温压与冷压法制备三元碳化物Cr_2AlC坯体的致密化机理  

Densification mechanism of ternary carbidesCr_2 AlC compact during warm and cold pressing

作　　者：董洪峰[1] 郭从盛[1] 

机构地区：[1]陕西理工学院材料科学与工程学院,汉中723003

出　　处：《粉末冶金技术》2015年第4期290-295,共6页Powder Metallurgy Technology

基　　金：陕西理工学院校级人才启动项目(SLGQD13(2)-17);陕西省教育厅专项科研计划项目(14JK1146)

摘　　要：以球磨Cr、Al、C_4(石墨粉)单质粉末制成的混合粉末为原料,分别采用温压和冷压法,在不同压力下制备三元碳化物Cr_2Al坯体;利用Kawakita模型建立温压、冷压坯体相对密度和压力间关系,用松装密度测定仪、显微硬度计、OM、SEM、EDS和阿基米德原理表征粉末松装密度、粉末及坯体显微硬度、组织、形貌、分布和坯体密度。结果表明:Kawakita模型拟合方程的精确度高,由于单质粉末经球磨后产生"核壳"结构,改变整体粉末性能,使得球磨粉初始屈服强度值在Cr粉和Al粉之间,且在冷压条件下与模型拟合值相似,而温压Al粉的高温蠕变使得球磨粉初始强度拟合值小于试验值;Al粉在温压和冷压条件下不同的变形性和加工硬化造成的温、冷坯体组织差异均导致了Kawakita模型拟合误差。A ternary carbides Cr2AlC compact was shaped by warm and cold pressing technology at different pressure using the Cr, Al and graphite ball milled powder as raw material. The Kawakita model was used to establish the function of relative density and pressure, and the apparent density, microhardness of powder and compact, microstructure, morphology, distribution and density of compact were investigated by apparent density tester, hardness tester, OM, SEM, EDS and Archimedes principle. The results show that Kawakita model has high precision and the fitting initial yield strength value is similal to that of experimential one in cold pressing which is in the range of Cr and Al because of core-shell structure during ball milling. The fitting initial yield strength value is less than that of experimential one in warm pressing. The fitting error of Kawakita model occur because of microstructure difference caused by the different deformability and work hardening.

关 键 词：温压 球磨 Cr_2AlC Kawakita模型 致密化机理 

分 类 号：TQ174.758[化学工程—陶瓷工业]