JP2008138242A - Wear resistant coating, and article having the wear resistant coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wear resistant coating (116) comprising a hard lining (118) including a metal alloy matrix in which a plurality of hard particles are dispersed; and a plurality of nanolayers (120) arranged on the hard lining (118). <P>SOLUTION: A plurality of the nanolayers (120) have mutually different characteristics. Also, a method for making the wear resistant coating (116) is provided. This method comprises: a step where a substrate is provided; a step where the hard lining (118) is arranged; and a step where a plurality of the nanolayers (120) are arranged on the hard lining (118). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present technology generally relates to wear resistant coatings. More particularly, embodiments of the technology relate to low friction and wear resistant coatings that are stable in high temperature applications such as gas turbine aircraft engines that may be subjected to temperatures from about 40 degrees Celsius to about 900 degrees Celsius.

Abrasion resistant coatings are widely used to improve the hardness and wear behavior of base materials in many structural applications, including cutting tools, automotive parts, and turbine parts. Often, aircraft and helicopters with gas turbine engines operate in high temperature, low humidity, and corrosive atmospheres. For example, in gas turbine aircraft engines, variable vanes used to regulate air flow through the compressor are exposed to temperatures as high as 500 degrees Celsius during takeoff. These variable vanes are also subjected to significant loads between the vanes and the bushings that support the vanes. For example, the loads may include radial loads up to about 150 lbs (about 68 kg) and axial loads up to about 20 lbs (about 9 kg) as a result of forces exerted by airflow across the vane. Commercial engines reach altitudes on the order of 40,000 feet (12,200 m), and moisture availability is very low at such levels. In the absence of the proper amount of moisture, conventional lubricants such as graphite lose their effectiveness, resulting in undesirable friction and wear, among other components, particularly between the vanes and bushings. Therefore, there is a need for techniques to lubricate these components and protect them from unwanted wear in a variety of operating conditions including high temperatures, high altitudes, low humidity, and the like.
US Pat. No. 6,797,335 US 2003/0108852 US Pat. No. 6,492,011 US Pat. No. 5,266,389 US Patent No. 2005/0058850 A1 US Patent No. 2005 / 0079370A1 EP0471005B1 EP0695931B1 WO00 / 08234

  Therefore, there is a need to improve wear resistant coatings that can operate under these severe conditions.

  In one aspect, embodiments of the present invention provide an abrasion resistant coating comprising a hard backing comprising a metal alloy substrate in which a plurality of hard particles are dispersed and a plurality of nanolayers disposed on the hard backing. . The plurality of nanolayers have different characteristics.

  In another aspect, embodiments of the present invention provide a method for making an abrasion resistant coating. The method includes providing a substrate, placing a hard backing, and placing a plurality of nanolayers on the hard backing. The plurality of nanolayers have different characteristics.

  In yet another aspect, embodiments of the present invention provide an article. The article includes a component and a wear resistant coating disposed on the component. The abrasion resistant coating includes a hard backing comprising a metal alloy substrate in which a plurality of hard particles are dispersed and a plurality of nanolayers disposed on the hard backing.

  In one exemplary embodiment, the present invention provides an engine that includes a variable vane assembly consisting of a bushing or a pair of bushings and a blade stem called a trunnion. The bushing has an inner surface in contact with the outer surface of the trunnion. The inner surface of the bushing and the outer surface of the variable vane are coated with an abrasion resistant coating that is placed on top of the rigid backing with a metal alloy substrate in which multiple hard particles are dispersed, and on the rigid backing. A plurality of nanolayers.

  These and other aspects, advantages, and salient features of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

  In the following description, like reference numerals designate like or corresponding parts throughout the several views of the drawings. It should also be understood that terms such as “top”, “bottom”, “outward”, “inward”, “cover”, etc. are for convenience and should not be interpreted as limiting terms. Further, whenever it is stated that a particular aspect of the present invention comprises or consists of at least one of a group of many elements and combinations thereof, this aspect refers to any of the elements of this group, It should be understood that it includes or consists of either individually or in combination with any of the other members of this group.

