2025 年 64 巻 1 号 p. 93-100
High–temperature deformation and dynamic recrystallization (DRX) behaviors of Cu–Sn–P alloy were systematically investigated comparing with those of Cu and Cu–P alloy. Annealing behavior of post DRX was also examined. Addition of P and Sn to Cu increased deformation stress at elastic region as well as those at plastic deformation region such as peak and steady–state flow stresses. Especially, the effects of Sn were notably large and, hence, onset of DRX was much delayed. Sn addition also influences the reduction of DRXed grain size and strongly impeded grain coarsening during annealing after DRX. 3D–atom probe tomography analysis revealed enrichment of P and Sn at grain boundary and the areas nearby grain boundary. This result strongly suggested formation of interstitial and substitutional atom pairs (i.e., P–Sn dipole) at grain–boundary region, which had the effect of retarding grain–boundary migration by the elastic interaction between P–Sn atom pairs and grain boundary and, hence, resulted in raising deformation stresses.
