Abstract: An apparatus for surface-hardening steel balls includes a container having projections protruding inwardly from and extending longitudinally along an inner wall; a support shaft having projections extending outwardly from and longitudinally along the support shaft; a container driving mechanism which rotates the container in one direction; and a support shaft driving mechanism which rotates the support shaft in an opposite direction. In operation, the container's projections transfer the balls from a lower portion of the container to a higher portion where the balls are dropped to the lower portion while the support shaft's projections strike the steel balls when the steel balls are dropping to the lower portion.

Abstract: The present invention is a method and apparatus for peening the internal surface of non-ferromagnetic hollow parts. Ferromagnetic peening elements are inserted into the non-ferromagnetic hollow part, and a magnetic dipole creates a magnetic field through the non-ferromagnetic hollow part attracting the peening elements which contact a portion of the internal surface of the non-ferromagnetic hollow part. The magnetic field is disengaged and a second magnetic dipole creates a second magnetic field, thereby causing the peening elements to contact a second portion of the internal surface. The magnetic dipoles are repeatedly turned on and off, thereby causing repeated impact within the interior of the hollow part until the internal surface attains a predetermined stress level.

Abstract: A method for quality assurance of a laser shock peening process that quantitatively analyzes a single laser shock peened dimple or spot. The method measures a first interior surface of the first dimple to obtain height data and the processes the height data to obtain production volumetric data of the dimple. The volumetric data may then be compared to a predetermined correlation of test volumetric data and high cycle fatigue failure based on high cycle fatigue tests of test pieces that were laser shock peened in the same or similar laser shock peening apparatus as the production workpieces. The test pieces may each have a failure precipitating flaw within a laser shock peened area of the test piece that was laser shock peened in the same or similar laser shock peening apparatus. Preferably, the measuring is performed using a profilometer such as an interferometric optical profilometer.

Abstract: A method of coating a golf club head under vacuum conditions with an open hanger type shot blasting machine includes the steps of forming a blank of golf club head; grinding the blank to form large pores on the surface of the blank; polishing the blank to form a refined blank containing fine pores on the surface thereof; hanging multiple refined blanks on hangers in an opening hanger type shot blasting machine to rotate and move the blanks into a vacuum rear portion of the machine. Meanwhile, shot blasting material containing mixed shot grit and powdered metal coating material is centrifugally thrown with mechanical throwing arms, so that shot grit strikes and forms numerous deeply depressed pores on the refined blanks. The shot grit quickly leaves the surfaces of the refined blanks due to a reactive force produced during impact of the shot grit on the blanks.

Abstract: A shot peening method for gears capable of hardening a gear without formation of projections on the tops of its teeth and gears having no projections and treated by this shot peening method are provided. After a preliminary shot has been performed to harden the top of a tooth of the gear by shooting only at the top of the tooth using an air nozzle, a bottom land shot is performed by shooting shots at a bottom land in a substantially perpendicular direction thereto with an air nozzle, whereby the gear is entirely hardened.

Abstract: The invention relates to a method for producing a diaphragm spring where only specific portions of the diaphragm spring are subjected to a shot-peening process. The shot-peening step is performed only to one side of an outer circumferential portion and an inner circumferential portion of the elastic portion (5a) of the diaphragm spring (5).

Abstract: The present invention for producing a substantial two-way shape memory effect within a composition substantially only exhibiting one-way memory is realized by first plastically deforming the alloy into a predetermined shape and then work hardening, such as through grit blasting, a selected portion of the outer surface of the alloy. Advantageously, this later type of work hardening selectively transforms only the outer portion of the alloy into a region of "super-elasticity" which acts as a biasing force to re-strain the alloy upon cooling. As such, two-way shape memory elements--which recover their original shape upon heating, yet deform into a second desired shape upon cooling--may be made to produce actuators exhibiting strain amplitudes of as much as 3% while exerting a force in excess of about 10,000 psi.

Abstract: Fatigue-resistance is significantly increased by performing shot peening using fine shots. A plurality of particles of hard metal having a diameter ranging from 20 to 100 micrometers are ejected onto a surface of a steel workpiece at an impinging speed greater than 80 m/second. The impinging speed is controlled so that the upper limit of temperature rising of the surface of the workpiece is maintained at a temperature more than 150.degree. C. but less than the temperature at which recovery recrystallization and austentizing of steel occurs.