  As used herein, a hard backing is a layer having a hardness value of at least about 700 Vickers hardness. As used herein, a nanolayer is to be understood as a layer having a layer thickness of, for example, less than 500 nanometers. In certain embodiments, the nanolayer may have a thickness of less than 400 nanometers, or less than 300 nanometers, or less than 200 nanometers, or less than 100 nanometers. In some embodiments, some such nanolayers may be placed on top of each other to create a multi-nanolayer integrated layer potentially having a large overall thickness.

  In compressors, such as those used in turbine engines, variable vanes perform the function of regulating the air flow through the compressor by performing angular actuation. These variable vanes are actuated through a control system to ensure optimal operation of the high pressure compressor without stalling. The operational reliability and performance of these systems can be improved by the following features. That is, a) low fine wear and sliding wear, b) operate with low enough friction for operation of the operating system, c) not subject to wear or seizure, d) thermally stable, and e ) Operate at high altitude with very low moisture level. Certain embodiments of the present invention are directed to wear resistant coatings for protecting such components. Further, the disclosed embodiments can be used in centrifugal and reciprocating compressors, such as fan blade dovetail pin assemblies, piston rings, and cam rocker arms in stationary vanes and stems of industrial gas turbine engines and navigation engines. It can also be used in other stationary and moving components, such as the vane stem bushing assembly at

  FIG. 1 is a schematic diagram of a gas turbine engine 10 having one or more wear resistant coatings of the present invention disposed on various components as described in detail below. For example, the wear resistant coating may include a hard backing comprising a metal alloy substrate in which a plurality of hard particles are dispersed and a plurality of nanolayers disposed on the hard backing. The illustrated gas turbine engine 10 includes a low pressure compressor 12, a high pressure compressor 14, and a combustor 16. The engine 10 also includes a high pressure turbine 18 and a low pressure turbine 20. The compressor 12 and the turbine 20 are coupled by a first shaft 24, and the compressor 14 and the turbine 18 are coupled by a second shaft 26. During operation, air passes through the low pressure compressor 12 and compressed air is supplied from the low pressure compressor 12 to the high pressure compressor 14. The air compressed to a high pressure is sent to the combustor 16. The gas stream from combustor 16 drives turbines 18 and 20 and then exits gas turbine engine 10. In addition, one or more wear resistant coatings of the present invention can be placed on various components to improve the wear resistance of the gas turbine engine 10 under various operating conditions.

  FIG. 2 is a partial conceptual view of one embodiment of a gas turbine engine compressor 14 as shown in FIG. 1, where various surfaces may be coated with one or more wear resistant coatings of the present invention. For example, the wear resistant coating may include a hard backing comprising a metal alloy substrate in which a plurality of hard particles are dispersed and a plurality of nanolayers disposed on the hard backing. The compressor 14 includes a plurality of stages, each stage including a row of rotor blades 40 and a row of variable blade assemblies 44. In one exemplary embodiment, the rotor blade 40 is supported by a rotor blade disk 46 and coupled to the rotor shaft 26. The rotor shaft 26 is surrounded by a casing 50 that extends circumferentially around the compressor 14 and supports the variable blade assembly 44. Each of the variable wing assemblies 44 includes a variable wing 52 and a wing stem 54, which extends substantially perpendicularly from the turret 56. Specifically, the blade base 56 extends between the variable blade 52 and the blade stem 54. Each wing stem 54 extends through a respective opening 58 defined in the casing 50. The casing 50 includes a plurality of openings 58. The variable vane assembly 44 also includes a lever arm 60 that extends from each variable vane 52 and changes the orientation of the vanes 52 relative to the flow path through the compressor 14 through the compressor 14. It is used to selectively rotate the variable wing 52 to facilitate increased control of the air flow. In particular, one or more of these components may include one or more anti-wear coatings, as discussed in detail further below.

