Torch versus oven preceramic soldering of a nickel-chromium alloy

Base metal preceramic solder joints have been described as unpredictable and inconsistent in tensile strength. Compared to base metal postsoldered joints, presoldering with a gas-oxygen torch produces weaker joints that have increased porosity and voids. This investigation compared the tensile strength of base metal solder joints presoldered with a gas-oxygen torch to that of joints presoldered in a porcelain oven under vacuum. The mean (± SD) solder joint tensile strength was 460.0 (± 99.4) M Pa for the oven-soldered and 520.2 (± 37.8) M Pa for the torch-soldered specimens. A strong, consistent, void-free preceramic solder joint was produced between a nickel-chromium base and gold solder by both torch- and oven-presoldering techniques; however, preceramic soldering with a torch tended to result in a stronger bond.