Williams, W. Lee
Head, Physical Metallurgy Branch, Metallurgical Laboratory, U. S. Naval Engineering Experiment Station, Annapolis, Md.
Pages: 10 Published: Jan 1957
A study was made of soldered joints to determine susceptibility to gray tin formation at low temperature. Copper joints were soldered with tin, “pure” tin-lead alloys, and commercial tin-lead solders. The soldering time and temperature were varied to provide low and high copper contamination of the solder film. Impact, shear (sleeve-joint), and pressure-seal specimens were prepared. These were tested at −40 F, both with and without prior storage for 6.5 months at −40F. The cold-stored specimens were inoculated with gray tin to promote transformation. No deterioration was found in the commercial tin-lead solders. The “pure” tin-lead alloys had minute traces of gray tin. The plain tin exhibited marked transformation. Copper contamination of the solder film during the soldering operation did not inhibit the formation of gray tin.
Paper ID: STP44117S