Research On Microalloying And Arc Erosion Resistance Of Cu-Cr-Te Alloy

In recent years,with the continuous and rapid development of the field of new energy vehicles,higher requirements have been put forward for the performance of high-strength and high-conductivity copper alloys,especially for the development of copper alloys with excellent arc resistance,which has important strategic significance and practical value.This paper uses copper tellurium alloy as the base alloy,and adds Cr and rare earth elements（La,Ce,Y）as alloying elements to improve the performance of copper tellurium alloy,and then prepares a copper alloy with arc resistance function,and studies and analyzes the mechanism of the influence of alloying elements on the microstructure and properties of copper alloy.The findings are as follows:The existing forms and action mechanism of chromium and Tellurium in the alloy and the effects of different content of Cr on the mechanical and electrical properties of the alloy were studied.The results show that Cr element is uniformly distributed on the metal matrix in the form of single substance in Cu-Cr-Te alloy,and Te element is distributed at the grain boundary in the form of Cu₂Te.The microstructure of Cu-Cr-Te alloy is composed of Cu matrix,Cu₂Te granular phase and Cr elemental.With the increase of Cr content,the effect of second phase strengthening and fine grain strengthening is enhanced,and the mechanical properties of the alloy are significantly improved.When the chromium content is 0.7%,the as cast Cu-Cr-Te alloy has the best comprehensive properties,and the tensile strength reaches 192.5mpa.After adding rare earth yttrium,Te₃Y₂/Te Y dense phase appears in the structure,with uniform and dense structure,fine grain size,clear grain boundary and obvious refining effect.The microstructure of Cu-Cr-Te-Y alloy is composed of（Te₃Y₂/Te Y+Cu₂Te）dense phase+Cu₂Te granular phase+elemental Cr phase.With the increase of Y element content,the number of dense phases increases,and the strength of fine and densely distributed particles is enough to hinder the dislocation movement.Dispersion strengthens the copper alloy matrix,which significantly improves the strength of the alloy.The tensile strength of Cu-0.7Cr-0.5Te-0.3Y alloy is 235 MPa,which is 46.88%higher than that of Cu-Te alloy without Cr and Y elements.After adding rare earth lanthanum,the average grain size of Cu-0.7Cr-0.5Te-x La alloy decreases significantly.With the increase of La content,the grain size further decreases and the grain refinement effect is obvious.The microstructure of Cu-Cr-Te-La alloy is composed of（La Te₃/La₂Te₃+Cu₂Te）mixed phase+Cu₂Te granular phase+elemental Cr phase.After adding rare earth Ce,the average grain size of Cu-0.7Cr-0.5Te alloy decreased significantly and the grain refinement effect was obvious.The microstructure of Cu-Cr-Te-Ce alloy is composed of（Ce Te₃/Ce₂Te₃+Cu₂Te）mixed phase+Cu₂Te granular phase+elemental Cr phase.The addition of tellurium and chromium reduces the intensity of the ablation current of the first contact of the electrode,while the addition of yttrium increases the ablation current;The addition of alloying elements will increase the hardness of the copper alloy and thus reduce the wear volume during friction;In the argon arc welding anti-arc ablation experiment,Cu-0.7Cr-0.5Te-0.1Y alloy has the best performance,the surface is smooth,there is obvious metallic luster,and there is no obvious ablation pit.Cu₂Te phase,elemental Cr phase,and high melting point intermetallic compounds（Te₂Y₃）formed by Y and Te are the main reasons for improving the arc ablation resistance of copper alloys.