摘要
采用小颗粒TiC包覆SiC陶瓷颗粒,在惰性气体保护下选用无压浸渗方法制备了高铬铸铁/TiC-SiC复合材料;利用SEM/EDX观察和分析了液态铸铁在SiC预制体中的浸渗情况、组织特征和成分分布;结合高铬铸铁/Ti-SiC复合材料的组织特点和浸渗行为特点,分析了TiC粉体对浸渗行为和复合材料组织的影响。观察结果表明,当TiC加入量≤10%(质量分数,下同)时,Fe/Cr合金无法润湿SiC颗粒,而当加入量≥20%时,Fe/Cr合金和预制体之间润湿性得到改善,增加TiC含量更有利于Fe/Cr合金浸渗;基体中大尺寸SiC颗粒消失,出现了尺寸接近毫米级的条状单质碳,这与高铬铸铁/Ti-SiC复合材料的组织差异较大。对比两种复合材料组织发现,添加Ti粉末在金属液中可与C结合生成TiC,而添加的TiC颗粒在组织中呈鹅卵石状,边缘圆润,出现金属液与陶瓷颗粒之间的互溶。在浸渗过程中,添加TiC和Ti与浸渗金属发生的反应不同,且高质量分数的TiC对金属液浸渗过程有明显的促进作用。
High chromium cast iron/TiC-SiC composites were fabricated by SiC ceramic particles coating with TiC particles of few microns and pressureless infiltration under the protection of inert gas.The infiltration situation,microstructure characteristics and composition distribution were observed and analyzed by means of SEM/EDX.Finally,combined with the microstructure characteristics and infiltration behavior of high-chromium cast iron/Ti-SiC composites,the effect of TiC powder on infiltration behavior and composite structure was analyzed.The observation results show that Fe/Cr alloy cannot wet the preform SiC particles when TiC addition≤10%(mass fraction,as follow),while the wettability between Fe/Cr alloy and preform is improved when TiC addition≥20%,increasing the TiC content is more conducive to Fe/Cr alloy infiltration.The large-sized SiC particles in the matrix disappear,and strip-shaped elemental carbon with a size close to millimeters appeares,which is quite different from the microstructure of high-chromium cast iron/Ti-SiC composites.Comparing the microstructure of the two composite materials,it is found that the added Ti powder can combine with C to form TiC in the molten metal,while the added TiC particles are cobblestone-like in the microstructure with rounded edges,mutual dissolution between molten metal and ceramic particles occurs.During the infiltration process,the added TiC and Ti react differently with the infiltrated metal,and the high mass fraction of TiC can significantly promote the molten metal infiltration process.
作者
朱俊璇
杨帆
尹梦涛
刘海云
Zhu Junxuan;Yang Fan;Yin Mengtao;Liu Haiyun(School of Materials Engineering,Lanzhou Institute of Technology,Lanzhou Gansu 730050,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan Shanxi 030024,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2022年第11期216-222,共7页
Heat Treatment of Metals
基金
2022年甘肃省重点人才项目。
关键词
金属陶瓷复合材料
SiC陶瓷复合材料
浸渗法
微观组织
metal-ceramic composites
SiC ceramic composite material
infiltration method
microstructure
