Laser Metal Deposition, or Laser Additive Manufacturing, is an advanced technique depositing layers using a laser beam. Our goal is to optimize a coaxial powder nozzle for a narrower laser beam, enhancing precision in the cladding process, especially for thin walls. We redesigned an existing nozzle to focus the gas-powder stream into a narrow jet, improving deposition within the melt pool. The optimized powder nozzle, achieved through simulations and experiments, aims to elevate the effectiveness of laser cladding for intricate applications.
Research Highlights
- Development of a new coaxial powder nozzle for laser additive manufacturing of thin walls using novel simulation modeling and experimental tests for validating the simulations.
- Attainment of in-depth knowledge regarding the impact of nozzle design characteristics on powder-jet behavior, a crucial foundation for future research in laser additive manufacturing nozzles.
Challenges
In the realm of laser additive manufacturing for thin walls, the challenge lies in harnessing a small laser beam to minimize the heat-affected zone and preserve the substrate’s microstructure. The initial hurdle involved identifying suitable simulation methods and software for powder and gas jets, necessitating an extensive literature review and potential acquisition of new skills. Adjusting the nozzle design to impact the geometric properties of the powder jet presented a substantial challenge, demanding both theoretical comprehension and practical implementation skills. Achieving this required a profound understanding of the process and its influencing factors to establish a correlation between the nozzle’s geometrical parameters and the attributes of the resulting powder jet.
Our Solution
Aligned with the project’s goals, our focus was on optimizing the design to minimize the convergence diameter of the powder jet. The process involved a meticulous approach utilizing simulations, experimental procedures, and insights from academic references. To kickstart this, an extensive literature review was conducted, identifying effective simulation methods and software for powder and gas jets. Simultaneously, suitable methodologies and tools for hands-on experiments were determined. The parameters of a powder nozzle also identified using image processing algorithms showcasing in the Figure 2. This comprehensive stage provided valuable insights into the powder jet’s geometry, particle velocity within the nozzle, and facilitated the establishment of a correlation between the nozzle’s geometric parameters and the resulting powder jet attributes.
Powder and gas jet simulations, crucial to our methodology, were validated against experimental results. See Figure 3 for a concise overview of the simulation stages.
After modifying the nozzle design, we simulated the new model, and upon validation, it was approved for fabrication. The Figure 4 showcases the CAD representation of the newly designed nozzle, along with the manufactured and assembled part in the write picture.
Outcomes
- A comprehensive understanding of how nozzle design characteristics influence powder-jet behavior was attained, laying the foundation for future research in cladding nozzles.
- The project resulted in the development and manufacture of an optimized coaxial powder nozzle for thin walls through a series of simulations and experiments.