  FIG. 3 is an exploded view of a variable stator vane assembly 44 including one or more wear resistant coatings according to some embodiments of the present technology. A wing airfoil 62 is shown as a cutaway view. A cast-in blade stem 64 is located at the radially outer end of the blade airfoil 62. The wing stem 64 includes an attachment mechanism 66, shown here as a threaded connection, although other equivalent connection methods such as spline attachments may be used. The wing stem 64 extends through an opening 68 in a casing 70, also shown as a cutaway view. The opening 68 includes a counterbore 72 that receives an internal washer 74. A bushing 76 slides into the opening 68 over the upper wing stem 64 and fills the remaining space in the opening 68 to improve the sliding engagement between the casing 70 and the upper wing stem 64. The internal washer 74 can be replaced with a flange of a rotary bushing with a flange. In this case, a washer (not shown) separates the lever arm 77 from the case. The first end 80 of the lever arm 77 is assembled onto the wing stem 64 and is secured to the wing stem 64 by a clamping mechanism 82, shown here as a lock nut. The clamping mechanism 82 cooperatively mates with the attachment mechanism 66 illustrated as the threaded end of the upper wing stem 64 and secures the attachment mechanism 66 to the wing stem 64. The lever arm 77 includes a second end 84 that is integrally attached to the first end 80 by a web 86. A protrusion 88 extends from the second end 84 and is received by the opening of the actuation ring. A second bushing 90 covers the projection 88 and fits into the opening of the actuation ring, improving the sliding engagement between the actuation ring and the projection 88.

  At the radially inner end of the blade assembly 44, a cast-in lower blade shaft 92 extends radially inward from the blade airfoil 62. The blade shaft 92 includes a first large-diameter shaft 94 and a second small-diameter shaft 96. A second bushing 98 is assembled over the lower wing shaft 94 received by the optional shroud 100. A seal 102 is assembled radially inward of the shroud 100, and the seal 102 contacts the shroud 100 by teeth 104 located on the rotating device of the engine. The teeth 104 penetrate into the seal 102 and form a barrier against air leakage. An optional third tightening mechanism 106, illustrated as a lock pin, extends through at least one boundary of the seal 102, through the shroud 100, through the second bushing 98, and through the opening 108 in the lower wing shaft 94. If an optional tightening mechanism 106 is used, another tightening mechanism such as a threaded bolt or lock nut may be substituted for the lock pin. Optionally, a washer is placed between the large diameter portion 92 facing the stem and the shroud 100.

  FIG. 4 is an exploded view showing a cross section of the airfoil 62 including the inner bushing 110 and the outer bushing 112 together with the trunnion 113. In some embodiments, the airfoil 62 may include a single bushing 114 as shown in FIG. Bushings and washers can be manufactured by various techniques such as injection molding or high temperature sintering of ceramics. Bushings are generally strong and have excellent wear characteristics. In some embodiments, the bushing is made of an inexpensive wear material that is easily replaceable and designed as a consumable. To determine the type of bushing for a particular design, e.g., coefficient of thermal expansion, operating temperature range, yield strength and elastic modulus of the mating material, force on the mating material, wear per cycle, during service life Physical properties such as the number of cycles are used to determine the relative wear that will be experienced in an application. Wear resistant coatings according to certain embodiments of the present invention applied to the inner surface of bushings 114, 110, or 112 and the outer surface of trunnion 113 generally prevent or substantially minimize wear loss and Protect.

  The aforementioned systems and components may be coated with one or more wear resistant coatings as illustrated with reference to FIGS. Turning first to FIG. 6, one embodiment of the wear resistant coating 116 includes a single hard backing 118 and a plurality of nanolayers 120. Specifically, the hard backing 118 includes a metal alloy substrate in which a plurality of hard particles are dispersed, and the hard backing is disposed on the substrate 121. Next, the plurality of nanolayers 120 are disposed on the hard backing 118. The hard backing 118 improves the wear resistance of the nanolayer 120 and substantially protects the substrate 121 from damage under friction. The substrate 121 may be any one of the components detailed above with reference to FIGS. 1-5, and may be a device or component for other applications or systems.

  In one embodiment, the hard backing 118 has a hardness value greater than about 700 Vickers hardness, in another embodiment the hardness value is greater than about 800 Vickers hardness, and in another embodiment, the hardness value is about In yet another embodiment, the hardness value is greater than about 1000 Vickers hardness, and in yet another embodiment, the hardness value is greater than about 1200 Vickers hardness. Hard backing 118 includes one or more materials selected to generally maintain or improve the corrosion resistance of the substrate material, depending on the usefulness and application of the coated article. The hard backing 118 is characterized by proper toughness and crush strength, stability to the operating temperature of the coated article, oxygen resistance, and compatibility with the top nanolayer 120.

