As both companies and technologies evolve, service centers like Tico Titanium Inc., Wixom, Mich., are exploring technologies such as laser, plasma, wire EDM and waterjet in an effort to expand their capabilities beyond sawing plate and shearing sheet.
Tico has locations in Wixom, Mich., and Oak Ridge North, Texas. It stocks inventories of commercially pure titanium and titanium alloy products, including fasteners and fittings, pipe and tube, and milled products, ranging from ingots and bars to plate and sheet, that it distributes to customers around the world for petrochemical, utility, mining, pulp and paper, and military applications.
In 1992, the company chose to expand its processing capabilities by adding waterjet cutting to its repertoire. Today, it’s an experienced user of the technology.
According to Joe Newland, fabrications manager at Tico, when working with titanium, the waterjet process has several advantages over plasma, laser and wire EDM cutting.
Abrasive waterjets use an erosion process to cut material, which can cut titanium at a rate 25 percent faster than stainless steel. And because it is a cold-cutting process, there are no heat-affected areas left on the parts and no additional forming of oxide layers.
"There are undesirable oxide layers that form during plasma, laser and wire EDM cutting," Newland points out. "These oxide layers must then be mechanically removed by a secondary operation. The waterjet-cut surface requires no secondary operation."
Tightening tolerances
Since 1992, waterjet technology has improved drastically--largely as a result of computer-driven controllers. Tico’s original machine was limited both in the tolerances it could hold and its table size. It needed to be replaced with updated technology that could make the company’s processing faster, more accurate and more powerful.
"Our initial experience with waterjets had proven the technology to us," says Chris Combs, operations manager. "We had been in contact with Flow International [Kent, Wash.] for quite some time and had talked with some of their customers. We were interested in the advances they were making and product support that just wasn’t available from our existing supplier. When we reached the point that we were ready to upgrade, we decided to go with a Flow machine."
The first Flow International Corp. system Tico purchased was a Mach 3 with an intensifier pump. "We immediately saw a marked improvement in accuracy," Combs says. "The software was user-friendly and easy to learn. We were programming and cutting parts the first week."
The Windows-based FlowMaster software is designed specifically for waterjet cutting. Users only need to input material, thickness and edge quality, and the FlowMaster will set the correct acceleration, speed and piercing parameters. In addition, FlowMaster controls and displays all machine and pump functions, allowing the operator to easily control the cutting system and monitor the progress of a cut. No advanced training is needed because no CNC programming or complex computer language is used.
Tico also took advantage of the nesting program included with FlowMaster. The FlowNest module allows the designer to nest parts on full sheets, remnants or even place parts within larger parts. It is designed specifically for waterjet applications to maximize material usage. Features include common line cutting to save time and improve productivity, optimized cut path to reduce rapid moves and improve cycle time, user-defined crop line for efficient remnant processing and part avoidance to minimize cutting-head collision.
"Another significant improvement is our material yield," Combs says. "When you are cutting expensive material like titanium, it’s absolutely critical that you get the best material yield. We had previously been achieving yields of 70 to 75 percent. The combination of the Flow machine and FlowNest gives us very tight tolerances and optimizes the number of parts we can get out of our plate and sheet stock.
"Now our material yields are outstanding, as much as 85 percent to 95 percent, depending on part shapes," he continues. "In fact, when we finish cutting material on our waterjets, the webbing is usually so small and thin that you can pull it off and ball it up in your hands."
A dynamic duo
The ability to cut parts at or near required tolerances trickles down the supply chain to Tico’s customers, saving them money because there is no need to purchase more metal than is absolutely necessary.
"When we decided to purchase our second Flow system, we took into account that our standard mill plates are roughly 96 inches by 240 inches, so we wanted a system that could handle that size to improve our material utilization and reduce handling time," Combs says. "We purchased the first WMC 3080, with a 3-meter-by-8-meter cutting table, to handle that plate size and maximize our cutting schedule. Some plate nestings can cut for up to 40 hours straight."
The company also added on Dynamic Waterjet to speed up cutting time and improve taper control. Flow invented and patented Dynamic Waterjet with Active Tolerance Control in 2001 specifically to counter taper and stream lag.
Stream lag occurs when the exit point of the jet that is cutting the part lags behind the entrance point. It causes geometry errors as it sweeps out cone shapes instead of circles and causes corner wash-out.
V-shaped taper naturally occurs as the power of the waterjet dissipates while cutting through material. The faster the cut speed, the greater the kerf taper error. As with stream lag, the way to reduce taper has been to slow down the cutting speed.
However, with Dynamic Waterjet, advanced SmartStream mathematical models work to tilt the head to the side to eliminate taper and tilt it forward to control the stream. As a result, parts are produced two to four times faster than on a conventional waterjet and part tolerances can be as tight as one to three thousandths of an inch. These improvements are shown in the cut quality, often eliminating secondary processes completely.
The operator simply enters basic cutting parameters, including material type and thickness, cut speed and desired edge quality, and the software does the rest.
"Our customers were not always satisfied with parts waterjet cut from thick plate because of the taper," says Lynn Brace, Tico sales manager. "Now with Dynamic Waterjet, we stock and waterjet cut up to 6-inch-thick titanium slab, forgings and plate. The system is so accurate that we are often able to provide our customers with finished product for immediate use."
"Providing a complete bill of materials cut to the required tolerances with a clean, straight edge is a great benefit to fabricators," says Jeffrey White, Tico vice president. "By utilizing the Flow system, Tico can offer products that save the customer time and money by reducing machining time, edge preparation time and weld fit-up time. This lowers overall costs and fabrication time on a major project. The supply of precision-cut parts is a key to our success in the market."
The company has come a long way from its first waterjet, which had a ± 0.030 tolerance with a 5-foot-by-10-foot table. Combining two table sizes with the Dynamic Waterjet and FlowMaster nesting capabilities creates a more productive environment at Tico. "We’re very satisfied with our Flow systems," Combs says. "They allow us to be extremely efficient in time and material usage. And that benefits us as well as our customers." MM
Tico Titanium Inc. is owned and managed by Lawrence Holdings Inc. Its sister companies include Alloy Metals of Michigan, Supra Alloys of California and Snappy Materials of Connecticut. Lawrence D. Buhl III, CEO of Lawrence Holdings Inc., was recently elected to the board of directors for the International Titanium Association.
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