Abstract: An electromagnetic peening apparatus includes a first electromagnetic coil having a first face configured to conform to a first surface of a workpiece, and a second electromagnetic coil having a second face configured to conform to a second surface of the workpiece. A carriage positions the first and second coils in abutting contact with the workpiece at respective first and second faces and surfaces. A power supply powers the coils to produce electromagnetic force therein to plastically deform the workpiece at the first and second surfaces to effect a compressive layer therein.

Abstract: A shot peening system for peening the tubes of a steam generator continuously generates a shot stream and withdraws the shot stream dispensing nozzle into a vacuum chamber in an end effector while repositioning the nozzle for peening the next tube. A load tank forms an air lock for recycling shot recovered and cleaned by the vacuum system to a pressurized peen tank which feeds the recycled shot to a feed valve for mixing with a flow of compressed air to generate the shot stream. The pressure on the shot in the feed tank and the pressure of the compressed gas supplied to the feed valve are independently regulated to adjust the concentration of shot in the shot stream. The feed valve is constructed for ease of assembly and repair, and directs flow of a purge gas across the shot feed orifice and into a purge line which cycles shot and debris purged from the feed valve to the shot cleaning equipment on the vacuum side.

Abstract: The invention describes a method and apparatus for peening objects by means of ultrahigh velocity waterjet. The apparatus includes means for holding and producing relative motion in three dimensions of both the workpiece and the jet. Control means are provided to allow uniform and variable depth peening of complex shapes and automatic variations in relative speed, standoff distance, angle and pressure. The method includes the use of entrained disappearing particles in the waterjet to facilitate peening.

Abstract: An apparatus produces compressive stress in a component surface. Positioning of a contact area of the component surface is controlled to situate a contact area of the component surface relative to an indenter element. The indenter element is fixtured to cause an indentation at the contact area. The force of the indentation is measured as the indenter element contacts the contact area, and controlled responsive to the amount of force measured and the desired compression. The system allows deep compressive stresses to be generated without the surface damage associated with conventional peening.

Abstract: A method for improving the endurance of a blade base (6) of the disc (1) of a disc chipper, a blade base and a disc chipper. A wearing plate (10) is attached to the surface (18) of the blade base facing towards the chip opening (7), the wearing surface (10) of which is shot peened.

Abstract: A peening particle support having a plurality of asymmetrically arranged peening particles positioned to minimize tracking on a workpiece. The peening particles are attached to an exposed surface of the peening particle support. The peening particle arrangement includes three or less peening particles with substantially the same non-zero radial distance from a center of the exposed surface. The peening particles are preferably arranged in at least one linear array of peening particles.

Abstract: An apparatus is disclosed for carrying out a method whereby parts are treated in a fluidized bed created within an enclosure that provides for movement of air generally upwardly through the enclosure, and where the parts are passed through the fluidized bed in such a fashion as to present the entire surface of the part to be treated to the particles of the fluidized bed as a result of causing the parts to be treated to follow a circuit within the bed, and wherein the parts are further rotated each on its own axis during said path of travel through the bed.

Abstract: Process for the manufacture of a containment element for a fluid heated to a temperature exceeding 850.degree. C. A blank made of a refractory metal alloy is coated with a glass-based adhesive, at least one film made of a glass suitable for the material and the plasticity temperature of the blank is laid down on it, the blank is heated to the plastic temperature and subjected to a first stamping operation to shape the chamber of the containment element, followed by a second stamping operation to form the inner or outer flaps of the chamber. The element is then cooled, and finally, heat-treated.

Abstract: A method of preparing fretting wear resistant titaniumbase alloy orthopaedic implants includes the steps of shot peening the surface of the implant with spherical ceramic beads of a selected size and density, and with selected intensity such that the fretting wear resistance of the implant is increased and wherein the implant surface is uniformly peened to create a compressively-stressed region within the surface of approximately 100-300 microns depth.

