TECHNOLOGY/BUSINESS OPPORTUNITY Laser beam shaping for improved microstructure and defect control in laser-based metal additive manufacturing or welding processes

Opportunity: Lawrence Livermore National Laboratory (LLNL), operated by the Lawrence Livermore National Security (LLNS), LLC under contract no. DE-AC52-07NA27344 (Contract 44) with the U.S. Department of Energy (DOE), is offering the opportunity to enter into a collaboration to further develop and commercialize its laser beam shaping for improved microstructure and defect control in laser-based metal additive manufacturing or welding processes.

Background: Parts fabricated by additive manufacturing (AM) typically have mechanical properties that differ from parts produced by conventional manufacturing. There may be microstructural differences such as the presence of elongated grains or high concentrations of dislocations in an AM part.

Of the different metal AM methods, laser powder bed fusion (LPBF) presents particular challenges due to the relatively small-sized powders (typically 10 - 50 um) used and the interactions of the metal with the tightly focused laser. Common defects, such as incomplete melting, gas porosity, and high residual stresses, are difficult to avoid and present significant challenges to printing reliability.

These challenges often result in small windows of acceptable processing parameters that can give the optimal properties. Optimizing one property will often deteriorate another property, i.e. optimizing density can decrease microstructure uniformity or residual stress. Conversely, improving microstructure uniformity can decrease density.

A large contributor to these issues is that the typical LPBF laser beam profile used have a Gaussian shape; these beams are non-optimal for the laser AM process because of laser-material interactions during printing that are undesired such as keyholing (laser-vapor interactions), spatter and porosity (melt pool instabilities) and anisotropic mechanical properties (large thermal gradients).

In metal AM using directed energy deposition or in laser-welding processes, there is a need for controlling the melt pool shape, depth, and flow, which can be achieved by beam shaping.

Description: LLNL researchers have developed a novel system that can shape the profile of the laser beam during printing or welding. The phase engineered approach in beam shaping enables in situ process control of its energy distribution at melt-relevant timescales.

Advantages/Benefits: Refinement of metallic grain structure grants control in the printing or welding process. Arbitrary grain refinement allows LPBF printed parts to mimic mechanical properties of forge cast parts. LLNL’s system is less expensive compared to multi-laser systems with faster scanning and higher energy density. With improved speed, control, and higher energy density the process window is widened when LLNL’s novel approach is applied.

Potential Applications: metal additive manufacturing, laser welding Development Status: Current stage of technology development: TRL ? 0-2 ? 3-5 ? 5-9 LLNL has filed for patent protection on this invention. LLNL is seeking industry partners with a demonstrated ability to bring such inventions to the market. Moving critical technology beyond the Laboratory to the commercial world helps our licensees gain a competitive edge in the marketplace.

All licensing activities are conducted under policies relating to the strict nondisclosure of company proprietary information. Please visit the IPO website at https://ipo.llnl.gov/resources for more information on working with LLNL and the industrial partnering and technology transfer process.

Note: THIS IS NOT A PROCUREMENT. Companies interested in commercializing LLNL's Laser beam shaping for improved microstructure and defect control in laser-based metal additive manufacturing or welding processes should provide an electronic OR written statement of interest, which includes the following:

Company Name and address. The name, address, and telephone number of a point of contact. A description of corporate expertise and/or facilities relevant to commercializing this technology. Please provide a complete electronic OR written statement to ensure consideration of your interest in LLNL's Laser beam shaping for improved microstructure and defect control in laser-based metal additive manufacturing or welding processes. The subject heading in an email response should include the Notice ID and/or the title of LLNL’s Technology/Business Opportunity and directed to the Primary and Secondary Point of Contacts listed below. Written responses should be directed to:

Lawrence Livermore National Laboratory Innovation and Partnerships Office P.O.

Box 808, L-779 Livermore, CA 94551-0808 Attention: IL-13971