Despite all its industry-changing capabilities, most additive manufacturing (AM) technologies have problems. They produce parts that are far from finished. The stronger the printed material, the more difficult it is to bring a printed part to a finished state, and for parts made of metal, once the build cycle is finished, there are many steps such as de-powdering, separation from the build, etc. This means that a post-processing step will be required. Removal of plates, supports, heat treatment, non-destructive testing (NDT), and most commonly, trips to the milling department are expensive and time consuming.
“Once the print step is complete, there is always unfinished business left,” says Dr. Jason Jones, CEO and co-founder of Hybrid Manufacturing Technologies. “This makes secondary post-processing operations a very important part of the additive process.”
He explains that these flies in metal AM ointments often account for half of the cost of the finished product. Additionally, post-processing costs can be much higher for safety-critical components or components that require extensive machining. Even worse, it can be difficult or impossible to reach deep into the complex cavities and internal passageways where metal AM is prized, potentially impacting part performance.
straddle the manufacturing fence
One increasingly popular solution to all of this is hybrid manufacturing, which combines additive and subtractive processes in one machine. Here, metal powder or wire feedstock is deposited onto the workpiece while a concentrated energy source (usually a laser or plasma arc) melts and fuses the material to the part surface. Then, if necessary, use a milling cutter to finish the surface and shape of the mechanical part, either intermittently or after printing the part. The hybrid machine also automates many other post-processing steps, such as support removal and several types of inspections. For many materials, parts can be removed from the machine and ready for use.
Jones and his team, along with DMG Mori, Okuma, Mazak, and a handful of other CNC equipment manufacturers that have jumped on the hybrid additive bandwagon in a big way, are pioneering the commercialization of hybrid manufacturing and are “Done in one.” We have expanded the possibilities of Take mantras to a whole new level. But what if you're a machine shop, OEM, research organization that needs a custom head combination, or wants to add a head to your existing CNC for cost reasons?
Mr. Jones recognizes this need and has worked for the past 11 years to bring AM to the subtractive masses. The company's AMBIT line of interchangeable multi-material directed energy deposition (DED) and material extrusion heads provides the functionality described above, but can be installed on virtually any of his CNC machining centers and lathes. Masu.
“We have built a suite of tools that can also produce finished parts on general-purpose machines and repair worn or damaged blades, mold cavities, seating surfaces, etc.,” he says. “That's been our goal since the company was founded. What's new is that he can provide a complete workflow, all under digital control, on one machine. No one else has ever done that. plug.”
Introducing NDT to the machine
He talks about the unique ability to not only add metal to a workpiece, but inspect it immediately after deposition. “Because DED is a thermal process, cracks can form. Our solution uses eddy current probes to look for cracks during the construction process and detect failures that are typically not discovered until the part is completed. This greatly reduces the possibility of
Hybrid Manufacturing Technologies' AMBIT lineup also includes ultrasound and laser scanning heads. As Jones points out, making NDT an integral part of the hybrid manufacturing process avoids the need for standalone, very expensive inspection equipment and all that comes with it. Eddy current and other inspection techniques he incorporates into CNC machine tools allow operators to check parts as often as necessary.
In some cases, “one of our ultrasound heads can be used to avoid a post-construction CT scan, which is a time-consuming and expensive process,” he says. “In many ways, hybrid manufacturing is an automation solution that allows you to reduce costs by not having to pay for robots or skilled operators to move parts from machine to machine, while also making workflows more It’s simpler and more controllable.”
Detecting and mitigating cracks during manufacturing is a great accomplishment, but what about stress relief, hardening, and hot isostatic pressing (HIP)? Most 3D printed metals require some degree of machining after heat treatment. Isn't that necessary? It depends on the application, says Jones.
“If you are using a cast alloy that is intended for extensive heat treatment, this workflow may not be applicable. By moving to alloys, global heat treatments may be unnecessary if lasers can be utilized for localized heating during the construction process. Additionally, entirely new generations of alloys are in development, many of which It is currently commercially available and responds well to localized heat treatment possible with hybrid additive manufacturing machines.”
Try mixing it up
However, the possibilities for hybrid manufacturing extend even further. Rather than making the entire part out of heat-treatable tool steel, why not print the critical parts in an alloy like Inconel or cobalt, and print the rest in cast iron or some other cheaper material? not only provides a better end product, but also lowers costs and shortens lead times.
Similarly, combining polymers and metals in the same build can significantly improve part performance. Although there is no natural bond between these materials, his team demonstrated how a fastener-free mechanical joint can be created by machining a dovetail channel and extruding plastic into it. did. More examples come from Iowa State University, where he used one of HMT's polymer deposition heads in his CNC machining center to do just that in many ways. The result is a polymer composite airfoil that is much more difficult to manufacture using traditional methods.
Additionally, many hybrid additive systems, including AMBIT, can print mixed powders and multiple metals simultaneously, facilitating the development of new alloys and bonding materials that would otherwise be out of reach. The key, says Jones, is to determine which works best on which substrate. “We are still early days as an industry, but we believe machine learning and artificial intelligence will play a huge role in optimizing the combination and joining of these materials.”
A very productive decade
Jones is a founding member of the ASTM F42 standards committee. He chairs his SME AM technology community and received the organization's Dick Aubin Award for Additive Manufacturing Innovation in 2014. He and business partner Peter Coates have earned dozens of patents and built a successful business. When asked how the two met, his answer was surprising at first.
“It was true love,” he laughs. “My wife wanted to study the history of 19th-century British painting for her graduate project, and London was the perfect place to pursue that. So of course I followed her. We went there. I thought I would only be there for a few years, but I ended up leaving after 10 years with two master's degrees and a PhD from the University of Warwick, and several children with me. I met my co-founder Peter Coates and launched Hybrid Manufacturing Technologies. It's been a very productive decade for all of us.”
Jones' interest in manufacturing began long before that. His family was in the construction business, so it was no surprise that the much younger Jones loved building things. He became interested in CNC machining during his university days and worked part-time as a machinist while studying engineering. It wasn't until he moved to the UK and started working for a British engineering company that he decided to expand his skills to include laser cutting and learn all he could about manufacturing. And when the company's managing director added his 3D printer to his lineup of CNC machines, Jones was hooked.
“That led to discussions with the Innovation Center at De Montfort University, where research was carried out using 10 3D printers and they also had a CNC machining center that no one knew how to operate. ” he says. “When I started working there part-time as a researcher, they were literally afraid of it. … When we got the CNC machine up and running, the collaboration between me and my co-founders began, and eventually the company It has developed into.”
promise of the future
A lot has changed since then. Jones points out that while 3D printing has been around for nearly 40 years, it has only become a relatively mature manufacturing process in the last 10 years. It's time to become part of the team.
“Everyone in this industry is constantly talking about the potential of 3D printing and whether it’s real or not, and rightly so,” says Jones. “If you look at the financial cycles associated with 3D printing, you will see that we have experienced at least two hype and bust cycles: one right after we founded the company, and one later. Recently. Now, again, will this promise be fulfilled? My answer is yes, but first we need to understand 3D printing not as a standalone performer, but as a manufacturing team. Must rebuild as an invaluable player within. Now is the perfect time to do just that. ”
