Improved Material Combination for Controlled Atmosphere Brazed Aluminium Radiators

A new fin material, FA6815 (AA3003+Si, Zn, Zr) which corrodes at a low rate and gives cathodic protection to 3005LL tubes and AA4343 braze filler is presented. It shows better sagging resistance and twenty per cent higher post-braze strength than conventional AA3003 and AA3003+Zn. A new age hardening material, FA7827 (AlMgSi-type) for header and side supports is also presented. It has tensile strength of 180 MPa after brazing and fifteen days natural ageing. The corrosion resistance is improved compared to AA3003 and AA6060. These two new materials in combination with 3005LL tubes allow for improved performance and cost benefits by downgauging.