Microstructures and properties of new Sn-Ag-Cu lead-free solder reinforced with Ni-coated graphene nanosheets

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

63 Scopus Citations
View graph of relations


  • Guang Chen
  • Fengshun Wu
  • Changqing Liu
  • Vadim V. Silberschmidt
  • Y. C. Chan

Related Research Unit(s)


Original languageEnglish
Pages (from-to)500-509
Journal / PublicationJournal of Alloys and Compounds
Online published21 Sep 2015
Publication statusPublished - 25 Jan 2016


This paper deals with microstructures and properties of SAC305 lead-free solder reinforced with graphene nanosheets (GNS) decorated with Ni nanoparticles (Ni-GNS). These Ni-coated GNS nanosheets were synthesized by an in-situ chemical reduction method. After morphological and chemical characterization, Ni-GNS were successfully integrated into SAC305 lead-free solder alloy with different weight fractions (0, 0.05, 0.1 and 0.2 wt.%) through a powder metallurgy route. The obtained composite solders were then studied extensively with regard to their microstructures, wettability, thermal, electrical and mechanical properties. After addition of Ni-GNSs, cauliflower-like (Cu,Ni)6 Sn5 intermetallic compounds (IMCs) were formed at the interface between composite solder joint and copper substrate. Additionally, blocky Ni-Sn-Cu IMC/GNS hybrids were also observed homogenously distributed in the composite solder matrices. Composite solder alloys incorporating Ni-decorated GNSs nanosheets showed slightly reduced electrical resistivity compared to the unreinforced SAC305 solder alloy. With an increase in the amount of Ni-GNS, the composite solders showed an improvement in wettability with an insignificant change in their melting temperature. Mechanical tests demonstrated that addition of 0.2 wt.% Ni-GNS would result in 19.7% and 16.9% improvements in microhardness and shear strength, respectively, in comparison to the unreinforced solders. Finally, the added Ni-GNS reinforcements in the solder matrix were assessed with energy-dispersive X-ray spectroscopy, scanning electron microscopy and Raman spectroscopy.

Research Area(s)

  • Lead-free solder, Mechanical properties, Melting temperature, Ni-coated graphene oxide, Raman spectrum, Wettability

Citation Format(s)