Effect of Cd and SPD on structure, physical, mechanical, and operational properties of alloy of Cu-Cr-Zr

Abstract

An increase in the service life of electrical products from copper and its alloys is directly related to an increase in the wear resistance of materials. Structural refinement and alloying with cadmium are known to have a positive effect on the strength characteristics and wear resistance of copper, which makes it possible, with a Cd content of 1% by weight, to increase the wear resistance of copper several times, but cadmium is considered an environmentally unsafe element. In this regard, the paper presents the results of studies of a widely used Cu-Cr-Zr alloy system in the ultrafine-grained (UFG) state, micro-alloyed with cadmium (0.2%, weight), in order to improve physical, mechanical, and operational properties, as well as environmental safety. Severe plastic deformation, providing structure refinement to ~150 nm, and microalloying with cadmium of a Cu-Cr-Zr system alloy, after a complete processing cycle, provides a tensile strength of 570±10 MPa and 67% electrical conductivity. At the same time, the abrasion resistance increases by 12 and 35% relative to the industrial systems Cu-Cd and Cu-Cr-Zr, respectively. The obtained characteristics are very promising for improving the operational properties of continuous welding tips, collector plates, and contact wires operating under conditions of intense wear.

Wear Performance of Cu–Cd, Cu–Be and Cu–Cr–Zr Spot Welding Electrode Materials

“…Hence, both adhesive and abrasive wear mechanism are observed. The amount of wear is correlated to the rise in temperature and contact pressure on sliding interfaces; similar results were reported by researchers [7,8,20]. An increase in temperature may cause localized welding, which leads to severe plastic deformation/ploughing under sliding conditions.…”

“…The newly developed alloy system exhibits excellent thermal stability at 400 • C, surpassing the thermal stability of cadmium bronzes by a factor of two. Additionally, this alloy system demonstrates significantly improved wear resistance compared to the existing Cu alloys [20,21].…”

Microhardness and Microstructural Evolution of Pure Nickel Processed by High-Pressure Torsion

“…For example, its flow stress during deformation at high temperatures should be significantly reduced, and at the same time, there are also excellent applications in the field of superplasticity [10,11]. Recently, a series of reports showed that SPD could produce materials that combine high strength and high ductility [12,13]. More importantly, because UFG materials have smaller characteristic sizes that are orders of magnitude smaller than in micro-parts, they can significantly reduce the "scale effect" of the micro-forming processing.…”

Low cycle fatigue behavior of Cu‐Cr‐Zr alloy with different cold deformation

“…[1][2][3] Cu-Cr-Zr alloy has become a research hotspot in recent decades due to its advantages to meet these requirements, [4][5][6][7] and previous researchers have shown its importance in the high-speed rail network. 2,6,[8][9][10][11][12] Cu-Cr-Zr alloy used in contact wires are usually produced by semi-continuous casting and cold working. [13][14][15][16] Since cold deformation introduces dislocations, twinning and residual stress, which are considered to be important during preparation process for improving the strength of materials.…”

“…With the rapid development of high‐speed electrified railways, researchers showed increasing interest in higher requirements for the performance of contact line materials (higher strength, higher conductivity, higher anti‐softening temperature and good plasticity) 1–3 . Cu‐Cr‐Zr alloy has become a research hotspot in recent decades due to its advantages to meet these requirements, 4–7 and previous researchers have shown its importance in the high‐speed rail network 2,6,8–12 …”