摘要
采用20μm、50μm、100μm和150μm的4种Si C颗粒,模压成形法制备Si Cp预制体,通过TG-DSC分析制定了烧结工艺参数,研究了颗粒尺寸对Si Cp预制体孔洞特征的影响。结果表明,通过控制原材料质量配比和烧结工艺制备的Si Cp预制体,可以满足液态浸渗法制备复合材料的强度要求;Si C颗粒尺寸对颗粒堆积间隙及淀粉氧化分解产生的间隙膨胀作用有重要影响,当预制体的原材料质量配比和烧结工艺条件相同时,随着Si C颗粒尺寸增大,4组Si Cp预制体的孔隙率呈现先降低后略有提高的趋势,为防止预制体制备失效,要求控制小颗粒尺寸预制体的造孔剂含量不宜过高,而较大颗粒尺寸预制体的粘结剂含量不宜过低。
SiCp preforms with different particulates of 20 μm, 50 μm, 100 μm and 150μm were prepared by compression molding method. With thermal gravity-differential scanning calorimetry （TG-DSC） analysis, the sinter parameters were determined. The effect of particulate sizes on porosity and pore formation of the preforms was investigated. The results show that SiCp preforms made by adjusting the mass ratio of raw materials and sintering process can meet the strength requirement for fabrication of SiCp/A1 composites by liquid aluminum infiltration. It is also found that the SiC particulate size, starch as pore-forming agent and aluminum phosphate selected as binder have combined effect on the preform pore fractions. The interval space of stacked particles related to their sizes and volume expansion of gap among SiC particles due to oxidative decomposition of starch are main affecting factors for the preform pore characteristics. The porosity fractions of SiCp preforms were decreased as SiC particulate size increase, whereas the fractions increased if the particles exceed a certain size. It is required to control the content of pore-forming agent and binder respectively for successive preparation of preforms with different particulate size.
出处
《铸造》
CAS
CSCD
北大核心
2015年第3期260-264,共5页
Foundry
基金
国家自然科学基金资助项目(51375171)
