Phase Equilibria Related to NiGa5 in the Binary Ni-Ga System

Chih-Chia Bill Chang; C R Kao

doi:10.3390/ma17040883

Phase Equilibria Related to NiGa₅ in the Binary Ni-Ga System

Materials (Basel). 2024 Feb 14;17(4):883. doi: 10.3390/ma17040883.

Authors

Chih-Chia Bill Chang¹, C R Kao^{1

2}

Affiliations

¹ Department of Materials Science and Engineering, National Taiwan University, Taipei 106216, Taiwan.
² Advanced Research Center for Green Materials Science & Technology, National Taiwan University, Taipei 106216, Taiwan.

Abstract

The assembly of Ga alloys with Ni or Ni alloy has been widely developed for various low-temperature applications in recent years. In the constituent Ni-Ga binary system, however, the phase equilibrium with the phase "NiGa₅" and its stability has scarcely been investigated. The present study used the diffusion couple technique combined with SEM-EPMA and XRD analysis to examine the phase stability and the homogeneity range of the phase. The results show that "NiGa₅" is a stable phase in the binary system with little homogeneity range and suggest that the peritectic reaction L+Ni3Ga7→NiGa5 lies between 112.0 and 115.5 °C. This work provides new information for the modification of the Ga-rich low-T region of the Ni-Ga phase diagram.

Keywords: EPMA; NiGa5; XRD; intermetallics; phase diagram; phase equilibria.

Grants and funding

NSTC 111-2634-F-002-016/National Science and Technology Council, Taiwan, R.O.C.