热压法制备W-Mo-Cr-Al_2O_3复合材料的微观结构与力学性能  

Microstructure and mechanical properties of W-Mo-Cr-Al_2O_3composites prepared by hot-pressing

作　　者：张博[1] 罗兵辉[1] 余金川 柏振海[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2014年第2期230-234,共5页Materials Science and Engineering of Powder Metallurgy

基　　金：湖南有色研究基金资助项目(20120619)

摘　　要：以亚微米级W、Mo、Al2O3粉末和微米级Cr粉为原料,在1 600℃下热压制备W-Mo-Cr-Al2O3复合材料,利用X射线衍射(XRD)、扫描电镜(SEM)和能谱分析(EDS)研究该复合材料的微观结构和断口形貌,测试复合材料的力学性能,对其断裂模式进行分析,并研究Al2O3含量对W-Mo-Cr-Al2O3复合材料性能的影响。结果表明:W-Mo-Cr-Al2O3复合材料中存在分布均匀的富W,Cr(W,Mo)金属相和Al2O3陶瓷相。W、Mo、Cr之间可以部分溶解,特别是Cr溶于Al2O3可增强金属相和陶瓷相的结合,使材料具有很高的强度和韧性。随Al2O3含量(体积分数)从10%提高到30%,材料的硬度提高17%,但抗弯强度和韧性分别降低8%和3%。复合材料的断裂模式为沿富W相/Al2O3相的界面、富W相/Cr(W,Mo)相界面及Cr(W,Mo)相/Al2O3相界面的沿晶断裂和Cr(W,Mo)相的穿晶断裂。W-Mo-Cr-Al2O3 composties were prepared using sub-micron W, Mo, Al2O3 and micron Cr powders by hot-pressing at 1 600 ℃. The microstructure of the composites were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and energy dispersive spectrometer （EDS）, besides, the mechnical properties and fracture mode of the composites were analyzed. Meanwhile, the effect of Al2O3 content on W-Mo-Cr-Al2O3 composites was studied. The results show that the composites are consisted of W-rich phase, Cr （W, Mo） phase, and Al2O3 phase. Tunsgten, molybdenum, and chromium can dissolve in each other partially. Especially, chromium can dissolve in alumina, which greatly increases the strength of the composites. With the content of Alumina increasing from 10 vol.%to 30 vol.%, the hardness increases by 30%, but the strength and toughness decrease by 8% and 3% respectively. The composite exhibits fracture mode of intergranular fracture between W-rich phase/Al2O3 phase and W-rich phase/Cr （W, Mo） phase, and cleavage fracture in Cr （W, Mo） phase.

关 键 词：W-Mo-Cr-Al2O3复合材料 热压 微观结构 力学性能 断裂模式 

分 类 号：TF125[冶金工程—粉末冶金]