Strength. That’s the first word that comes to mind when most of us think about 3D printing in metal. And expense is usually the second–but when it comes to fixing up a nation’s fighter jet, thrift is most likely not an issue. And if you were up against a constant adversary like North Korea, you’d want the best, most secure repairs possible for the main fleet’s F-15K fighter jet–especially if you were the one flying it.
When it came to the attention of the South Korean Air Force powers that they needed to modify and repair two high-powered turbine components (purchased from the US) that receive a great deal of exposure, they had to find a method that allowed for durability and could handle the 800 mm diameter turbines. With an aim to repair the turbine shroud with titanium alloy and the air seal with cobalt alloy, bringing the components up to speed without sacrificing any quality seemed to pose a challenge, initially.
The fighter jet in question has a bit of a familiar look for those who are interested in US military aircraft, as it is indeed a modified version of the McDonnell Douglas Boeing’s F-15E Strike Eagle, and has two GE F110-GE-129 jet engines. With their country and military situated in close proximity to the adversarial and unpredictable North Korea, staying on guard means more than just watching each other–it means having all military might at the ready constantly. This involves ongoing repair and maintenance, to the extreme, and of course planes require the ultimate so that they stay in the sky where they belong.
3D printer manufacturer InssTek was called in to save the day with their expertise in DMT technology, and put to the test with their Grand Teton 3D printer.
The DMT technology works as metal powders are melted with a high power laser. It’s one of the most current and progressive 3D printing technologies and was able to offer an almost immediate solution to repairing and modifying the South Korean aircraft components.
Metal powder is fed without interruption into the 3D printer and melted consistently by the laser, and then allowed to become solid again. DMT technology guards without fail against leaking, and the 3D printed components are often able to offer superior properties mechanically as well.
“DMT technology allows for technical solutions that were previously unthinkable with Fusion Powder Bed technology,” states the InssTek team on their website. “Molds with complex internal structure fully count sensors and cooling ducts, metal parts from different types of metal, repair of complex surfaces, modification, conversion, and special coating to work.”
“Already now our technology is widely used in many industries and makes great contribution to increasing productivity, with artificial joints for surgery and titanium parts for the aircraft industry being are just a couple of the countless examples.”
Repairing turbine shroud control
Their flagship piece of equipment, the Grand Teton 3D printer, allows for a massive build size of 2000 x 1000 x 1000 mm. It also features:
- A 5kW Ytterbium fiber laser
- Three metal powder hoppers, each with capacity of 3kg
- Tilt/rotation chuck
- Horizontal rotation spindle
InssTek collaborated with both GE and the Korean Aero Technology Research Institute in making the repairs with 3D printing.
“With this new method we can save not only the expense of several hundred thousand Euros each year, but also the repairing time has been dramatically reduced. Waiting for new spare parts for many weeks is now finally passé,” said Lieutenant Colonel B. S. Lee, who was responsible for the project.
InssTek’s technique and repairs were closely inspected and tested as all entities had the highest concern for quality, safety, and reliability. After using the DMT technology to make the required modifications, the components were released ‘without any restrictions or limitations.’
Discuss your thoughts on using 3D printing for repairing and modifying military aircraft components in South Korea to Use DMT 3D Printing Technology forum thread over at 3DPB.com.
The Grand Teton 3D printer
