Method of obtaining products
SUBSTANCE: invention relates to method of obtaining products from titanium-based material with coating, representing semi-spherical head of medical semi-spherical cutter. Workpiece from unalloyed titanium is made by cold sheet-stamping stamping and drilling holes with countersinking. Hole centres are placed on two spiral lines with left approach, converging in dome, with obtaining semi-spherical head of medical cutter. External head surface is polished to roughness Ra not more than 0.1 mcm and cutting elements are made by flanging sharpened edges from left side of holes outwards and their sharpening. Nitration with vacuum ion-plasma method to the depth not less than 50 mcm is carried out. Titanium nitrade TiN layers are precipitated until total thickness of said layers is 4-7 mcm with microhardness more than 7000 MPa.
EFFECT: high cutting properties of semi-spherical head of medical cutter and its wear resistance are ensured with preservation of corrosion resistance and biological inertness.
1 dwg, 1 ex
The invention relates to a method of obtaining products of titanium alloy, representing a hemispherical head medical hemispherical cutter for the development of the acetabulum of the pelvis prior to installation of the appropriate implant and designed for continuous use in aggressive biological environments. The main component of the cutter is cutting thin-walled hemispherical head, on the outer side of which is by flanging shaped cutting elements.
Often hemispherical head medical cutters are made of stainless thermally hardening of steel by stamping (see, for example, "Waldemar Link", "Implants", product catalog, 2000, "Plus Orthopedics", "Implants for Orthopaedics and traumatology", catalogue of VNIMI, De Puy ASR International, "Surgical technique", 2000, No. 9998-90-173). For the manufacture of the cutting head stainless steel sheet material is subjected to hot forging and subsequent quenching. Occurring during hardening deformation changes cause a violation of the geometric parameters of the cutter, which reduces its dimensional accuracy. In addition, the heat treatment results in changes to the composition of the steel in the surface layer and, consequently, to decrease its corrosion resistance, and cutting edges to increased fragility that m which can lead to cracking and fracture of the head.
As the prototype accepted "Way of obtaining products from titanium alloys and products obtained by this method (variants)", RF Patent №2338811, in accordance with which products, including medical devices, is obtained from the pseudo-α or low-alloy (α+β) titanium alloy, comprising the manufacture of the workpiece, the polishing, the nitriding vacuum ion-plasma method to a depth of not less than 50 μm, and the deposition of layers of titanium nitride TiN condensation method.
However, to get a thin-walled workpiece milling heads of these titanium alloys by cold sheet metal forming is impossible due to their low ductility (δ=5-10%).
The optimal state of the metal thin-walled hemispherical head medical cutters is high plasticity her inner region and a hardened surface layer.
The present invention is to provide high cutting properties of the hemispherical head of the medical cutters and wear resistance while maintaining corrosion resistance and biological inertness.
The technical result is the performance and reliability of medical cutters due to the exclusion of brittle fracture of its hemispherical head.
The problem is solved due to the fact that the method of obtaining medical cutters of the material on the basis of titans coating, includes the manufacture of the workpiece, the polishing, the nitriding vacuum ion-plasma method to a depth of not less than 50 μm and the deposition of layers of titanium nitride TiN condensation method is used for the procurement of unalloyed titanium by cold stamping and drilling holes with a countersink and hole centers have two helical lines with the left approach, converging in the dome, getting a hemispherical head medical cutters, after which the outer surface of the head is polished to a roughness Ranot more than 0.1 μm and perform cutting elements by flanging pointed edges on the left side of the hole to the outside and sharpening, and the deposition of layers of titanium nitride TiN is carried out to obtain the total thickness of these layers 4-7 microns with a hardness of more than 7000 MPa.