  The hard backing 118 can include a variety of suitable metal alloy substrates such as cobalt, cobalt-base superalloy, nickel-base superalloy, or iron-base superalloy. Such superalloys may be formed of nickel-based, iron-based, or cobalt-based alloys, and nickel, iron, or cobalt is generally the largest component in weight in a superalloy. Exemplary nickel-base superalloys contain at least about 40 percent by weight of nickel and several percent of cobalt, or chromium, or aluminum, or tungsten, molybdenum, titanium, or iron, or combinations thereof. As examples of nickel-based superalloys, the trade names include Inconel®, Nimonic®, Rene® (eg, Rene® 80-, Rene® 95, Rene®). 142, and Rene <(R)> N5 alloy), and Udimet <(R)>, including directionally solidified and single crystal superalloys. (INCONEL (R), Nimonic (R), and Udimet (R) are registered trademarks of the Special Metals Corporation corporate group, and Rene (R) is a registered trademark of the General Electric Company.) Cobalt-based superalloys contain at least about 30 percent by weight of cobalt, several percent nickel, or chromium, or aluminum, or tungsten, molybdenum, titanium, or iron, or combinations thereof. As examples of cobalt-based superalloys, the trade names are Haynes®, Nozzaloy®, Stellite®, and Ultimate® (Haynes® and Ultimate) are Haynes International. , Inc., and STELLITE (registered trademark) is a registered trademark of DELORO STELLITE COMPANY, INC.). In some embodiments, the hard backing 118 comprises a nickel chrome aluminum alloy, or a cobalt nickel chrome aluminum yttrium alloy, or a nickel cobalt chrome tungsten alloy, or a cobalt molybdenum chrome silicon alloy, the alloy comprising a solid solution reinforced cobalt base substrate and Laves. It consists of a phase interpenetrating network, which consists of about 25% or more molybdenum, 6% or more chromium, and more than 2% silicon.

  In the above embodiment, a plurality of hard particles are dispersed in the metal substrate of the hard backing 118. The hard particles may include one or more metal nitrides, or metal carbides, or metal borides, or combinations thereof. In some embodiments, the metal substrate includes tungsten carbide, or titanium carbide, or chromium carbide, or silicon carbide, or diamond, or titanium nitride, or silicon nitride, or cubic boron nitride, or titanium boride, or Particles of chromium oxide, aluminum oxide, zirconium oxide, silicon oxide, or combinations thereof may be dispersed. The plurality of hard particles have an average particle size ranging from about 100 nanometers to about 2 microns. In certain embodiments, the average particle size is in the range of about 100 nanometers to about 2000 nanometers, the majority in the range of about 100 nanometers to about 400 nanometers with the remaining particles being less than about 2000 nanometers. And in other embodiments less than about 1000 nanometers. Particles with a particle size between about 100 nanometers and about 400 nanometers also tend to strengthen the substrate, and particles below about 1000 nm provide wear protection without making the coating abrasive to the opposing material. Can bring. The volume of the plurality of hard particles varies from about 30 volume percent to about 70 volume percent of the total volume of the hard backing 118. In certain embodiments, the percentage of hard particles relative to the total volume of the hard backing 118 ranges from about 35 volume percent to about 65 volume percent, and in another embodiment between about 40 volume percent and about 60 volume percent. It is in. In another embodiment, in the range of about 45 volume percent to about 55 volume percent. In some embodiments, the spacing between the plurality of hard particles is in the range of about 100 nm to about 700 nm, and in another embodiment, in the range of about 100 nanometers to about 500 nanometers. The thickness of the hard backing is in the range of about 5 micrometers to about 500 micrometers. The thickness of the hard backing 118 should depend on the load exerted on the coating. In applications where the force exerted is high, the hard backing may need to be thicker to support the nanolayer coating. In an exemplary embodiment, a hard backing 118 comprising a metal substrate and a plurality of hard particles dispersed in the metal substrate is deposited by either fast oxygen fuel heat injection or fast air fuel injection. Hard backing 118 deposited by high speed air fuel technique can result in nanolayer retention, less decarburization, smaller spacing between hard particles, and lower brittleness of the binder used during deposition.

