Liquid Phase Separation and the Aging Effect on Mechanical and Electrical Properties of Laser Rapidly Solidified Cu100−xCrx Alloys

Metals

Song-Hua Si¹  Hui Zhang¹  Yi-Zhu He¹  Ming-Xi Li¹  Sheng Guo² 

[1] School of Materials Science and Engineering, Anhui University of Technology, Ma’anshan, Anhui 243002, China; E-Mails:;Surface and Microstructure Engineering Group, Department of Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden; E-Mail:

关键词: laser cladding;    Cu-Cr alloy;    liquid phase separation;    electrical conductivity;   

DOI  :  10.3390/met5042119

来源: mdpi

【 摘 要 】

Duplex structure Cu-Cr alloys are widely used as contact materials. They are generally designed by increasing the Cr content for the hardness improvement, which, however, leads to the unfavorable rapid increase of the electrical resistivity. The solidification behavior of Cu_100−xCr_x (x = 4.2, 25 and 50in wt.%) alloys prepared by laser rapid solidification is studied here, and their hardness and electrical conductivity after aging are measured. The results show that the Cu-4.2%Cr alloy has the most desirable combination of hardness and conductive properties after aging in comparison with Cu-25%Cr and Cu-50%Cr alloys. Very importantly, a 50% improvement in hardness is achieved with a simultaneous 70% reduction in electrical resistivity. The reason is mainly attributed to the liquid phase separation occurring in the Cu-4.2%Cr alloy, which introduces a large amount of well-dispersed sub-micron-scale Cr-rich particulates in the Cu-rich matrix.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.