(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 为了实现厚度达15 mm钨基合金正挤压棒坯的无缺陷脱脂，对大厚度正挤压棒坯的溶剂脱脂行为和机理以及大厚度棒坯溶剂脱脂过程的优化方法和效果进行研究。结果表明：大厚度棒坯的溶剂脱脂对温度非常敏感，极易产生脱脂缺陷；棒坯厚度增大，粘结剂脱除速率降低，产生缺陷的几率增大，d 12 mm和d 15 mm棒坯的适宜溶剂脱脂工艺为(30 ℃, 12 h)；d 15 mm棒坯在30 ℃下脱脂6 h，脱脂量不足30%，且随着脱脂时间的进一步延长，脱脂速率显著下降；大厚度棒坯的溶剂脱脂受扩散控制，棒坯越厚，扩散路径越长，棒坯脱脂速率越小；采用短周期多次浸溶剂方法来优化脱脂过程，实现了正挤压棒坯的无缺陷脱脂，且d 12 mm和d 15 mm棒坯的脱脂量分别可高达55%和45%以上。
关键字: 钨基合金；正挤压棒坯；溶剂脱脂；脱脂特性
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
