Reduce Reuse and Recycle Metal Powder Through Sustainable 3d Printing

It seems intuitive that additive manufacturing (AM) is sustainable, especially when considering the many pros: making parts when and where needed, only adding material where it is needed, more repeatable quality for complex internal cavities and the ability to use advanced designs that can combine multiple pieces into one part allowing significant space and weight savings. These benefits have demonstrated the ability to reduce the amount of material consumed per part and the number of parts manufactured (better first pass yield, inventory control and potentially longer part life).

Some have questioned the ability to reuse material, but it is primarily polymer-type materials that may degrade during the manufacturing process limiting its reusability. When applications require metals, studies have shown that oxidation-resistant metal powder can be reused without detrimental impact on the final microstructure (for critical parts it is important to validate that the required material properties are achievable). Metals are typically processed in environments with protective inert gases which limit the oxidation of powder and improve the opportunities for repeated use. A superalloy powder was reused over ten times in a Laser–Powder Bed (L-PB) process and the study indicated no change in particle size distribution, morphology and chemistry. Tensile bars were printed in multiple orientations and tested from each build showing no change in the mechanical properties over time (the unprinted powder was reused up to 15 times with no new powder added to the printer).

Efforts to reduce, reuse and recycle materials coupled with additive processes can play a role in reducing current Supply Chain issues and help create Sustainable products

Many metals are Recyclable and significant energy savings are associated with remelting steel, aluminium and other alloys to make into new parts (including car bodies, beverage containers and building materials). Recycling can shorten the supply chain by reducing the need to mine ore and refine it into usable compositions (energy-intensive operations). By keeping used materials separated (by composition), less energy is potentially needed to repurpose creating more value for the material. The clean dry powder can be remelted into the same alloy, additionally, many superalloy materials can be remelted into steel and stainless steel.

Further opportunities to reduce and reuse materials are associated with Directed Energy Deposition (DED, a specific type of laser AM processing). DED has demonstrated the ability to Repair complex parts that might have been defective when originally produced or after service in severe environments where the surface may have been degraded by wear or corrosion. Many of the materials used today to pursue green energy production, energy storage and electrification could be considered strategic and not necessarily abundant in all geographies. Efforts to reduce, reuse and recycle materials coupled with additive processes can play a role in reducing current Supply Chain issues and help create Sustainable products. These processes are a subset of the tools available to meet the advanced manufacturing needs of today.