4. Conclusions
(1) The IMC layer was formed on the aluminum side and the thickness of the IMC layer reached a few micro meters.
(2) The thickening of IMC layer was observed with applying post weld schedule, and linear increase of peak load was achieved with increased post weld time,which was attributed to longer di®usion time of Fe into liquid Al during increased post weld time.
(3) The uniform mixed layer was formed on interface between sheet type filler metal (Al-12Si) and steel sheet, and the bond strength is expected to be improved with using filler metal for resistance spot brazing.