熔渗法制备SiC/MoSi2复合材料  

Preparation of SiC/MoSi2 composites by melt infiltration method

作　　者：李路宁 吴吉光[1] 万龙刚[1] 梁鹏鹏 Li Luning;Wu Jiguang;Wan Longgang;Liang Pengpeng

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司先进耐火材料国家重点实验室

出　　处：《耐火材料》2020年第1期10-13,共4页Refractories

摘　　要：通过引入不同含量的SiC微粉(d 50=2.5μm),以碳化硅为主要原料,酚醛树脂为结合剂,改变SiC颗粒级配制得不同气孔结构的SiC坯体,在1970℃氩气气氛下保温2 h熔渗MoSi 2,制备出SiC/MoSi 2复合材料并研究了气孔结构对MoSi 2熔渗行为的影响。结果表明:(1)熔渗后试样的致密性和MoSi 2的熔渗率主要受坯体显气孔率和气孔孔径的影响,随着SiC微粉的增加,MoSi 2的熔渗率和坯体显气孔率都是先减小后增加的变化趋势;坯体中孔径为0.9~10μm的气孔被熔体填充,留下孔径大于10μm的气孔。(2)添加SiC微粉(d 50=2.5μm)可以缩小气孔孔径,提高SiC/MoSi 2复合材料的致密度;当SiC微粉(d 50=2.5μm)添加量为25%(w)时,熔渗后复合材料的显气孔率最小,为7.3%。SiC green bodies with different pore structures were prepared using SiC as the main raw material,phenolic resin as the binder,adding different contents of SiC micropowder(d 50=2.5μm)to adjust the particle size distribution of SiC.The SiC green bodies were infiltrated with melt MoSi 2 in argon atmosphere at 1970℃for 2 h to get SiC/MoSi 2 composites.The effect of the pore structure of SiC green bodies on the infiltration behavior of MoSi 2 was studied.The results are as follows:(1)the density after infiltration and the MoSi 2 infiltration rate of the samples are mainly affected by the apparent porosity and the pore size of the SiC green bodies;with the increase of the SiC micropowder addition,the infiltration rate of MoSi 2 and the apparent porosity of the green bodies decrease firstly and then increase;the pores with size of 0.9-10μm in the green bodies are filled with the melt,leaving pores larger than 10μm;(2)adding SiC micropowder(d 50=2.5μm)can reduce the pore diameter and increase the density of SiC/MoSi 2 composites;when the addition of SiC micropowder(d 50=2.5μm)is 25 mass%,the composite after infiltration shows the minimum porosity of 7.3%.

关 键 词：SiC/MoSi 2复合材料 气孔结构 MoSi 2熔渗率 

分 类 号：TQ175[化学工程—硅酸盐工业]