高强高导铜合金设计思路及其应用

综述了高强高导铜合金的设计思路，分析了不同高强高导铜合金的强化机制和导电机制，并指出了高强高导铜合金的发展动向。     

高强高导铜合金的研究状况

高强高导电铜合金是一类具有优良综合性能的功能材料和结构材料,被广泛应用于电子、机械等领域,本文阐述了高强高导铜合金的研究现状,系统介绍了此类合金的强化机理、制备方法及组织和性能特点,并且分析了稀土的作用机制及对该类铜合金性能的影响,最后展望了该类合金的发展前景。     

高强高导铜合金的研究现状及发展趋势

综述了高强高导铜合金的研究现状,系统阐述了合金化法和复合材料法制备高强高导铜合金的方法和机理;介绍了高强高导铜合金领域的研究热点和重点问题,即快速凝固法制备高强高导铜合金及稀土等微合金化元素在高强高导铜合金中的应用,分析了高强高导铜合金的发展趋势,指出沉淀强化和复合强化是提高材料强度并保持其良好导电性能的有效途径,并结合我国的资源特点,提出了推动该材料产业化应用的方向.     

高强高导铜合金强化技术研究进展

铜及铜合金在众多领域得到了广泛应用,然而随着现代工业技术的发展,传统强化方法得到的高强高导铜合金已不能完全满足对其综合性能的需求。从基体强化和表面改性两个方面综述了国内外高强高导铜合金强化技术的最新研究进展。主要介绍了喷射成型法、脉冲电沉积法等新型铜合金成型工艺技术和激光束表面熔覆、喷涂涂覆、离子注入技术及粉末包埋渗等表面改性技术,并展望了铜合金表面改性技术的发展趋势。     

高强高导电铜合金的研究现状及展望

综述了获得高强度导电铜合金的方法，介绍了发展该类合金的最新技术及其研究现状。     

高强高导高耐热铜合金的研究进展与展望

高强高导高耐热铜合金作为现代高新技术用关键材料之一,已被广泛应用于轨道交通、电子通信和导航控制等众多领域.本文以服役温度超过300℃的Cu-Ag、Cu-Ni-Si、Cu-Cr-Zr、Cu-Al2 O3和Cu-Cr-Nb等高强高导高耐热铜合金为对象,概述了它们的合金设计原则、制备特点和相关物理特性,分析了它们开发应用中所存在的问题,并对它们的发展趋势进行了讨论和展望.     

快速凝固高强高导铜合金的研究现状及展望

本文综述了快速凝固高强度主导电率铜合金的研究现状,并对将来的发展趋势作了展望,指出,快速凝固铜合金的凝固过程对合金的最终显微组织结构起重要作用,因而,对其进行深入细致的研究具有重要意义。     

高强高导电铜合金耐蚀性研究

采用乙酸盐雾试验和电化学方法对Cu-Ag和Cu-Fe-P两种高强高导电铜合金的腐蚀行为进行研究。通过SEM,EDS和XRD等方法分析合金的腐蚀形貌及腐蚀产物的组成。研究表明:Cu-Fe-P合金比Cu-Ag合金有更好的耐蚀性能。微量Fe和P的同时加入,可以综合利用Fe的细化晶粒和P的脱氧作用,细化和净化合金组织,在提高合金强度和电导率的同时改善合金的耐蚀性。     

铜合金引线框架材料的发展*

介绍了国内外铜合金框架材料研究,生产现状,叙述了开发高强,高导铜合金的基本原理及制备方法,半对国内外高强,高导铜合金的研究和开发应用情况进行了综合,同时评述了铜合金引线框架材料的发展动向。     

高强高导高耐热弥散强化铜合金的研究现状

综述了高强高导高耐热弥散强化铜合金的制备方法及其特点,比较了各种方法制备的弥散强化铜合金的性能,简述了国内外研究现状.     

