高纯阴极铜的生产实践

分析了金川高纯阴极铜试生产中的要点、难点 ,提出了相应的解决办法     

紫铜管的火焰钎焊工艺

紫铜的焊接性分析表明紫铜熔焊时易产生裂纹、未焊透和气孔等问题,而紫铜钎焊可避免这些问题的产生,进而介绍紫铜管的火焰钎焊工艺。     

超高纯铜的制备方法和应用

简要介绍了超高纯铜(UHPC)的几种精炼方法，以及它在工业方面的应用。并对超高纯铜的研究开发趋势及应用前景进行了展望。     

锂对工业纯铜力学性能的影响

在工业纯铜中加入微量锂,可提高工业纯铜硬态丝的抗拉强度和延伸率,这是由于锂的加入引起铜的晶格畸变从而产生固溶强化所致。同时,锂的加入提高了工业纯铜的再结晶强度,在铜的常规热处理制度下,试样仍保持较多的形变组织,从而退火后其强度下降较少,延伸率提高也较小。     

纯铜表面催渗渗铝及弥散强化研究

提出了用稀土合金CeCl3进行催渗的纯铜渗铝技术。采用渗铝—内氧化技术制备了Al2O3表面弥散铜基导电材料。研究了CeCl3合金催渗对渗铝层的影响和表面弥散层的显微组织及有关性能。结果表明:利用稀土合金CeCl3催渗的纯铜渗铝试样渗层厚度远高于同等工艺参数下未催渗的纯铜渗铝试样。内氧化后,能在渗铝层形成Al2O3弥散硬化层。     

箔绕式变压器用纯铜带的开发

本文就箔绕式变压器用铜带的技术要求，生产工艺特点和产品性能检测特别是高导电率铜带的导电率测试进行了论述。     

铸造纯铜冷却板的铸造实践与改造

提出单回路六通道纯铜冷却板的不足,对双回路八通道纯铜冷却板的结构形状和功能特点进行分析。选择的双回路八通道冷却板采用平做立浇,热端在上的浇注位置;确定上雨淋浇口通过冒口垂直引入型腔为浇注模式;设置下部放挂砂冷铁,上部按1∶50斜度加外补衬等要点为主的铸造方案。     

Biaxial Deformation Behavior and Enhanced Formability of Ultrafine-Grained Pure Copper

Coarse-grained commercially pure Cu was subjected to equal channel angular pressing at room temperature for 2 passes and 12 passes resulting in grain refinement down to the ultrafine scale. Uniaxial tensile testing revealed that as-ECAP Cu samples have very high strength, but low uniform elongation and elongation to failure, whereas small punch testing showed that strain in biaxial stretching of the as-ECAP Cu specimens was comparable to that in the coarse-grained Cu. Analysis of surface relief demonstrated extensive microlocalization of plastic flow into microshear bands during biaxial stretching of the as-ECAP Cu specimens. The effect of microstructure and stress state on formability of the material and the mechanisms governing its plastic deformation are discussed. It is suggested that although the high strength as-ECAP Cu exhibits poor ductility in uniaxial tension, in other strain paths such as biaxial stretching, it can show high formability which is sufficient for metal-forming processes.     

纯铜中微量锌的快速分析

本文提出测定纯铜中锌的快速分析方法。在1.2N盐酸介质中用高分子胺萃取,硝酸钾-碘化钾混合液反萃取后硫氰酸盐-结晶紫光度法测定锌。可在25分钟内完成一个试样分析。     

恒电流电解—BCO光度法测定纯铜中铜含量

样品经硫硝混酸溶解后,于含有硫酸和硝酸的酸性溶液介质中,在浸入溶液的两个铂电极间,调节适当的电压进行电解,电解终了时,将沉积在铂阴极上的金属铜洗净,烘干并称量,计算铜的质量分数。电解液中残余铜用BCO光度法测定后合并于主量中。分析误差完全在国标分析误差范围内,提高了纯铜中铜含量测定的准确度。     

铈对紫铜组织和力学性能的影响

加入适量的稀土元素可有效改善铜及铜合金组织与性能。紫铜中添加稀土后,进行熔炼、轧制和热处理试验,再通过室温拉伸、硬度试验、金相及扫描电镜观察,研究了微量铈对紫铜组织与力学性能的影响。利用等离子体发射光谱仪测定锭坯中铈的含量,并对稀土的收得率和熔炼渣成分进行了分析。力学性能测试和显微组织观察结果表明,铸态晶粒随着铈加入量的增加先减小后增大,且再结晶温度随着铈加入量的增加而提高;紫铜的强度、硬度和晶粒大小随着稀土含量的增加分别先升高后下降,当铈含量达0.04%时,紫铜试样获得最好的综合力学性能,即退火态试样的抗拉强度达到251M Pa,屈服强度为116M Pa,延伸率达到37.22%。     

