(1. 四川理工學院 機械工程學院，宜賓 644000；
2. 自貢硬質(zhì)合金有限責任公司，自貢 643011；
3. 中南大學 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 以沖模用高鈷ZL40.5硬質(zhì)合金作為研究對象，采用掃描電鏡(SEM)、X射線衍射(XRD)等方法對系列熱處理試樣進行分析，基于晶體學理論并結(jié)合Image J、Jade軟件研究ZL40.5硬質(zhì)合金微觀組織結(jié)構(gòu)參數(shù)(粘結(jié)相體積分數(shù)、晶粒度、鄰接度、殘余應力及晶格常數(shù))、斷口形貌及其性能。結(jié)果表明：淬火處理使WC晶粒形貌變圓潤，降低應力集中的發(fā)生，減少斷裂源；淬火回火處理后，粘結(jié)相中α-Co含量大幅提升，WC鄰接度降低，合金在保證硬度的同時強度和韌性得到提升；熱處理后合金斷裂以沿晶和韌性復合形式為主，淬火回火后表面壓應力提升最高。
關(guān)鍵字: 硬質(zhì)合金；熱處理；微觀組織；斷口形貌；綜合性能
（1. College of Mechanical Engineering, Sichuan University of Science and Technology, Yibin 644000, China;
2. Zigong Cemented Carbide Corporation Limited, Zigong 643011, China;
3. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The effects of heat treatment processing on microstructure of high cobalt ZL40.5 cemented carbide synthesized by gas pressing sintering were investigated using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Based on the crystallography theory and combined with Image J and Jade software, the properties of the alloy, such as hardness, bending strength and residual stress, were measured. The results show that the quenching treatment makes the morphology of WC grain round and smooth, reduces the occurrence of stress concentration and reduces the source of fracture. After quenching and tempering, the content of α-co in the bonding phase increases greatly, WC adjacency decreases, and the strength and toughness of the alloy are improved while the hardness is guaranteed. The fracture of the alloy after heat treatment is mainly in the form of intergranular and ductile composite，after quenching and tempering, the surface compressive stress increases to the highest.
Key words: cemented carbide; heat treatment; microstructure; fracture morphology; combination property
