Additive Manufacturing Overcomes Major Hurdle in Aerospace Industry

The recent announcement that Boeing and Norsk Titanium (www.norsktitanium.com) have received FAA approval to use additive manufactured to produce titanium structural components should help drive future growth in the industry.  The aerospace and automotive markets have been the primary consumers of additive machinery to produce metal parts.  These systems are primarily based on two machinery categories defined in additive manufacturing: direct energy deposition, and power bed fusion systems using either high-powered lasers or electromagnetic beam technology.

Norsk Titanium appears to have developed a solution based on a traditional gas tungsten electrode plasma arc welding (GTAW) techniques, but referred to as rapid plasma deposition (RPD).   The weld area is protected from atmospheric contamination by an inert shielding gas (argon), and titanium is used as the filler metal.  A constant-current welding power supply produces electrical energy, which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma.  GTAW is employed in manual welding applications, but is considered an extremely difficult technology in which to develop expertise. 

Norsk Titanium’s proprietary plasma arc technology is incorporated into a line of machines, called MERKE IV, which provide a highly controlled and pure environment.  RPD appears to be a diversion from the more common laser and electron beam technologies being employed by companies such as ARCAM, CONCEPT Laser, Irepa Laser, Matsuura Machinery, Mitsui Seiki, DMG Mori Seiki, EOS, and Optomec.  However, Nork Titanium’s machines require a larger footprint than any of the machines mentioned.  Specifications are not easily acquired, but to get a relative sense of size, each MERKE IV weighs in at 11,000 metric tons.  

From this analyst’s perspective, the MERKE IV machines currently represent the ultimate in additive manufacturing technology.  Norsk Titanium has partnered with Bosch Rexroth to develop a custom- engineered motion control solution requiring 10 axes of precision servo motion.  We don’t often see these types of applications, since the motion control system must be completely tied into the plasma cutting process where plasma intensity, table speed & acceleration, and angle of the electrode relative to the work piece.  The quality of the finished piece will depend on all aspects of the machine, from control of the titanium part build platform, feeding and handling of titanium wire entering the machine, to the real-time control of multiple plasma arc torches, and other factors.  According to Norsck Titanium, the combination of technologies integral to the MERKE IV have significantly improved the finish quality in the production piece, thereby requiring less subtractive machining to produce surfaces that meet manufacturing tolerances.  Precision motion control has been key technology driver in the quality improvements achieved in traditional subtractive manufacturing and laser cutting, but will now play a major role in the advancement of additive solutions. 

One of the major obstacles in the aerospace market has finally been overcome with the FAA’s approval of Boeings structural components on the Norsk Titanium machines.  Boeing expects to reduce the cost of each 787 Dreamliner by $2 to $3 million per aircraft.  Pricing for a hybrid laser additive machine from DMG Mori Seiki runs about $1.5 million.  Pricing of the Norsk Titanium’s MERKE IV and associated operating costs are not readily available, so we can’t determine the expected return on investment. However, since the technology appears to leapfrog the current alternatives, it’s likely that service bureaus will emerge to serve the industry.

We believe this announcement will encourage many other manufacturers in the highly-regulated aerospace market to consider additive as an option in their respective manufacturing strategies.