Abstract: A shot peening method and apparatus enables low intensity peening at a velocity which is equal to or less than the minimum velocity required to assure conveyance of the media through the transport hose in pneumatic systems or the minimum velocity necessary to project a coherent shot stream in the case of wheel systems.

Abstract: A trowel and related method of manufacture in which residual stresses are intentionally imposed upon the bottom working surface and/or the top mounting surface of a trowel blade. Stresses can be imposed, for example, by glass bead peening, shot peening, rolling, and/or brushing the metal trowel blade. Stresses are built up to a working stess level that remains substantially constant with further use of the trowel against abrasive, spreadable surfaces. Imposed stresses on the top and bottom surfaces can also be used to vary the resulting curvature of the blade.

Abstract: The velocity distribution of a solid particle travelling in a carrier flow, such as a flow of peening shot or balls, is measured by first passing the solid particles or balls forming the shot through light barriers to generate respective pulse trains. The light barriers have a defined spacing from each other and the time between the light signals is measured for calculating the velocity. Such calculation is possible based on the time difference between one first signal generated by the first light barrier and a plurality of signals generated at the second light barrier and based on the fixed spacing between the light barriers. The measurements are repeated for a sufficient number of times to obtain statistically valid numbers of measurements. A sum velocity distribution is calculated from these measurements.

Abstract: A surface finishing process for medical device shields achieves a highly scratch-resistant satin finish prior to encapsulation of the medical device within the shield. The satin finish is achieved by bead blasting the metallic substrate material with stainless steel beads before forming the final shield. The disclosed process eliminates the necessity for surface finishing the shield surface of a completed medical device.

Abstract: A die having a metallic block with a depression, the depression having at least one cross-sectional transition zone, at least one laser shock peened surface encompassing at least a portion of the zone, a region having deep compressive residual stresses imparted by laser shock peening (LSP) extending into the airfoil from the laser shock peened surface. The die has been found to be useful for cold rolling blanks such when the metallic block is a cold rolling die block. The die may be adapted for forming a gas turbine engine component, such as a compressor blade, having an airfoil such that the depression corresponds to the airfoil.

Abstract: Uniformly distributed compressive stresses are induced in the machined surfaces of brake drums and brake rotors. The compressive stresses cancel residual tensile stresses induced in the surfaces by machining operations during fabrication. Cancellation of the surface tensile stresses delays formation of cracks during service brake use and extends the service life of the brake drum or rotor. Shot peening is an applicable prestressing process which also imparts a surface roughness that reduces the time required to burnish brake pads to match the shape of the drum or rotor surface. The reduction of burnishing time reduces the amount of surface cracking caused by surface heating by brake pad high spots as the high spots are ground down.

Abstract: A peening particle support having a plurality of asymmetrically arranged peening particles positioned to minimize tracking on a workpiece. The peening particles are attached to an exposed surface of the peening particle support. The peening particle arrangement includes three or less peening particles with substantially the same non-zero radial distance from a center of the exposed surface. The peening particles are preferably arranged in at least one linear array of peening particles.

Abstract: A ferrous forging billet is treated before heating for forging by grit blasting it with aluminum oxide grit having a pre-blasting particle size in the range of from about 100 microns to about 180 microns, at a pneumatic pressure in the range of from about 60 psi to about 160 psi, and for a time period in the range of from about 30 seconds to about 60 seconds, so as to remove pre-existing scale from the surface of the billet stock, to roughen the cleaned billet surface and to embed particles of aluminum oxide in the cleaned and roughened billet surface, thereby to form a tightly adhering deposit of aluminum oxide particles which are dispersed over the billet surface and cover at least 10% thereof. This substantially inhibits the formation of oxides on the surface of the billet during heating for forging.

Abstract: Shot peening with a mixture of at least two sizes of shot can be used to obtain a textured finish press plate with desirable gloss features. The press plate is impacted with a mixture of shot having at least two different sizes to simultaneously obtain a texture and gloss control. A separate overblasting step to obtain a desired gloss uniformity is thereby avoided.

