Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B15/00—Machines or devices designed for grinding seat surfaces; Accessories therefor
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
  • A61L27/28—Materials for coating prostheses
  • A61L27/30—Inorganic materials
  • A61L27/303—Carbon
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L27/00—Materials for grafts or prostheses or for coating grafts or prostheses
  • A61L27/50—Materials characterised by their function or physical properties, e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23C—MILLING
  • B23C3/00—Milling particular work; Special milling operations; Machines therefor
  • B23C3/02—Milling surfaces of revolution
  • B23C3/05—Finishing valves or valve seats
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B1/00—Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
  • B24B19/02—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements
  • B24B19/028—Single-purpose machines or devices for particular grinding operations not covered by any other main group for grinding grooves, e.g. on shafts, in casings, in tubes, homokinetic joint elements for microgrooves or oil spots
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/02—Lapping machines or devices; Accessories designed for working surfaces of revolution
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
  • B24B37/042—Lapping machines or devices; Accessories designed for working plane surfaces operating processes therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/11—Lapping tools
  • B24B37/12—Lapping plates for working plane surfaces
  • B24B37/14—Lapping plates for working plane surfaces characterised by the composition or properties of the plate materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B24—GRINDING; POLISHING
  • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
  • B24B37/00—Lapping machines or devices; Accessories
  • B24B37/11—Lapping tools
  • B24B37/20—Lapping pads for working plane surfaces
  • B24B37/24—Lapping pads for working plane surfaces characterised by the composition or properties of the pad materials
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C8/60—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using solids, e.g. powders, pastes
  • C23C8/62—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using solids, e.g. powders, pastes only one element being applied
  • C23C8/64—Carburising
  • C23C8/66—Carburising of ferrous surfaces
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
  • A61F2002/30003—Material related properties of the prosthesis or of a coating on the prosthesis
  • A61F2002/30004—Material related properties of the prosthesis or of a coating on the prosthesis the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis
  • A61F2002/30031—Material related properties of the prosthesis or of a coating on the prosthesis the prosthesis being made from materials having different values of a given property at different locations within the same prosthesis differing in wettability, e.g. in hydrophilic or hydrophobic behaviours
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
  • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
  • A61F2002/3082—Grooves
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
  • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
  • A61F2002/30838—Microstructures
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
  • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
  • A61F2002/3084—Nanostructures
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/32—Joints for the hip
  • A61F2/36—Femoral heads ; Femoral endoprostheses
  • A61F2/3609—Femoral heads or necks; Connections of endoprosthetic heads or necks to endoprosthetic femoral shafts
  • A61F2002/3611—Heads or epiphyseal parts of femur
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2250/00—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2250/0014—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis
  • A61F2250/0056—Special features of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof having different values of a given property or geometrical feature, e.g. mechanical property or material property, at different locations within the same prosthesis differing in wettability, e.g. in hydrophilic or hydrophobic behaviours
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2400/00—Materials characterised by their function or physical properties
  • A61L2400/10—Materials for lubricating medical devices
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61L—METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS IN GENERAL; DISINFECTION, STERILISATION OR DEODORISATION OF AIR; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS OR SURGICAL ARTICLES
  • A61L2430/00—Materials or treatment for tissue regeneration
  • A61L2430/24—Materials or treatment for tissue regeneration for joint reconstruction

Definitions

• the present invention relates to workpieces having working surfaces and, more particularly, to a working surface and a system and method for production of the working surface.
• a lubricant is introduced to the zone of interaction.
• the lubricant film 20 between opposing surfaces 32 and 34 moving at a relative velocity V, forms an intact layer which permits the moving surfaces to interact with the lubricant.
• no contact between surfaces 32 and 34 occurs at all, and the lubricant layer is said to carry a load P that exists between the opposing surfaces. If the supply of lubricant is insufficient, a reduction in the effectivity of the lubrication ensues, which allows surface-to-surface interactions to occur.
• Fig. IB As shown schematically in Fig. IB, below a certain level of lubricant supply, the distance between opposing, relatively moving surfaces 32 and 34 diminishes because of load P, such that surface asperities, i.e., peaks of surface material protruding from the surfaces, may interact.
• an asperity 36 of surface 34 can physically contact and interact with an asperity 38 of surface 32.
• the asperities of surfaces 32 and 34 carry all of the load existing between the interacting surfaces. In this condition, often referred to as boundary lubrication, the lubricant is ineffective and the friction and wear are high.
• Fig. 1C (i)-(ii) schematically illustrate a working surface being conditioned in a conventional lapping process.
• a working surface 32 of a workpiece 31 faces a contact surface 35 of lapping tool 34.
• Contact surface 35 of lapping tool 34 is made of a material having a lower hardness with respect to working surface 32.
• the composition and size distribution of the abrasive particles are selected so as to readily wear down working surface 32 according to plan, such as reducing surface roughness so as to achieve a pre-determined finish.
• a load is exerted in a substantially normal direction to surfaces 32 and 35, causing abrasive particle 36 to penetrate working surface 32 and contact surface 35, and resulting in a pressure P being exerted on a section of abrasive particle 36 that is embedded in working surface 32.
• the penetration depth of abrasive particle 36 into working surface 32 is designated by h al ; the penetration depth of abrasive particle 36 into contact surface 35 is designated by h b i.
• abrasive particle 36 penetrates into lapping tool 34 to a greater extent than the penetration into workpiece 31, such that h bl > h al .
• workpiece 31 and lapping tool 34 are made to move in a relative velocity V.
• the pressure P, and relative velocity V of workpiece 31 and lapping tool 34 are of a magnitude such that abrasive particle 36, acting like a knife, gouges out a chip of surface material from workpiece 31.
• abrasive particle 36 is substantially stationary.
