MATERIALS - SILVER-COPPER-LITHIUM ALLOY - 17-7PH SANDWICH PANELS BRAZED WITH - EFFECTS OF ELEVATED TEMPERATURE ON - STRUCTURAL EVALUATION OF
GENERAL DYNAMICS CORP POMONA CA POMONA DIV
Pagination or Media Count:
A 12 x 13 x 25-in. sandwich panel was brazed with sterling Ag 0. 2 Li brazing alloy. After brazing, the panel was vacuum purged with air ten times. It was cut into specimens and tested at room temperature on a 120,000 lb Baldwin test machine. The results of the mechanical tests are given and photomicrographs showing the extent of oxidation in the brazed fillet are shown. The high strength after exposure was probably due to additional precipitation hardening of the steel during exposure. A corrosion condition previously observed on PH15-7 Mo brazed panels was found on the 17-7PH stainless steel panels of this test. Corrosion occurred on the steel adjacent to the brazing alloy-steel interfaces. It was most evident on the outer edges of the exposed honeycomb core. The condition was not evident immediately after cooling to room temperature. It apparently developed as the specimens stood in the moist air of the laboratory. The corrosion appeared as small brown growths or scale. The cause was not determined.
- Fabrication Metallurgy
- Couplers, Fasteners and Joints