Abstract: A method and apparatus for controlling a shot peening operation includes the measurement of pressures at two different points in a compound gas shot peening system. By comparing these pressure levels with the pressures set forth in a table for a given mass rate of flow of shot, the peening operator can control the velocity of the shot particles applied to the workpiece, thereby controlling peening intensity.

Abstract: By shot-peening, shots having almost spherical shape are impacted against a surface of a portion of a metal-product, the portion being one which is to be subjected to sliding action. The shots have a hardness higher than that of the metal-product. By the shot-peening, the surface of the metal-product is heated to a temperature higher than a predetermined temperature and very small concave portions, each having a circular arc-shaped cross section, are formed due to the impact of the shots. As a result, the structure of the surface layer of the sliding portion has high internal stress, high hardness and high toughness. Further, since very small concave portions are formed on the surface of the sliding portion, the surface tension of lubricating oil is not decreased and a stable oil film can be formed. In addition, the surface retains high hardness and toughness, even if sliding is performed for long time periods, and the concave portions are not deformed so that a stable oil film can be maintained.

Abstract: A metal current collecting substrate for an air cathode in an electrochemical metal air cell is provided for, wherein the substrate is hardened by one of the steps of sandblasting, shotblasting, plastic deformation of the substrate below the recrystallization temperature range of the metal thereof, and heating the substrate to above the transformation temperature of the metal thereof followed by quenching the substrate below the transformation temperature of the metal thereof. Catalytically active materials, most preferably a mixture of carbon and manganese dioxide, are pressed or otherwise disposed upon the hardened substrate. The substrate is capable of being connected to electrical circuitry. Most preferably, the substrate is a metal screen that has been hardened, roughened and pitted by sandblasting before the catalytically active materials are disposed thereupon, and before the substrate is incorporated into an electrochemical metal air cell.

Abstract: The invention is directed to a method for hardening a metallic part by shot blasting. In prior art hardening processes, debris from the projectiles is frequently encrusted on the surface of the part and forms indents whose bottom is often sharp and which may constitute a starting point for rupture caused by metal fatigue. The inventive process allows hardening without damaging the surface of the part. Prior to shot blasting, a metallic protection film which may, for example, be made of nickel or a nickel-base alloy, is electrolytically deposited on the part. The protection film is thick enough to adhere to the metallic part throughout the shot blasting step but thin enough to allow the shot blasting to work harden the part and to impart a residual compressive stress thereto. After the shot blasting is completed, the protection film is removed.

Abstract: A method and apparatus are provided for imparting a textured surface to a work piece, particularly a metal plate or platen used to impress a textured surface on a sheet of plastic laminate or the like. According to one form of the invention, a stream of balls having substantially uniform size, shape, and weight are propelled against a surface of the work piece at a velocity sufficient for the balls to create an impact impression on the surface of the work piece. Particular characteristics of the texture may be varied by changing the velocity, size, shape, weight, size of the stream, distance travelled by the steel balls, and the sweep rate over the work surface. A suction blast gun having a particular size air jet and nozzle projects the balls against the work piece which are fed to the gun through a magazine. The balls are propelled against the surface by a pressurized fluid.

Abstract: A rolling/sliding member for use in conditions of rolling and/or sliding contact with a mating member opposed to the rolling/sliding member under the following conditions;(a) the rolling/sliding member are formed with a large number of fine protrusions and depressions in at least the surface area which comes into contact with the mating member,(b) the total volume per unit area of the fine depressions is in the range of 5.times.10.sup.-8 to 5.times.10.sup.-7 cc/mm.sup.2, and(c) the average volume of the fine depression is 10 to 100 .mu.m.sup.3.

Abstract: A method of increasing the fatigue life and/or reducing stress corrosion cracking of metal coiled tubing made from a continuous length of strip material by shot peening one or both sides of the strip material along substantially the entire length of the strip material prior to milling the strip material into tubing. The continuous length of strip material is made up of individual strips welded together in end to end abutting relation and the welds are finished before the strip material is shot peened. Alternatively, or in addition to shot peening at least the side of the strip material that forms the interior surface of the tubing, the exterior surface of the tubing is continuously shot peened as the tubing is wound onto a reel or spool.

