LSP Technologies awarded grant from U.S. Navy to develop portable laser peening equipment

LSP Technologies (LSPT; Dublin, OH) is developing an in-service repair for fatigue and stress corrosion cracks on U.S. Navy watercraft using a portable laser peening system. Laser peening addresses the root cause of the repair problem—the stress state leading to crack growth, which is not addressed by current repair methodologies.

Existing repair methods for cracked aluminum-hulled watercraft have limitations and risks to their implementation in that they are not attempting to mitigate the tensile stress state present in the material that leads to crack formation and growth. Current repair processes are temporary because they are either inefficient or ineffective in mitigating the damage caused by fatigue cracking or stress corrosion cracking (SCC) and the related loss of water-tightness from cracks generated by these mechanisms. Crack tips, regardless of whether they are initiated by fatigue or stress corrosion cracking, are not prone to propagate when a compressive stress is applied around them.

The objective of the new contract is to develop highly portable laser peening equipment that can easily be moved around a ship, providing a method to permanently modify the stress state near a crack tip and prevent further crack growth. The project will enable efficient and effective long-term onboard repairs.

Laser peening induces deep-reaching compressive residual stresses in a metallic material that reduces the realized stress state of the material under operational loading conditions, keeping the stress state below the threshold for crack growth. Laser peening alone will induce enough force to close cracks to water intrusion or clamp cracks from further growth. When combined with sealant already used in the current repair practice, such as the application of sulfide sealant, laser peening treatment will provide a long lasting water tight repair.

Recent advancements in laser peening systems allow them to rival or surpass the processing rates, cost-effectiveness, and reliability of conventional surface processes such as shot peening and ultrasonic impact treatment. “This portable system would be another valuable addition to LSPT’s new line of Procudo laser peening systems,” says Dr. Jeff Dulaney, founder and CEO of LSP Technologies. “We anticipate that the portable laser peening system market, with the system’s ease of use and lower price point, will be significant for the company and a valuable piece of field equipment,” he adds.

For more information, please visit www.lsptechnologies.com.