The invention relates to the processing of materials by cutting, fine cutting. The cutting plate includes a cutting element of the superhard material with a curved cutting edge formed by the intersection of the front and rear surfaces. To obtain a low roughness of the processed surface by reducing the complexity of grinding the back surface of the cutting element of superhard material made in the form of two intersecting conical surfaces with parallel axes. With this cutting edge includes Central and side sections, and the radius of curvature of the Central section of greater radius of curvature of the side portions. 4 Il. The invention relates to the treatment of materials by cutting, in particular for fine turning.Known cutting plate, equipped with a cutting element of superhard material, in which the cutting element has two cutting edges formed by the intersection of the flat front and rear surfaces (VP of Jedi and other Cutting tools, with superhard and ceramic materials and their applications: a Handbook. - M.: Mashinostroenie, 1987, S. 50-51).The main disadvantages of the known plate apply the x alloys plate, equipped with polycrystalline diamond).To obtain the necessary in this case, the magnitude of the radius between the cutting edges of the plate (usually more than 2 mm), you need to Shine at sharpening a significant amount of material that, because of the very low grindability of superhard materials, will lead to an unjustified increase in the complexity of sharpening.The objective of the invention is obtaining a low roughness of the processed surface by reducing the complexity of the grinding plate.This objective is achieved in that the cutting plate containing the cutting element of superhard material with a curved cutting edge formed by the intersection of the front and rear surfaces, the rear surface of the cutting element of superhard material made in the form of two intersecting conical surfaces with parallel axes, with the cutting edge includes Central and side sections, and the radius of curvature of the Central section of greater radius of curvature of the side portions.In Fig.1 - cutting plate in isometric in Fig.2 is a top view, Fig.3 - section a-a in Fig.2, in Fig.4 - scheme to the choice of parameters of the insert.The cutting element 1 (Fig.1) in the form of a truncated cone, having the radius r, is the front surface of the cutting element 1 and the side surface of the cone is part of the rear surface of the cutting element, forming the lateral parts 3 and 4 of the cutting edge with a radius of curvature r.The intersection of the surface of a cone whose axis O2-O2parallel to the axis About1-O1the source of a truncated cone (Fig.2, 3), and the front surface of the cutting element is formed of a Central section 5 of the cutting edge (Fig.1) having a radius of curvature R, with R>r.This site provides reception given the surface roughness and is created by grinding, which is a layer of material with a maximum thickness of(Fig.4). The value ofspecifies the length of the active part of the cutting edge 5. This length is characterized by the dimension b (Fig. 4).To obtain the required geometry of the cutting plate, you need to find a cutting element with a base radius of the cone r, the smaller the selected value of R, and to sharpen the conical rear surface having the axis O2-O2and the angle of inclination of the generatrix axis(Fig.3), providing the value of b. Thus the value of the removal tool of the control edges, equal to the R.Example. For the cutting element with r=1.8 mm (a radius have, for example, diamond-carbide cutting inserts SVBN) to get R=3 mm and b=1 mm, must be removed for sharpening layer of material with a maximum thickness ofequal 0,132 mm For famous plate with the angle between the edges in the plan, equal to 90 degrees, obtaining a radius equal to 3 mm, would require removal of the layer of superhard material with a maximum thickness of 1,242 mm With R=4 mm the maximum reading for the claimed and known plates respectively 0,176 1,656 mm and mm, R=5 mm - 0.2 mm and 2.07 mmThe cutting plate according to the present invention operates as follows. Initially, the work enters one of the side portions of the cutting edge 3 or 4 (depending on the feed direction), removing the major part t' of the allowance for processing t (Fig.4). Then the Central part of the cutting edge 5 cuts off the remaining portion of the allowance t", removing machining marks left lateral part of the cutting edge.Cutting elements are mounted in housings standard carbide inserts, including a Central hole. It is advisable to use a cutting element as part of a truncated cone, having a plan is cutting element in the form of a sector, used in the known plates, and a slot in the plate under the cutting element is more technologically advanced.The application of the proposed insert will allow you to get a low roughness of the machined surface while reducing the complexity of the grinding plates.
ClaimsThe cutting plate containing the cutting element of superhard material with a curved cutting edge formed by the intersection of the front and rear surfaces, wherein the rear surface of the cutting element of superhard material made in the form of two intersecting conical surfaces with parallel axes, with the cutting edge includes Central and side sections, and the radius of curvature of the Central section of greater radius of curvature of the side portions.
FIELD: technological processes.
