Effects of nano-Al2O3 and nano-ZrO2 on the microstructure, behavior and abrasive wear resistance of WC-8Co cemented carbide

WC-8wt.%Co cemented carbides with varied nano-Al2O3 and nano-ZrO2 contents were prepared respectively following conventional powder metallurgical procedures. Effects of nano-Al2O3 and nano-ZrO2 on the microstructure, behavior, and abrasive wear resistance were investigated. The result shows that a finer and more homogenous microstructure can be achieved by increasing nano-Al2O3, and increasing nano-ZrO2 makes the microstructure more refined. Nano-Al2O3 and nano-ZrO2 could both help to give increased hardness. Transverse rupture strength is higher if the above nano-oxides are doped appropriately, whereas excess addition is deleterious. Abrasive wear resistance presents different variations with respect to increasing nano-Al2O3 and nano-ZrO2. By contrast, increasing nano-ZrO2 enhances the abrasive wear resistance more effectively than increasing nano-Al2O3. The influence of the two nano-oxides contents on the abrasive wear resistance does not almost vary with wear time, and the optimum addition level of nano-Al2O3 in WC-8%Co cemented carbide is 0.3 wt.% from the stand of abrasive wear resistance. In addition, both of the nano-oxides can retard the increase of wear rate in long-term abrasive wear.