TWI Industrial Member Report Summary 1038/2013
By Sullivan Smith
Background
In this project a scanning laser was used to join dissimilar materials. The concept of weld pool stirring was investigated as a means of dispersing intermetallic phases and achieving welded joints without the use of flux. Using this approach high quality joints were produced in the material combinations of; aluminium - copper and aluminium to titanium.
Industrial Challenge
The creation of high quality dissimilar materials joints is seen as a major technological challenge across many industry sectors. In the electronics industry the joining of aluminium to copper for electrical connections is required for automotive batteries and power generation. The aerospace industry employs titanium and aluminium components and structures, a direct fusion welding technology to join these components is required to increase the design scope of new aircraft.
Key Findings
- Dissimilar metal combinations were successfully joined without the use of a flux
- The heat input into welds was accurately controlled using a scanning laser allowing highly controlled melting and mixing of the materials
- The welds produced achieved significantly better mechanical properties than weld made with a continuous wave laser
- Large joint areas could be produced enhancing mechanical properties and enabling good current transfer for electrical applications