Investigation of preparation and characteristics of Sn–Bi eutectic powders derived from a high shear mechanical approach

Fusible Sn–Bi eutectic alloy particles were synthesized from bulk Sn–Bi alloy via a high-shear mechanical approach. The morphology, composition, and structure of the as-prepared Sn–Bi alloy particles were characterized by XRD, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry, and Fourier-transform infrared spectroscopy. The particles were found to be spherical and consist of the tetragonal phase of tin as well as the rhombohedral phase of bismuth. In addition, there were large amounts of poly(N-vinylpyrrolidone) coated on the particles.

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► Sn–Bi eutectic powders were prepared by a high shear mechanical approach. This approach is a green one because no chemical reaction occurs in the process and the high boiling point solvent can be used repeatedly.
► The melting point of the as-prepared powders is about 140 °C, which is in agreement with the low melting point solder for industrial applications.
► The size of Sn–Bi eutectic powders can be controlled by addition of Poly(N-vinylpyrrolidone) (PVP) due to the adsorption.