Comparative Study of Wear Resistance of Cemented Carbides WC-Ni-Al and WC-Co Subjected to Micro-Scale Abrasive Test

The combination of tungsten carbide (WC) and cobalt forms the most common cemented carbide on the market, as it is one of the most widely used materials industrially due to its excellent combination of properties. However, the search for a substitute binder is motivated by cobalt's high cost, toxicity, and low corrosion resistance. In this scenario, nickel (Ni) has stood out for meeting the necessary requirements and offering good corrosion resistance. However, its product presents a loss in mechanical properties. To improve these properties, the addition of alloying elements, such as aluminum (Al), was studied. This work aims to compare the micro-abrasive wear resistance of WC-Co and WC-Ni-Al cemented carbide. The micro-scale abrasion tests were carried out in a test rig with fixed-ball configuration, AISI 52100 steel ball and abrasive slurry composed of water and silicon carbide (SiC). The volume loss of the samples was the parameter used to determine micro-abrasive wear resistance. The samples were characterized before and after testing using scanning electron microscopy to identify the predominant wear mechanisms. WC-Ni-Al cemented carbide presented a microstructure similar to WC-Co, but pores and binder islands were observed. The micro-scale tests showed that WC-Ni-Al cemented carbide, despite its higher porosity, presented superior micro-abrasive wear resistance than WC-Co cemented carbide, indicating that the addition of Al contributed significantly to the increased wear resistance of this cemented carbide. This result also demonstrates the feasibility of using WC-Ni-Al cemented carbide as a substitute for WC-Co in applications involving abrasive wear.