• relative velocity V is selected such that a corresponding shear force Q is large enough, with respect to pressure P, such that the direction of combined force vector F on abrasive particle 36 causes abrasive particle 36 to rotate.
• the material of lapping tool 34 that is in contact with abrasive particle 36 is substantially unyielding (i.e., of low elasticity) with respect to the particles in the abrasive paste, these particles are usually ground up quite quickly, such that the abrasive paste must be replenished frequently.
• bonded abrasives such as grinding wheels, coated abrasives, loose abrasives and abrasive cutting tools.
• Abrasive particles, the cutting tools of the abrasive process are naturally occurring or synthetic materials which are generally much harder than the materials which they cut.
• the most commonly used abrasives in bonded, coated and loose abrasive applications are garnet, alpha alumina, silicon carbide, boron carbide, cubic boron nitride, and diamond. The relative hardness of the materials can be seen from Table 1:
• abrasive is normally dictated by economics, finish desired, and the material being abraded.
• the abrasive list above is in order of increasing hardness, but it is also coincidentally in order of increasing cost with garnet being the least expensive abrasive and diamond the most expensive.
• a soft abrasive is selected to abrade a soft material and a hard abrasive to abrade harder types of materials in view of the cost of the various abrasive materials.
• a hard abrasive to abrade harder types of materials in view of the cost of the various abrasive materials.
• exceptions such as very gummy materials where the harder materials actually cut more efficiently.
• the harder the abrasive grain the more material it will remove per unit volume or weight of abrasive.
• Super-abrasive materials include diamond and cubic boron nitride, both of which are used in a wide variety of applications.
• the contact surface of the lapping tool is eventually consumed by the abrasive material, requiring replacement. In some typical applications, the contact surface of the lapping tool is replaced after approximately 50 workpieces have been processed.
• Sensitivity to the properties of the abrasive paste including paste formulation, hardness of the abrasive particles, and particle size distribution (PSD) of the abrasive particles.
• the lapping processing must generally be performed in several discrete lapping stages, each stage using an abrasive paste having different physical properties.
• a mechanical device including: (a) a metal workpiece including a working surface for contacting a liquid, the working surface including a nanometric, adhesive, solid film containing carbon atoms, the film being intimately bonded to the workpiece, wherein the film is intimately bonded to the workpiece on one face of the film, and wherein an opposing face of the film is exposed, for contacting with the liquid.
• the working surface is for bearing a load
• the device further including: (b) a contact surface, disposed substantially opposite the working surface; (c) a lubricant, disposed between the working surface and the contact surface, and (d) a mechanism for causing a relative movement between the working surface and the contact surface.
• the solid film has an average thickness of less than 200 nanometers.
• the solid film has an average thickness of at least 5 nanometers.
• the solid film has an average thickness of 5- 100 nanometers.
• the solid film has an average thickness of 10-50 nanometers.
• the solid film is a polymeric film.
• the metal workpiece contains metal atoms of at least one metallic element, and wherein, in a plurality of nanometric monolayers of the working surface, the monolayers include both the carbon atoms and the metal atoms, wherein, for any particular monolayer of the monolayers, Ri is an atomic ratio defined by:
• N c is a number of the carbon atoms in the particular monolayer
• N M is a number of the metal atoms in the particular monolayer, and i is a monolayer number of the particular monolayer, and wherein, in a first, outer monolayer of the monolayers, i equals 1, and if,- is equal to at least 0.8.
• Ri is equal to at least 0.95.
• Ri is equal to at least 0.98.
• i 20
• R 1 is equal to at least 0.20
• i 20
• R 1 is equal to at least 0.30
• / 2O 5 and wherein R 1 is equal to at least 0.40.
• / equals 30, and wherein R 1 is equal to at least 0.25.
• the metal workpiece has microrelief in the working surface.
• the microrelief includes a plurality of grooves having a maximum depth of 5-30 microns, and a width of 100- 1000 microns.
• the working surface is a metal workpiece is a metal cup of an artificial hip joint
• the contact surface is disposed on a metal joint head surrounding the cup.
• a mechanical device including: (a) a metal workpiece having a working surface; (b) a contact surface, disposed generally opposite the working surface, the contact surface for moving in a relative motion to the working surface; (c) a plurality of abrasive particles, the particles disposed between the contact surface and the working surface, and (d) a mechanism, associated with at least one of the working surface and the contact surface, for applying the relative motion, and for exerting a load in a substantially normal direction to the contact surface and the working surface, the contact surface for providing an at least partially elastic interaction with the plurality of abrasive particles, the contact surface having a Shore D hardness within a range of 40-90, the contact surface having an impact resistance within a range of 4-12 J/m, and wherein, upon activation of the mechanism, the relative motion under the load causes a portion of the abrasive particles to penetrate the working surface so as to modify at least one surface property of the working surface.
• the abrasive particles are freely disposed between the contact surface and the working surface. According to still further features in the described preferred embodiments, the abrasive particles are disposed within a paste.
• the Shore D hardness is at least 65.
• the Shore D hardness is within a range of 70-80.
• the impact resistance is within a range of 4-9 J/m.
• the impact resistance is within a range of 5-8 J/m.
• the Shore D hardness is within a range of 65-90, and wherein the impact resistance is within a range of 4-9 J/m.
• the Shore D hardness is within a range of 70-80, and wherein the impact resistance is within a range of 5-8 J/m.
• the contact surface is disposed on a lapping tool.
• the contact surface is attached to a lapping tool base with an adhesive force of at least 10 kg/cm2.
• the contact surface is attached to a lapping tool base with an adhesive force of at least 50 kg/cm2.
• the contact surface is attached to a lapping tool base with an adhesive force of at least 80 kg/cm2.
• the abrasive particles include alumina particles.
• the composition of the contact surface includes at least one polymer. According to still further features in the described preferred embodiments, the composition of the contact surface includes polyurethane.
