Analysis of Solidification Crack Susceptibility in GTAW of 7000 Series Aluminum Alloys Using Weld Pool Shape

Abstract

In this study, a model to predict solidification cracking in fusion welding of aluminum alloys was developed using the shape of the molten pool and the strain rate of the welds. The influence of each factor of the melt pool on solidification cracking was determined statistically. For the regression model of solidification cracking, the melt pool at the front side and the strain in the weld zone at the back side were simultaneously measured during the welding process of 7000 series aluminum alloys. The welded specimens were classified based on the presence or absence of solidification cracking using appearance analysis. A regression model was used to obtain the relationship between the shape of the measured melt pool and strain in the weld zone, and a logistic regression model was employed to establish the relationship between the strain in the weld zone and the occurrence of solidification cracking. Finally, these two regression models were combined to obtain a regression model that predicted the occurrence of solidification cracking based on the shape of the melt pool. This study presents a novel method that combines weld pool shape and welds strain analysis to predict solidification cracking, offering a highly accurate and statistically validated model for preventing cracking in aluminum alloy welding.