Weld inspection technology to be commercialized

The automotive industry relies heavily on resistance spot welding in the fabrication and assembly of steel sheet components and structures; the average car uses more than four thousand spot welds. Manufacturers typically inspect the quality of welds with a pry-check, an expensive and destructive process in which samples of welded parts are manually torn apart.

ORNL's infrared imaging system can help automakers quickly determine whether a weld is good or bad without damaging the part. The infrared check can be performed in a few seconds, offering industry a low-cost and non-destructive alternative to monitor welds in real time.

"The idea is to measure every weld, or at least every critical weld," said ORNL's Zhili Feng, one of the technology's developers. "It gives automakers an efficient method to immediately send feedback to the production lines."

APLAIR Manufacturing Systems and ORNL staff will collaborate to improve and validate the technology under a cooperative research and development agreement, including tests on an industrial-scale assembly line.

"The automotive industry is constantly seeking innovation and the integration of new technology into its vehicles," said Jack Sisk, Vice President APLAIR Manufacturing Solutions. "The complexity of new technology in the vehicles being produced today is profound and at an unprecedented pace. The infrared imaging system offers a new technology that is exactly the type of innovation the automotive manufacturers are looking for. This technology will allow the automotive manufacturers and their suppliers to produce vehicles that are higher quality and safer for their customers."

The current version of the ORNL technology can be applied to a wide range of steel welds regardless of the material's surface finish or thickness. ORNL researchers plan to expand the technique to other metals, which could help automakers explore the use of new high-strength, lightweight materials such as aluminum alloys and magnesium alloys. These types of materials typically require more stringent welding conditions and are more difficult to evaluate with the standard pry-check test.

"This technology will enable increased use of innovative materials in auto body structures to meet needs for fuel efficiency and crashworthiness," said ORNL's Jian Chen.

APLAIR intends to make a commercial product based on the ORNL technology available within two years. With product validation nearly complete, APLAIR has selected several strategic partners to move the technology forward and into the market. Currently, APLAIR has developed the plans for process validation of the systems hardware and software and will begin building the prototype system in 2015.

"After some time working with the researchers at ORNL to understand the technology we very quickly knew of many applications in manufacturing with the automotive industry being a prime candidate," said APLAIR CEO Robert Watts. "We have had industry interest in the technology from the beginning of this project and are anxious to get the technology to market."

ORNL's development of the weld inspection technology was supported by the Vehicle Technologies Office in DOE's Office of Energy Efficiency and Renewable Energy.