  In some embodiments, the hard backing 118 includes a nickel coating with a phosphorus or boron additive. Such coatings have a hardness in the range from about 700 Vickers hardness to about 1000 Vickers hardness, but the wear resistance and hardness can be further improved by adding hard particles to the substrate by co-deposition. . The added hard particles may include silicon carbide, silicon nitride, alumina, cubic boron nitride, or diamond.

  In general, the plurality of nanolayers 120 have different characteristics. For example, the plurality of nanolayers 120 may include a plurality of alternately overlapping first and second layers 122 and 124. The first layer 122 includes a first material, and the second layer 124 includes a second material that is different from the first material. The first material includes a material comprising a metal nitride, or metal boride, or metal carbide, or a combination thereof. The second material includes a material that includes a metal, or metal nitride, or metal boride, metal carbide, or a combination thereof. In an exemplary embodiment, nanolayer 120 includes alternating layers of metal carbide such as TiC / ZrC. In another exemplary embodiment, nanolayer 120 includes alternating layers of metal nitride such as TiN / ZrN. In yet another exemplary embodiment, nanolayer 120 includes alternating layers of metal nitride and metal carbide, such as TiN / TiC. In some embodiments, a metal layer may be included between the nitride layer and the carbide layer. In an exemplary embodiment, nanolayer 120 includes alternating layers of metal and metal nitride, such as TiN / Ti / TiN.

  In general, the nanolayer 120, components, and related manufacturing methods of the present invention have higher hardness, better wear resistance, impact resistance, and corrosion resistance than would otherwise be expected by mixing rules. , And provide clearance control. This is because, when alternating layers of materials with different elastic moduli and crystal structures are combined, the overall resistance to dislocation migration through the structure increases.

  In some embodiments, the thickness of each of the plurality of first layers 122 and second layers 124 ranges from about 3 nanometers to about 500 nanometers. In another embodiment, the thickness ranges from about 10 nanometers to about 200 nanometers. In some embodiments, the thickness ranges from about 20 nanometers to about 100 nanometers. The thickness of the individual layers 122, 124 can also be adjusted individually to control the hardness, strain tolerance, and overall stability of the nanolayer coating when subjected to processing thermal stresses. The total thickness of the nanolayer 120 may range from about 1 micron to about 25 microns. In some embodiments, the total thickness ranges from about 1 micron to about 20 microns. In another embodiment, the total thickness is in the range of about 5 microns to about 10 microns. The number of first layers 122 and second layers 124 utilized may vary depending on the thickness of each layer and the desired thickness of the nanolayer 120. The total thickness of the coating is to be operated and depends on the components that can be constrained by the total space available between the contacts.

  In one exemplary embodiment, the wear resistant coating 116 includes a hard backing 118 comprising a cobalt chrome alloy in which tungsten carbide particles of micron to sub-micron dimensions are dispersed, and a plurality of TiNs disposed on the hard backing 118. It includes alternating layers 120 of nanolayers and ZrN nanolayers. In one exemplary embodiment, the wear resistant coating 116 comprises a hard backing 118 comprising a metal alloy in which a plurality of metal oxide particles are dispersed, where the metal alloy includes a material comprising nickel or cobalt or iron; It includes alternating layers 120 of a plurality of metal nitride nanolayers disposed on a hard backing 118. Placing the nanolayer 120 over the wear resistant hard backing 118 introduces a gradual hardness gradient and prevents premature distortion of the nanolayer 120, thus reducing the hardness and wear resistance of the overall coating 126. Improve.

  Abrasion resistant coatings are suitable for moderately high operating temperatures. In certain embodiments, the abrasion resistant coating 116 is thermally stable up to a temperature of at least up to about 500 ° C., in another embodiment up to at least about 600 ° C., and in yet another embodiment up to at least about 700 ° C. . Nanolayer coatings retain morphological stability at temperatures well above the expected operating temperature range. The nanolayers of the present invention maintain adequate acid resistance up to about 650 ° C., well above the expected operating temperature range of the variable vane. The underlying hard backing is thermally stable up to about 500 ° C. In the higher temperature range, the composition of the hard backing may change to a superalloy substrate having a gamma prime phase reinforced by thermally more stable hard particles such as chromium carbide or aluminum oxide.

