铜含量对钴铬钼铜合金抗菌性和耐腐蚀性的影响

目的探讨铜含量对钴铬钼铜合金体外抗菌性及耐腐蚀性的影响。方法真空冶炼法制备4种不同铜含量(质量分数分别为2%、3%、5%、7%)的钴铬钼铜合金试件,不含铜的钴铬钼合金作为对照。采用电化学法测定试件的耐腐蚀性,覆膜法分析试件对金黄色葡萄球菌和大肠埃希菌的抗菌性。结果与不含铜的钴铬钼合金相比,铜含量为2%~5%时钴铬钼铜合金的自腐蚀电位升高,腐蚀电流密度降低,点蚀电位升高。随着铜含量的增加,合金的杀菌率提高,当铜含量大于5%时,合金的杀菌率高达99%。结论铜的加入会影响钴铬钼合金的耐腐蚀性和抗菌性,当铜添加量为5%时,钴铬钼铜合金兼具较高的耐腐蚀性和良好的抗菌性。

含砷锑复杂铜合金处理研究进展

介绍了含砷锑复杂铜合金的产生及近年来传统方法处理此类合金的工艺进展,并对真空蒸馏技术处理含砷锑复杂合金,综合回收银、金、镍、铜、铅等有价金属进行了报道。

含硫镍铜合金浸后残渣的加压浸取

宾都雷镍公司在津巴布韦拥有一个年产1.4万吨金属镍的冶炼—精炼联合企业,冶炼厂产出一种水淬合金,其典型成份为含镍65%、铜25%、砷0.6%、硫6%.该物料在精炼厂经过两段奥托昆普硫酸浸取法处理,生产高纯阴极镍和低级阴极铜,同时产出一种含镍约12%、铜65%并富集了合金中所有硫元素的残渣,渣中还含可观的铂族金属.目前这种渣返回冶炼厂处理,既增加生产费用,又造成金属损失.今后可能处理来自Great Dyke的含铂铁镍矿,那么残渣中的贵金属含量会大幅度增加,这就促使改进工艺以提高镍、铜和贵金属的直收率.通过对浸后残渣几种处理方案的评价,选择了基于在硫酸溶液中进行非氧化性加压浸出的Sherritt处理工艺.产出含铜70%、硫20%、镍小于1%、砷小于 0.5%的硫化铜精矿,后者适于熔炼和火法精炼成铜阳极,再进行电解精炼得到高级阴级铜,贵金属从阳极泥中回收.为选择流程和建立一个并入现行精炼厂的加压浸取工序提供设计参数,进行了开发试验.文中对试验作了详细讨论,还介绍了计划于1995年开工的工业规模加压浸取车间的设计.

含Cu镁锂合金组织与性能调控研究进展

镁锂合金具有超低密度、极高的比强度与比刚度、优异的电磁屏蔽性能及阻尼性能,目前广泛应用于追求轻量化的航空航天、新能源汽车、电子产品、生物医疗等领域。由于合金元素镁和锂均为活泼金属,在服役过程中镁锂合金会存在多种形式的腐蚀过程,同时二元镁锂合金强度较低,以上两点严重制约了其广泛应用。耐蚀涂层可以有效提高镁锂合金的腐蚀抗力,含铜镀层被证实能够提升镁锂合金耐蚀性。改善镁锂合金强度的工艺主要有合金化、热处理、加工变形等,其中合金化是最基本的强化手段。Cu合金化可以对镁锂合金中的组织与性能进行调控,改善镁锂合金的强度。本文对含Cu镁锂合金的研究进展及其应用情况进行综述,总结了目前含Cu镁锂合金耐蚀与力学性能的相关研究成果,重点梳理了铜元素在镁锂合金中的作用,为含Cu镁锂合金的实际应用提供一定的理论指导。

硫酸铜的生产

硫酸铜是重要的铜化合物，用途广泛。叙述了以废铜、铜合金废料、氧化铜矿、氧化硫化混合铜矿、含铜废液等为原料生产硫酸铜的工艺及其特点。

Influence of Cu addition on microstructure and hardness of near-eutectic Al-Si-xCu-alloys

The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu（x = 2%,3%,4% and 5%） was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand molds at 690 °C and solidified.The solution treatment was performed at 500 °C for 7 h and then the specimens were cooled by water quenching.The samples were respectively aged at 190 °C for 5,10 and 15 h to observe the effect of aging time on the hardness of matrix.Also differential thermal analysis was used to obtain the transition temperature of the equilibrium phases at cooling rate of 30 K/min and to determine the effect of Cu content on the formation of quaternary eutectic phases and the melting point of-（Al） ＋ Si.The results show that as Cu content in the alloy increases,the hardness of matrix increases due to precipitation hardening,the melting point of -（Al） ＋ Si decreases and the amount of these eutectic phases increases,quaternary eutectic phase with melting point of 507 -C forms when Cu content is more than 2%.

Influence of Cu content on microstructure and mechanical properties of thixoformed Al-Si-Cu-Mg alloys

The effects of Cu content on the microstructure and mechanical properties of thixoformed Al-6Si-xCu-0.3Mg(x= 3,4,5and 6,mass fraction,%) alloys were studied.The samples were thixoformed at 50%liquid content and several of the samples were treated with the T6 heat treatment.The samples were then examined by optical microscopy(OM),scanning electron microscopy(SEM),energy dispersive X-ray(EDX) spectroscopy and X-ray diffraction(XRD) analysis,as well as hardness and tensile tests.The results show that the cooling slope casting and thixoforming process promote the formation of very fine and well distributed intermetallic compounds in the aluminium matrix and the mechanical properties of the alloys increase considerably compared with the permanent mould casting.The results also reveal that as the Cu content in the alloy increases,the hardness and tensile strength of the thixoformed alloys also increase.The ultimate tensile strength,yield strength and elongation to fracture of the thixoformed heat-treated Al-6Si-3Cu-0.3Mg alloy are 298 MPa,201 MPa and 4.5%,respectively,whereas the values of the thixoformed heat-treated alloy with high Cu content(6%) are 361 MPa,274 MPa and 1.1%,respectively.The fracture of the thixoformed Al-6Si-3Cu-0.3Mg alloy shows a dimple rupture,whereas in the alloy that contains the highest Cu content(6%),a cleavage fracture is observed.

Correlation between supercooled liquid region and crystallization behavior with alloy composition of La-Al-Cu metallic glasses

Bulk metallic glasses (BMGs) with large supercooled liquid region are promising materials for superplastic forming. In this paper, we demonstrate a microstructure-based strategy to pinpoint the composition with the largest supercooled liquid region in La 86 x Al 14 Cu x (x=16 at%-20 at%) metallic glass system. By monitoring the changes in crystallization behavior of the glassy alloys with composition to search for the alloys exhibiting eutectic crystallization, the glassy alloys with the largest supercooled liquid region in the given alloy system can be found. The metallic glasses with Cu contents of 16 at%-19 at% exhibited two crystallization peaks, and the primary crystallization product was identified to be α-La by means of DSC, XRD and TEM. The increase in Cu content resulted in the decay of the primary crystallization peak and the increase in onset temperature of crystallization, leading to the enlargement of supercooled liquid region. By further suppressing the α-La primary crystallization with increasing Cu content up to 20 at%, the eutectic crystallization of α-La and LaCu 13 through one crystallization reaction occurred upon heating, where the largest supercooled liquid region of 65 K for La 66 Al 14 Cu 20 glassy alloy was located. This study indicats that, in a given glassy alloy system, a larger supercooled liquid region can be achieved by optimizing the alloy compositions to suppress the primary crystallization.