注射成形铜/钨复合材料溶剂脱脂行为研究

Solvent Degreasing Behavior of Copper/Tungsten Composites Prepared by MIM

以注射成形铜/钨复合材料生坯为研究对象,采用二氯甲烷为溶剂,对成分为CuW5以及CuW15的两种成分的生坯,采用不同粉末装载量、不同形状的试样进行溶剂脱脂。重点考察了溶剂脱脂工艺参数对脱脂行为的影响,还就坯件本征特点对于溶剂脱脂行为的影响进行了分析探讨,最后计算了本实验条件下,用二氯甲烷脱脂的动力学参数,为后续实验条件的设定提供了理论依据。实验结果显示,脱脂温度与时间对于溶剂脱脂是综合外因;在研究脱脂行为时,考虑坯件本体特征的影响十分重要,坯件厚度对于溶剂脱脂影响很大,形状的复杂性几乎不影响脱脂率。粉末形态不够规则,生坯内部孔隙多,溶剂脱脂更易持续进行,达到更大的脱脂量。脱脂初期脱脂速率由扩散控制,呈线性变化,当脱脂时间达到10h以后,脱脂速率将转变为由溶解和扩散混合控制。

Taking copper / tungsten composites green parts prepared by MIM as investigation object and carrene as solvent,the solvent degreasing behavior of two kinds of copper / tungsten composites,Cu-5wt% W and Cu-15wt% W,prepared by MIM were researched.The results show that the degreasing temperature and degreasing time are external causes of solvent degreasing;the character and thickness of the parts have great effect on solvent degreasing,the complexity of the part shape almost has no effect on solvent degreasing;the irregular powder shape and more holes in green parts are favourable to solvent degreasing;at the incipient stage of degreasing,the degreasing rate is controlled by diffusion and changes linearly,after 10hdegreasing,the degreasing rate is controlled by both diffluence and diffusion.