A number of common soft solders were used as a basis for an investigation of the properties of soft solders in relation to their performance in a cyclic-loading apparatus. Split brass capsules, joined with a test solder, were subjected to pressure ranging from 0 to 20 psi with a maximum resultant temperature of 255 F. The compositions of the more promising solders were modified by the addition of constituents designed to improve their high-temperature properties.

Small amounts of nickel, manganese, chromium, germanium, tellurium, and cerium were added to 30 tin — 70 lead and 70 tin — 30 lead solders. The test results indicated that all of these additions improved the performance of the 70 tin — 30 lead solder, but only nickel, germanium, and cerium had any beneficial effect on the performance of 30 tin — 70 lead solder. Other additions to these solders and to 15 tin — 85 lead solder also were investigated.

Some work on the corrosion effects of antifreeze solutions on soldered joints was included in this program. The effects of joining brass material with tinlead solders containing various amounts of antimony also were studied briefly.