• the composition of the contact surface includes an epoxy material.
• the composition of the contact surface includes both an epoxy material and polyurethane.
• the composition of the contact surface includes both an epoxy material and polyurethane, and wherein the Shore D hardness is within a range of 65-90, and the impact resistance is within a range of 4-9 J/m.
• the composition of the contact surface includes an epoxy material and polyurethane in a weight ratio of 25:75 to 90: 10.
• the composition of the contact surface includes an epoxy material and polyurethane in a weight ratio of 1 :2 to 2: 1.
• the composition of the contact surface includes an epoxy material and polyurethane in a weight ratio of 3:5 to 7:5.
• the composition of the contact surface includes polyurethane in a range of 20% to 75%, by weight.
• the composition of the contact surface includes polyurethane in a range of 40% to 75%, by weight.
• the composition of the contact surface includes polyurethane in a range of 40% to 65%, by weight.
• the composition of the contact surface includes at least 35% of an epoxy material, by weight. According to still further features in the described preferred embodiments, the composition of the contact surface includes an epoxy material in a range of 40% to 70%, by weight.
• the metal working surface includes a steel working surface.
• a lapping method including the steps of: (a) providing a system including: (i) a metal workpiece having a working surface; (ii) a contact surface, disposed generally opposite the working surface, the contact surface having a Shore D hardness within a range of 40-90, the contact surface having an impact resistance within a range of 4-12 kJ/m, and (iii) a plurality of abrasive particles, the particles freely disposed between the contact surface and the working surface; (b) exerting a load in a substantially normal direction to the contact surface and the working surface, (c) lapping the workpiece by applying a relative motion between the working surface and the contact surface, and wherein the contact surface and the abrasive particles are selected, and the relative motion under the load is performed so as to (i) effect an at least partially elastic interaction between the contact surface and the abrasive particles such that at least a portion of the abrasive particles penetrate the working surface, and (ii) modify
• the contact surface and the abrasive particles are selected, and the relative motion under the load is performed so as to deposit a polymeric, adhesive film on the working surface.
• the polymeric, adhesive film is at least partially derived from the contact surface.
• the lapping method further including the step of: (d) applying microrelief to the working surface to produce at least one recess. According to still further features in the described preferred embodiments, step (d) is performed prior to the lapping.
• the abrasive particles include alumina particles.
• the composition of the contact surface includes both an epoxy material and polyurethane.
• the composition of the contact surface includes both an epoxy material and polyurethane, and wherein the Shore D hardness is within a range of 65-90, and the impact resistance is within a range of 4-9 J/m.
• the composition of the contact surface includes an epoxy material and polyurethane in a weight ratio of 1 :2 to 2: 1.
• the composition of the contact surface includes an epoxy material and polyurethane in a weight ratio of 3:5 to 7:5.
• the composition of the contact surface includes polyurethane in a range of 40% to 75%, by weight.
• the composition of the contact surface includes an epoxy material in a range of 40% to 70%, by weight.
• Fig. IA is a schematic description of the mechanically interacting surfaces having an interposed lubricating layer
• Fig. IB is a schematic description of mechanically interacting surfaces having interacting asperities
• Fig. lC(i)-(ii) schematically illustrate a working surface being conditioned in a conventional lapping process
• Fig. 2 is a description of a generalized concept of one aspect of the invention.
• Fig. 3A is a schematic side view of a grooved cylinder in accordance with the invention.
• Fig. 3B is a schematic view of a metal plate, the working surface of which is grooved, in accordance with the invention.
• Fig. 4A is a pattern of dense sinusoidal grooving, in accordance with an embodiment of the invention.
• Fig. 4B is a pattern of sinusoidal grooving, in accordance with an embodiment of the invention.
• Fig. 4C is a sinusoidal pattern of grooving, containing overlapping waves, in accordance with an embodiment of the invention.
• Fig. 4D is a pitted pattern of grooving in accordance with an embodiment of the invention.
• Fig. 4E is a pattern of rhomboidal grooving, in accordance with an embodiment of the invention
• Fig. 4F is a pattern of helical grooving, in accordance with an embodiment of the invention.
• Fig. 5 is a flow chart of the process of conditioning a working surface in accordance with one embodiment of the invention employing recessed zones;
• Fig. 6 A is schematic view of an interacting surface of the invention.
• Fig. 6B is a schematic description of a side view of the interacting surface of Fig. 6A;
• Fig. 7A is a cross-sectional schematic description of a pre-machined surface
• Fig. 7B is a cross-sectional schematic description of a leveled surface
• Fig. 7C is a cross-sectional schematic description of the leveled surface after micro-grooving
• Fig. 7D is a cross-sectional schematic description of a grooved surface having conditioned ridges
• Fig. 8A is a cross-sectional schematic description of a working surface of the invention, prior to processing
• Fig. 8B is a cross-sectional schematic description of the working surface, after micro-grooving, the micro-grooves being surrounded by bulges;
• Fig. 8C is a cross-sectional schematic description of a leveled micro- grooved surface, after lapping
• Fig. 9A is a cross-sectional schematic description of a lapping tool - working surface interface prior to lapping, in accordance with the invention.
• Fig. 9B is a cross-sectional schematic description of the lapping tool - working surface condition after lapping has progressed, in accordance with the invention.
