MICROSTRUCTURAL ANALYSIS THROUGH TRIDIMENSIONAL INVERSE HEAT TRANSFER MODEL IN GTA ALUMINUM ALLOY WELDING
Elisan dos Santos Magalhães1; Edmilson Otoni Correa1; Ana Lúcia Fernandes de Lima E Silva1; Sandro Metrevelle Marcondes Lima E Silva1
1 Universidade Federal de Itajubá - UNIFEI
doi:10.20906/CPS/COB-2015-0286
Resumo
In order to study the Heat Affected Zone (HAZ) in GTA aluminum 6060 T5 alloy welding, a previously developed numerical software based on the tridimensional diffusion equation with moving source and phase change was used. The amount of heat flux delivered to the plate was minimized through a non-linear interactive BFGS (Broydon-Fletcher-Goldfarb-Shanno) inverse technique. GTA welding experiments were performed using thin aluminum plates in four t+ experimental conditions. These plates were cut on the HAZ and were analyzed using an optical microscope. Through the peak temperatures and heating rate obtained by the software, the grain size throughout the HAZ during age hardening was studied. The study found a linear correlation between the grain size on the HAZ and the positive polarity. The study also presented that the cooling rate after the GTAW torch is off is the same for the fusion zone, HAZ and base material. Consequently, the significant change on the microstructure occurs while the GTAW torch is turned on.
Palavras-chave: Inverse problems; Heat flux and temperature estimation; GTAW process; Microstructural Analysis