Revealing the Effect of Phase Composition and Transformation on the Mechanical Properties of a Cu–6Ni–6Sn–0.6Si Alloy

• Published in: Materials Vol. 14; no. 18; p. 5201
• Main Authors: Liang, Zhuanqin, Fan, Wenxin, Wang, Pengfei, Wang, Yushuai, Zhang, Kai, Zhao, Junsheng, Peng, Lijun
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 10.09.2021; MDPI
• Subjects: Alloys; Annealing; Chemical precipitation; Composition effects; Copper; copper–nickel–tin alloy; Deformation; Ductility; Ductility tests; Elongation; Fourier transforms; Gamma phase; Induction melting; Mechanical properties; Microstructure; Phase composition; Precipitates; primary phase; Room temperature; Solution heat treatment; solution treatment; Tensile strength; Tensile tests; Tin base alloys; Japan
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma14185201

In the present study, a Cu–6Ni–6Sn–0.6Si alloy is fabricated through frequency induction melting, then subjected to solution treatment, rolling, and annealing. The phase composition, microstructure evolution, and transition mechanism of the Cu–6Ni–6Sn–0.6Si alloy are researched systematically through simulation calculation and experimental characterization. The ultimate as-annealed sample simultaneously performs with high strength and good ductility according to the uniaxial tensile test results at room temperature. There are amounts of precipitates generated, which are identified as belonging to the DO22 and L12 phases through the transmission electron microscope (TEM) analysis. The DO22 and L12 phase precipitates have a significant strengthening effect. Meanwhile, the generation of the common discontinuous precipitation of the γ phase, which is harmful to the mechanical properties of the copper–nickel–tin alloy, is inhibited mightily during the annealing process, possibly due to the existence of the Ni5Si2 primary phase. Therefore, the as-annealed sample of the Cu–6Ni–6Sn–0.6Si alloy possesses high tensile strength and elongation, which are 967 MPa and 12%, respectively.