Waterjet technology allows Nuclear Alloys to cut close-to-finished parts

November 2016 - Waterjet cutting is known for its ability to cleanly and cost-effectively process complex parts from materials—such as plastics, metal matrix composites, high-strength steels and titanium—that sometimes are challenging to cut with other methods. In addition to cutting quickly and accurately without heat-affected zones, waterjet cutting allows parts to be nested closely together, saving precious amounts of expensive material. 

Jim Fields, national sales manager for Techni Waterjet, Lenexa, Kansas, says waterjet machines will cut titanium “as easily as aluminum.” Other fabrication or machining methods can “cause the material to work harden and generate a lot of heat. Once there has been a surface hardening, the material becomes very difficult to cut and will, in fact, catch fire.” Because waterjet is a cold-cutting process, it eliminates any heat-related problems. 

Nuclear Alloys Corp., Wilson, New York, cuts titanium, among other materials. It has “trimmed [titanium] slabs for rolling, cut many small components and cut sheet metal used for aerospace applications,” says Dave Schulz, general manager. “The biggest benefit to waterjet cutting titanium or other exotic alloys is the ability to reduce or eliminate further machining operations,” he says, noting that waterjet cutting is “largely unaffected by the material grade, where the impact of titanium or work hardening alloys is significant on machining speeds and feeds.” 

Techni's Quantum NXT uses direct servo technology, which replaces hydraulic cylinders with efficient, reliable and controllable servo linear actuators.

Beyond blanks

Founded as a specialty metals supplier to machine shops and fabricators serving the military and defense market, Nuclear Alloys today has expanded its customer base to include commercial, industrial, rapid transit, food, defense and marine markets. 

The company purchased its first waterjet cutting machine in 1990 and has decades of experience using this technology to cut parts—from single-piece orders to large-volume production runs. Waterjet has become “both faster and more precise over the last 20 years,” Schulz says. “The introduction of high pressure gives the option to cut at higher feed rate, and dynamic or 5-axis heads allow for greater accuracy and more intricate cutting.”

Advances in waterjet technology have allowed Nuclear Alloys to move beyond blanking two-dimensional shapes to producing “finished parts with bevels, weld prep or even angled holes. We’re also able to cut more cost effectively using lights-out capabilities due to better machine sensing and diagnostics,” he continues.

Nuclear Alloys installed Techni’s TJ 1026-X2 waterjet with a 5-axis cutting head and lights-out capabilities in 2012. It recently upgraded the machine with Techni’s new Quantum NXT electric servo pump. “We started with a Gen 1 ESP 66 pump,” Schulz says, “and recently replaced it with a Gen 2 ESP 55.” The new pump has “performed very well” and after about 1,200 hours of work has only required “very minimal service”—just regular maintenance at proper intervals. 

The Quantum NXT is neither a direct drive nor an intensifier pump; instead of incorporating a crankshaft or hydraulic cylinders, it relies on direct servo technology that replaces hydraulic cylinders with efficient, reliable servo linear actuators. The servo motor directly envelops a high-load precision ball screw, which houses the ceramic plungers that reciprocate back and forth to create the pumping action. The pump’s design provides control over the output pressure and volume of the water displaced, which allows operators to program any pressure and flow rate from zero to full capacity, and the pump only uses the power required for the cutting process. There are no additional power losses, regardless of whether the cutting head is open or closed or if the pressure or flow is reduced. 

Fields says the Gen 2 pump has improved hardware and software that increase efficiency and lower operational costs. Moving to the new pump gave Nuclear Alloys “a standalone platform,” he says. “Component life was increased as the result of improved cooling and oil flow routing through the system.”

Waterjet machines equipped with 5-axis cutting can take on complex jobs, such as beveling, chamfering and parts for decorative applications.

The Quantum NXT is able to produce 20 percent more power than Techni’s original electric servo pump and can be connected to any waterjet machine. “The pump runs very quietly, requires less power than traditional intensifier pumps, and it’s also easy to monitor and adjust pump settings through the control,” Schulz says. 

Feedback from customers like Nuclear Alloys “is key to growing improvements in any industry,” says Fields. Techni had seen development “go kind of flat in improving technology and, in fact, [we] were told by many that a servo-driven pump just couldn’t be done.” Techni’s engineers “are driven to solve customers’ problems. Our market research showed the frustration our customers had with status quo features. The waterjet process has several challenges unto itself.  The communication from our customer base allows us to think ahead and address these challenges specifically.”

Dynamic cutting

Nuclear Alloys has several waterjet machines, but its Techni model is the only one equipped with 5-axis cutting. As a result of that capability and the machine’s large table, it can take on certain jobs that the other equipment cannot, such as beveling, chamfering and decorative applications. Nuclear Alloys can handle plate up to 10 feet by 25 feet that weigh 12,000 pounds. 

“It’s allowed us to pick up some new work, as well as do beveling on current customers’ parts,” Schulz says, work these customers were either doing themselves or outsourcing to another vendor. “Now we can basically give them a finished part in a one-step process.”

Finished parts streamline customers’ operations by “eliminating the need for secondary operations such as machining,” Schulz says. “The waterjet has the ability to produce a finished part, or close to finished, while reducing wasted material at the same time. Parts can be nested and material utilized to minimize drop sizes and waste. With dynamic and 5-axis cutting, even more parts can be finished on the waterjet without further processing. MM