STUDY OF PHASE TRANSFORMATIONS BY X-RAY DIFFRACTION AND ENERGY DISPERSIVE SPECTROMETRY MICROANALYSIS IN WELDED JOINTS AA5083-H116 WITH GMAW-P PROCESS AND SHIELDED GAS MIXTURE 80AR19HE1O2

Abstract

In this work are were studied phase transformations in a single pass welding joint of AA5083-H116 alloy using GMAW-P automated process, 80Ar19He1O2 shielding gas mixture, ER5183 filler metal, and different heat inputs. The methodology included a preliminary analysis using optical microscopy, which identified morphological changes in microstructure of studied welding regions. Computational thermodynamic simulation based on Calphad method was used to calculate phase stability fields in Al-Mg alloys. Scanning electron microscopy and energy dispersive spectrometry techniques were used to identify, both morphology, and chemical composition of precipitates in welded regions. Finally, X-ray diffraction was used to obtain diffraction patterns of the regions under different welding conditions. Results showed that under different heat inputs values predominates Al-rich FCC matrix with Mg in solid solution, whereas, proportions of second phase of: FeAl6, FeAl and MnAl12 in regions welding were modified.