Articles techniques et présentations

The aim of the study is to predict the formation of porosities in the case of spot laser welding of tantalum. During the interaction, a deep and narrow cavity, called the keyhole, is generated. At the end of the interaction, surface tension provokes the collapse of the keyhole. Gas bubble can then be trapped into the melting pool, and give birth to residual porosities, according to the solidification time.

A model has yet been developed to simulate keyhole collapse. This model was presented at the last COMSOL European conference. The purpose of the present study is to simulate the bubble up rise. The problem is especially complex due to the high surface tension of the liquid tantalum (2.1 N.m-1).