• Fig. 9C(i)-(iii) are an additional cross-sectional schematic representation of a working surface being conditioned in the inventive lapping process
• Fig. lOA-1 and Fig. 10A-2 are photographic representations of wetting patterns of a reference working surface that was initially covered with oil, wherein Fig. lOA-1 represents the prior-art working surface 5 seconds after an oil drop was distributed, and Fig. 1OA 1-2 represents the identical working surface, 60 seconds after the oil drop was distributed;
• Fig. lOB-1 and Fig. 10B-2 are photographic representations of wetting patterns of an exemplary inventive working surface that was initially covered with oil, wherein Fig. lOB-1 represents the inventive working surface 5 seconds after an oil drop was distributed, and Fig. 1OB 1-2 represents the identical work surface, 60 seconds after the oil drop was distributed;
• Fig. 1 IA is a sputter depth-profiling plot of various elemental compositions in a conventional working surface
• Fig. 1 IB is a sputter depth-profiling plot of various elemental compositions in a working surface of the present invention
• Fig. 12A is a schematic, cross-sectional diagram showing a solid, carbon-containing film deposited on a working surface, according to the present invention
• Fig. 12B shows a portion of the diagram of Fig. 12 A, after removing several nanolayers of the working surface
• Fig. 13 is a schematic drawing of an exemplary tribological system according to one aspect of the present invention.
• Fig. 14A is a cross-sectional schematic illustration of a pre-coated surface
• Fig. 14B is a cross-sectional schematic illustration of the coated surface of Fig. 14A;
• Fig. 14C is a cross-sectional schematic illustration of the micro-grooves of the surface of Fig. 14B, in accordance with another embodiment of the invention.
• Fig. 15 is a cross-sectional schematic illustration of a working surface covered by a pitted plastic cover, in accordance with another embodiment of the invention.
• Fig. 16 is a cross-sectional schematic illustration showing a cross- sectional velocity profile of a fluid being transported in a conduit having an interior working surface according to the present invention
• Fig. 17 is a cross-sectional schematic illustration of an artificial joint for implanting in a living body
• Fig. 18 is an isometric schematic description of an experimental set-up for testing discs conditioned in accordance with the invention.
• Fig. 19 is a schematic illustration of a test rig for evaluating the tribological properties of rollers processed according to the present invention, in a "one drop" test;
• Fig. 20 shows the friction coefficient at the stop point of the test, for each roller.
• Fig. 21 provides plots of the friction coefficient ( ⁇ ) and wear (h) as a function of friction length (L).
• the present invention is an improved work surface, and a system for production of the improved work surface.
• lubricated surfaces in relative sliding motion are treated to produce less wear and friction in the course of interaction.
• the process of the invention transforms a working surface, forming two zones, one having a high degree of lubricant repellence, and the other having a relative attraction towards the lubricant.
• the two zones are interposed as will be described later on.
• One zone constitutes an assembly of well-distributed structures on the working surface, having a more pronounced attraction towards the lubricant.
• a schematic representation of the concept of the invention is shown in Fig. 2, to which reference is now made.
• a schematic working surface is shown which is composed of a combination of zones.
• the zones marked A are lubricant attractive and the zones marked R are relatively lubricant repelling.
• the difference between the zones with respect to attraction to the lubricant is associated with a structural difference.
• the structural aspects of the system of this embodiment of the invention are schematically described in reference to Figs. 3A-B.
• a cylinder 50 has its surface structured such that one or more grooves, such as helical groove 52, are engraved on the surface.
• such grooves have a maximum depth of about 5-30 microns, and a width of about 100-1000 microns.
• the remainder of the original surface is one or more ridges, in this example, a helical ridge 54.
• the exterior of cylinder 50 includes two zones, the superficial zone that includes the ridges, and the recessed zone including the grooves.
• a metal slab 60 has been processed in accordance with the present invention.
• the working surface after undergoing a frictional interaction with another element (not shown), includes grooves 62, the assembly of which become the recessed zone, and alternate ridges 64, which form the superficial zone of the working surface of metal slab 60.
• Figs. 4A-F are provided exemplary, schematic patterns of recesses, such as microgrooves, which are suitable for the structural aspects of embodiments of the present invention.
• Figs. 4A-B show sinusoidal patterns of varying density;
• Fig. 4C shows a sinusoidal pattern containing overlapping sinuses,
• Fig. 4D shows a pitted pattern;
• Fig. 4E shows a pattern of rhomboids, and
• Fig. 4F shows a helical pattern.
• the diversity of optional patterns is very large, and the examples given above constitute only a representative handful.
• the processing in accordance with the present invention involves forming a surface possessing lubricant repelling zones.
• the surface is a compound surface possessing both lubricant attractive zones and lubricant repelling zones.
• the lubricant repelling zone is a superficial zone of the working surface, which can be produced either by mechanically processing the working surface, or by coating the superficial zone with a lubricant-repelling coat.
• mechanical processing of a working surface for the purpose of conveying particular frictional properties requires a change in the relief of the working surface.
• a preferred process for conditioning the working surface described schematically in Fig. 5, forming a recessed zone and conditioning the superficial zone take place in the following order: in step 90, the working surface is machined by abrading and/or lapping so as to obtain a high degree of flatness and surface finish.
• the recessed zone is formed as will be explained later on, and in step 94, conditioning of the superficial zone takes place.
• Lapping is a suitable, preferred technique for such conditioning of the superficial zone. Lapping can achieve a very good flatness rating, and very good finish.
• the lapping technique uses a free-flowing abrasive material, as compared to grinding, which uses fixed abrasives.
• Fig. 6A describes schematically an interacting surface 100, the working surface 102 of which is to be processed in accordance with an embodiment of the invention.
• a schematic sectional view of the surface is shown in Fig. 6B, indicating the position of an enlarged view of the cross-section shown in Figs. 7A-D.
• the pre-machined surface 106 is shown.
• Fig. 7B 5 the machined surface is shown leveled.
• Fig. 7C surface 106 is shown after microgrooves 108 have been formed.
• the working surface has been transformed, to convey lubricant-repelling properties to superficial zone 109.
• a new layer has formed within the superficial zone, this layer designated schematically by the number 110. This layer will be discussed in greater detail hereinbelow.
• Figs. 8A-B a cross-section in the working surface is schematically represented by line 120.
