The Precipitation and Strengthening Mechanism of Cu-Ni-Si-Co Alloy

Abstract:

The precipitates, mechanical properties and strengthening effect of Cu-Ni-Si,Cu-Ni-Si-Co0.8 and Cu-Ni-Si-Co1.9 alloys are investigated. It is concluded from the TEM and XRD analysis that the strengthening of Cu-Ni-Si-Co alloy is mainly attributed to precipitates of both Ni₂Si and Co₂Si phases, with the same structures and very close lattice parameters. The addition of 1.9 wt% Co barely affects the precipitation process of Ni₂Si or Co₂Si, and may not be beneficial for enhancing the strength. The strengthening of Cu-Ni-Si-Co alloy is determined by the Orowan mechanism, and a critical precipitate radii r_c about 1.5 nm corresponding to the peak strength is obtained through the theoretical analysis. It can be deduced that the peak strength of aged Cu-Ni-Si-Co alloy is obtained with the microstructures containing metastable phase and Ni₂Si (or Co₂Si) precipitates.

• Periodical: Materials Science Forum (Volume 749)
• Pages: 294-298
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.749.294
• Online since: March 2013
• Authors: Qiang Song Wang, Guo Liang Xie, Xu Jun Mi, Bai Qing Xiong, Xiang Peng Xiao
• Keywords: Cu-Ni-Si-Co Alloy, Orowan Strengthening, Precipitation

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