还原铜粉之注射成形

Injection molding of oxide-reduced copper powders

平均粒度约10μm的微细还原铜粉因不规则粉末形态及残留有较高的氧含量,而不易以注射成形工艺来制备高性能产品。本研究发现,采用具较多量之主干高分子为基础的多元粘结剂能克服不规则粉末形态所导致之严重粉末间之磨擦,而将这种微细还原铜粉顺利的注射成形。烧结时,若能在烧结孔洞封闭之前将粉末中的残留氧化物有效的予以还原,如在低于900℃之温度下给予适当保温,则注射成形组件之烧结密度可高达95%理论密度。在此条件下,注射成形组件的导电率可达纯铜导电率的80%以上。

Fine oxide-reduced copper powders of about 10 μm in mean particle size are irregular in particle shape and high in oxygen content, which pose difficulty in achieving good properties in injection molding. Injection molding was possible when a multi-component binder having a large fraction of the backbone polymer was used. Injection molded parts could be sintered to a density of about 95% theoretical, if reduction of the residual oxides in the powder was effectively carried out prior to closure of pores during sintering. Under such a condition, the injection molded parts could attain an electrical conductivity higher than 80% that of pure copper.