- THE MAGAZINE
The two companies were merged in 1987, and Centorr Vacuum Industries was created. “It was the perfect fit between the two companies,” says Bill Nareski, CEO. “It gave the company an extremely broad product line from the smallest laboratory type of furnace to full production, industrial type equipment.” In January 1997, CVI was acquired by its management team, headed by Nareski. The management’s role as owners and managers has provided for greater flexibility and motivation in creating and maintaining satisfied customers.
Today, CVI is a high-temperature vacuum/controlled atmosphere furnace manufacturer with an installed base of over 6000 units worldwide. The company’s furnace offering ranges from large commercial and production units with hot zones over 3 x 3 m, to smaller lab and research and development furnaces for use at temperatures over 3000 degrees C. CVI also has a fully staffed Aftermarket Field Service group, which provides spare parts, hot zones and field service, as well as furnace maintenance programs, upgrades and retrofits, rebuilds, and controls. The company’s manufacturing facilities have been repeatedly expanded and now include a group of integrated shops staffed and equipped for machining, metal forming, fabricating, electro-mechanical assembling, and operational testing of complete furnace and related processing systems.
A Strong FoundationCVI’s 40,000-square-foot main facility houses a 10 x 10 x 10-ft pit that allows for two-story equipment simulation, which is important for the company’s optical fiber drawing furnace product line and its metal and ceramic wire annealing furnaces. CVI’s fiber drawing furnaces support the photonics and telecommunications industry, while its metal and ceramic wire annealing furnaces are used in the specialty metals business to produce unique alloy wire formulations.
The main building also houses the company’s Applied Technology Center laboratory, where CVI offers R&D support and toll firing services in both metal and graphite hot zones to 2200 degrees C, as well as continuous furnace testing in its 2000 degrees C cold-wall belt furnace design. The laboratory also includes a small air furnace, laboratory scales and a Leco carbon analyzer. This fully equipped and staffed laboratory has delivered innovative solutions to challenging high-temperature materials processing problems for many of its customers, especially in new or growing markets like advanced ceramics and metal/ceramic injection molding. “This is a unique type of engineering, because there are really no schools that give furnace design degrees,” says Nareski. “It’s a knowledge base that’s home-grown. We do fundamental research and development in this area to create our own standards for ultra-high-temperature design.”
Process evaluation is an important aspect of customer service, enabling prospective users of high-temperature equipment to test ideas and perfect operating procedures so that equipment can be properly specified to perform planned operations. Testing in the lab’s continuous furnace has allowed refractory metals and advanced ceramics manufacturers to produce high-quality materials in a quarter of the time required in a conventional batch furnace design due to the reduced furnace cross-section and lower thermal mass. Because of the variable and programmable belt speed, ramp rates of over 100?C/min are possible, allowing for sophisticated thermal shock testing of ceramic formulations.
Through its work in the laboratory, CVI has gained extensive experience with various ceramic materials, including SiC, B4C, Si3N4, AlN, BN, sapphire and carbon-carbon composites, enabling customers to “test run” different gas atmospheres, vacuum levels and hot zone materials when developing a new process. With the ability to run furnaces in high vacuum, low vacuum and partial pressures of argon, nitrogen and hydrogen, almost any ceramic composition can be processed. In the past, this laboratory has been used for U.S. Department of Energy (DOE) projects with the purpose of designing new low-cost ceramic formulations.
This year, capital investments have been made in facilities and equipment in order to support both production and research and development in the field of ceramics.
Expanding CapabilitiesIn January 2002, CVI announced that it had completed construction on a new building at its headquarters in Nashua, N.H. In addition to the main building, the company added a 40 x 40 x 55 ft-high tower facility with a 5-ton hook and crane, featuring an 800-amp service and 350-KVA chilled glycol system. The new facility enables CVI to design and build large hot presses, chemical vapor deposition and chemical vapor infiltration furnaces, and other vertical furnace designs for custom applications, and the improved utilities allow for the in-house testing of these large units.
This $500,000 investment was necessary to support recent interest in advanced ceramics for the semiconductor, automotive and armor markets. Even though these markets have slowed down in the last year due to the economy, Nareski is optimistic. “While the industry in general has had its ups and downs, we think over the long term there’s definitely a very bright future for it,” he says. “And as the need for advanced materials grows, the need to operate at ultra-high-temperatures and controlled atmosphere grows also. CVI is taking an expanding position and delivering equipment to service those thermal processing needs in the future.”
To date, the new building has been used for the construction of two large-scale vacuum/controlled atmosphere hot presses for advanced ceramics—one in China and one in the U.S.—as well as several tall vertical special application furnaces. The two hot presses feature state-of-the-art technology and break new ground in traditional hot pressed design. New features were required due to the high material tolerances of the SiC, B4C, Si3N4, TiB2, AlN and BN advanced ceramics being processed. One unit includes a computer-controlled strategy, incorporating Intellution® HMI software with an Allen Bradley PLC, which was designed in-house by CVI engineers. The system offers unprecedented control over the entire hot press process and provides extensive data recording capabilities. The second hot press includes both force and position control for maximum flexibility during the press cycle. The closed loop monitoring of both tonnage and distance is made possible through the use of CVI’s proprietary FC-2 I/O card for precise pressing accuracy and programmable pressing ramp profiles.
Both presses are designed to reach high pressing forces up to 300 tons at temperatures of 2300 degrees C for the processing of these advanced ceramics. Both chambers are fitted with a unique fan-cooled design (with and without integral heat exchangers), which enables rapid cooling of large loads from 2300 to 100 degrees C in under 8-10 hours. The presses also feature partial pressure and positive pressure inert gas systems with CVI’s patented Sweepgas™ technology for the debinding of ceramic binders and various process offgassing prior to final sintering and pressing. This procedure eliminates the need for two separate furnaces to accomplish debinding and high-temperature pressing, saving both time and money.
CVI has been at the forefront of high-temperature vacuum/controlled atmosphere furnace manufacturing for decades, and Nareski has no intention of slowing down. “My long-term goal for the company is to build on the position of strength we already have and bring Centorr Vacuum Industries to a point where we are considered universally the primary resource for ultra-high-temperature equipment in all the significant applications,” he says. “The need for this type of equipment is only going to grow in the future, and we’re going to be prepared to meet that need.”