Jeff Kiszonas, EDM product line manager for Makino Inc., hopes the webinar he presents on Jan. 17 will enlighten some in the aerospace industry. He will discuss the results of new tests by Makino at a Nadcap-certified, independent laboratory: the new generation of EDM machines don't damage surfaces like they used to--and get parts made faster and cheaper.
"It's really just to open the eyes of some people in the aerospace industry to say, 'Hey, guys, you really need to reconsider your old specifications for this process. Look at what the new machines are capable of.'"
The presentation is part two of a webinar on the subject. The first part was given last July and is available online at www.makino.com. Kiszonas also hopes to present his findings at a Society of Manufacturing Engineers event in Toronto this May.
Several aerospace manufacturers, including Lockheed Martin Aeronautics, have recently performed extensive testing of parts made by EDM to determine if the process is effective and economical.
Makino went a step further to get more specific results. It tested 18 samples of three different aerospace alloys: Ti 6-4 titanium, 17-4 PH stainless steel, and 6061-T6 aluminum.
"What we found out, in the old days 30-40 years ago, EDM would leave anywhere from two to six thousands thickness of heat-affected zone [HAZ] that would contain micro-cracks, recast layer and annealed laver," Kiszonas notes.
"The EDM process today leaves no HAZ, and recast is down to less than .0004"," he says. "Micro-cracks are almost non-existent. Modem EDMs can produce parts with finishes down to 0.5micron Ry, tolerances in the submicron range, and leave the surface of any part with virtually no damage.
"The needs of manufacturing are driving EDM builders to develop machines that will maintain extreme accuracy while completing jobs faster. Useable wire diameters are down to 0.0008", Fine Hole drilling machines have produced clean, accurate holes of 22 micron diameter, and some builders offer customized machines for specific needs."
For the testing, conducted at IMP Test Labs of Lansing, NY, the samples were produced on Makino EDNC43S RAM EDM and SP43 Wire EDM machines using various electrode and wire materials.
However, the webinar will not focus on any particular machine, Kiszonas says. Lockheed's testing concluded that all major manufacturers' machines today obtain similar results. Makino's machines were slightly better--but only by...