共沉淀反应条件与分散剂对Cu-Al_2O_3粉末性能的影响

以酸碱含铜刻蚀废液为原料,聚乙烯醇(PVA)为分散剂,并采用添加可溶性铝盐络合共沉淀的方法制备了含铝铜的前驱体粉末,最终采用高温煅烧-氢气还原工艺制备了纳米Al_2O_3弥散强化铜粉末。采用激光粒度仪、SEM-EDS、XRD等研究了络合共沉淀过程中工艺参数对弥散铜粉末及Al_2O_3弥散相粒度的影响。结果表明:通过控制络合共沉淀过程中的反应条件,可制备出粒度小于1.5μm且分布较窄的纳米Al_2O_3弥散强化铜粉末,最佳工艺参数为:母液浓度1.0 mol/L,沉淀氨水浓度20%(体积分数),反应温度70℃,p H值为7;调节分散剂的含量可控制弥散相的粒度及分布,PVA与铜离子的物质的量比为0.4∶1.0时,制备出的纳米Al_2O_3弥散相粒度小于100 nm,粒子间距100~200 nm;粉末经氢气烧结950℃保温60 min,烧结试样的密度为8.45 g/cm~3,硬度为115 HB。

Influence of co-precipitation reaction parameters and dispersant on performance of Cu-Al2O3 powders

The nano-Al2O3-dispersed strengthening copper-based powder was prepared with acidic and alkaline waste cupric liquor as raw material,polyvinyl alcohol (PVA) as dispersant,adding soluble aluminum salt to coprecipitation,calcination and hydrogen reduction.The effects of co-precipitation process parameters on the particle size of Cu-Al2O3 powder and dispersed phase Al2O3 were checked by laser particle size analyzer,SEM-EDS and X-ray diffraction.Results show that,the Cu-Al2O3 powder with particle size of less than 1.5 μm and narrow size distribution is prepared by controlling co-precipitation reaction parameters as follows,mother liquor concentration of 1.0 mol/L,precipitation ammonia concentration of 20％ (volume fraction),reaction temperature of 70 ℃ and pH value of 7.The particle size and distribution of dispersed phase is controlled by the content of dispersant.The nano-Al2O3-dispersed phase is less than 100 nm particle size and 100-200 nm particle spacing when the content ratio of PVA and copper ion is 0.4:1.0.After sintered at 950 ℃ in hydrogen for 60 min,the sintered body has density of 8.45 g/cm3 and hardness of 115 HB.