ABSTRACT
The effect of heat treatment on the mechanical properties and microstructures of Cu–6.9Ni–2.97Al–0.99Fe–1.06Mn alloys was investigated. The results show that the microstructure of the as-cast alloy mainly consists of an alpha-copper matrix and γ-phase Ni3Al particles. The microstructure of the alloy after solution treatment at 950°C for 2 h is a single-phase alpha-copper supersaturated solid solution and the second-phase strengthening disappears. After ageing treatment at 550°C for 6 h, the γ-phase particles are fully precipitated, and the mechanical properties of the alloy are significantly improved. The tensile strength is increased from 305 to 588 MPa. Quasi-cleavage fracture with shallow dimples appeared in the Cu–6.9Ni–2.97Al–0.99Fe–1.06Mn alloy aged at 550°C for 6 h.
Disclosure statement
No potential conflict of interest was reported by the authors.