纯铜棒材三辊螺旋轧制过程数值模拟

三辊螺旋轧机适合于多品种、小批量、难变形材料的小尺寸管棒材开坯。通过对三辊螺旋轧制辊形设计和轧制过程进行研究,根据轧辊辊形计算方程,获得三辊螺旋轧机轧辊各段辊形参数。采用Simufact.Forming软件模拟了纯铜棒材三辊螺旋轧制过程。结果显示,纯铜棒材在三辊螺旋轧制过程中的变形规律为圆形—三角形—圆形的连续过程,轧件在变形段温度可达360℃左右,在轧辊与轧件接触区域内的最大应力为590MPa,最大等效塑性应变为3.8。轧辊在Z轴方向上所受最大载荷为43k N,而在X、Y轴方向上的最大载荷为350k N。Z方向的轴向力有助于铜棒的轴向咬入和抛出,X、Y方向的径向力主要起到减径和定径的作用。     

高电流密度脉冲电解制备纯铜的研究

在小型电解槽中研究高电流密度脉冲电解制备纯铜的工艺条件 ,并用XRD、SEM及等离子体质谱仪研究杂质对阴极铜沉积的结构和组成的影响。研究表明 :3 0℃时 ,脉冲电解制备纯铜的工艺条件为 :平均电流密度80 0A/m2 ,峰电流密度 40 0 0A/m2 ,脉冲宽度 2 0ms ,脉冲频率 10 0Hz,占空比 1∶4。不用添加剂时 ,电解液中有害杂质的允许含量为 (g/L) :As5+ ≤ 0 0 3、Sb3+ ≤ 0 0 0 5、Bi3+ ≤ 0 0 0 5 ;用添加剂 (mg/L) :Cl- 3 0、(NH2 ) 2 CS 0 75～ 1 0、glue 1 0～ 1 5 ,电解液中有害杂质的允许含量为 (g/L) :As5+ ≤ 0 5、Sb3+ ≤ 0 0 3、Bi3+ ≤ 0 0 5。测试结果表明 :当电解液中不含杂质时 ,铜沉积 (2 2 0 )晶面为择优取向 ,结晶形态为层状 ,电解液中含杂质时 ,铜沉积的 (2 2 0 )晶面择优取向更强 ,结晶形态为层状混块状。     

Effect of Heat Input Conditions on Microstructure and Mechanical Properties of Friction-Stir-Welded Pure Copper

Defect-free friction stir welds of 5-mm-thick pure copper plates were produced in relatively low heat input conditions. The characteristics of the microstructure and mechanical properties of the welded joints were investigated. The stir zone (SZ) exhibited equiaxed recrystallized grains, whose size decreased as the heat input was decreased. The percentage of high-angle grain boundaries (grain boundary misorientation angle >15 deg) in the SZ was quite high (90.2 to 94.5 pct) and increased as the heat input was increased. When the heat input was decreased, the percentage of the twin boundaries (TBs) dropped, and the number of the twin lamellas was reduced. Under a very low heat input condition, the typical characteristics of thermomechanically affected zone (TMAZ) were discernible; however, the TMAZ was characterized by a recrystallized grain structure at higher heat input conditions. The grains in the heat-affected zone (HAZ) were slightly coarsened compared to those in the parent material (PM), but the grain size varied a little under different parameters. The hardness of the SZ increased as the heat input was increased, and the lowest hardness appeared at the HAZs where the welds failed. The ultimate tensile strength (UTS) was similar to that of the PM under various heat input conditions, but the yield strength (YS) and elongation were lower. The YS increased as the lowest hardness value increased, and the elongation decreased due to the enhanced strain localization.     

电感耦合等离子体原子发射光谱法测定纯铜中微量元素

以硝酸溶解样品,采用电感耦合等离子体原子发射光谱(ICP-AES)法测定纯铜中As、Bi、Zn、Sb、Pb、Fe、Sn、Ni等八种微量杂质元素的含量。通过试验选择各元素最佳分析谱线,并对基体干扰及共存元素之间的干扰进行探讨。在选定的实验条件下,方法的检出限为2.0~14.4ng/L,样品加标试验回收率在96%~102%之间。结果表明,用本法测定标准样品中8种元素的含量,测定值与认定值相符,相对标准偏差(RSD)均小于6%。     

尾气吸收法代替纯铜还原法配制亚硝基硫酸

主要阐述利用工业硫酸吸收废酸处理尾气中的NO、NO2气体。从而配制用于分析一硝的亚硝基硫酸标准溶液，并与现行企标Q／HCFSF-1997《标准溶液制备与标定》中采用纯铜还原法制取氧化氮气体配制的亚硝基硫酸溶液的方法做了对照，确定了利用废酸处理尾气配制亚硝基硫酸溶液方法的可行性。可代替现行纯铜还原法配制亚硝基硫酸标液。从而可以大量节约所消耗的水、电、试剂等成本。同时还可以消除用纯铜还原法制取的氧化氮对人体造成的危害。