April 2010 - There’s a reason titanium gets the tough jobs--defibrillators, artificial joints, fighter jets. Its tensile strength, bio-compatibility, resistance to corrosion and strength-to-density ratio make it an in-demand commodity for a wide range of high-end products.
Those qualities would not only make a nice double-edged sword, but they can also be a double-edged sword for shops trying to fabricate titanium quickly and economically.
So when Vulcanium Metals Inc., a Chicago-area service center that specializes in titanium, went looking for a laser to fabricate the material, it needed a machine that could cut to exacting tolerances and be able to do it efficiently in both small and large batches.
To walk that fence, Vulcanium opted for a 4-kilowatt Mazak Hyper Turbo-X laser machine with an automated material handling system. Although created to cut steel up to 1 inch thick, the machine’s frame seems to have been built with titanium in mind.
Its enclosed box-frame design incorporates tabbed laser-cut sides and cross-members that are connected by a series of tie rods. According to Mazak, the frame design serves to dampen vibrations more quickly than cast or welded frames and thus improve the finish of the cut material.
Quality surface finish is critical for Vulcanium and its customers, both for aesthetic and monetary reasons. Titanium is relatively rare (it cannot be found in nature in metallic form), and not too long ago, Vulcanium could sell a 3-foot-by-8-foot sheet of it for $16,000, or about $1,000 a pound, according to Jim Ellis, the company’s vice president of global operations.
Hence, the shop’s use of argon assist gas, which is five times the price of nitrogen, to achieve pristine edge quality. More common assist gases would provide too sloppy an edge.
"When someone’s paying a high dollar-per-pound price for titanium, they don’t want slag or dross hanging off the side," Ellis says. "Because it’s such a high-priced commodity to begin with, the marketplace demands jewelrylike quality--good smell, good feel and everything else."
The HTX also features a six-torch changer magazine with a 10-nozzle changer. After loading up the correct torch and nozzle combination, the machine inspects the nozzle tip with a camera to look for spatter or other problems. If the machine finds an irregularity, its software launches a refinish operation with an onboard grinding wheel and wire brush. The HTX then does a focal length calibration of the new cutting head combination.
Given the cost of argon, the automated cutting head system offers an important advantage for Vulcanium: controlled assist gas usage.
"The optimum-size nozzle for the material thickness is critical to gas consumption," says Mazak Marketing Manager Marc Lobit. "Machines without an automatic nozzle changer either require manual nozzle changing or cutting with compromised settings, which would, in the case of argon gas, cost up to an additional $40 per hour to operate."
Juggling material well
The HTX is the only laser Vulcanium uses. However, because the shop runs on-demand for a lot of its laser business, the HTX might run for four or 24 hours a day, depending on the day’s order sheet.
The machine also puts a wide range of material thicknesses across the laser for Vulcanium’s worldwide customer base, for which Ellis is glad to have 4,000 watts of cutting power.
"The 4,000 watts, some might say, would be overkill on some of our thinner-sheet applications; however, by having the capability of running 4,000 watts, it allows us great flexibility [in] being able to provide both a cosmetic and quality-produced product," Ellis says.
For a value-added processor that has to juggle batches of two or three parts with longer jobs that run overnight, lights-out material handling is a must.
"But we also needed it to not be such an integral part of the machine that it would physically restrict us from manually loading and unloading," Ellis says. "So this laser, and the material handling system that we purchased with it, offered us a nice compromise."
Fewer steps in, fewer dollars out
When it comes to the HTX’s fabricating abilities, nobody at Vulcanium is talking about compromise, especially when it comes to streamlining production.
Before the company purchased the HTX, for example, operators may have sheared a sheet first and then carried it to a turret punch for further processing. After that, an operator may have had to deburr it and then take it to a press brake or other machine for further fabrication.
That series of steps has gotten shorter because "this laser has allowed us to basically load up a full sheet, turn on the laser beam and let it do its job," Ellis says. "By the time it’s done, we have it completely profiled, with holes in it and everything else. It’s pretty much prepared to go on to the next processing step."
With titanium, a reduction in processing steps isn’t always a given. Veteran metallurgist Herb Tolchinsky explains that although titanium is stronger at high temperatures than carbon steel and aluminum, it’s also more difficult to form into complex shapes.
"A fabricator must be aware that the cut edge may be contaminated, causing cracks due to its brittle nature," says Tolchinsky, former chief metallurgist for a major fastener company. "A remelt zone may be a problem if it cannot be removed by a mechanical operation."
So far, though, Vulcanium has been able to use the HTX’s range of fabricating abilities to its advantage. Ellis hopes that capability will mean more value-added services for his customers. Nobody is petitioning for more of the current economic slump, but it has brought a certain change in attitude that Ellis is hoping keeps the HTX busier in the future.
"The manufacturing end customer drives what end products we supply to them," Ellis says. "Honestly, I think with the economic downturn that we’ve experienced, there’s at least a little more willingness on the part of our commercial customer base to accept value-added processed material into their facilities.
"I think the marketplace is really beginning to wrap their arms around the value of having material that hits the floor and is ready for the next production step," he adds. "They have reduced inventory costs; they don’t have to bring in full sheet. The advantages are numerous."
Adding the HTX hasn’t so much opened doors into new markets as enhanced Vulcanium’s ability to serve its main laser customers in the medical and industrial markets.
"The costs aren’t the only driver of our activity, but they’re certainly a good motivator," Ellis says. "Anytime we can reduce a three- or four-step process to a two- or three-step process, it’s going to provide advantages, both monetarily and in service. We’re pleased with the capabilities we’ve been able to acquire off of the laser." MM