(中南大學 粉末冶金國家重點實驗室，長沙 410083)
摘 要: 為了實現(xiàn)厚度達15 mm鎢基合金正擠壓棒坯的無缺陷脫脂，對大厚度正擠壓棒坯的溶劑脫脂行為和機理以及大厚度棒坯溶劑脫脂過程的優(yōu)化方法和效果進行研究。結(jié)果表明：大厚度棒坯的溶劑脫脂對溫度非常敏感，極易產(chǎn)生脫脂缺陷；棒坯厚度增大，粘結(jié)劑脫除速率降低，產(chǎn)生缺陷的幾率增大，d 12 mm和d 15 mm棒坯的適宜溶劑脫脂工藝為(30 ℃, 12 h)；d 15 mm棒坯在30 ℃下脫脂6 h，脫脂量不足30%，且隨著脫脂時間的進一步延長，脫脂速率顯著下降；大厚度棒坯的溶劑脫脂受擴散控制，棒坯越厚，擴散路徑越長，棒坯脫脂速率越小；采用短周期多次浸溶劑方法來優(yōu)化脫脂過程，實現(xiàn)了正擠壓棒坯的無缺陷脫脂，且d 12 mm和d 15 mm棒坯的脫脂量分別可高達55%和45%以上。
關(guān)鍵字: 鎢基合金；正擠壓棒坯；溶劑脫脂；脫脂特性
tungsten heavy alloy
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:In order to succeed in debinding thick parts of tungsten heavy alloy with thickness about 15 mm, the solvent debinding process and mechanism of big size forward extrusion parts were studied. The optimization methods of sample solvent debinding process and their effects were discussed. The results show that solvent debinding process of thick parts is sensitive to solvent debinding temperature and is easy to generate debinding defects. With the increase of the thickness of samples, the binder debinding ratio decreases, the formation probability of debinding defects rises under the optimum solvent debinding condition of (30 ℃, 12 h). The binder removal of d15 mm bar is less than 30% at 30 ℃ for 12 h, and the debinding rate decreases significantly with further increasing debinding time. The solvent debinding process of thick parts is a diffusion controlled process, the larger the thickness of samples is, the longer the diffusion path and the lowder the debinding rate are. Taking a short cycle times immersing solvent method to optimize the debinding process, the debound parts have no defect, and the debinding efficiency levels of d12 mm and d15 mm reach up 55% and 45%.
Key words: tungsten heavy alloy; forward extrusion parts; solvent debinding; debinding characteristics
