Japanese electronics manufacturer Mitsubishi Electric Corporation announced today that it has developed a new metal additive manufacturing process that utilizes a “unique dot forming technology” that combines laser, CNC and CAM technologies. The novel process, to be presented at the 29th Japan International Machine Tool Fair in Tokyo, is reportedly capable of producing high quality parts with few voids and at a very fast speed.
The new dot forming technology relies on a laser wire directed energy deposition (DED) process to fuse metal wire as it is deposited. This process uses focused thermal energy to fuse the metal wire, reducing the risk of oxidization by over 20% because the high temperature area is limited to a precise spot forming area.
By working with laser wire DED, Mitsubishi Electric says it has also achieved advantages compared to powder-based metal AM processes. Namely, the process developed by Mitsubishi does not come with the risk of voids forming, making it suitable for producing dense objects at a more rapid pace.
In terms of applications, the Japanese multinational states that its metal AM technology can be used to produce near-net parts for the aerospace and automotive industries. Additionally, the technology can work with parts that have been manufactured using different processes, meaning it is suitable for build-up repair applications.
The process is capable of producing parts with hollow or overhanging geometries and is compatible with laser-welding wire materials. This facet of the technology, says the company, helps keeps costs down, as the materials are inexpensive and readily available. They are also better for the environment than conventional metal powders.
Drawing from CNC technologies, Mitsubishi Electric has integrated a pulsed laser and minimized heat input into its dot forming process, which ensures there is enough cooling time between when the wire is melted. As the company explains:
“When shaping 3D objects using the laser wire DED method, the laser is used to melt and deposit the material. Heat generated by the laser and heat from the just-deposited material are transferred to the deposition base. If the laser is continuously irradiated, the temperature of the deposition base rises. If a new molten material is then deposited on this extra-hot base, it can take time to solidify, during which time the shape can collapse under its own weight.”
Another notable benefit of Mitsubishi’s dot forming technology is that the pulsed laser irradiation, the supply of metal and shield gas and shaping position can all be controlled synchronously. This allows for shape accuracies 60% more precise than more traditional consecutive forming technology and reduces the risk of shape collapse.
As mentioned, Mitsubishi Electric will be presenting the metal AM process at the upcoming Japan International Machine Tool Fair. A commercial version of the dot forming technology is expected to be launched in the fiscal year ending in March 2021. The innovative technology is covered by five patents within Japan and one from abroad.