From laser drilling, to plasma coating, to airflow measurement this company is a one-stop shop for metal fabrication
David A. Belforte
TurboCombustor Technology Inc. (TCT) was founded in Gas City, Indiana, as Hoosier Metal Spinners in 1951, a supplier of sheet metal fabrications for jet engine parts. The company moved to Stuart, Florida, in 1967 and changed its name to ERK Inc., a move predicated by the owner’s yearning to seek warmer climates and to be closer to Pratt & Whitney, a major customer. In 1980 it was purchased by Chromalloy America, a leading repairer of aircraft engine components. At that time ERK was one of the only OEM suppliers of components in the Chromalloy stable of companies.
A typical drilling job is producing thousands of effusion holes in a combustor liner.
The name of the company was changed to TurboCombustor Technology (TCT) in 1985 and the following year it expanded the operation into an 82,000 ft2 building, which was increased by another 23,000 ft2 in 2001. In 2004 the company was acquired by two equity groups, CAI Funds and Aero Equity. It acquired Treasure Coast Machine, in 2006, a machine shop also serving the turbine engine market.
Today the company employs 310 people and continues on a growth pattern that follows trends in the turbine engine business.
TCT is a manufacturer of complex sheet metal fabrications for turbine jet engines; 90 percent of which are for aerospace and 10 percent industrial and marine. The business is split 50/50 between commercial and government customers. It is essentially a “build to print” company, a contract manufacturer that is good at concurrent engineering services. It is not unusual for the company to sit with a customer to offer design assistance for producibility concepts.
In essence it is a one-stop shop for parts it manufactures for customers. For a combustor order, for example, it buys high-temperature sheet metal stock, castings, and forgings and completes all the fabrication processes in-house and then ships a completed component to customers that include all the leading jet engine manufacturers. As a one-stop shop it can control all the processing steps, cycle times, yields, and theoretically the cost of the product. The company’s core competency is in laser drilling, plasma coating, and air flow measurement and the supporting process technologies services that go with this to produce the one-stop shop concept.
The company counts among its customers all the leading turbine engine manufacturers and it ships products to these companies’ locations both domestically and internationally.
When the company started in Stuart it installed two Raycon four-axis units in 1989 that had tilt and rotary motion capability. These units were powered by a Convergent Omega Nd:YAG laser and a Convergent Super 48 CO2 laser. A Laserdyne 780 Beam Director was installed in 1993; the company ran these systems until 1996 when it replaced the Raycon units with more Laserdyne units. Currently it operates nine Laserdyne Nd:YAG drillers; five Model 890s, two Model 780s, one Model 550, and two Model 790s, in addition TCT has a second Model 790 with a CO2 laser. The CO2 work load is two shifts while the Nd:YAG laser load is three shifts per day. These 10 laser systems make up what is called the “laser village.” Gary Loringer, laser engineer/supervisor, who is responsible for the laser systems says the company continuously monitors work loads to anticipate any scheduling conflicts. Right now indications are that it will need to add more laser drilling capacity and it is currently evaluating steps to accomplish this, including the purchase of two more units.
Ten laser systems make up the company’s “laser village” on the production floor.
Skilled operators are a necessity and TCT has 22 at this time, and it is looking to add four more people right now, although the market is tight for trained or capable machine operators. Loringer looks for people with a computer or CNC background, but he usually ends up finding a quick learner that he can train.
Operators are expected to perform routine maintenance, lens cleansing, filter changes, etc. but service and deeper maintenance is performed by Loringer and the maintenance staff. They also rely on phone support from the equipment manufacturer to keep the systems operational. According to Loringer the 10 units are running on a three-shift per day, 6-7 days per week schedule. Experience is that the laser systems are running at the mid-90 percent uptime level with the downtime split equally between laser and system problems and routine maintenance. Lamp changes for the Nd:YAG laser only take 10 minutes and even on a heavy-duty job, like drilling a combustor liner, the lamps only need changes every 2-3 weeks, so this can be built into the schedule. No laser systems are held in reserve for substitution for one that is down.
And speaking of schedules, the work load for these machines varies as customer orders ebb and flow. Right now the engine business is good so the machines are fully loaded. A typical drilling job, producing thousands of effusion holes in a combustor liner can take from 2-50 hours depending on the number of holes per liner, size of liner, number and size of holes, and whether it is drilled by percussion, trepanned, on-the-fly, or a combination of all three. So scheduling machines with a mix of customer parts, each with a varying number of flow holes and types of holes can be a nightmare. Routine scheduling is done by computer but in the final analysis Loringer does the fine tuning to ensure a smooth flow of work. The majority of cycle time is drilling effusion holes, CO2 laser cutting is for dilution holes and most sheet metal trimming.
A typical part flow is; take a flat sheet of high alloy metal (usually 0.040-0.100 in thick), roll it, weld (usually with TIG), heat treat, thermal barrier coat, laser drill effusion holes, deburr holes, air flow test, and then final process by drilling dilution holes. Customers want a certain air flow in a combustor and after drilling, the air flow measurement tells TCT whether it needs to resize some holes to meet customer specifications
Normal hole size is 0.020 in. and is typically drilled at a 20-30 degree angle from the part surface. Some combustor designs employ compound angle effusion holes, which require a multi-axis contouring head to achieve the proper drilling angles.
TCT is always in “pursuit of the perfect hole;” one with no heat affected zone that meets all the customers’ specifications. Lou Surette, co-president, laughs when he says this, but it is obvious that this phrase is more than a marketing pitch. He means it when he says they strive for the highest quality in customer parts. After all, the company produces, on average, about 3 million holes per month, 2 million of which are drilled through thermal barrier coatings (a not so simple task) and 2.5 million holes are air flow tested to customer specifications.
TCT produces laser drilled components for all the major air and land turbine engines. For several customers the company has trained TCT employees to perform in-house quality assurance so that parts shipped conform to requirements. These customer-designated quality inspectors are another key factor in TCTs continuous drive to achieve the perfect hole.
Loringer would like to implement lean manufacturing practices for his laser machines but he does not think a cellular approach will work for their production floor requirements. So for the present the company will keep the laser village approach.
Business in the aerospace sector, primarily aircraft engines is good and expectations are that it will continue this way for some time. So the future looks bright for TCT, a 39-year-old OEM manufacturer.