Abstract: A method for enhancing the rust resistance and the surface finish of a non-ferrous workpiece, such as aluminum, is disclosed. The method comprises the step of impinging the workpiece surface for a predetermined amount of time with a high velocity stream of ferrous particles. The ferrous particles preferably have a hardness less than approximately 40 Rockwell C, preferably 20-40 Rockwell C, and still more preferably 30-40 Rockwell C. The particles are not tempered before impinging. This substantially eliminates stress cracks in the ferrous particles, thus substantially preventing any particulate ferrous matter from becoming imbedded in the impinged workpiece surface, which imbedded particulate matter may be prone to rust.

Abstract: The present invention relates to a method and apparatus for surface treating and putting under compression prestress the inside wall of a cavity, in particular a cylindrical cavity of circular section. The apparatus comprises a bulb-shaped vibrator provided with a tubular portion designed to be engaged in an orifice of a cavity to be treated. It is associated with a vibration exciter designed to excite the vibrator at its resonant frequency. The treatment is obtained by shot in the form of balls being projected against the walls of the cavity and returned into the treatment field by a reflector. The method is particularly applicable to treating holes that are designed to receive the fixing pins of turbine blades.

Abstract: A shot blasting device is provided for shot-blasting surfaces, particularly of a turbo aero engine, which are inaccessable by a straight pipe. The device includes a shot-blasting pipe which is suitably shaped for entering cavities to be shot blasted. The shot-blasting pipe extends from a rotor where the shot is directly deposited. A column affixes pressures pipes to the rotor and shot-blasting pipe to apply compressed air to the shot and eject the shot out of the rotor and through the shot-blasting pipe.

Abstract: A fastener for use with a rotary peening flap to secure at least two overlapping strap portions together. The fastener includes a shaft for extending through apertures in the overlapping strap portions, a head adjoining one end of the shaft, and an elastic washer at the other end of the shaft. The head of the fastener forms an included edge angle of greater than approximately 90.degree. at the intersection of the bottom and side surfaces of the head. The fastener maintains the overlapping portions of the strap under compression to prevent peening debris form becoming lodged between the fastener and the strap and between the overlapping portions of the strap and to prevent slippage between the strap and the fastener and between the strap portions. The elastic washer has sufficient elasticity to maintain compression as the strap portions become substantially thinner over prolonged use. A peening flap incorporating the fastener is also disclosed, as is a hub assembly incorporating the peening flap and fastener.

Abstract: A method and apparatus for increasing blade fatigue strength in a turbine engine. The blades in the turbine engine are configured so as to reduce stress at the tip of the blades during operation of the turbine engine, thus increasing blade fatigue strength. This stress reduction helps to counteract the detrimental effect of abrasive tip coatings on blade fatigue strength. In one embodiment, the tip of the blade is chamfered in order to reduce the stress on the tip of the blade. An abrasive coating is then applied to the tip of the blade to assist the blade in seating into an abradable outer air seal. In another embodiment, an abrasive coating is applied to a center portion of the tip of the blade, with the periphery of the abrasive coating being set back from the opposing surfaces of the blade.

Abstract: A method and apparatus for controlling a shot peening operation includes the measurement of pressures at the nozzle which directs the shot unto the workpiece and just downstream of the point where the conveying medium (generally compressed air) is communicated into the transport hose. By comparing these pressure levels with the pressures set forth in a table for a given mass rate of flow of shot through the transport hose, the peening operator can control the velocity of the shot particles applied to the workpiece, thereby controlling peening intensity.

Abstract: The metal of the wall of the part (13a) in a zone which includes defects such as cracks is melted, over a defined depth, by moving over the surface of the part with the aid of a melting device (21), and then solidified. Next, a surface layer of the metal of the wall of the part (13a) which has been melted and then solidified is subjected to compression by repeated impacts of solid particles. The melting is preferably performed by a transferred-arc plasma (22) and the compression by balls set into motion by a vibrating part. The invention applies in particular to the repair of a tubular adaptor (13a) penetrating the head (1) of a nuclear-reactor vessel.

