The Need

Manufacturers seek low-density, high-strength metals that can withstand environmental stress. High-strength aluminum alloys (AAs) are increasingly used for light-weighting in automotive and aerospace structure applications, but welds with such alloys are susceptible to environmental degradation, which may contribute to stress corrosion cracking. To develop lighter, more energy efficient vehicles for aerospace and automotive applications, it is critical to establish welding techniques for high-strength AAs, specifically those in the 7000 series that can be 80% stronger than 6000 series alloys, that are not vulnerable environmental exposure.

The Technology

Researchers at The Ohio State University, led by Dr. Wei Zhang, have developed an efficient, cost-effective cold metal transfer (CMT) method that dresses the toe region of the weld to reduce stress corrosion cracking on welds of a 7000 series AA. This technology compares favorably to the existing friction stir processing (FSP) method.

Commercial Applications

• Welding equipment and consumables
• Automotive manufacturing
• Construction
• Oil and gas pipelines

Benefits/Advantages

• Reduces 7000 series aluminum alloy stress corrosion cracking
• Uses the same fixture used for primary welding and is easily adoptable in the automotive assembly line
• Amenable to complex shaped structures
• Reduced equipment costs
• Provides a true metallurgical bond that is stable and durable
• Significant corrosion resistance
• Fabricators with primary gas metal arc welding for a tandem process to further increase the productivity