Sheet unalloyed titanium grades VT1, VT1-0 has a high plasticity (δ over 30 - 55%), which makes it suitable for cold forming hemispherical billet head medical cutters. The resulting workpiece is cut off at the calculated diameter according to the size of the cutter, and then using the template on the surface of the workpiece is performed by drilling holes with a reamer. Hole centers have two helical lines with the left approach, converging in the dome, i.e. back in the direction of the milling of the acetabulum to avoid her through the passage, that can lead to patient injury.
The external surface of the billet heads with holes is subjected to grinding and polishing to obtain a roughness Ranot more than 0.1 μm to reduce the skid resistance of the free surface of the head of the bone when it is processed.
After flanging pointed edges and forming the cutting elements of the cutter head is subjected to nitriding at a temperature of 560-600°C for 40-60 minutes until the thickness of the hardened layer is more than 50 μm. To enhance the effect of hardening after nitriding optionally form a coating of 4 layers of titanium nitride TiN by plasma deposition from the vapor phase at a temperature of 400-420°C total thickness of 4-7 microns with a hardness of more than 7000 MPa.
The drawing shows the milling head on a spherical surface which made cutting elements (1), arranged in two helical lines (2) with the left approach, converging on the dome cutters. Milling is carried out by arrow (3).
Manufacturing process flow head medical cutters is as follows.
Fabrication of hemispherical billet head cutter carried out by the method of cold forming of sheet thickness of 1 mm of unalloyed titanium (grades VT1, VT1-0) and the crop on the estimated diameter of the hemisphere corresponding t the PA size cutters. The kit includes 11 types of sizes of cutters from 40 to 60 mm, Then on the surface of the workpiece using templates carry out the holes with a reamer with a diameter of 4 mm with the sharpening of the edges with the inner surface of the workpiece along two helical lines with the left approach, converging to the dome. Drilled workpiece is ground and polished to obtain a surface roughness Raless than 0.1 microns. The next operation is flared edges out using a special tool to a height of 1 mm from the left edge of the holes and pre-sharpening cutting edges protruding. Honed milling head is subjected to a preliminary surface hardening by means of vacuum ion-plasma nitriding at a temperature of 560-600°C for 40-60 min, after which the microhardness of the surface amounted to 5500 MPa. The final operation is the deposition on the nitrided surface of the head at a temperature of 400-420°With 4 layers of titanium nitride with a total thickness of 4-7 μm, which further increases the surface microhardness, which is not less than 7000 MPa.
An example of performing the method.
The milling head is made of cold rolled sheet, titanium grade VT1 thickness of 1.0 mm by cold stamping. After running the holes according to the technology described above, the cylinder is polished to sherokhovatost the surface R a=0,08 μm to form cutting edges. Hardening of the workpiece is performed by the method of ion-plasma nitriding at a temperature of 560°C for 50 min and then applying 4 layers of titanium nitride with a total thickness of 5 μm at a temperature of 400°C. After processing, the surface microhardness was 7800 MPa.
Wear a medical of the cutter head, treated under the proposed method, with a diameter of 56 mm was determined according to GOST 28684. As the test showed, during the cutting process on the plates of the PCB efficiency of the cutter and the radius of the blunting of the cutting edges has not changed. The ultimate state of one of the cutters 5 was achieved only after 52 cycles of testing, which indicates their high wear resistance and high cutting properties.
High corrosion resistance and biological inertness of titanium alloys are well known and greatly exceeds the corrosion resistance of stainless steels when working in corrosive environments, including the human body.
The titanium medical kits cutter heads, processed by the proposed method and the developed design submitted for testing in cyto them. Neprehrava in the Department of bone pathology. Within 9 months of use cutters found no deterioration in their health and traces to which Rosie.
Thus, the use of a hemispherical head medical cutters of unalloyed surface-hardened titanium processed by the proposed method and the claimed design ensures high cutting properties, corrosion resistance and biological inertness, as well as enhanced security in the processing of the acetabulum.
