Repair, remanufacturing and enhancement – Surface Engineering for Advanced Materials in Australia: Laser Metal Directed Energy Deposition.
Introduction
The Australian Research Council (ARC) Industrial Transformation Training Centre in Surface Engineering for Advanced Materials (SEAM) will be Australia’s premier manufacturing Research and Development centre that focuses on applied research with tangible outcomes to nurture and cultivate the industrial innovation leaders of tomorrow. This article is one in a series highlighting some of the research fields that the centre focussed on and aim to give an overview on the state of the art in Australia and what technologies are available to improve the performance of products for manufacturers in Australia.
Surface engineering is a field of materials engineering that focusses on modifying the surface to improve their performance. As surface engineering is a multidisciplinary field it has use-cases for a range of applications, including for improved wear and corrosion resistance, reducing infections from biomedical implants, and even improving the optical capabilities of telescopes in space.
Laser-based directed energy deposition (DED-LB), commonly known as laser cladding and laser metal deposition (LMD), is an industrially important additive manufacturing process used for the creation of enhanced surfaces as well as general additive manufacturing.
How does it work?
DED-LB is an additive manufacturing process that is essentially a laser welding process. The process utilises a high-powered laser and powder feeding system to deposit overlapping welds on a metallic substrate. The process has the distinct advantage over other additive manufacturing methods in that it has long been used industrially for repair and remanufacturing of large-scale components and has much greater size capability than powder-bed type AM systems.
What can you do with it?
DED-LB is a very versatile process that is capable of additively manufacturing metal and metal matrix composite components in a variety of shapes and sizes. DED‑LB is commonly used to repair worn metallic components such as the bearing surfaces of industrial shafts, pump components etc. such that their usable life can be extended. In these applications the material deposited is the same (or similar to) the parent material. In other instances, there can be a desire to remanufacture a component such that it would outperform the original. In these instances, materials with higher corrosion resistance, metal matrix composites with extremely high wear resistances or more environmentally friendly hard-chrome replacements can be deposited.
SEAM Laser Metal Deposition (LMD) Working Group
This working group brought together ECR’s across the Centre who have a focus in laser metal deposition studies. Through this collaboration, ECR’s are better able to understand the physics underlying the LMD process without infringing on industry partner IP. This group has delivered four main outcomes:
- Coating and Repair of Additive Manufactured Components:
Researchers have successfully developed a crack detection algorithm for laser-cladded coatings. Multiple microphone arrays have been created to enhance crack detection accuracy, and acoustic signatures have been correlated with cracking to validate the effectiveness of the technique. - Additive metal manufacturing for aerospace applications – high speed laser deposition of thin metal coatings
A new process, which has been reported in literature and which is attracting increasing attention from an industrial perspective is ‘high-speed’ (HS)-DED-LB. The technology investigated and developed, examined the process parameters for depositing high quality coatings and characterise their microstructure and wear and corrosion performance. This project has developed the potential to deliver new laser coating technology for repair of large surface areas of aerospace components more economically while reducing environmental impacts. - Optimisation of surface properties of additive components using an additive/subtractive machine
The project utilised the DMG Mori Lasertec 3D 5-axis printer, known for faster deposition rates and the capability to perform laser deposition welding and milling in a single machine. The Working Group focused on enhancing defect prediction and geometric accuracy using the Lasertec65 3D hybrid printer, complemented by previously developed 4D visualization and machine learning tools. - High-Speed Laser Cladding
The whole project team tested various cladding materials using high-speed laser cladding, showcasing the capability to clad alloys from different metal alloy classes. Specific alloys for commercial applications have been identified with potential for validating cladding performance through accelerated environmental and wear testing.
More information:
Feature in Materials Australia Magazine December 2024: Crack Detection Algorithm
Feature in Materials Australia Magazine September 2024: GA v WA powders
