Phase II Amount
$1,003,901
The major drawback of existing laser systems for metal laser additive manufacturing (LAM) is the lack of agile/adaptive control of laser beam characteristics during deposition and after-processing of each layer. The desired improvement of micro-structure and surface finish, mitigation of residual stress, and increase of processing speed are difficult to achieve with the currently used technology based on utilization of a single Gaussian-shape laser beam for powder material processing. The proposed Scalable Adaptive Laser Array for Additive Manufacturing (SALAAM) Phase II development is based on emerging high-power coherent fiber array and adaptive beam control technologies developed by the Optonicus for DoD (directed energy) applications for almost a decade. In the SALAAM approach, multiple beams for LAM are generated in a coherent fiber-collimator array system composed of a densely packed array of adaptive fiber-collimators, with integrated capabilities for individual precision beam pointing and steering using Optonicus-developed fiber-tip x-y position control modules. The SALAAM system enables the development advanced laser energy sources and control systems capable of simultaneous projection of several laser beams whose characteristics, such as optical power, focal spot size, angular pointing and steering, can be individually controlled to generate optimally-shaped spatiotemporal distributions of laser power at the powder material.
Benefit: The proposed SALAAM energy source with multiple laser beams and feedback sensors provides a new breakthrough advanced spatiotemporal control of energy flux for AM in metals. The SALAAM development will provide first transitioning of the DoD high energy laser weapon technology to industrial applications including additive manufacturing and advanced laser material processing with multi-kW class laser systems (dissimilar material joining, welding, cutting, etc.). Advanced additive manufacturing using laser energy sources is a rapidly emerging technology that, with further innovations such as in the proposed SALAAM R&D, can provide critical advantages to the United States in the ongoing world-wide competition for new high-tech jobs and markets and facilitate significant reduction in energy consumption, and manufacturing cost for AM parts with equivalent quality to those now made in traditional machining processes. Manufacturers world-wide continue to seek out technologies that can improve LAM systems flexibility and accuracy with additional goals to speed up AM processes, make manufacturing more energy efficient, productive, and profitable. The laser systems that are currently used for metallic AM in various industries suffer from lack of agile/intelligent control of laser beam characteristics. They use the brute force of laser power to melt and/or evaporate materials without real-time process monitoring and intelligent feedback control of laser beam characteristics based on information directly obtained from the work piece. The SALAAM system will provide these benefits to the aircraft, automotive and the general manufacturing sectors. With the increasing demand for LAM the laser technology must address stricter fit-form-function requirements such as: on-the-fly adaptation to microstructure and property changes in the processed materials under the impact of laser beam, sensing and correction of laser-power-induced distortions, improvement of LAM processing speed, AM parts surface quality, increase of volume and, performance and energy efficiently improvement. The SALAAM approach can be also applied to the growing area of remote laser power beaming technology where there are similar needs for multiple laser beam control for optimal transferring of laser power to electrical power.
Keywords: Integrated Computational Materials Engineering, 3D printing systems, Laser Additive Manufacturing, Metal Additive Manufacturing, powder bed, heat affected zone, laser energy sources, Selective Laser Melting