  FIG. 7 includes an abrasion resistant coating 126 that includes a plurality of nanolayers 120 disposed on a hard backing 118 as shown in FIG. 6 and further illustrates a lubricating layer 128 disposed over the nanolayer 120. 1 illustrates one exemplary embodiment. The lubricating material of the lubricating layer 128 may be selected to be stable up to the operating temperature of the coated article and under low humidity conditions. The lubricating material may include tungsten disulfide, or molybdenum disulfide, or hexagonal boron nitride, or tungsten telluride, or tungsten selenide, or molybdenum telluride, or combinations thereof. In one exemplary embodiment, the lubricating material is tungsten disulfide. Tungsten disulfide provides low friction properties at temperatures up to about 550 ° C. even in the absence of moisture, which is a common case at high altitudes (> 35,000 feet) (> 10,670 m).

  Embodiments of the present technology also include a method for making an abrasion resistant coating as detailed above. FIG. 8 is a flow diagram illustrating a method according to an embodiment of the invention. The method 130 includes providing a substrate 121 in step 132, placing a hard backing 118 in step 134, and placing a plurality of nanolayers 120 on the hard backing in step 136.

  The process of depositing the coating begins by pretreating the substrate surface to be coated. The first step is to remove debris and oxide from the substrate. Well-known cleaning techniques such as degreasing, grit blasting, chemical cleaning, and / or electrochemical polishing can also be used to obtain the desired surface cleaning and finishing.

  The placement of the hard backing in step 134 includes methods such as electroless plating, or fast oxygen fuel heat injection, or active combustion high speed air fuel injection, or electron beam physical vapor deposition. In some embodiments, the hard backing is a metal alloy substrate deposited by either high speed oxyfuel heat injection or active combustion high speed air fuel injection. Advantageously, the hard backing deposited by these techniques results in nanolayer retention, less decarburization, smaller spacing between hard particles, and lower brittleness of the binder. Electroless plating is also used when the hard backing includes a nickel coating with boron or phosphorus doping. To further improve the wear characteristics, a hard backing may be dispersed in the electroless nickel substrate. The arrangement of the plurality of nanolayers in step 136 includes physical vapor deposition.

  Another aspect of the invention is to provide an article. The article includes a component and a wear resistant coating disposed on the component. The wear resistant coating includes a hard backing comprising a metal alloy substrate having a plurality of hard particles dispersed therein, and a plurality of nanolayers disposed on the hard backing. The hard backing includes any metal superalloy having a plurality of hard particles dispersed therein. The coating includes a plurality of nanolayers disposed on a hard backing. The properties of the hard backing and nanolayer are described in the wear resistant coating embodiment above. The article includes a machine having components that move along each other covered by the wear resistant coating of the present invention. The article includes an engine having a component coated with the wear resistant coating of the present invention. The engine includes a turbine engine having variable stator vanes comprising the aforementioned components. The engine is a turbine engine having a variable vane including a trunnion and a bushing, the bushing having an inner surface in contact with the outer surface of the trunnion, and the inner surface of the bushing and the outer surface of the variable vane are resistant to each other. Includes a turbine engine that is coated with a wear coating. The article includes a vehicle having this component. In one exemplary embodiment, the vehicle is an aircraft.

  Using a hard backing as a buffer between the nano-multilayer coating and a durable but ductile substrate helps provide a tribo system that can support high surface loads, but provides high wear resistance . Thus, wear resistant coatings according to some embodiments of the present invention are suitable for all types of substrates and are stable to relatively high temperatures.

  The above-described embodiments of the present invention serve as a general template for preventing fine wear, sliding wear, and friction of components under conditions where external lubrication is not possible. Although embodiments of the present invention have been described with respect to aircraft engine variable vanes and bushings, the concepts described in the present invention can also be used in other applications where fine wear under similar operating conditions remains an issue. Moreover, the described invention can also be utilized for similar material contact surfaces under sliding wear conditions.

  The following examples serve to illustrate the characteristics and advantages provided by the embodiments of the present invention and are not intended to limit the present invention to these embodiments.

