Micro Hardness Of Mwcnt Reinforced 70Sn-30Bi Solder Alloys

In this study different weight percentages of copper coated multi-walled carbon nanotubes (MWCNTs) have been incorporated into 70Sn-30Bi solder alloy to form nanocomposite solder. Pure tin and bismuth were melted together in argon gas atmosphere to make 70Sn-30Bi alloy. Copper coated MWCNTs were produced by electroless copper deposition method. Pre-activated, activated and copper coated MWCNTs were characterized using SEM and EDS. MWCNTs reinforced SnBi composites were made by cold rolling process followed by the hot pressing. Micro hardness of the both the pure alloy and composites with different percentages of Cu/MWCNTs was measured using QV-1000 Vickers hardness tester at room temperature. Characterization results revealed a linear trend of increase in micro hardness with the addition of coated MWCNTs. The enhanced micro hardness is believed due to the improved interfacial bonding between matrix and CNT as well as better dispersion to efficiently utilize the potential of high strength reinforcements inside the composites and increased fracture toughness that arises from bridging mechanism of the coated MWCNTs as the crack propagates