中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 32 No. 4 April 2022 |
（1. Department of Industrial Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Bangkok 10520, Thailand;
2. Department of Industrial and Production Engineering, Faculty of Industry and Technology, Rajamangala University of Technology Rattanakosin Wang Klai Kangwon Campus, Prachuapkhirikhan 77110, Thailand）
Abstract:The effect of Cu content on the microstructure, grain orientation and mechanical properties of Sn-xCu (x=0-4.0 wt.%) lead-free solder was studied. Results showed that added Cu induced the formation of intermetallic phases. Only the η Cu6Sn5 and ε-Cu3Sn phases were present in the β-Sn matrix. For all contents, the strongly preferred orientation of the β-Sn phase was formed on the {001} plane. In Sn doped with 1.0 wt.% Cu, the η-Cu6Sn5 phase exhibited the preferred orientation of {0001} plane, whereas doping with 3.0 or 4.0 wt.% Cu transformed the preferred orientation to the {010} plane. In addition, only the {0001} and planes were present in the ε-Cu3Sn phase. The high Cu contents contributed to an increased number of low-angle boundaries, high residual strain, tensile strength and microhardness.
Key words: lead-free solder; Sn-Cu alloys; crystallographic orientation; microstructure; intermetallics; mechanical properties
