Study on hydration of tungsten carbide and cobalt in cemented carbide tool

Tungsten, cobalt, iron and other metal elements will be moved when the cemented carbide tool is used to cut steel. The mobility will be reduced when water-based cutting fluid is used, but some elements in water-based cutting fluid will result in the hydration of tungsten carbide and cobalt in cemented carbide tool. This paper will research on the hydrolysis phenomenon of the tungsten carbide and cobalt in cemented carbide through soaking experiments, friction experiments, electrochemical detection experiments and spectrum analysis. The experiment results show that the influence of the sodium phosphate solution and sodium carbonate solution on the hydrolysis of tungsten carbide and triethanolamine solution on the hydrolysis of cobalt are great. Through using Benzotriazole solution, the hydrolysis of tungsten carbide and cobalt will be reduced. The hydrolysis mechanism of tungsten carbide is that it will be oxidized into tungsten oxide first and then dissolving in water, however, the hydrolysis mechanism of cobalt is that the cobalt ions go directly into water.