纳米增强金属陶瓷的组织及热冲击性能  

Microstructural characteristics and thermal shock resistance of nano-powder reinforcing cermets

作　　者：许育东[1] 刘宁[1] 石敏[1] 晁晟[1] 张宝华[1] 刘雪敏[1] 刘斌[1] 

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《复合材料学报》2006年第5期44-50,共7页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(No.50072003);安徽省自然科学基金(No.03044902);合肥工业大学博士专项基金(No.103-035029)

摘　　要：为了进一步提高金属陶瓷的力学性能及其刀具的高速切削性能,研究了纳米增强金属陶瓷的显微组织特征和热冲击性能。扫描电镜和透射电镜分析表明:组织中陶瓷相呈现典型的芯-壳结构特征;芯为TiC或Ti(C,N),而壳则为(Ti,Mo,W)(C,N)固溶体。纳米增强金属陶瓷机制为细晶强化、弥散强化和固溶强化。热冲击实验表明:随着热循环的进行,材料中孔洞的数量、孔洞的尺寸以及微裂纹的尺寸随之增大;同时,热循环过程中出现的表面氧化、裂纹长大、偏转以及桥接现象也很显著。与常规Ti(C,N)金属陶瓷相比,纳米增强金属陶瓷的抗热冲击性能明显提高。Microstructural characteristics and thermal shock resistance of nano-powder reinforcing Ti（C,N） based cermets were investigated in order to efficiently improve the mechanical properties of Ti（C, N） based cermets and the high-speed cutting behaviors of cermets cutters. SEM and TEM analyses show that the coarser ceramic particles exhibit a typical core-rim structure （core is usually referred to as TiC or Ti（C,N） and rim is virtually a （Ti, Mo,W） （C,N） solid solution）. The nano-powder reinforcing mechanisms can be summarized as grain fining strengthening, dispersion strengthening and solid solution strengthening. The thermal shock tests on nano- powder reinforcing cermets and conventional cermets show that the quantity and size of the voids plus the size of micro-cracks in both cermets increase and other phenomena such as surface oxidation, cracks growth, cracks deflection and cracks bridging are found to become increasingly apparent with thermal shock cycles, and the nano-powder reinforcing cermets possess a better thermal shock resistance in comparison with conventional cermets.

关 键 词：纳米增强金属陶瓷 组织 热冲击性能 孔洞 

分 类 号：TB332[一般工业技术—材料科学与工程]