(1. 昆明理工大學 材料科學與工程學院，昆明 650093； 2. 江西理工大學 工程研究院，贛州 341000)
摘 要: 以Mo粉、Co粉和自主研發(fā)的WC-6Co復合粉為原料，通過球磨、SPS制備Mo添加量為1%(質量分數(shù))的細晶WC-6Co硬質合金。利用XRD、SEM、XPS、維氏硬度計和電化學工作站等研究SPS燒結溫度、保溫時間對合金組織和性能的影響。結果表明：隨著SPS燒結溫度的升高和保溫時間的延長，WC-6Co-1Mo合金相對密度和斷裂韌性持續(xù)增加，維氏硬度先增大然后略有下降。當燒結溫度為1250 ℃、保溫時間為5 min時，制備的合金綜合性能最佳。與相同工藝制備的WC-6Co和WC-6Co-4Mo合金進行對比，發(fā)現(xiàn)添加適量Mo能夠有效抑制WC晶粒的長大，提高合金的硬度和韌性，但相對密度減小；同時，也能夠增強合金在HCl溶液的耐腐蝕性能。
關鍵字: WC-6Co硬質合金；Mo；燒結參數(shù)；顯微組織；耐腐蝕性能
（1. School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China; 2. Project Research Institute, Jiangxi University of Science and Technology, Ganzhou 341000, China）
Abstract:Using Mo powders, Co powders and WC-6Co composite powders as raw materials, the fine-grained WC-6Co cemented carbides with 1% Mo (mass fraction) addition were fabricated by ball-milling and spark plasma sintering technology. The effects of sintering temperature and holding time on the microstructure and properties of cemented carbides were investigated by XRD, SEM, XPS, Vickers hardness tester, electrochemical workstation, and so on. The results show that the relative density and fracture toughness of cemented carbides with 1% (mass fraction) Mo addition increase as the sintering temperature and holding time increasing. The Vickers hardness increases until the maximun value, and then follows a decreasing trend with the increase of sintering temperature and holding time. The best comprehensive properties achieve at temperature of 1250 ℃ ant holding time of 5 min comparing with WC-6Co and WC-6Co-4Mo cemented carbides prepared by the same processes. The results show that the appropriate content of Mo is beneficial for refining the WC grains, increasing the hardness and fracture toughness significantly. However, the relative density decreases with the addition of Mo slightly. Moreover, the corrosion resistance of WC-6Co cemented carbides in HCl solution increases with Mo addition.
Key words: WC-6Co cemented carbide; Mo; sintering parameter; microstructure; corrosion resistance