• Fig. 8B microgrooves 120 are formed, accompanied by bulges 122.
• Fig. 8C the superficial zone has been processed by lapping, leveling off the bulges and producing the plastically deformed layer 124.
• lapping is a preferred mechanical finishing method for obtaining the characteristics of the working surface of the mechanical element in accordance with the present invention.
• the lapping incorporates a lapping tool, the surface of which is softer than the working surface of the processed mechanical part.
• the abrasive grit must be much harder than the face of the lapping tool, and harder than the processed working surface. It is essential that the abrasive grit is not too hard or brittle, thus, diamond grit appears to be inappropriate for the inventive lapping technology.
• Aluminum oxide has been found to be a suitable abrasive material for a variety of lapping surfaces and working surfaces, in accordance with the invention.
• Figs. 9A-B schematically present progressive steps in the inventive lapping process, in which the conditioning of the working surface is promoted.
• the initial condition is shown schematically on the microscopic level in Fig. 9A.
• the irregular topography of working surface 132 (disposed on workpiece 131) faces lapping tool 134 and is separated by an irregular distance therefrom.
• Abrasive particles 136 and others are partially sunken in the lapping tool 134, and to a lesser extent, in working surface 132.
• the working surface and the lapping tool are made to move in a relative motion designated by arrow 138. This motion has an instantaneous magnitude V.
• abrasive particles such as abrasive particle 139, are now rounded to some extent, losing some of their sharp edges in the course of rubbing against the surfaces.
• abrasive particles 136 penetrate into working surface 132 and gouge out material therefrom, as the process continues, and the abrasive particles become rounded, substantially no additional stock is removed from the processed part. Instead, the lapping movement effects a plastic deformation in working surface 132 of workpiece 131, so as to increase the micro-hardness of working surface 132.
• Fig. 9C (i)-(iii) are an additional schematic representation of a working surface being conditioned in a lapping process and system of the present invention.
• a working surface 132 of a workpiece 131 faces a contact surface 135 of lapping tool 134.
• contact surface 135 of lapping tool 134 is made of a material having a greater wear-resistance and a lower hardness with respect to working surface 132.
• the composition and size distribution of the abrasive particles are selected so as to readily wear down working surface 132 according to plan, such as reducing surface roughness to a pre-determined roughness.
• a load is exerted in a substantially normal direction to surfaces 132 and 135, causing abrasive particle 136 to penetrate working surface 132 and contact surface 135, and resulting in a pressure P being exerted on a section of abrasive particle 136 that is embedded in working surface 132.
• the penetration depth of abrasive particle 136 into working surface 132 is designated by h a2 ; the penetration depth of abrasive particle 136 into contact surface 135 is designated by h b2 - Abrasive particle 136 penetrates into lapping tool 134 to a much greater extent than the penetration into workpiece 131, such that h b2 » In ⁇ significantly, because of the substantial elastic character of the deformation of inventive contact surface 135, the penetration depth of abrasive particle 136 into contact surface 135 is much larger than the penetration depths of identical abrasive particles into contact surfaces of the prior art (under the same pressure P) 5 i.e., h b2 > h bl, where h M is defined in Fig.
• the penetration depth of abrasive particle 136 into working surface 132, h a2 is much smaller than the corresponding penetration depth, h a i, of the prior art, i.e., h a2 ⁇ h al .
• abrasive particle 136 acting like a knife, gouges out a chip of surface material from workpiece 131. This chip is typically much smaller than the chips that are gouged out of the working surfaces conditioned by lapping technologies of the prior art.
• relative velocity V is selected such that a corresponding shear force Q is large enough, with respect to pressure P, such that the direction of combined force vector F on abrasive particle 136 causes abrasive particle 136 to rotate.
• the elasticity of lapping tool 134 and contact surface 135 results in less internal strains within abrasive particle 136, with respect to the prior art, such that a typical particle, such as abrasive particle 136, does not shatter, rather, the edges of the surface become rounded.
• An idealization of this rounding phenomenon is provided schematically in Fig. 9C(Ui).
• the working surfaces of the present invention have an intrinsic microstructure that influences various macroscopic properties of the surface. Without wishing to be limited by theory, it is believed that the inventive lapping system effects a plastic deformation in the working surface, so as to improve the microstructure of the working surface.
• modified microstructure is a greatly increased micro-hardness.
• characteristic wetting property of the inventive surface as shown in lOB-1 and Fig. 10B-2.
• the characteristic wetting property of a reference surface is shown, for comparative purposes, in Figs. lOA-1 and Fig. 10A-2.
• HRC annealed SAE 4340 steel
• a single drop of C22 oil was dispersed over the entire surface of each specimen, such that coverage or wetting was substantially 100%.
• the wetted area was monitored as a function of time.
• Fig. lOA-1 represents the reference working surface 5 seconds after the oil drop was distributed
• Fig. 10A1-2 represents the identical working surface, 60 seconds after the oil drop was distributed.
• the reference surface specimen remained completely covered by the layer of oil, and continued to be completely covered for the entire duration of the test (24 hours).
• Fig. lOB-1 and Fig. 10B-2 are photographic representations of wetting patterns of an exemplary inventive working surface that was initially covered with oil, wherein Fig. lOB-1 represents the inventive working surface 5 seconds after an oil drop was distributed, and Fig. 1OB 1-2 represents the identical work surface, 60 seconds after the oil drop was distributed.
• Fig. lOB-1 represents the inventive working surface 5 seconds after an oil drop was distributed
• Fig. 1OB 1-2 represents the identical work surface, 60 seconds after the oil drop was distributed.
• the wetted area decreased rapidly in a matter of seconds.
• the characteristic dimensionless wetting coefficient defined by:
• this liquid repelling quality of the inventive working surface is associated with reduced friction and wear, reduced risk of seizure, and extended operating life of mechanical elements incorporating such surfaces.
