Modification of Paraffin Wax for Manufacturing Difficult-to-Form Green Compacts and Its Application in WC-Co Cemented Carbides

The production of deep well-shaped WC-Co cemented carbide blocks via industrial powder pressing remains a challenging technical problem, primarily due to the unsuitability of the forming agent. The forming agent paraffin wax was modified through four types of modifiers, including organic high-molecular-mass resins, plasticizers, surfactants and lubricants. The qualitative screening of resin types was explored and an orthogonal experiment involving the combination of these four paraffin wax modifiers was conducted to obtain an optimized quantitative ratio of modifiers. The results reveal that the insertion of the small molecule chain of resin into the interstitial spaces of paraffin wax crystals is likely a crucial factor for improving the compatibility between the resin and paraffin wax. Through orthogonal experiments, the optimized formulation for the forming agent is determined: 100 parts of 58# paraffin wax, 15 parts of EVA-2, 4 parts of DPHP, 4 parts of oleic acid amide and 2 parts of stearic acid. This optimized formulation is applied to industrial production at one Chinese company, and qualified deep well-shaped cemented carbide products are achieved, which contain 90wt% WC and 10wt% Co.