The method of obtaining medical cutters from a material based on titanium coated, including the manufacturing of the workpiece, the polishing, the nitriding vacuum ion-plasma method to a depth of not less than 50 μm and the deposition of layers of titanium nitride TiN condensation method, characterized in that is used for the procurement of unalloyed titanium by cold stamping and drilling holes with a countersink and hole centers have two helical lines with the left approach, converging in the dome, getting a hemispherical head medical cutters, after which the outer surface of the head is polished to a roughness Ranot more than 0.1 μm and perform cutting elements by flanging pointed edges on the left side of the hole to the outside and sharpening, and the deposition of layers of titanium nitride TiN is carried out to obtain the total thickness of these layers 4-7 microns with a hardness of more than 7000 MPa.
SUBSTANCE: procedure consists in part heating, in nitriding during heating in nitrogen containing gas from 390 - 410°C to 500 - 570°C during 1 - 4 hours and in cooling from 500 - 570°C to 350 - 400°C during 40 - 60 minutes in plasma of glowing discharge directly upon heating.
EFFECT: upgraded quality and consumer qualities of threaded parts, increased efficiency and reduced expenditure of resources by nitriding during heating and cooling.
SUBSTANCE: here is claimed procedure for strengthening items of titanium alloys. The procedure consists in heating surface of an item in nitrogen medium; also, heating is performed with a concentrated heat source with density of power 103-104 Wt/cm2, current strength 80-150 A and rate of source transfer relative to an item - 0.005-0.01 m/sec.
EFFECT: increased wear and corrosion resistance of items of titanium alloys.
3 cl, 3 dwg, 2 ex
SUBSTANCE: invention can be used for treatment of long-length precision cylinders of well pumps operating under abrasive wear conditions. The procedure for ion-vacuum nitriding long-length steel part in glow discharge consists in heating part at temperature 400-450°C, in isothermal conditioning during 20-30 minutes, in preliminary nitriding at temperature 480-510°C for 60-120 minutes, in final nitriding at temperature 20-50°C above temperature of preliminary nitriding during 8-16 hours and in cooling to 350-400°C during 40-60 minutes.
EFFECT: production of part with uniform nitrided layer and hardness of surface.
SUBSTANCE: procedure for treatment of parts out of titanium alloys consists in cathode sputtering and nitriding. Before and after nitriding parts are annealed in vacuum. For nitriding there is supplied mixture of gases consisting of 10 wt % of nitrogen and 90 wt % of argon. Further, parts are vacuum heated in non-uniform plasma of higher density which is created between a part and a screen due to effect of a hollow cathode. Thus there is facilitated formation of regular macro non-uniform structure. Structure of cells of the screen is honeycomb-like. Parts are annealed before and after nitriding at temperature 800°C during 2 hours, while nitriding is carried out at temperature below α→β of transition of titanium alloy.
EFFECT: increased contact durability and wear resistance of hardened layer due to creation of regular macro non-uniform structure of material, expanded functionality of described procedure.
2 cl, 4 dwg, 2 ex
SUBSTANCE: procedure consists in vacuum heating items in plasma of nitrogen of higher density. Plasma of nitrogen of higher density is generated in toroid region of electron motion formed with crossed electric and magnetic fields. Under effect of magnetic field created with two cylinder magnets one of which is hollow, electrons move along cycloid closed trajectories.
EFFECT: intensified item nitriding, increased contact durability and wear resistance of strengthened layer.
1 dwg, 1 ex
SUBSTANCE: procedure for plasma boriding metal surface out of titanium, of ally on base of titanium, of steel or of ferrochromium consists in introducing KBH4 into reaction chamber, where H corresponds to halogen. KBH4 is heated to temperature sufficient for release of BH3. BH3 is subjected to plasma discharge. There are generated activated boron containing particles diffused in metal surface. In an alternative procedure of the invention KBH4 is thermally decomposed producing KH and BH3. BH3 is directed to plasma formed with inert gas. Also, composition and conditions of plasma generation are selected to facilitate decomposition of BH3 into BH2 + and H. BH2 + is diffused into metal surface.
