Recycled Surgical Implants Aid in AM Sustainability

As the population ages and hip, knee, and shoulder joint replacement surgery becomes a rite of passage, there’s a surplus of metal nails, screws, and plates looking for new purpose. 6K Additive and Surgical Metal Recycling Pty Ltd. (SMR) of Australia have decided to embrace that mission with a new partnership to transform end-of-life surgical implant materials into new fodder for sustainable AM materials.

Once implants are removed for replacement or after someone dies, there have been limited options for reclaiming and reusing the existing materials, which contain valuable metals and alloys. Historically, reclaimed implants have been processed in induction furnaces that draw a massive amount of energy and thus result in a significant carbon footprint. The partners now plan to process those materials with 6K’s production-scale UniMelt platform, which features proprietary process technology based on high-frequency microwave plasma. The UniMelt platform is designed to create advanced materials like those used in AM and battery production with a process that is fast and environmentally friendly.

The two organizations will leverage out-of-spec implants, swarf, and used metal AM powder supplied by SMR, reprocessing the materials through 6K Additive’s UniMelt production-scale microwave plasma platform initially in the United States and later in Europe. The resulting premium powders can then be used in subsequent AM applications—the ultimate goal being to create new certified implants from existing parts through a sustainable and circular supply chain.

“Being able to source feedstock and recycle medical implants is the first innovative step toward our mission,” said Frank Roberts, President of 6K Additive. “There is a growing population that requires medical titanium implants for knees, spine, and hips, and this agreement creates a path to recycle these parts and enable new implant production with sustainably sourced feedstock.”

Initial efforts will focus on titanium (Ti64) materials to be expanded to incorporate cobalt chrome. UniMelt’s process removes oxygen from the titanium powder, which helps improve the material grade, and also ensures greater than 90% yield of the desired particle size distribution compared to alternative processes. In fact, in a commissioned lifecycle assessment of its powders, 6K Additive found that its UniMelt process delivered, at minimum, a 74% energy reduction and a 78% carbon emission reduction compared to competing processes.

Said Pecht: “By recycling, re-using, and rejuvenating the metals we already have in the country, we can massively reduce the environmental impacts of metal extraction and processing for virgin material.”

Watch this video to learn more about 6K and the UniMelt process.