热处理工艺对高强高导铜合金组织级性能的影响

本研究利用多道次等径角挤压工艺制备了超细晶Cu-Cr-Zr合金棒,在450 ℃人工时效4h后,获得最佳综合性能:抗拉强度610 MPa,断裂延伸率12.5%,硬度199 HV,电导率77%IACS。通过EBSD技术和TEM分析,揭示了该工艺条件下合金主要的强化机制:超细晶组织贡献了260.6 MPa,析出相强化贡献了149 MPa,加工硬化效果为163.9 MPa。相比于等径角挤压试样,析出相取代了固溶原子,强化效果显著提高;而位错密度降低,加工硬化效果显著降低。     

Aging process optimization for a copper alloy considering hardness and electrical conductivity

A multi-objective optimization methodology for the aging process parameters is proposed which simultaneously considers the mechanical performance and the electrical conductivity. An optimal model of the aging processes for Cu–Cr–Zr–Mg is constructed using artificial neural networks and genetic algorithms. A supervised artificial neural network (ANN) to model the non-linear relationship between parameters of aging treatment and hardness and conductivity properties is considered for a Cu–Cr–Zr–Mg lead frame alloy. Based on the successfully trained ANN model, a genetic algorithm is adopted as the optimization scheme to optimize the input parameters. The result indicates that an artificial neural network combined with a genetic algorithm is effective for the multi-objective optimization of the aging process parameters.     

Three principles for preparing Al wire with high strength and high electrical conductivity

The trade-off relation between the strength and the electrical conductivity has been a long-standing dilemma in metallic materials. In the study, three key principles, i.e. elongated grains, sharp texture and nano-scale precipitates, were presented for preparing Al wire with high strength and high electrical conductivity based on the specially designed experiments for breaking the mutually exclusive relation between the strength and the electrical conductivity. The results show that the elongated grains could lead to a higher electrical conductivity in Al wire without sacrificing the strength; while, the 111 sharp texture can efficiently strengthen the Al wire without influencing the electrical conductivity. Furthermore, nano-scale precipitates with proper size can simultaneously improve the strength and electrical conductivity of Al alloy wire. Under the guidance of the above three key principles, Al wires with high strength and high conductivity were prepared.     

Enhancement of strength and electrical conductivity for a dilute Al-Sc-Zr alloy via heat treatments and cold drawing

Developing heat-resistant conductors with high strength and high electrical conductivity is a key issue in the electrical conductor industries, as the ever-increasing power transmission poses higher requirement on the thermal stability of electrical conductor wires. Dilute Al-Sc-Zr alloys are considered as promising candidates due to the excellent heat resistance and high electrical conductivity, but the low strength always limits their application on electrical wires. Yet, few efforts on process design have been made in dilute Al-Sc-Zr alloys to enhance the strength. Here, various kinds of processing paths via combination of cold drawing, ageing and/or annealing were conducted to improve the strength and electrical conductivity of a dilute Al-Sc-Zr alloy. Results show that enhanced strength and electrical conductivity were obtained after cold drawing + ageing or pre-ageing + cold drawing + annealing treatments processes. Optimal properties (194 MPa in ultimate tensile strength and 61% IACS in electrical conductivity) were obtained through cold drawing followed by ageing. Microstructure evolution which affects strength and electrical conductivity was systematically investigated using TEM and 3DAP. The enhanced strength was mainly attributed to the suitable interactions between strain strengthening and precipitation strengthening. The enhancement in electrical conductivity was caused by precipitation of solute atoms and recovery of defects. These results provide foundations for the processing design of Al-Sc-Zr conducting wires with good properties and push forward their potential application in heat resistant conductor industries.     

Modification of AA-6201 alloy for manufacturing of high conductivity and extra high conductivity wires with property of high tensile stress after artificial aging heat treatment for all-aluminium alloy conductors

In this paper, a modification method to manufacture high conductivity (HC) and extra high conductivity (EHC) wires with high strength properties from AA-6201 redraw rod has been presented. In the experiments, redraw rod has been produced using an extrusion press. In conventional heat treatment processing of HC and EHC wires produced from unmodified AA-6201 alloy, the wires should be exposed to artificial aging at 175 °C with soaking time higher than 6 h or at 195 °C/4 h to have conductivity above nominal value 52.5–53%IACS. Thus, wires gain high conductivity but decrease their tensile stress due to incoherence precipitation. However, this negative effect on the tensile stress can be prevented by the method explained in this study. This is inoculation of molten AA-6201 alloy in tundish with 3% AlB₂ compound in 9.5-mm rod form to decrease detrimental effect of Ti, Cr, Zr and V on the conductivity. Thus the wires produced from modified alloy do not need treatment time higher than 6 h at 175 °C to reach high and extra high conductivity. So, the alloy wires have got rid of exposing excessive aging and keep their tensile stresses at maximum level due to treatment at low temperature. Inoculation principles of the molten metal and homogenisation parameters that affect properties of HC and EHC wires were explained in details. Using modified AA-6201 wires AAAC conductor with extreme conductivity and also tensile stress was manufactured. Results from measurements of tensile and conductivity of HC and EHC wires taken from conductor samples have been tabulated to show effects of AlB₂.     

