Papers

ICMCTF2002 Session A2-1: Coatings to Resist Wear at High Temperatures

Wednesday, April 24, 2002 10:30 AM in Room Esquire/Towne

Wednesday Morning

Start	Invited?	Item
10:30 AM		A2-1-7 Novel Composite Coating Technology in Primary and Conversion Industry Applications B. Allcock, P. Lavin (Monitor Coatings and Engineers Limited, United Kingdom) Historically, electroplated coatings have always represented the most cost-effective method for applying deposits of metals and alloys that were pure and dense mirroring in general the properties of the parent metal. For engineering purposes, particularly in conversion industries such as steel manufacturing and primary industries such as oil extraction, coating specifications far exceed conventional coating capabilities. In response to these requirements, Monitor Coating and Engineers Limited have developed a series of composite coatings, incorporating Monitox^tm our unique coating technology, which provides effective solutions to the adverse operating environments associated with these and other industrial applications. Capable of functioning in extreme environments where corrosion, abrasion, fatigue, friction and erosion are merely starting blocks in the design of a coating system; the composite coating technology developed by Monitor Coatings and Engineers shows significant technical and commercial advantage. In the oil industry, field studies have shown the composite coating to exceed two orders of magnitude the life expectancy compared to conventional coatings in high temperature, heavy particulate laden fluids with salinity in excess of 360,000 ppm of chloride ions. In the steel industry, continuous casting mould plates have shown an increase in life expectancy of between 4 and 8 times. With virtually unmeasurably low wear rates, there are marked improvements in the down stream steel surface quality while at the same time, the integrity of the original copper asset is maintained. Here the coating design strategy and the coating formulation and selection are described together with the performance characteristics of the coating systems. Monitor Coatings and Engineers Limited is an independently owned thermal spray and thermo-chemical coatings company situated in Newcastle upon Tyne in the North East of England. Offering a comprehensive and diverse range of metallic, ceramic and cermet coating solutions, Monitor employ the latest plasma and high energy coating techniques for a range of industrial sectors including textile, aerospace, oil industry and steel manufacturing.
11:10 AM		A2-1-9 Wear Observations of PVD TiAlCrY(O)N Coated High-Speed Milling Tools at Cutting Temperature up to 950°C W-D. Münz, Q. Luo, G. Robinson, C.P. Constable (Sheffield Hallam University, United Kingdom); I.J. Smith (Bodycote SHU Coatings Ltd., United Kingdom) As high-speed milling becomes an established manufacturing process for a range of die steels, milling tools of improved wear resistance at elevated cutting temperatures are required. A nano-crystalline multilayered TiAlCrY(O)N coating has been grown on a ball-nose cemented carbide tool using combined cathodic arc etching and unbalanced magnetron sputtering deposition. When dry milling hardened steel A2 (HRC58) at a cutting speed of ~20,000rpm and 500m min_-1, the cutting temperature reaches 950°C. Cutting tools precoated eith yttrium-containing TiAlN based coatings outperform tools coated with arc-evaporated non-yttrium-containing TiAlN. In this paper, we present SEM observations on a series of TiAlCrYN coated tools being used for a range of cutting times between less than one minute to 30 minutes, combined with detailed X-ray energy dispersive spectroscopy and Raman microscopy. Different wear failure modes are determined for the flank and rake sides and the cutting edge. The oxidation resistance of the TiAlCrY(O)N coating has been found to play a significant role in the reduced sliding wear at the flank surface and improved thermal oxidation resistance at the rake surface.}
11:30 AM		A2-1-10 Synthesis and Characterization of Nanolayered TiB₂/TiC Multilayers for Dry Machining and High-Temperature Tribological Applications K.W. Lee, Y.-W. Chung, K. Ehmann, L. Keer (Northwestern University) TiB₂/TiC nanolayered superlattice coatings were synthesized by dc dual-cathode magnetron sputtering. Under appropriate deposition conditions, we obtained coatings with TiB2(001) and TiC(111) preferred orientation. Room-temperature hardness of these coatings approaches 50 GPa, far exceeding the rule-of-mixture value. Wear and durability tests on coated M2 steels and C6 WC cutting inserts demonstrated the improved room temperature tribological performance of these coatings under unlubricated conditions compared with standard coatings such as TiN. High-resolution transmission electron microscopy and low-angle x-ray diffraction studies confirmed that the layer structure of these coatings was preserved after one-hour vacuum annealing at 1000C. The room-temperature hardness was preserved after such annealing. In addition, these coatings were exposed to an oxygen environment at 800-1000C. They were characterized before and after the heat treatment in terms of surface roughness, residual stress, and nanoindentation hardness. These results will be presented and discussed in terms of the coatingâ€™s potential in dry machining and high-temperature tribological applications.
11:50 AM		A2-1-11 Thermal Spray Coatings for High Temperature Wear Applications - An Overview R.C. Tucker, Jr. (The Tucker Group, LLC) Thermal spray coatings have been used for many applications requiring resistance to both wear and corrosion at high temperatures because of the variety of materials that can be applied using thermal spray processes. The coating materials and processes, the effect of coating microstructures on wear and corrosion, and some guidelines for the use of the coatings for wear resistance at high temperatures will be review. A variety of applications from various industries including gas turbines, primary metals, and oil and gas production will be discussed.