Shop perfects laser cutting brass, titanium

Parviz Shahriari, the director of engineering at GEMVIS, a Montreal-based contract manufacturer, doesn't give up easily. He hasn't followed conventional thinking but, instead, has pursued work others wouldn't touch. He's experimented, tweaked, and perfected unconventional processes, and judging by what his 30-employee shop offers, his tenacity has paid off significantly.

Two not-so-easy capabilities his shop touts—laser cutting brass and titanium—have helped the company grow. Brass reflects the laser light for poor cut quality; titanium burns when subjected to the laser's heat. For each challenge, Shahriari said, his team charged ahead to see if they could laser-cut these challenging materials while meeting or beating quality standards.

The first brass job came earlier this decade. The shop's waterjet system didn't have the required accuracy, and the part geometry wasn't conducive for milling. Sounds like a dead end, right? Not so fast.

Tweaking the System

GEMVIS took a look at its laser. It's extremely accurate; it can cut complex geometries; wouldn't it be great if it could cut brass? Conventional thinking said otherwise: Using a CO₂ laser to cut brass, a highly reflective metal, produces poor cut quality, right?

Shahriari and his team decided to experiment anyway. They altered the angle of the cutting head slightly to account for reflectivity, and tweaked the gas mixture to provide better shielding to the outside air. With the laser system's protective shield in place and the operators wearing protective glasses to protect against the intense visible light, shop engineers tweaked, found problems, then tweaked some more, until they finally got the cut quality to where it could pass muster.

Since then the shop has made somewhat of a name for itself by laser cutting brass. It's given the business a competitive advantage and true differentiation that has drawn customers from hundreds, sometimes thousands of miles away.

"The cut quality is excellent," Shahriari said. "Now we're getting customers from as far away as California, Texas, and Florida."

Expanding Capabilities

Now consider the shop's titanium-cutting capability. Initial demand came from a job requiring a high-value prototype for the medical industry. Shahriari's team used that same tenacity to experiment and perfect the process. "For titanium we had to modify the nozzle and use a special mixture of assist gas, to ensure the metal would not burn."

For this the shop developed, in-house, a nozzle that would utilize the assist gas in such a way that would more fully envelop the work zone, forming more of a barrier between the laser and the ambient air. That, he said, prevented the oxygen from reaching the hot part. Today the shop laser cuts titanium regularly and, again, gives it significant market differentiation.

All this experimentation has paid off—big-time. In 2004 a 4,000-square-foot facility housed the entire operation. Today the company has 41,000 sq. ft. and within the near future, Shahriari said he plans to move the company to a new, 100,000-sq.-ft. facility.

GEMVIS isn't alone in its laser cutting capability, of course. A quick Google search reveals that other shops also offer brass and titanium laser cutting, but it's probably safe to say GEMVIS is one among only a few who promote the CO₂ process.

Not For the Novice

Shahriari added a word of caution. Without in-house R&D talent and expertise, he admitted that sometimes tenacity can send a shop down a quixotic path of trial and error. If he didn't employ technicians who really understood the laser process, he wouldn't have even thought to start such experimentation. A failed attempt to push a machine tool's capabilities can be a costly enterprise.

But according to Shahriari, GEMVISemploys experienced laser technicians, and judging by the shop's growth in recent years, the company has put their experience to good use.