• a lapping tool with a thin (e.g., 0.05 - 0.4 mm), somewhat elastic layer (or producing a lapping tool including or substantially consisting of a thick elastic layer, typically up to, or exceeding 10mm), promotes both the micro-hardness and the lubricant repellence of a conditioned working surface.
• the mechanical criteria with which such a layer should preferably comply include:
• the hardness of the layer should be selected such that the layer does not appreciably break or grind the abrasive powder
• the weight ratio of epoxy cement to polyurethane ranges from about 1:2 to about 2:1, and even more preferably, from about 3:5 to about 7:5.
• the elastic layer should contain, by weight, at least 10% polyurethane, preferably, between 20% and 75% polyurethane, more preferably, between 40% and 75% polyurethane, and most preferably, between 40% (inclusive) and 65% (inclusive).
• the elastic layer should preferably contain, by weight, at least 10% epoxy, more preferably, at least 35% epoxy, yet more preferably, at least 40% epoxy, and most preferably, between 40% (inclusive) and 70% (inclusive).
• the inventive contact surface (lapping surface) should have the following combination of physical and mechanical properties:
• impact resistance within a range of 3-12 J/m, preferably 4-9 J/m, and most preferably, 5-8 J/m, according to ASTM STANDARD D 256-97;
• adhesive strength preferably of at least 10 kg/cm 2 , more preferably, at least 50 kg/cm 2 , more preferably, at least 80 kg/cm 2 , yet more preferably, at least 100 kg/cm 2 , and most preferably, at least 120 kg/cm 2 , to the lapping tool base, for those applications that utilize a lapping tool base, and/or to the particular working surface being used, as will be explained in further detail hereinbelow.
• a steel (AISI 1040) sample 403 underwent grinding and subsequently was machined using abrasive paste (containing alumina particles), using the lapping tool and method of the present invention.
• abrasive paste containing alumina particles
• Standard or reference sample 40 also of AISIl 040 steel, underwent grinding, and was not subjected to further treatment.
• the elemental composition of Fe samples at the surface and in-depth concentration distributions (“sputter depth-profiling") were estimated by surface- sensitive Auger Electron Spectroscopy (AES) combined with controlled argon-ion bombardment.
• the surface of standard sample 40 contains (in atom%) approximately 20% Fe, 44% C, and 36% O.
• the surface of sample 403 contains substantially 0% Fe 5 and approximately 88% C and 12% O.
• the AES depth profiling shows that the C content of standard sample 40 drops rapidly - within 1-2 nm - to about 5%, while the Fe content surges to over 85% at a depth of 4 nm from the surface.
• the AES depth profiling shows that the C content of sample 403 drops gradually and almost linearly over 40-50 nm - to about 10%.
• the C content of sample 403 is approximately 50%, which is higher than the C content of standard sample 40 at the surface.
• the Fe content increases largely according to the decrease in the C content, such that at a depth of 20 nm from the surface, the Fe content of sample 403 is still less than 50%.
• an extremely- thin, typically nanometric, solid, carbon-containing coating or film 420 is applied on the working surface 410.
• a substantial (though not necessarily exclusive) source of the carbon-containing coating is the carbon-containing material on the surface of the inventive lapping tool.
• the source of the carbon-containing coating can be carbon- containing particles and materials (e.g., polymeric materials) added to the abrasive paste used in the lapping process.
• asperities 412,414, which protrude from working surface 410 are also covered by coating 420.
• coating 420 exhibits wear, particularly in the area covering the asperities.
• the asperities themselves, such as asperity 414 undergo attrition.
• an exposed surface area 416 of asperity 414 is largely surrounded by exposed coating area 422. Consequently, any lubricant in the vicinity of exposed surface area 416 tends to migrate from exposed coating area 422 towards exposed surface area 416 of asperity 414, such that superior lubricating conditions are maintained.
• the coating or film in Fig. 12a is a nanometric film having an average thickness of up to 200 run, and more preferably, 5-200 nm. Typically, the nanometric film has an average thickness of 5-100 nm. Excellent experimental results have been obtained for working surfaces having nanometric films of an average thickness of 5-50 nm.
• plastic coatings described in Figs. 14A- 14C have a thickness that is similar to that of the grooves, and always exceeds several microns.
• the material source of the nanometric film is from the inventive contact surface of the lapping tool, or from materials disposed in the paste.
• the nanometric film is intimately bonded to the working surface by filling the nanometric contours of the working surface.
• the nanometric film is strongly adhesive to the working surface. Consequently, the film is not subject to the phenomena of peeling, flaking, crumbling, etc., which characterize coatings of the prior art.
• the nanometric film is bonded, on one side, to the surface of the workpiece, and on the opposite side, the nanometric film becomes the working surface of the workpiece, being exposed to the lubricant and to the frictional forces resulting from the relative motion of the working and counter surfaces (and the load thereon).
• FIG. 13 is a schematic drawing of an exemplary tribological system 500 according to one aspect of the present invention.
• Tribological system 500 includes a rotating working piece 502 (mechanism of rotation, not shown, is standard), having a working surface (contact area) 503 bearing a load L, a counter surface disposed within stationary element (bushing) 504, and a lubricant (not shown) disposed between working surface 502 and counter surface 504.
• Working surface 503 is an inventive working surface of the present invention, as described hereinabove.
• Recessed zones (grooves 506) serve as a reservoir for the lubricant and as a trap for debris.
• inventive lapping method and inventive working surface produced thereby, after producing grooving patterns in the working surface, achieves a surprisingly-high performance with respect to prior-art lapping surfaces combined with the identical grooving patterns, and as demonstrated experimentally (see Example 3 and Table 4 below).
• a plastic coat is applied on the working surface instead of mechanically conditioning the superficial zone.