SUBSTANCE: invention claims diamond tool manufactured with monocrystallic diamond, synthesised under high pressure by temperature gradient method, so that the claimed diamond crystal contains not more than 3 parts per million of nitrogen. The tool features a blade with its edge oriented in plane (110), so that Knoop scale hardness at the plane (100) in direction <110> is higher than in direction <100>. Such synthetic monocrystallic diamond is synthesised by temperature gradient method under superhigh pressure and high temperature, and its crystals contain nickel atoms introduced by atomic substitution or boron and nickel atoms introduced by atomic substitution.
EFFECT: obtaining cheap synthetic monocrystallic diamonds with reduced flaw number.
24 cl, 4 ex, 2 tbl, 7 dwg
SUBSTANCE: it is prepared mixture of abrasive dust of coarse grain and, at least, of one fine grain, mixture of powders is compacted and impregnated by metals or alloys. In the capacity of powders, at least, of one fine grain there are used powders, surface of which fulfil wettability conditions by impregnating metals or alloys.
EFFECT: method provides increasing of working layer height of elements, and also receiving in the element defined content of abrasive grains for optimal external environment.
12 cl, 1 dwg, 5 ex
SUBSTANCE: there are used powders of super-hard materials of at least two granularities. Also, porous base of the element is made of powders of super-hard materials of higher granularity. Porous base is placed in a bath with suspension containing powders of small granularity and these powders are settled in pores of porous base with electric current transmitted through suspension, where upon all grains of super-hard material are bound with binding.
EFFECT: utilisation of powders of super-hard materials of small granularity including nano dimensions for fabrication of cutting elements with uniform distribution of grains in volume; reduced time of process.
SUBSTANCE: invention relates to production of heat-resistant polycrystalline diamond composites for production of cutting elements. On the boundary of division on the substrate of ceramic material, metal or cermet applied is heat-resistant diamond plate, which contains a layer of first impregnating material, selected from VIII group of periodic system of chemical elements or eutectic composition of said elements and placed between lower surface of said heat-resistant diamond plate and upper surface of said substrate. Material of coating from boron nitride, graphite or aluminium oxide is applied on the surface of said diamond plate, except the surface on the boundary of division. After that, applied on each other heat-resistant diamond plate and substrate are subjected to thermal cycle, consisting of heating, temperature support and cooling, ensuring transition of, at least, part of said impregnating material into liquid state for migration into heat-resistant diamond plate and into said substrate in the area of the boundary of division for their connection to each other. Said first impregnating material is used in amount, ensuring, at least, 90% of its transition into material of said substrate and plate.
EFFECT: production of working elements of metal-processing instrument, external part of which possesses high hardness, with internal one possessing high shock viscosity, is ensured.
41 cl, 10 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to PCD diamond to be used in production of water-jet ejectors, engraving cutters for intaglio, scribers, diamond cutters and scribing rollers. PCD diamond is produced by conversion and sintering of carbon material of graphite-like laminar structure at superhigh pressure of up to 12-25 GPa and 1800-2600°C without addition of sintering additive of catalyst. Note here that sintered diamond grains that make this PCD diamond feature size over 50 nm and less than 2500 nm and purity of 99% or higher. Diamond features grain diameter D90 making (grain mean size plus grain mean size × 0.9) or less and hardness of 100 GPa or higher.
EFFECT: diamond features laminar or fine-layer structure, ruled out uneven wear, decreased abrasion.
15 cl, 5 tbl, 5 ex
FIELD: process engineering.
SUBSTANCE: invention relates to production of cutters from cemented carbide with superhard tips for destruction of hard and abrasive materials. Cutter (100) comprises insert (110) including superhard tip (112) jointed with support body (114) from cemented carbide with stem (118) and steel holder (120) for said insert (110). Steel holder (120) comprises shaft (122) for connection with tool arbour (not shown) and channel (126) to accommodate stem (118). Said stem fits in said channel through at least 4 cm. Volume of support body (114) from cemented carbide makes at least 10 cm3. Stem surface area adjoins the channel surface inner area making at least 20 cm3 while stem diameter making at least 1.5 cm and not over 4.0 cm. Cutter stem is fitted in steel holder channel with interference fit of 0.002-0.3%.
EFFECT: higher tool hardness, longer life.
13 cl, 11 dwg, 1 tbl
SUBSTANCE: invention relates to polycrystalline diamond for use in a variety of instruments. Polycrystalline diamond is characterized in that it comprises a sintered diamond grains having an average grain diameter of more than 50 nm and less than 2500 nm, the purity of 99 % or more and the grain diameter of D90, is (average grain diameter + average grain diameter of × 0.9) or less, wherein the polycrystalline diamond has a lamellar structure and has a hardness of 100 GPa or more.
EFFECT: water jet nozzle cutter for engraving gravure scriber, cutting tool and scribing clip from such material ensures stable processing over a long period of time as compared with conventional tools comprising monocrystalline diamond and the sintered diamond compact containing metal binders.
13 cl, 5 tbl, 62 ex