Wetting and spreading of molten SnPb solder on a Cu–10%Nb micro-composite

• Published in: Journal of alloys and compounds Vol. 477; no. 1; pp. 278 - 282
• Main Authors: Yeo, Hwan Kyun, Han, Kwan Hee
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 27.05.2009; Elsevier
• Subjects: Applied sciences; Brazing. Soldering; Cu–10%Nb micro-composite; Exact sciences and technology; Joining, thermal cutting: metallurgical aspects; Metals. Metallurgy; Scanning electron microscopy; Solder; Spreading; Wetting; Solder; Scanning electron microscopy; Wetting; Spreading; Cu–10%Nb micro-composite; Tin alloy; Niobium alloy; Composite material; Contact line; Lead alloy; Cu―10%Nb micro-composite; Surface tension; Sessile drop method; Copper alloy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2008.10.150

The wetting and spreading behaviors of molten SnPb solder on a Cu–10%Nb micro-composite and pure Cu are investigated by sessile drop experiments at 250 °C for various times up to 500 s. Very limited extent of spreading of molten solder on the Cu–10%Nb micro-composite is observed, as compared with the spreading on pure copper. Whereas the wetting angle becomes essentially zero for pure Cu after 100 s reflow, it remains as high as about 30° for the Cu–10%Nb alloy, even after a prolonged reflow. Insoluble Nb particles in the copper matrix appear non-wetting with molten SnPb solder and are responsible for both limited spreading and high wetting angle for the Cu–10%Nb micro-composite. The observed quasi-static wetting angle of molten SnPb solder for the Cu–10%Nb is discussed in terms of a surface tension balance at the contact line, utilizing the rule of mixture for surface tension in a wetting system which contains non-wetting particles.