Abstract: This invention relates to a sensor for monitoring the operation of a suction-type shot peening machine. Such structures of this type, generally, measure the vacuum in the gun mixing chamber of the suction-type shot peening machine. Changes in this sensor will be indicative of either gun surging or changes in shot delivery rate or velocity. Its output will, therefore, provide diagnostic information on the performance of the process.

Abstract: Uniformly distributed compressive stresses are induced in the machined surfaces of brake drums and brake rotors. The compressive stresses cancel residual tensile stresses induced in the surfaces by machining operations during fabrication. Cancellation of the surface tensile stresses delays formation of cracks during brake service use and extends the service life of the brake drum or rotor. Shot peening is an applicable prestressing process which also imparts a surface roughness that reduces the time required to burnish bake pads to match the shape of the drum or rotor surface. The reduction of burnishing time reduces the amount of surface cracking caused by surface heating by brake pad high spots as the high spots are ground down.

Abstract: This invention relates to a constant flow control device for a pressure pot shot peening machine. Such structures of this type, generally, assure that the air flow and the pressure drop through the pressure pot shot peening nozzle remain independent of uncontrolable upstream conditions, thus assuring constant velocity of the shot stream regardless of shot delivery hose routing or wear.

Abstract: Surface anomalies on pipe are removed preparatory to corrosion coating. The removal is conducted by brushing with wire brush elements or COMAX brush elements which may rotate about axes parallel to the pipe axis or substantially radially off the pipe. Both kinds of brush elements may be used in combination. Before subjecting the pipe to brushing, the surface is particulate blasted to remove ferric oxide and better expose surface anomolies. After wire brushing, the surface is again particulate blasted to provide an anchor pattern of indentations promoting adhesion of the coating.

Abstract: A method for shot peening a first tube external to and concentric with a second tube comprising the steps of forming a slot through the second tube; positioning a shot peening device adjacent the notch in the second tube for propelling shot peening balls; propelling the shot peening balls through the slot in the second tube for shot peening the second tube; and rotating the second tube in increments for shot peening an entire circumferential portion of the first tube positioned outwardly and radially from the slot.

Abstract: An aluminum alloy member is heated to 470.degree.-550.degree. C., and is quenched to room temperature for hardening. Then the aluminum alloy member is heated to 160.degree.-220.degree. C., and is cooled, which is carried out in a cooling process of a tempering treatment. As the aluminum alloy member is in a softening state in the cooling process, plastic working such as shot peening treatment is performed on the surface of the aluminum alloy member. Thereafter, the temperature of the aluminum alloy member falls to room temperature. In this way, it is possible to generate a great amount of compression residual stress in the aluminum alloy member, without performing a severe plastic working treatment on the surface thereof. Since the present invention requires no severe plastic working treatments on the surface of the aluminum alloy member, this causes no severe surface roughness thereon.

Abstract: An Almen type gage with an improved test strip support mechanism, which concentrates the holding force at the contact points. The support mechanism includes four paired contact balls and a permanent magnet engaged between the paired balls to magnetically hold the test strip against the contact balls. Each contact ball seated atop a set screw turned into a test platform with the magnetic flux of the permanent magnets passing through both the contact balls and the set screws.

Abstract: This invention relates to measuring shot peening coverage by impact dent characterization. Such methods of this type employ a non-destructive, automated computer analysis by analyzing dent characteristics to determine shot coverage of a particular surface.

Abstract: The invention relates to a spacer for a rotary peening apparatus having a hub and a plurality of peening flaps that are spaced about and retained by the generally cylindrical peripheral surface of the hub. Each peening flap includes several peening rivets attached to a distal end of the peening flap. The spacer of the present invention positions the peening flaps at at least two locations inward of one of the hub ends of the hub, which enables the rotary peening apparatus to impart a uniform surface finish to a surface.

Abstract: A process for cold working an elongated form of a steel alloy includes the step of forming a matte texture on substantially all of the surface of the elongated form. The matte texture is characterized by a plurality of random, minute, shallow indentations, uniformly distributed on the elongated form's surface. The process provides an elongated form of steel alloy that has a significantly improved capability to carry lubricant into a cold working tool or die, thereby benefiting the cold workability of the elongated form. An apparatus for carrying out the process according to the invention, in line with one or more other processing operations is also disclosed.