WC/NiCrMo钢基复合材料的断裂行为及特征  

FRACTURE BEHAVIORS AND CHARACTERISTICS OF WC/NiCrMo STEEL MATRIX COMPOSITES

作　　者：杨瑞成[1] 陈奎[1] 王凯旋[1] 吕学飞[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料重点实验室,兰州730050

出　　处：《复合材料学报》2005年第3期130-134,共5页Acta Materiae Compositae Sinica

基　　金：甘肃省自然科学基金资助项目(ZR96061)

摘　　要：采用单边缺口梁(SENB)法、扫描电镜和电子理论,研究了碳化钨(WC)增强钢基复合材料经960～1040℃奥氏体化及淬火、回火共12种状态的断裂行为和断口特征。实验结果表明,该材料在具有高强度(σbb～2200MPa,σbc～3000MPa)高硬度(HRC62～68)的同时,还具有较高的SENB断裂韧性(～30MPa·m1/2),断口形貌主要特征为WC解理、基体准解理及分散韧窝和韧窝带。研究发现,高体积分数(～40%)的硬质相对材料的断裂韧性和断裂行为起决定性作用,基体内存在的具有高共价键强的含碳结构单元和具有较多晶格电子的αFe(Ni)结构单元共同作用,既给予硬质相以强韧支持,又产生断裂时的微观延性。The fracture behaviors and fractographic features of WC/NiCrMo steel matrix composites under 12 kinds of conditions, after austenization between 960-1040°C then quenching and tempering, were investigated using single edge notched beam (SENB) method, SEM and electron theory analysis. The results show that the material has high strength (σbb-2200 MPa, σbc-3000 MPa) and hardness (HRC 62-68), and higher fracture toughness (∼30 MPa&middotm1/2). The main fractographic appearances are WC cleavage, quasi-cleavage of matrix, dispersed dimples and dimple bands. The numerous hard phases of WC(∼40%) play a dominant role in fracture toughness and fracture behavior, and based on the alloy electron theory, both of the containing carbon structure units with high bond strength and α-Fe(Ni) structure units with more lattice electron in matrix contribute to the strong-tough support to the hard phases and lead to micro-ductility during fracture.

关 键 词：WC/钢基复合材料 硬质相 断裂韧性 断口形貌 价电子结构 

分 类 号：TB331[一般工业技术—材料科学与工程] TB111.57[理学—数学]