• the procedure for coating the working surface includes first covering the working surface with a precursor of the coat.
• the main stages in the processing of a working surface in accordance with this embodiment of the invention are illustrated in Figs. 14A-C, to which reference is now made.
• Fig. 14A 5 the working surface is designated 150.
• Fig. 14B a plastic coat 152 is disposed on working surface 150. After coat 152 is deposited, portions of coat 152 are removed, by way of example, by subjecting working surface 150 and coat 152 to micro-grooving, as shown schematically in Fig. 14C.
• the micro-grooves or recesses 154 penetrate through plastic coat 152 and into working surface 150.
• ridges 153 having a surface made of plastic coat 152, constitute a superficial zone
• recesses 154 constitute a recessed zone.
• the recessed zone is more attractive to the lubricant applied to the working surface than is the superficial zone.
• the working surface is pre- processed by grinding. Subsequently, the surface is coated by a layer of lubricant repelling tape, containing holes. The results of this procedure are shown schematically in Fig. 15.
• Working surface 160 is covered with a plastic perforated sheet 162, in which holes such as hole 164 are punched prior to coating.
• the working surface is micro- structured to obtain a plurality of recesses. This can be achieved by various methods known in the art, including mechanical cutting, laser engraving, and chemical etching. Methods for producing regular micro-relief in mechanical parts is taught by M. Levitin and B. Shamshidov in "A Disc on Flat Wear Test Under Starved Lubrication", Tribotest Journal 4-2, December 1997, (4), 159, the contents of which are incorporated by reference for all purposes as if fully set forth herein.
• the inventive work surface is utilized in the internal wall of a surface of a vessel or conduit used for the transport of fluids, so as to reduce the friction at the surface of the internal walls, and correspondingly reduce the pressure loss and energy cost of pumping the fluid.
• conduit refers to a vessel used for the transport of at least one liquid.
• Conduit is specifically meant to include a tube, pipe, open conduit, internal surface of a pump, etc.).
• Figure 16 is a schematic diagram showing a cross-sectional velocity profile 180 of a fluid being transported in a conduit 182.
• the forces of adherence adjacent to an inner working surface 183 of wall 184 are appreciably reduced.
• the thickness of the boundary layer adjacent to inner working surface 183 is also appreciably reduced, such that bulk-phase flow occurs much closer to wall 184 than in conventional metal conduits.
• the inventive work surface and inventive lapping method and device are utilized in the production of artificial joints, e.g., hip joints.
• artificial joints e.g., hip joints.
• Conventional hip joints suffer from a number of disadvantages, which tend to reduce their effectiveness during use, and also shorten their life span.
• the synovial fluid produced by the body after a joint replacement operation is considerably more diluted and thus 80% less viscous than the synovial fluid originally present, the artificial joint components are never completely separated from each other by a fluid film.
• the materials used for artificial joints, as well as the sliding-regime parameters, allow only two types of lubrication: (i) mixed lubrication, and (ii) boundary lubrication, such that the load is carried by the metal femoral head surface sliding on the plastic or metal acetabular socket surface. This results in accelerated wear of the components, increasing the frictional forces, and contributes to the loosening of the joint components and, ultimately, to the malfunction of the joint.
• the high wear rate of the ultra-high-weight polyethylene (UHMWPE) cup results in increased penetration of the metal head into the cup, leading to abnormal biomechanics, which can cause loosening of the cup.
• polyethylene debris which is generated during the wearing of the cup, produces adverse tissue reaction, which can induce the loosening of both prosthetic components, as well as cause other complications.
• Increased wear also produces metal wear particles, which penetrate tissues in the vicinity of the prosthesis.
• fibrous capsules formed mainly of collagen, frequently surround the metallic and plastic wear particles. Wear of the metal components also produces metal ions, which are transported, with other particles, from the implanted prosthesis to various internal organs of the patient. These phenomena adversely affect the use of the prosthesis.
• bone and bone cement particles which remain in the cup during surgery, or which enter the contact zone between the hip and the cup during articulation, tend to become embedded in the cup surface. These embedded bone particles can cause damage to the head, which can, in turn, bring about greatly increased wear of the cup.
• microrelief technology improves lubrication and friction characteristics, and facilitates the removal of wear debris, bone fractions, and bone cement particles from the friction zone between the male and female components of the joint.
• metal joint head 441 is engaged within a metal cup 442.
• metal joint head 441 has grooves 444 (recesses, pores, etc.) according to microrelief technology known in the art. More importantly, metal joint head 441 has been subjected to the lapping methods of the present invention, so as to produce the inventive working surface.
• the surface of metal joint head 441 is coated with an extremely-thin, typically nanometric, carbon-containing (or polymeric) coating or layer, as described hereinabove with reference to Figure 12a.
• FIG. 18 An interchangeable set of carbon steel discs of 30 mm diameter, such as disc 186, rotatable around an axle, is made to rotate against a flat counter-plate 192 for measuring wear.
• the discs are made of carbon steel grade 1045, having an HRC of 27-30.
• Electrical motor or gear 190 supplies the torque for the rotation.
• Counter-plate 192 has a support 194, which has an adjustable height for controlling the force applied on disc 186.
• a permanent load of a 100 N is applied to the disc in the direction of the counter plate 192.
• One drop of Amoco Industrial Oil 32 (equivalent to ASTM 150 Turbine Oil) is applied to the dry friction surface before activating the motor to achieve a constant rotation rate of 250 rpm.
• the time to seizure which is the accumulated time from start of turning, until the time in which movement was stopped by seizure, was measured.
• the disc was rotated at 180 rpm.
• a group of control discs was subjected to finishing by grinding.
• a second group of discs was subjected to micro-grooving.
• a third group of discs was subjected to micro-grooving and to lapping, according to the present invention.
