燃烧合成过程中因熔化析出作用导致摩尔体积下降形成的小孔隙。
Four kinds of porous materials with Ti: Si atomic ratios of 1: 1, 5: 4, 5: 3, and 3: 1 were prepared by combustion synthesis using Ti and Si powders as raw materials. Phase composition, pore structure and micro-morphology were analyzed. The results show that with the increase of Ti content, the reaction degree of Ti-Si system first aggravates and then decreases, and the combustion temperature shows the trend of first increasing and then decreasing. The maximum combustion temperature reaches 2075 K. The combustion products are respectively TiSi, Ti5Si4, Ti5Si3 , Ti5Si3-based. The porosity of porous material is 42.43% ~ 49.42%, the volume median pore diameter is 64.10 ~ 18.11μm, and the highest compressive strength reaches 23.15MPa. The pore-forming mechanism mainly includes the original pores between the powder compacts, the in situ pores formed by the flow of the melted silicon particles during the combustion synthesis reaction, the large pores formed by the combination of the in-situ pores and the original pores between the particles, Combustion synthesis process due to melting precipitation led to the decline in the molar volume of small pores.