Conductive flux for welding aluminium - contg. sodium- and potassium- chlorides and pref calcium fluoride and silicon dioxide

摘要

A conductive flux for welding 20-80mm thick sheets of Al (alloy) contains NaCl and KCl in ratios between 7:1 and 25:1. Pref. compsns. have NaCl:KCl ratio 9-12:1 with addn. of 5-9 wt. % CaF2 and 2-6 wt.% SiO2. KCl and SiO2 reduce the tendency for electrical breakdown present with pure NaCl and CaF2 lowers volatility. The flux permits cheaper and less critical operating conditions than are possible with MIG or electron-beam welding, and is more stable and less volatile than existing Li halide fluxes.