A study of electrodepositing Sn–SiC composite coatings with good welding performances

Abstract

Sn–SiC composite coatings with a good welding performance were electrodeposited in a bath containing 55 g L⁻¹ Sn(CH₃SO₃)₂, 160 g L⁻¹ methyl sulfonic acid (MSA), 10 mg L⁻¹ OP-21, 30 g L⁻¹ SiC nano-particles and 50 mg L⁻¹ sodium dodecyl sulfate (SDS), at an inclination angle of the plating tank θ of 45°, a temperature of 20 °C and a cathode–current density of 3 A dm⁻² for 15 minutes. The incorporation of SiC nano-particles in the Sn deposits refines the crystalline grains. The solder spreading performance and Sn whiskers of the Sn–SiC coatings composited with 1.0–2.3 wt% SiC are better and smaller than that of the pure Sn coating, respectively. Only when the intercalation of SiC nano-particles into the Sn grain boundary is firm and homogeneous could coatings with a good welding performance be obtained.