EFFECT: wear resistant metal surface produced without change of volume of substrate at boriding and with reduced consumption of poisonous chemicals.
13 cl, 1ex
SUBSTANCE: procedure for nitriding steel items in glow discharge consists in vacuum heating items corresponding to cathode in plasma of nitrogen of higher density. Plasma of nitrogen of higher density is formed in a near cathode area with a beam of electrons generated and accelerated with an auxiliary anode. Electrons emitted from an electron gun are directed to the anode and to the auxiliary anode generating electron gas flow facilitating collision of electrons with neutral particles and maintaining plasma existence. Velocity of electrons motion is controlled with the auxiliary anode connected to its own source of power.
EFFECT: intensified nitriding, increased contact durability and wear resistance of strengthened layer.
1 dwg, 1 ex
SUBSTANCE: procedure consists in placement of item into plasma chamber, in supply nitrogen or gas mixture into discharge interval between cathode and anode at low pressure of 0.01-1 Pa, also gas mixture consists of mixture of nitrogen and of at least one of following gases: argon, neon, helium or hydrogen, in applying voltage between cathode and anode with fine-structure mesh and in ignition arc or glow low voltage discharge with cold cathode creating plasma emitter of electrons in zone of fine structure mesh. Further, negative voltage of 0.1-1 kV is supplied between the anode and grounded walls of the plasma chamber, surface of the item is ion-cleaned from oxide films by means of supplying negative bias voltage 100-500 V relative to walls of the plasma chamber onto the item. The item is heated to working temperature facilitating diffusion of nitrogen atoms into volume of the item by growth of voltage between the anode and grounded walls of the plasma chamber and current of discharge between the anode and cathode. Atoms of nitrogen are diffused into volume of the item at values of negative bias voltage on the item 0-150 V relative to the grounded walls of the plasma chamber or at floating potential of the item.
EFFECT: raised surface hardness of item, elimination of deformation after treatment, increased fatigue point and wear resistance of processed item.
4 dwg, 1 ex
FIELD: machine building.
SUBSTANCE: according to invention steel items are nitrided in glow discharge by means of vacuum heating in plasma of nitride of increased density; further, items are quenched. Also, plasma of nitride of increased density is generated in a circular region of rotation of electrons caught with magnetic field, power lines of which are parallel to treated surface. Notably, electron cloud is maximally localised at the part-cathode.
EFFECT: intensified process of nitriding, increased contact service life and wear resistance of strengthened layer.
1 ex, 2 dwg
FIELD: machine building.
SUBSTANCE: items out of steel and alloy are subjected to cathode sputtering and vacuum heating in plasma of glow discharge of increased density; also, plasma consists of mixture containing nitrogen and inert gases; mixture is formed between item and shield. Notably, non-uniform plasma of glow discharge is formed by means of the shield with cells, thus a differential structure in material is created by forming heterogeneous structures. Additionally, the transition section between sections with different structures has a micro-non-uniform structure with gradual transition from one kind into another.
EFFECT: increased contact service life and wear resistance of strengthened layer, expanded functionality.
3 ex, 6 dwg, 1 tbl
FIELD: engines and pumps.
SUBSTANCE: part operating in sliding contact at lubrication rate is covered with thin film with tribological function. Thin film is applied to the surface containing rough profiles. Roughness of the profile and their average periods have been specified in order to improve tribological properties so that ratio A of values of square of average period of profile (PSM), which is expressed in mcm to roughness of profile (Pα), which is expressed in mcm, as determined by the French standard ISO 4288, exceeds or is equal to:
EFFECT: obtaining thin film having improved tribological properties.
7 cl, 1 tbl, 1 ex
FIELD: machine-building industry.
