Additive manufacturing (AM) still looms large in our science fiction imaginations in the form of Star Trek-like replication machines that will create just about anything (in between commercials) with the push of a button. The truth, however, is that additive manufacturing is still a highly complex process that requires a great deal of preparation and post-printing work—most of it manual. The high costs of such manual labor-intensive processes, therefore, has restricted metal AM to low-volume, high price tag parts, such as those for aircraft or surgical applications. Until automation improves, it will be a hard challenge to achieve large volume production, like that required for automotive or industrial applications, at reasonable costs.
Digital Metal has introduced a fully automated, no-hand production concept for metal additive manufacturing. (Image source: Digital Metal)
Many metal AM companies today are engaged in increased automation of the printers as well as post-production and maintenance tasks to further AM technology. Sweden’s Digital Metal, a proprietary binder-jetting AM technology company created by Höganäs AB, says it can deliver high levels of resolution for small objects combined with high surface quality, as well as unprecedented automation (“no-hand production”) that makes metal AM feasible for high-volume production. Digital Metal is known for producing small, high-volume components using its high-precision DM P2500 system.
“For AM to move into serial or mass production productivity, it needs to improve substantially,” Ralf Carlström, general manager for Digital Metal AB, told Design News. “Today, AM serial production is primarily found in segments with comparatively low volumes, like aerospace and medical implants, where the alternative cost is high. Moving on to high-volume segments like automotive will require productivity to increase substantially through more efficient processes.”
Automation Is Key to AM Success
Carlström said Digital Metal is making great strides into territories previously ruled by conventional manufacturing technologies, from components with single or multiple internal channels to lightweight structures for aerospace. Any application that involves complex metal parts can potentially benefit from the technology, he added. It’s the automation, however, that will help even more companies be able to afford metal AM for a wider variety of applications.
Digital Metal’s automation technology uses robotics to focus primarily on the most laborious manual step in metal AM, which is depowdering the system after printing. Traditionally, this was a step done by human workers using specially designed glove boxes for safety. In the company’s newest AM system, this manual process has been replaced with a CNC-operated depowdering machine. CNC-controlled movements during de-powdering are based on information from the printing process. This increases the automation and productivity while retaining detail accuracy, resolution, surface finish, and tolerances for about 30 different geometries. Users can choose precisely how (and how much) they want to automate formerly manual tasks, according to Carlström.
“All automation is flexible, but large volumes will facilitate the implementation of production lines with a high degree of automation,” he told Design News.
While the automated removal of powders isn’t unique to Digital Metal, the way it’s done doesn’t influence powder properties negatively over time. So the company’s newest system overcomes many of the challenges of powder reuse, which can lead to distortion of the particles over time. Powder reuse or recycling times can directly affect the affordability of AM parts—particularly when it comes to titanium parts.
Robots Moving Sintering Places
The next automated task is the placing of the part on sintering plates. Finally, a robot moves the plates to the sintering furnace. During this step, the parts will undergo debinding and sintering, either in batches or for continuous production. Essentially, almost all manually intensive work can be eliminated from the AM process.
“Most AM technologies show a very low level of automation,” said Carlström. “Our aim is to change that. With the new no-hand production line, our customers can further improve their productivity and lower the production costs. Almost all manually intensive work can be eliminated and, in addition, the powders removed in the cleaning machine can be recirculated in the process, thus minimizing waste. As we see it, the Digital Metal technology is now applicable for serial production of high-volume components.”
According to Digital Metal, some modifications need to be done to existing printers in order to implement their fully automatic production line system. The printing capabilities and the automation have attracted the interest of several European companies in automotive and aerospace industries, and Digital Metal said it has signed a number of agreements with manufacturers.
“We believe there is a huge potential for our unique technology,” said Carlström. “Not only is it very fast and cost-effective, it is also able to create complicated and highly detailed designs with wide material choice.”
Tracey Schelmetic graduated from Fairfield University in Fairfield, Conn. and began her long career as a technology and science writer and editor at Appleton & Lange. Later, as the editorial director of telecom trade journal Customer Interaction Solutions (today Customer magazine), she became a well-recognized voice in the contact center industry. Today, she is a freelance writer specializing in manufacturing and technology, telecommunications, and enterprise software.