• the results of a one-drop test are provided in Table 2. The path of the disc until seizure, the coefficient of friction, and the intensity of wear (measured by peak depression formed on the counter-plate as a result of the friction with the disc) were calculated.
• the inventive working surface of the present invention incorporated in various mechanical elements that engaged in frictional forces, reduces friction and wear, risk of seizure, and prolongs the operating life of such elements.
• punching applications the qualities of the working surface are improved, and a power reduction of up to 30% is observed.
• the inventive working surface, and the inventive system for production thereof were applied to 120 mm cylinder sleeves of diesel engines and to 108 mm diameter motorcycle engines.
• the results of the tests demonstrate that for a given performance level, the use of sleeves having the inventive work surfaces, as compared with conventional sleeves, reduces fuel consumption.
• the sleeves having the inventive working surfaces have a characteristically longer lifetime, and lose less oil.
• liquid attracting zone refers to a zone within a working surface in which the characteristic dimensionless wetting coefficient is greater than 0.95, and typically greater than 0.98, 60 minutes after the initial dispersion of oil on to the working surface.
• characteristic dimensionless wetting coefficient is defined by:
• Aft A 0 wherein A(t) is the nominal wetted area of the working surface as a function of time, and A 0 is the nominal surface area of the working surface, and wherein the liquid used for determining A(t) is No. 22 industrial oil.
• No. 22 industrial oil As used herein in the specification and in the claims section that follows, the term "No. 22 industrial oil”, “C22 industrial oil”, and the like refers to a standard industrial oil for mechanical applications, having a viscosity of ⁇ 22 centistokes at 40 0 C.
• nominal surface area refers to a surface area of the surface based on the global geometric dimensions, without regard to microstructure. Hence, a square, 4cm x 4cm working surface has a nominal surface area of 16cm 2 .
• EXAMPLE 2 A roller on block tribo-tester was used to evaluate the tribological properties of rollers processed according to the present invention, in a "one drop test".
• the test rig is described schematically in Fig. 19.
• a rotating roller 2 is brought into contact with a stationary block 3 under a given load P while a very small amount of lubricant (one drop) is applied to the contact.
• a force transducer 4 is used to measure the friction force F and a proximity probe 9 measures the variation in the gap, thus providing the total wear of roller 2 and block 3. Both friction and wear are continuously monitored and recorded as functions of time.
• the test duration is defined as the time elapsed from the start of the test until the end of the test due to the occurrence of events (a) or (b) described above, or the time corresponding to the maximum friction in case of event (c). It should be noted that in this special case (c), the test is continued for about 20 minutes beyond the "test duration" prior to complete stop. For each new test, block 3 is moved horizontally in its holder 6 to provide a fresh contact.
• Table 2 presents the test duration, in minutes, of each roller, and indicates the type of event that caused the stop of the test.
• Fig. 20 shows the friction coefficient at the stop point of the test for each roller.
• AU rollers processed in accordance with the present invention showed an increased friction up to a certain maximum value, followed by a decrease in the friction. The maximum friction coefficient in these 4 rollers was no more than 0.18.
• Roller #5 had a friction coefficient of 0.11, which was the lowest friction coefficient of the six rollers.
• FIG. 21 A graph of the friction coefficient ( ⁇ ) and wear (h) as a function of friction length (L) is provided in Fig. 21.
• a roller on block tribo-tester was used to evaluate the tribological properties of rollers in a "one drop test”. Sliding distance tests were performed on each of four hardened-steel roller specimens, using a hardened-steel block as the counter-surface.
• Roller specimen I was prepared using a conventional lapping method; roller specimen II was prepared using a lapping method of the present invention; roller specimen III was prepared by grooving followed by the conventional lapping method used in preparing roller specimen I, and roller specimen IV was prepared by grooving followed by the inventive lapping method used in preparing roller specimen II.
• roller specimen H 5 prepared using a lapping method of the present invention achieved a sliding distance of 1373 meters, nearly double that of reference roller specimen I, which was prepared using a conventional lapping method.
• roller specimen IV, prepared by grooving followed by the inventive lapping method used in preparing roller specimen II achieved a sliding distance of 9060 meters, more than a fourfold increase in sliding distance with respect to that of reference roller specimen III, which was prepared by grooving followed by using the conventional lapping method used in preparing roller specimen I.
• the inventive lapping method performs well with respect to the conventional lapping method
• the combination of the inventive lapping method with standard grooving methods achieves a surprisingly-high performance with respect to prior-art methods of grooving and lapping.
• impact resistance refers to the impact resistance, with notch, in units of kJ/m, as determined by ASTM STANDARD D 256-97 and/or ISO STANDARD 180:1993.
• Shore D hardness refers to a measure of the resistance of material to indentation, according to the standard ASTM test.
• the hardness testing of plastics and hard rubbers is most commonly measured by the Shore D test, with higher numbers signifying greater resistance.
• freely disposed relates to the free- flowing state of abrasive particles as in typical lapping methods of the prior art.
• the term "intimately bonded”, with respect to a film and a working surface refers to a nanometric, adhesive film having a contour that complements the micro-contour of the working surface, such that the film is firmly attached to the working surface along the entire contour thereof.

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• 2005
  • 2005-03-10 WO PCT/IL2005/000284 patent/WO2006027768A1/en active Application Filing
  • 2005-03-10 IN IN3733CHN2014 patent/IN2014CN03733A/en unknown
  • 2005-03-10 JP JP2007529128A patent/JP2008511459A/ja active Pending
  • 2005-03-10 EP EP05718857.5A patent/EP1784270A4/de not_active Withdrawn
  • 2005-03-10 CN CNA2005800297638A patent/CN101014434A/zh active Pending
  • 2005-03-10 KR KR1020077005192A patent/KR20070050056A/ko not_active Application Discontinuation

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