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Indexed by:期刊论文

Date of Publication:2017-08-01

Journal:PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL

Included Journals:Scopus、SCIE

Volume:27

Issue:4

Page Number:467-473

ISSN No.:1002-0071

Key Words:Cu-Ni-Si alloys; Composition design; Cluster-plus-glue-atom model; Microhardness; Electrical conductivity

Abstract:Cu-Ni-Si alloys are widely used due to their good electrical conductivities in combination with high strength and hardness. In the present work, minor-alloying with M = (Cr, Fe, Mo, Zr) was conducted for the objective of further improving their hardness while maintaining their conductivity level. A cluster-plus-glue-atom model was introduced to design the compositions of M-alloyed Cu-Ni-Si alloys, in which an ideal composition formula [(Ni, Si, M)-Cu-12]Cu-3 (molar proportion) was proposed. To guarantee the complete precipitation of solute elements in fine d-Ni2Si precipitates, the atomic ratio of (Ni, M)/Si was set as 2/1. Thus the designed alloy series of Cu-93.75(Ni/Zr)(3.75)Si-2.08(Cr/Fe/Mo)(0.42) (at%) were arc-melted into ingots under argon atmosphere, and solid-solutioned at 950 degrees C for 1 h plus water quenching and then aged at 450 degrees C for different hours. The experimental results showed that these designed alloys exhibit high hardness (HV > 1.7 GPa) and good electrical conductivities (>= 35% IACS). Specifically, the quinary Cu93.75Ni3.54Si2.08(Cr/Fe)(0.42)Zr-0.21 alloys (Cu-3.32Ni-0.93Si0.37(Cr/Fe)-0.30Zr wt%) possess both a high hardness with HV = 2.5-2.7 GPa, comparable to the highstrength KLFA85 alloy (Cu-3.2Ni-0.7Si-1.1Zn wt%, HV = 2.548 GPa), and a good electrical conductivity (35-36% IACS).