**Development of High-Performance Current Copper Alloys**

48 Copper Alloys – Early Applications and Current Performance – Enhancing Processes

Vykhodets, V. B., Geld, P. V., Demin, V. B. Men, A. N., Murtazin, I. A. & Fishman A. Ya.

Zinkle, S. J. & Fabritsiev S. A. (1994). Copper alloys for high heat flux application. *Atomic and Plasma-Material Interaction Data for Fusion*. Vol 5 (December 1994), pp. 163-191.

*Solidi (a)*, Vol. 9, Iss. 1, (January 1972), pp. 289-300, ISSN-1862-6319

(1972). Isotope effect in the Solubility of Hydrogen in FCC Metals. *Physica Status* 

**3** 

**Properties of High Performance** 

H.-A. Kuhn, I. Altenberger,

*Wieland-Werke AG, Ulm,* 

*Germany* 

A. Käufler, H. Hölzl and M. Fünfer

**Alloys for Electromechanical Connectors** 

Miniaturization of electronic and electromechanical components and increasing cost of materials are the driving forces for developments of high performance copper alloys for automotive and computer technologies. Electromechanical connectors are current carrying spring elements. Miniaturization requires improved mechanical strength and medium to high electrical conductivities. For automotives this components have to operate in temperature ranges between -40°C and 180°C under hood. For a good reliability during lifetime of vehicles or multimedia devices designing engineers also expect good formability, excellent resistance against stress relaxation and fatigue behavior. The design of small boxlike connectors has to overcome the contradiction between high strength and good formability. Nature of alloys also reveals reduced electrical and thermal conductivity at improved strength and vice versa reduced strength at higher conductivity. Nevertheless, development of modern copper based connector materials intends to improve strength, electrical conductivity and bending behavior simultaneously. Furthermore, a long life time of connector devices requires excellent thermal stability and resistance against fatigue

In a first step the following contribution will focus on the metallurgical principles for alloy design. The role of alloying elements is described. The diverse directions of material development include optimization of standardized alloys like tin bronzes and development and processing of new alloy compositions. Beside properties of grain refined tin bronze CuSn8 with standardized chemical composition this article presents latest developments on

Corson has first described in 1927 the mechanism of precipitation of nickel silicides in copper (Corson, 1927). The successful story of CuNiSi-alloys for connector devices has started in the early 80ies (Hutchinson, 1990; Tyler, 1990; Robinson, 1990). Until today research is focused on understanding processing and optimization of standardized C70250 (UNS-designation) like CuNi2Si and related alloys of the first generation (Lockyer, 1994; Kinder, 2009). The success of an ongoing research on these alloys is due to an excellent combination of strength, conductivity, deformation behavior and thermal stability. Therefore these alloys have been applied to diverse connector and lead frame devices. In

**1. Introduction** 

damage.

precipitation hardened Corson-type alloys.
