SPRINGFIELD, Ohio—Techniques Surfaces USA (TS USA), a subsidiary of HEF Group, provides job shop surface treatment and coating services that extend the life of mechanical components by reducing friction, wear, and corrosion. What many manufacturers may not realize is that TS USA operates what is reported to be the largest salt bath nitriding equipment in North America at its plant in Chattanooga, Tennessee.
“This is the largest liquid nitriding facility in the Americas, and was designed specifically for long cylinders and heavy components,” said Rajiv Ajuha, CEO and president of TS USA, in an emailed response. “We can now liquid nitride parts as long as 15 feet.”
The 35,000-square-foot Chattanooga facility has a 50-foot ceiling clearance. It is also fully equipped for cylinder OD polishing after nitriding, Ajuha said.
“We have been in the field of tribology since the 1950s and are constantly developing our surface coatings and treatment processes and capabilities,” Ajuha said. “Not only do we treat customer parts through a global network of 65 facilities, but we also manufacture the consumables and processing equipment utilized for the coatings and treatments we offer. So, we control all the key aspects of the process—and hence, can ensure consistency and repeatability.”
Customers look to TS USA for solutions to challenging part performance problems. They’re typically seeking to enhance the performance of precision mechanical components. A key to accomplishing this goal is to reduce part wear, friction, and corrosion. TS USA can solve these problems by employing a range of surface coatings and treatments to modify the surfaces of components. But its capabilities apply equally well to stamping and forming tools, including dies, forging tools, extrusion tools, and injection molds, Ahuja said.
“We work in a consultative fashion, using our technical knowledge of tribology; vast global experience; and diverse surface engineering options to select or develop the best solutions for customers,” Ahuja said. “We offer these solutions at prices that deliver significant value to our customers.”
TS USA offers diamond-like carbon (DLC) coatings, physical vapor deposition (PVD) coatings, and liquid nitriding, also known as salt bath nitriding (Arcor®, QPQ®, and Melonite®). The company provides electroless nickel plating, phosphate coatings, and a variety of PTFE (polytetrafluoroethylene, or Teflon) coatings. It also provides tribology testing services to evaluate wear and contact modes of specific mechanical components.
TS USA’s surface treatments and coatings are said to facilitate a non-stick surface and reduce wear and friction when applied to dies and molds. They are also used to reduce wear, friction, and corrosion of industrial mechanical components, such as fasteners, pins, shafts, pulleys, slides, spindles, yokes, seals, gears, sleeve bushings, and bearings. Ditto for a variety of automotive components, such as parts used in internal combustion engines and transmissions.
The full list of automotive component applications is much longer, comprising ball pins, brake rotors, caliper pistons, camshafts, clutch discs, crankshafts, and cylinders, to name a few. Differential carriers, door stop cams, and drive shafts are also on the list, as are gears, gear box actuators, hubs, latches, piston wrist pins, rocker arms, and starter motor shafts. Automotive part applications also include steering jacks and pinions, turbocharger components, engine valves, and wiper system output shafts.
Other industry applications for TS USA’s services are components for industrial machinery and equipment, such as gears, compressors, and pumps; hydraulic and pneumatic equipment; medical instruments; and equipment for the oil and gas, aerospace, and food and pharmaceutical processing industries, Ajuha said.
The company delivers its products and services through a network of facilities in 25 countries across the globe. Ajuha said that TS USA employs about 200 people in its seven U.S. facilities, and a total of more than 2,500 people worldwide.
Tech Nickel, Inc., a plating and metal treating company in Benton Harbor, Michigan, joined HEF Group in 2018. The company provides a facility through which TS USA can offer salt bath nitriding, electroless nickel, and hard-chrome plating, Ajuha said.
One of TS USA’s projects required it to surface-treat piston rods and cylinders for vehicle suspension systems (shock absorbers), lift gates, and large hydraulic cylinders of dump trucks and construction equipment. For this application, TS USA’s customers had been using chrome plating for wear and corrosion resistance, Ahuja said.
“The major challenge was to convince the customers that our liquid nitriding technology—which was a little more expensive than the traditional chrome plating option—offered significant performance improvements,” he said.
TS USA replaced chrome plating with its Arcor liquid nitriding surface treatment. Ahuja said the treatment offers six to seven times higher corrosion resistance than chrome plating, as well as better frictional properties that reduce seal wear.
“Liquid nitriding is also superior to pre-nitrided (gas or plasma) tubes and rods in terms of corrosion resistance. It offers much lower risk of cracking, peeling, or flaking because it is not a coating, but an integral part of the surface, as opposed to chrome plating that goes on top of the cylinder’s surface,” he said.
Ahuja added that, unlike chrome plating, liquid nitriding improves the fatigue resistance of the base material. It also provides impact and bend resistance comparable to chrome plating.
“Finished tubes, rods, and plunger can be liquid nitrided without issues of distortion,” he said. “The process is very price competitive to chrome plating and other nitriding technologies or pre-nitrided tubes and rods.”