SUBSTANCE: tool is cleaned and degreased and then treated with a solution of high-molecular fluoride containing compositions with temperature being maintained when tool is rotated at 12000 rev/min and/or treated ultrasonically at frequency not bringing the solution to cavitations. The nano-structured hardening coating TiCr-TiCrN-TiN is then applied from separated plasma.
EFFECT: increased wear resistance and effectiveness of cutting tool operation due to improved coating adhesion with tool surface and reduced number of micro and macro- defects at cutting edges.
SUBSTANCE: procedure consists in cleaning chamber in medium of inert gas at item cleaning, in ion etching and ion plasma nitriding whereupon there is additionally performed ion etching of item surface. Ion-plasma nitriding with successive ion etching is performed in N stages, where N is integral number, and N≥1 till saturation with nitrogen of near-surface layer of metal of depth to 500 mcm. Further, there is applied coating by the method of physical sedimentation from vapour phase by application of a micro-layer of nano layers of thickness 1-100 nm of titanium, aluminium and silicon, application of a micro-layer of nano-layers of thickness 1-100 nm of nitrides of titanium, aluminium, and silicon or application of micro-layer in form of amorphous matrix of silicon nitride with solid inclusions of nitride of titanium and aluminium with typical distances between the said inclusions 1-100 nm.
EFFECT: coating with increased service life under conditions of erosion, corrosion and high temperature.
5 cl, 2 tbl, 2 ex
SUBSTANCE: multi-layer heat resistant coating is made with gradient of aluminium by thickness. Coating consists of alternate layers of thickness from 0.1 to 3 mcm each containing nickel, chromium, aluminium, and yttrium. Also, number of layers amounts from 10 to 100. Starting from surface of a specimen each successive layer has concentration of aluminium higher, than in a preceding layer. The first from surface of the specimen layer of coating contains aluminium - 4 %, nickel - 70.7 %, chromium - 25 %, yttrium - 0.3 %, while the last from surface of the specimen layer of coating contains - 12 %, nickel - 66.7 %, chromium - 21 %, yttrium - 0.3 %.
EFFECT: raised corrosion resistance.
SUBSTANCE: here is claimed alloy on base of quazi-crystal system Al-Cu-Fe for application of wear resistant nano structured coating. Alloy contains copper in form of independent phase and tungsten carbide at the following ratio of components, wt %: copper 2-5, tungsten carbide 20-40, quazi-crystal of system Al-Cu-Fe - the rest. Also, quazi-crystal of system Al-Cu-Fe has the following composition, wt %: aluminium 65, copper 21.5-23.5, iron 11-13.5. Technical result of the invention is increased wear resistance due to increased micro-hardness of material together with increased adhesion and cohesion strength of applied coating.
EFFECT: alloy possesses high micro hardness and can be used for application of wear resistant coating.
SUBSTANCE: here is disclosed heat proof coating on base of nickel for blade body of gas turbines and internal combustion engines containing chromium, aluminium and yttrium. Contents and ratio of chromium and aluminium in coating varies along profile of the blade body. Also, coating contains wt % in entrance edge 1 of the blade: nickel 65.7, aluminium 10, chromium 24, yttrium 0.3, while coating contains wt % in exit edge 3 of the blade: nickel 65.7, aluminium 12, chromium 22, yttrium 0.3. Coating of suction face 2 contains wt %: nickel 65.7, aluminium 6, chromium 28, yttrium 0.3. Coating of pan 4 of the blade contains wt %: nickel 65.7, aluminium 4, chromium 30, yttrium 0.3.
EFFECT: simultaneous high corrosion resistance both to sulphide and oxide corrosion in all zones of blade.
