WC/Co-B_4C复合材料的组织结构及力学性能  

MICROSTRVCTURE AND MECHANICAL PROPERLIES OF WC/Co-B_4C COMPOSITE

作　　者：李世波[1] 温广武[1] 张宝生[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院

出　　处：《金属学报》2001年第6期663-667,共5页Acta Metallurgica Sinica

摘　　要：在Ｂ４Ｃ基体中掺入不同含量的 ＷＣ／Ｃｏ（其中 ＷＣ的质量分数为 ９４％；Ｃｏ为６％）；采用热压烧结法得到了高致密度的复合材料．当ＷＣ／Ｃｏ的体积分数达到４０％时，在１９００℃，３５ ｍｉｎ；３５ＭＰａ的条件下，复合材料的相对密度＞９８％，弯曲强度和断裂韧性分别为４５３ＭＰａ和 ８．７ ＭＰａ·ｍ１／２．利用ＸＲＤ； ＳＥＭ； ＴＥＭ分析了复合材料的物相组成及显微组织．研究了不同含量的 ＷＣ／Ｃｏ对复合材料力学性能的影响，并探讨了复合材料的增韧机制分析认为，复合材料致密度的提高是强度提高的主要原因；热膨胀系数失配产生的残余应力场是赋予材料高韧性的主要增韧机制，同时微裂纹的存在也是材料韧性提高的原因．W-B-C composite with higher relative density was fabricated by hot-pressed B4C matrix with addition of different volume contents of WC/Co, which makes sintering easy and the composite has high toughening properties. The relative density of composites with addition of 40%WC/Co that sintered at 1900 degreesC for 30 minutes under 35 MPa pressures, is up to 98%; the flexural strength and fracture toughness are 453 MPa and 8.70 MPa(.)m(1/2), respectively. The phases and microstructure of W-B-C composites have been studied by means of XRD, EDS, SEM, TEM. The influence of different contents of WC/Co on mechanical properties of composite was analyzed, and the mechanisms of toughening were also discussed. The high relative density makes the composites have a high strength of 453 MPa and the mismatch between thermal expansion coefficients of matrix and second phases results in a residual stress field which is the main toughening mechanism. In addion, the existing microcrack also plays an important role to improve the toughness of composites.

关 键 词：WC/Co-B4C复合材料 组织结构 力学性能 增韧机制 

分 类 号：TB333[一般工业技术—材料科学与工程]