TiH_2粉末模压成形剂优化研究

Research on the binder for TiH_2 powder die pressing

选择硬脂酸、十八醇、十八胺、金刚烷以及它们之间的混合物作为模压候选成形剂,以润滑粉体、润滑模具和同时润滑三种方式进行润滑,系统研究了它们对TiH2粉体成形性的影响。结果表明,单纯TiH2粉成形性非常差,添加成形剂能够显著改善粉体的成形性能。成形剂以第一种方式加入时,单一成分的成形剂很难达到相对密度较高和保形效果较佳的要求,而混合型即十八醇中添加少量金刚烷效果较好。采用润滑模具方式比较容易获得高质量压坯、成形剂用量少、压坯密度高、外观质量好。相比而言,同时润滑方式没有表现出明显的优势。研究还发现,压制压力是能否获得优质高密度压坯的关键因素之一,合理的TiH2粉体压制压力范围为600~700MPa。

With Stearic acid, Octadecanol, Octadecyl amine, Adamantane and their intermixtures as candidate binders, the effect of candidate binders on the compactibility of TiH2 powders was systematically studied and those binders were used in three ways： blending with Till2 powders, being coated on the surface of a pressing mold＇ s cavity and simultaneously adopting the former two ways. The results show that though the compactibility of pure TiH2 powders is too poor to obtain a fine compact, TiH2 powders with binders can get better compactibility. In the first way intermixture binders show better compactibility than single one and among them a mixture of octadecanol with some of Adamantane is the best. It is revealed that in comparison with other two ways coating a binder on the surface of a pressing mold＇ s cavity not only notably reduces binder dosage, but also insure to get a high quality green compact with higher relative density and better surface quality, but the third way shows little obvious advantage. Moreover, it is also found that pressing force plays a key role in fabricating a compact with high density and good geometry quality and a reasonable pressing force for TiH2 powders is between 600 -700MPa.