摘要
本文对两种WC—Co硬质合金的耐冲蚀性进行了考察,二者均呈现脆性材料冲蚀特点。其组成相的晶粒尺寸、硬度、百分含量与形貌对材料的冲蚀行为有巨大影响,在高温下尤为明显。材料的耐磨性随磨料硬度增加而降低。超细晶粒硬质合金具有更佳的耐磨性,但其磨蚀机理与商用硬质合金相似。软磨粒冲蚀引起软的Co相粘接剂浸蚀,导致WC相脱落。硬磨料冲蚀时,材料的转移主要是由于低角度时的切削和犁耕,高角度时的疲劳断裂组成,二者均伴有大面积的塑性变形。
Erosion resistance of two series of WC-Co cermets was examined at the impact wear rig, both of which behaved specifically as brittle materials under solid particle impacting. Their erosive behavior largely depended on grain size, hardness, component phase percentage and mophology, especially at the elevated temperatufe. Although the ultrafine cermet samples seemed to be superiour to the commercial ones against erosion, The material removal was controied by similar mechanism, The bond componant,Co,whith relatively low hardness eroded firstly and WC grain detached accordingly because of losing support under low angle impingenment by soft particle. Contrastly with hard particle erosion wear process was caused by cutting and plowing under low angle impacting and by fatigue fracture under high angle incident. Moreover a great deal of plastic deformation generally occured throughout the whole angle range.
