摘要
在C/C复合坯体中掺杂SiC、ZrC等可显著提高其高温抗氧化性。以Zr-Si混合粉末为熔渗剂,密度为1.6 g/cm3的多孔C/C为复合坯体,采用反应熔渗法(RMI)制备C/C-SiC-ZrC复合材料,研究了复合材料的组织结构、物相组成及力学性能,并对复合材料组织结构的形成机理进行了分析。结果表明:熔渗剂中Zr含量不同时,制备的复合材料均主要由C,ZrC和SiC相组成;随熔渗剂中Zr含量由15%增加到45%,制备的复合材料中SiC含量逐渐降低,熔渗剂中Zr含量为30%时复合材料中ZrC含量最高;C/C复合坯体内的孔隙被反应生成的ZrC相及SiC相充分填充,C/C-SiC-ZrC复合材料表面均出现一层较致密的SiC-ZrC衍生层;ZrC与C和SiC均有良好的界面结合状态,在ZrC颗粒长大和粗化过程中,形成了部分含内嵌SiC晶粒的较大ZrC颗粒;其中采用5号渗剂(Zr30Si50C20)制备的复合材料抗弯强度达到最大值180.6 MPa,表面出现厚度约128.9μm SiC-ZrC衍生层。
C/C-SiC-ZrC composites were prepared by reactive melt infiltration(RMI)with using Zr-Si mixed powder as infiltrant and porous C/C with density of 1.6 g/cm3 as the primary body.The structure,phase composition and mechanical properties of composites were studied,and the formation mechanism of composite structure was further analyzed.Results showed that when the content of Zr in the infiltrant was different,the composites were mainly composed of C,ZrC and SiC phases.With the increase of Zr content in the infiltrant from 15%to 45%,the SiC content in the prepared composites decreased gradually.When the Zr content in the infiltrant was 30%,the ZrC content in the composites was the maximum.Meanwhile,the pores in the C/C composite body were fully filled by the ZrC phase and the SiC phase formed by the reaction,and a dense SiC-ZrC derivative layer appeared on the surface of the C/C-SiC-ZrC composites.In addition,ZrC possessed good interfacial bonding state with C and SiC.During the growth and coarsening process of ZrC particles,some larger ZrC particles with embedded SiC grains were formed.Among them,the flexural strength of the composite prepared by the infiltration agent#5(Zr30Si50C20)reached a maximum of 180.6 MPa,and the thickness of the SiC-ZrC derivavtive layer on the surface was about 128.9μm.
作者
徐一溪
易茂中
王喜云
周哲
XU Yi-xi;YI Mao-zhong;WANG Xi-yun;ZHOU Zhe(No.1 Middle School of Lixian County,Changde415500,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha410083,China)
出处
《材料保护》
CAS
CSCD
北大核心
2019年第9期88-94,共7页
Materials Protection
基金
XXX装备预研项目相关基础研究资助
作者简介
通信作者:周哲(1988-),博士研究生,主要从事超高温陶瓷改性C/C复合材料以及相图、材料热力学在表面改性材料中的应用等研究,E-mail:zhouzhe0810@126.com
