MELD Exploits Plastic Deformation of Metals with Non-Melt Additive Manufacturing
Additive manufacturing has been a catalyst in improving speed and efficiency during the product development process. However, the technology has been limited in the size and materials available to be produced. MELD Manufacturing believes it has the remedy for these limitations, and it has garnered numerous accolades for its patented MELD process, including the 2018 “Create the Future” award in the Robotics/Automation/Manufacturing category. The design contest is produced by Tech Briefs Media Group.
While additive manufacturing has thus far relied on melting materials to produce custom components, the MELD process does not require taking metals up to their melting points. Instead, materials are brought to their plastic deformation state and then formed into the desired shape. By not melting the materials, MELD believes it is taking additive manufacturing beyond just an evolutionary step.
“I think this is revolutionary,” Chase Cox, Director of Technology at MELD Manufacturing, told Truck and Off-Highway Engineering. “We’re not doing any melting at all. We’re exploiting the plastic deformation of the metal in a very similar manner to friction stir welding. The revolutionary part is that it frees you up from the restrictions of the melt-based processes.”
Through 12 years of research, MELD has realized several advantages that the company is leveraging through this process. First, the manufactured component can be produced in an open-air environment, which allows for a dramatic increase in the size of component created as there is no vacuum chamber required for fabrication. This can be key to the increased use of additive manufacturing in the heavy-duty vehicle market due to the sizeable scale of parts needed during product development.
Another advantage is the ability to work with a wider variety of metals than ever before. The MELD machines are capable of working with the standard array of aluminum and steel alloys as well as stronger metals like titanium and nickel alloys. There are also new possibilities to work in multi-metal environments or with non-weldable metals. Incorporating aluminum onto steel or magnesium is possible. However, the MELD process is still subject to physics-level material limitations, like forming steel onto aluminum.
An additional advantage of not melting the materials during the manufacturing process is the ability to retain the physical properties of that material. Grain structures can be optimized to ensure proper strength attributes are retained since hardness can be reduced by 10% or more through the melting process. Other issues found in melting processes like hot cracks, pores, and residual stresses can also be eliminated.
However, the MELD process has experienced its share of engineering challenges.
“The evolution of a new technology is driven by increasing demands,” Cox explained. “It’s always a new ‘this’ that customers want that pushes our technology. We do one material, and then they want a more difficult one. It keeps our engineers pushing the limits of our equipment—making it bigger, making it more robust, improving the control systems.”
MELD has worked with large truck and defense armored-vehicle applications, but there is more growth to be seen for additive manufacturing in the heavy-duty vehicle industry, according to Cox. One application the company believes it can aid is in joining structural components. Joining parts of dissimilar metals can prove difficult, but MELD believes it can provide solutions for that process. However, some vehicle hurdles still remain for additive manufacturing. Major body components will continue to be formed through traditional techniques due to the thin structure and large shape, Cox said.
To meet the increasing interest of clients, MELD is launching an operator training course at its Virginia-based facility.