粉末注射成形蜡基粘结剂溶剂脱脂行为

来源期刊：中南大学学报(自然科学版)2001年第6期

论文作者：祝宝军 曲选辉 陶颖 肖平安 秦明礼

文章页码：599 - 603

关键词：粉末注射成形;蜡基粘结剂;溶剂脱脂

Key words：powder injection molding; wax-based binder; solvent debinding

摘    要：以YG8硬质合金为实验对象,研究了蜡基粘结剂注射成形生坯的溶剂脱脂行为,考察了时间、温度、生坯形状、厚度、表面积、粉末装载量和液固比对脱脂速率的影响,分析了各因素影响脱脂速率的原因.研究结果表明:溶剂脱脂速率随温度升高而升高,随时间的延长而降低;脱脂初期扩散是控制性环节,温度是影响脱脂速率的主要因素,脱脂后期溶解成为控制性环节,浓度差成为影响脱脂速率的主要因素;液固比越大,则脱脂速率越快,粘结剂最高脱除率越高;生坯粉末装载量越高,则脱脂速率越慢,粘结剂最高脱除率越低;生坯形状对脱脂速率影响的本质是生坯厚度和表面积的影响;脱脂速率与生坯表面积成正比,与生坯厚度的平方成反比.

Abstract: The solvent debinding process of wax-based binder in powder injection molding(PIM) was studied systematically, and the effects of debinding temperature, shape, thickness, surface area and powder loading of green parts, and liquid/solid ratio on solvent debinding behavior were investigated. Itwas found that the solvent debinding rate was high at the beginning, and then decreased, however, it would increase with temperature increasing. The solvent debinding process was controlled by diffusion initially, and temperature was the dominant parameter. Then dissolution control and binder concentration became the most important factor. The bigger the volume ratio of solvent and green parts was, the higher the debinding rate and binder loss ratio were. The higher the powder loading of green parts was, the lower the debinding rate and binder loss ratio were. The effect of green parts′shape on debinding rate was in essence the effect of green parts′surface area and thickness, and regression analysis indicated that debinding rate was in direct ratio with specimens′surface area, while it is in inverse proportion with the square of specimens′thickness.