Process Control Techniques for Laser Peening of Metals

Author:  See Below
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002062
Year of Publication:  2002
Abstract:  
Authors Rob Specht, Fritz Harris, Laurie Lane, Metal Improvement Co., Paramus, NJ, USA Dean Jnoes, Rolls-Royce plc, Bristol, UK Lloyd Hackel, Tania Zaleski, John Halpin, Lawrence Livermore National Laboratory (LLNL), Livermore, CA, USA Mike Hill, UC Davis, CA, USA Wilfried Wubbenhorst, Metal Improvement Co., Haan-Gruiten, Germany Abstract Laser Peening, also known as Lasershot SM and Laser Shock TM Peening, is a surface treatment, which can induce compressive stresses in metals at depths exceeing 1 mm. This produces a more damage tolerant component, which resists fatigue and Stress Corrosion Cracking (SCC) failures better than components treated with conventional shot peening. A new Laser Peening facility was brought on line in early 2002 by MIC in Livermore, CA. This facility utilizes a Lawrence Livermore National Laboratory (LLNL) designed solid state laser employing Neodymium doped laser glass slabs and phase conjugation technology to enable high energy & high laser repetition rate combined with excellent beam quality. Laser Peening process parameters have been identified which will impact on the final depth of compressive stresses in a metal component. Process control techniques widely utilized in conventional shot peening have been adapted for use in Laser Peening with good success. As a result, Suppliers and Users of Laser Peening have a reliable method of monitoring the critical process parameters in a manner that will lead to consistency of production operation and repeatability of end results.