PCS原位热解法低温制备自结合碳化硅材料的研究  

Preparation of self-bonded silicon carbide materials by in-situ pyrolysis at low temperatures

作　　者：郭鹏[1] 王刚[1] 袁波[1] 韩建燊[1] 

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,河南洛阳471309

出　　处：《耐火材料》2016年第3期185-188,共4页Refractories

摘　　要：为了在较低温度下制备性能较好的自结合碳化硅材料,在黑碳化硅的基础配料中引入聚碳硅烷(PCS),以二乙烯基苯(DVB)作溶剂和交联剂,经混练、成型、烘干后,于1 450℃保温5 h热处理,制备由聚碳硅烷原位热解产生的SiC结合的碳化硅材料,主要研究了PCS加入量(分别为黑碳化硅质量的3%、5%和7%)和热处理气氛(分别为N_2气氛和埋炭气氛)对碳化硅材料体积密度、显气孔率、常温耐压强度、常温抗折强度、高温抗折强度、抗热震性、物相组成和显微结构的影响。结果表明:1)随着PCS加入量的增加,热处理后碳化硅试样的致密度、常温强度、高温强度和烧后线收缩率均增大。2)在PCS加入量相同时,在两种气氛中热处理制备的碳化硅试样的致密度差别很小,但在N_2气氛中热处理制备的碳化硅试样的常温抗折强度、常温耐压强度和高温抗折强度均比在埋炭气氛中制备的小。3)在N_2气氛中热处理制备的碳化硅试样中含有少量Si_2N_2O,而在埋炭气氛中制备的碳化硅试样由β-SiC和α-SiC组成;在两种气氛中热处理制备的碳化硅试样中都生成了纤维状物质,但在埋炭气氛中制备的碳化硅试样的纤维状物质更多,长径比更大。This work aims at preparing high performance self-bonded silicon carbide materials at relatively low temperatures. Self-bonded silicon carbide materials were prepared by in-situ pyrolysis using black silicon carbide as the basic ingredient,introducing polycarbosilane( PCS),divinylbenzene( DVB) as a solvent and a crosslinking agent,mixing,forming,drying,and then firing at 1 450 ℃ for 5 h. The influence of the PCS addition( 3%,5% and 7% of the black silicon carbide content) and heat treatment atmosphere( N_2 and carbon embedded atmosphere) on the bulk density,apparent porosity,cold compressive strength,cold modulus of rupture,hot modulus of rupture,thermal shock resistance,phase composition and microstructure of the silicon carbide materials were researched. The results show that:( 1) with the addition of PCS increasing,the density,cold and hot strength,and shrinkage rate of the fired silicon carbide specimens improve gradually;( 2) with the same PCS addition,the difference in density of the silicon carbide specimens fired in two atmospheres is small; the specimens fired in N_2 have lower cold compressive strength and cold and hot modulus of rupture;( 3) the silicon carbide specimens fired in N_2 atmosphere contain a small amount of Si_2N_2 O,while the silicon carbide specimens fired in carbon embedded atmosphere consist of β-SiC and α-SiC; the silicon carbide specimens prepared in the two atmospheres both have fibrous materials,but the fibrous materials in silicon carbide specimens fired in the carbon embedded atmosphere is more and of greater fiber aspect ratios.

关 键 词：聚碳硅烷(PCS) 自结合碳化硅 低温制备 

分 类 号：TQ163.4[化学工程—高温制品工业]