In-situ reduced non-oxidized copper nanoparticles in nanocomposites with extraordinary high electrical and thermal conductivity

Copper has received considerable attention for conductive nanocomposites as an alternative to costly silver or gold. However, practical application has been impeded by its susceptibility to oxidation in air. Here we report a novel scalable synthesis method of non-oxidized copper nanoparticles (InSituCuNPs) by pre-mixing and in-situ reducing copper formate-(butylamine-octylamine) complex inside soft epoxy matrix. The solid–liquid phase change of the copper formate complex, during the nanocomposite spark-plasma-sintering process, promotes uniform dispersion. Even the outermost atoms of InSituCuNPs are not oxidized since they are surrounded by the thick matrix polymer as soon as in-situ reduced into metallic copper, resulting in high electrical (15,048 Scm⁻¹) and thermal (28.4 Wm⁻¹K⁻¹) conductivities of the nanocomposite. Furthermore, a small addition of 1-dimensional carbon nanotubes decorated with 0-dimensional copper nanoparticles (<4 nm), together with bi-functionalization, dramatically enhances connectivity between the InSituCuNPs, resulting in air-stable and record-high 31,974 Scm⁻¹ and 74.1 Wm⁻¹K⁻¹ for isotropic copper-based nanocomposites. The nanocomposite also provides a small thermal resistance (2.64 × 10⁻⁶ m²KW⁻¹) and excellent heat dissipation performance.     

Ultrafine grained copper alloy sheets having both high strength and high electric conductivity

The ultrafine grained (UFG) microstructure, mechanical properties and electric conductivity of the Cu alloys severely deformed by accumulative roll bonding (ARB) process were systematically investigated. High density of grain boundaries introduced by the ARB process has significant effect on strengthening but little effect on the electric conductivity. The UFG Cu alloys with submicometer grain sizes can achieve both superior mechanical properties and high electric conductivity.     

碳纳米管对微胶囊铜复合浆料导电性能的影响

为提高铜浆料的导电性能,利用微胶囊技术对铜粉表面做改性处理,添加碳纳米管为导电增强相,制备碳纳米管-微胶囊铜复合浆料。利用四探针测试仪、扫描电子显微镜(SEM) 等研究了微胶囊铜粉的抗氧化性能及碳纳米管的参数、添加量对铜浆料导电性能的影响,分析其导电机理并建立导电相连接模型。研究结果表明:微胶囊化的铜粉具有较好的抗氧化性和导电性。当碳纳米管与铜粉的质量比为4∶[KG-2mm]96时,采用管径1~2 nm,长度5~30 nm的碳纳米管制备的复合浆料的电阻率达到最小值6.05 mΩ·cm,与纯铜浆料相比降低了89.39%。以碳纳米管-铜复合浆料与铜浆料分别制得导电膜,两者相比,前者更平坦、更致密,导电相间的接触更紧密,大量的碳纳米管覆盖在铜粉颗粒表面或填充铜粉颗粒间隙,同时碳纳米管之间相互“吸引”,形成致密的网状结构,在铜粉颗粒之间建立起大量的导电“桥梁”,从而改善了复合浆料的导电性能。     

颗粒种类及制备工艺对铜基材料性能影响

以纯铜为基体,以WC、AlN、TiN、MgB2等具有不同导电性能与密度的陶瓷颗粒为增强相,采用粉末冶金工艺制备了WCp/Cu、AlNp/Cu、TiNp/Cu和MgB2p/Cu系列复合材料.研究了不同增强颗粒、制备工艺的不同环节对铜基复合材料导电性能的影响.结果表明:相同制备工艺及体积分数条件下,以具有不同导电性能与密度的陶瓷颗粒作为增强相的铜基复合材料的导电性能相近,混粉、压制、烧结、复压及复烧等工艺环节对铜基复合材料导电性能有不同程度的影响,提高铜基复合材料的致密度为提高其导电性能的关键.