  The outer surface of the variable vane stem was coated with various hard backing compositions by the active combustion high speed oxygen fuel method, the active combustion high speed air fuel method, and the electroless Ni diamond composite coating method. These coatings are named hard backings 1, 2, and 3, respectively. Hard backing 1 was cobalt with tungsten carbide thermal spray dispersion by the fast oxygen fuel method. Hard backing 2 was cobalt chrome with tungsten carbide thermal spray dispersion by the active combustion high speed air fuel method. The hard backing 3 was electroless nickel hard particle composite plating. The particle size of tungsten carbide was between 0.2 and 5 micrometers. The coating thickness was 150-200 micrometers. The portion with the hard backing 3 was then further coated with a double alternating layer of titanium nitride (TiN) and zirconium nitride (ZrN) using the PVD cathodic arc technique, with each layer having a thickness of 120 nanometers. The total thickness of the TiN / ZrN multilayer system was 8 micrometers. The wear of the coated part was measured using a custom test device that simulated the operating conditions of the reciprocating part. The coated stem was moved against the Tellite 6 bushing. The test was conducted for 100 hours with this test equipment and the wear of both the bushing and the stem coating were measured.

  The wear was plotted for the parts covered by various hard backings. Plot 138 is shown in FIG. Bars 140 and 142 show stem and bushing wear without any coating and form a reference line. Bars 144 and 146 each show wear of the stem and bushing with the hard backing 1. Bars 148 and 150 indicate the wear of the stem and bushing with the hard backing 2, respectively. Bars 152 and 154 show stem and bushing wear with a hard backing 3 with a TiN / ZrN nanolayer coating, respectively. Plot 138 shows that the hard backings 1 and 2 are about 4-6 times lower than the wear on the trunnion as compared to the baseline uncoated sample.

  The outer surface of the variable vane stem was coated with a TiN and ZrN nanolayer to a thickness of 8 micrometers. This was moved for 8 hours relative to the Bushing of Style 6 in the simulation test in the test apparatus. Another stem is first coated with a hard backing 4 which is an electroless nickel diamond composite plating with a thickness of 200 microns, on which an 8 micron PVD coating of TiN / ZrN nanolayer with a total thickness of 8 microns is deposited. It was. The layer thickness of each of TiN and ZrN was 120 nm. This was also run under the same operating conditions as in Example 1. FIG. 10 shows a plot 156 illustrating the wear comparison of the top two coatings compared to an uncoated specimen. Bars 158 and 160 each show stem and bushing wear without any coating. Bars 162 and 164, respectively, show stem and bushing wear with a TiN / ZrN nanolayer without any hard backing. Bars 166 and 170 each show stem and bushing wear with a hard backing 4 with a TiN / ZrN nanolayer. The wear of the TiN / ZrN coated stem 162 was 40% lower than the uncoated specimen 158. However, the stem with TiN / ZrN on the hard backing 4 did not show any wear in the 8 hour test (bar 166), showing a significant improvement over the uncoated specimen.

  While only certain features of the invention have been illustrated and described herein, many variations and modifications will occur to those skilled in the art. For example, in the above sections, the embodiments refer to aircraft engines, but are valid for other components that are similarly exposed to mechanical, chemical, and thermal stresses. Therefore, it is to be understood that the appended claims are intended to cover such modifications and changes as fall within the true spirit of the invention.

