Defect formation during welding and their effect on mechanical properties of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo

Purpose and goal

The purpose of this project was to explore how and why pores/defects form under certain welding process parameter settings. The aim was to be able to explain the formation of the found defects, and to be able to distinguish between “dangerous” and “non-dangerous” defects. Systematic characterization was conducted of weld defects and weld geometries, and in addition, their influence on mechanical properties was evaluated, for titanium alloy welds.

Expected results and effects

The results in this project have increased the understanding of the relationship between welding process parameters with defect formation and weld geometry of titanium alloy welds. Defects’ and weld geometries’ influence on mechanical properties have been explored in this project. These results enables improved design/optimization capabilities for titanium alloy welds in structural manufacturing. The project will render in a new Ph.D. with expertise skills in an area of high relevance to the involved company.

Planned approach and implementation

A Ph.D. student employed at Chalmers University has been mainly responsible to lead the project, with support from supervisors in both academia and at the company. The company performed all welding trials as well as mechanical testing of welds. The Ph.D. student conducted the analysis of the results from these evaluations, such as fractography and microscopy. Dissemination of results from this project was conducted through regular project meetings, publication in scientific journals, and through conferences.