2 cl, 1 dwg
SUBSTANCE: to pre-cleaned surface of the substrate there applied are layers of coating by means of magnetron sputtering; at that, first, titanium adhesion layer is applied by magnetron sputtering of titanium target in inert gas; then, titanium nitride TiN layer is applied by sputtering of titanium target in gas mixture of inert and reaction gases; after that, alternating layers of two-component zirconium nitride ZrN are applied by sputtering of zirconium target in gas mixture of inert and reaction gases and zirconium by sputtering of zirconium target in inert gas. Then, alternating layers of three-component titanium and zirconium nitride TiZrN are applied by simultaneous sputtering of titanium and zirconium targets in gas mixture of inert and reaction gases and zirconium by sputtering of zirconium target in inert gas.
EFFECT: mutual location of layers in the coating provides minimum heat stresses at boundaries of layers and it is the most favourable from the point of view of coating material fatigue strength at action of dynamic thermal power loads at operation under conditions of increased temperatures.
SUBSTANCE: procedure consists in sedimentation of alternate layers of metals and their nitrides at cleaning surface of blades with ions of argon and in ion implantation in process of sedimentation. Blades are preliminary polished and cleaned in an ultra-sonic bath. Blades are cleaned with argon ions by means of gas plasma produced by supply of short-pulse high frequency high voltage negative potential of bias on blades. Further, argon plasma is changed to nitrogen plasma and ion implantation of nitrogen is performed with the same parameters of bias potential. Generation of nitrogen plasma is interrupted, and there is produced plasma of titanium; it is purified from micro-particles and bias potential is supplied on blades with the same high frequency parametres facilitating implantation of titanium ions into a surface layer and blades heating, when blades reach temperature required for coating sedimentation. With reduced bias potential an under-layer of titanium is applied on blades. Alternated layers of titanium nitride and titanium-aluminium nitride are settled; notably, the layer of titanium nitride is settled at production of nitrogen plasma, while the layer of titanium-aluminium nitride - at titanium-aluminium plasma.
EFFECT: raised resistance to wear, erosion, corrosion and high temperature at maintaining mechanical properties and cyclic fatigue of blades.
12 cl, 3 tbl, 4 dwg
SUBSTANCE: three-layer coating is applied on working surfaces of cutting tool by vacuum-plasma-procedure. Nitride of titanium and zirconium is applied as a lower layer at pressure of nitrogen in a chamber of the installation 7.5·10-4 Pa and temperature 600°C. The same nitride alloyed with chromium is applied as an intermediate layer at pressure of nitrogen in the chamber of the installation 7.5·10-4 Pa and temperature 550°C and nitride of titanium and chromium is applied as an upper layer at pressure of nitrogen in the chamber of the installation 4.3·10-3 Pa and temperature 500°C.
EFFECT: increased functionality of cutting tool and quality of processing.
1 tbl, 1 ex
SUBSTANCE: three-layer coating is applied on working surfaces of cutting tool by vacuum-plasma-procedure. Carbonitride of titanium and niobium is applied as a lower layer at pressure of acetylene in a chamber of the installation 7.5·10-4 Pa and temperature 600°C. The same carbonitride alloyed with aluminium is applied as an intermediate layer at pressure of acetylene in the chamber of the installation 7.5·10-4 Pa and temperature 550°C and carbonitride of titanium and aluminium is applied as an upper layer at pressure of acetylene in the chamber of the installation 4.3·10-3 Pa and temperature 500°C.
EFFECT: increased functionality of cutting tool and quality of processing.
1 tbl, 1 ex
SUBSTANCE: invention refers to medicine, namely traumatology and orthopaedics. Injured finger flexor tendons are replaced within a fibrous synovial canal. For the purpose of the plastics, a graft made of a xenopericardial plate in the form of a twisted cylinder with cuffs on its ends and with ligatures along its length is used. The graft is attached to the tendon by ligaturing the graft inside the tendon stem; the ligatures are exteriorised on an external surface and tied together. A suture area is covered and reinforced with the cuffs to be anchored by separate interrupted suturing.
EFFECT: method provides adequate recovery of the lost function of the finger flexor tendons, prevention of potential complications, reduced injures.