1 is a schematic view of a gas turbine engine according to an embodiment of the present technology. 1 is a partial schematic view of a compressor of a gas turbine engine according to an embodiment of the present technology. 1 is an exploded view of an exemplary variable vane assembly according to an embodiment of the present technology. FIG. 1 is a schematic view of a system having a wear surface between a bushing and a shaft according to an embodiment of the present technology. FIG. 1 is a schematic view of a system having a wear surface between a bushing and a shaft according to an embodiment of the present technology. FIG. 1 is a cross-sectional view of a structure having an anti-wear coating according to one embodiment of the present technology. 3 is a cross-sectional view of a structure having an abrasion resistant coating according to another embodiment of the present technology. FIG. 2 is a flow diagram of a method for making an abrasion resistant coating according to an embodiment of the present technology. FIG. 6 illustrates wear in a component covered by various wear resistant coatings according to one embodiment of the present technology. FIG. 3 illustrates wear in a component covered by various wear resistant coatings according to another embodiment of the present technology.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Turbine engine 12 Low pressure compressor 14 High pressure compressor 16 Combustor 18 High pressure turbine 20 Low pressure turbine 24 1st shaft 26 2nd shaft 40 Rotary blade 44 Variable blade assembly 50 Casing 52 Variable blade 54 Blade stem 56 Blade base 58 Opening part 60 Lever Arm 62 Airfoil 64 Cast-In Type Blade Stem 66 Mounting Mechanism 68 Opening 70 Casing 72 Counterbore 74 Internal Washer 76 Bushing 77 Lever Arm 78 Washer 80 First End 82 Tightening Mechanism 84 Second End 86 Web 88 Projection 92 Lower wing shaft 94 Large diameter shaft 96 Small diameter shaft 98 Second bushing 100 Shroud 102 Seal 104 Tooth 106 Tightening mechanism 108 Opening 110 Internal bushing 112 External bushing 113 Trunnion 114 Bushing 116 Abrasion Resistant Coating 118 Hard Backing 120 Nanolayer 121 Substrate 122 First Layer 124 Second Layer 126 Abrasion Resistant Coating 128 Lubricating Layer 130 Method 132 Method Step: Provide Substrate Preparation 134 Method Step: Hard Backing Placement 136 Method steps: Placement of nanolayers 138 Plot 140 Bar wire-wear of stem without coating 142 Bar wire-wear of bushing without coating 144 Bar wire-wear of stem with hard backing 1 146 Bar wire-hard back Wear of Bushing with Brace 1 148 Bar Wire-Wear of Stem with Hard Back 2 150 Bar Wire-Wear of Bushing with Hard Back 2 152 Bar Wire-Wear of Stem with Hard Back 3 154 Bar- Bushing wear with hard backing 3 6 Plot 158 Bar-wear of stem without coating 160 Bar-wear of bushing without coating 162 Bar-wear of stem with nanolayer 164 Bar-wear of bushing with nanolayer 166 Bar-hard back Wear of stem with pad 4 and nanolayer 170 Bar-wear of bushing with hard backing 4 and nanolayer

Claims (12)

A hard backing (118) comprising a metal alloy substrate in which a plurality of hard particles are dispersed;
An abrasion resistant coating (116) comprising a plurality of nanolayers (120) having different properties disposed on the hard backing (118). The wear resistant coating (116) of any preceding claim, wherein the hard backing (118) has a hardness value of at least 700 Vickers hardness. The metal alloy substrate is cobalt, cobalt chrome alloy, cobalt alloy, nickel alloy, iron alloy, nickel chrome aluminum alloy, cobalt nickel chrome aluminum yttrium alloy, nickel cobalt chrome tungsten alloy, or cobalt molybdenum chrome. The wear resistant coating (116) of any preceding claim, comprising a material comprising a silicon alloy. The plurality of hard particles are tungsten carbide, titanium carbide, chromium carbide, silicon carbide, diamond, titanium nitride, silicon nitride, cubic boron nitride, titanium boride, chromium oxide, or oxidation. The wear resistant coating (116) of any preceding claim, comprising a material comprising aluminum, or zirconium oxide, or silicon oxide, or a combination thereof. The wear resistant coating (116) of any preceding claim, wherein the nanolayer (120) comprises a material comprising a metal nitride, or metal boride, or metal carbide, or a combination thereof. The wear resistant coating (116) of any preceding claim, wherein the hard backing (118) has a thickness in the range of 5 microns to 500 microns. A hard backing (118) comprising a cobalt chromium alloy in which nanoparticles of tungsten carbide are dispersed;
An abrasion resistant coating (116) comprising a plurality of TiN nanolayers and alternating layers of ZrN nanolayers disposed on the hard backing (118). A component and a wear resistant coating (116) disposed on the component;
The wear resistant coating (116) comprises a hard backing (118) comprising a metal alloy substrate having a plurality of hard particles dispersed therein, and a plurality of nanolayers (120) disposed on the hard backing (118). Including an article. The article of claim 8 including an engine having the component. The article of claim 9, wherein the engine comprises a turbine engine having a variable vane comprising the component. The engine includes a turbine engine having a variable vane including a trunnion and a bushing, the bushing having an inner surface in contact with the outer surface of the trunnion, the inner surface of the bushing and the variable vane The article of claim 10, wherein an outer surface is coated with said anti-wear coating (116). The article of claim 11, comprising a vehicle having the component.

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