Inthispaper,thebrazingmechanismofLY12aluminumalloyatmiddlerangetemperaturewaspresented.TheCsF-AlF3non-corrosivefluxwasutilizedtoremovethecomplexoxidefilmonthesurfaceofLY12aluminumalloy.TheresultsrevealedthattheoxidefilmwasremovedbytheimprovedCsF-AlF3fluxaccompaniedwiththeoccurrenceofreactionaswellasdissolutionandthecompoundsCsFplayedanimportantroletoremovetheoxidefilm.Actually,thehighactivityofflux,say,theabilitytoremovetheoxidefilm,wasduetothepresenceofthecompounds,suchasNH4F,NH4AlF4andcompositemoltensalt.TheproductionofHFwasthekeyissuetoacceleratethereactionandenhancetoeliminatetheoxidefilmbydissolution.ItwasfoundthattherareearthelementLaatsmallpercentagewasnotenrichedattheinterface.Moreover,therareearthfluorideenhancedthedissolutionbehavior.
