1344 results about "Cemented carbide" patented technology

The invention belongs to the field of metal materials, and provides a hard alloy wear-resistant steel ball suitable for mine ore grinding and a preparation method thereof.The hard alloy wear-resistant steel ball is prepared from waste steel pig iron as a basic raw material and chemical components including 2.1%-2.2% of C, 9.8%-10.0% of Cr, 0.10%-0.20% of V and 0.03%-0.06% of Ti; a core-shell precipitated phase microstructure design with MN / MCN as a hard core and chromium carbonitride as a gradient self-passivation shell layer is formed through medium-frequency induction furnace smelting, controlled nitrogen introduction establishment of a V-Ti-C-N microalloy system, bottom pouring solidification and austenitizing quenching and tempering heat treatment processes, and the performance indexes that the surface hardness is HRC60-63 and the core hardness is HRC54-58 are achieved; the average particle size of a core-shell precipitated phase is in dispersed distribution of 20-200nm, the shell thickness is 5-50nm, and the alloy steel ball has excellent wear resistance and corrosion resistance under the high-impact and high-wear working conditions of wet ore grinding, solves the problem of insufficient wear resistance and corrosion resistance of a traditional alloy steel ball, and has wide mine ore grinding application value.

The invention discloses a high-hardness tungsten carbide-cobalt hard alloy and a preparation method thereof. A production raw material formula comprises the following components in parts by mass: 100 parts of tungsten carbide powder, 6-20 parts of cobalt powder, 0.2-1.3 parts of a composite sintering aid, 0.5-4 parts of a wet grinding medium and 0.2-4 parts of a forming agent, the composite sintering aid is composed of rare earth oxide and cobalt phosphide according to the mass ratio of (1-5): 1. The method has the advantages that on the premise that the toughness of the tungsten carbide-cobalt hard alloy is slightly improved, the hardness and wear resistance of the alloy are remarkably improved, and the industrial problems that the hardness improvement of the tungsten carbide-cobalt hard alloy with a single sintering aid is limited and the toughness of the alloy is lost are solved.

The utility model belongs to the technical field of control valves, and discloses a novel valve seat sleeve of a large-pressure-difference regulating valve, which comprises a regulating valve seat body, an anti-erosion WC (Wolfram Carbide) valve seat sleeve, a compression valve seat sleeve nut and a positioning screw. On the basis of keeping the function of the original valve seat sleeve, the WC hard alloy valve seat sleeve is embedded on the valve seat body, so that the problems of valve seat cavitation, scouring and abrasion failure caused by the use environment of a control valve adjusting core component are solved under the condition of reducing the use amount, the service life of the core component is prolonged, and the service life of the core component is prolonged. And long-period, safe and reliable operation of core components in an application environment is ensured.

The invention discloses a brazing method for improving the welding strength of a polycrystalline diamond cutter and a hard alloy. The brazing method comprises the following steps that S1, brazing filler metal alloying is conducted; and S2, the PCD tool bit and the hard alloy matrix are subjected to vacuum brazing. According to the brazing filler metal, an Ag-Cu-Co system is adopted, Ag mainly plays a role of a solder matrix and provides plasticity and thermal conductivity, Cu mainly plays a role of forming an eutectic structure with Ag and reducing the melting point, and Co mainly plays a role of wetting the surfaces of PCD and hard alloy. Co infiltration is adopted in the preparation process of the PCD tool bit used in the method, so that a certain amount of Co exists on the PCD surface, and the hard alloy tool body also contains Co, and therefore, a small amount of Co in the brazing filler metal can better wet the welding surface according to the similar intermiscible principle. In the vacuum brazing process, additional pressure does not need to be applied, when the brazing filler metal is molten, the brazing filler metal is evenly laid on the welding face under the action of the pressure of the PCD tool bit on the upper portion and the capillary effect, the redundant brazing filler metal can flow out of the two sides of the mold, and the flatness of the welding surface can be effectively guaranteed.

The invention belongs to the field of hard alloy, and particularly relates to a preparation method for improving abrasion resistance of hard alloy and the hard alloy. The preparation method comprises the following steps that S1, superfine tungsten carbide, medium-particle tungsten carbide, cobalt powder and tantalum carbide are obtained; s2, superfine tungsten carbide, tantalum carbide and cobalt powder are mixed and then subjected to first wet grinding, and first slurry is obtained; s3, medium-particle tungsten carbide is added into the first slurry for second wet grinding to obtain second slurry, and the second slurry is dried and pressed to obtain a pressed blank; and S4, the pressed blank is subjected to first sintering, and then second sintering is conducted to obtain the hard alloy. The superfine tungsten carbide is added to promote complete development of tungsten carbide grains and reduce abrasive wear, the superfine tungsten carbide and the fine-particle cobalt powder are pretreated, and the two-stage sintering process is adopted, so that uniform distribution of a cobalt phase in the sintering process is improved, the bonding strength of the tungsten carbide grains and a cobalt phase interface is enhanced, and the wear resistance of the abrasive is improved. Therefore, wear resistance of the hard alloy is improved.

The invention relates to the technical field of powder metallurgy materials, and discloses a binding-phase-free hard alloy and a preparation method thereof.The binding-phase-free hard alloy comprises, by mass, 75-80 parts of WC; 8 to 12 parts of TiC; 5 to 8 parts of TaC; 3 to 5 parts of ZrC; 1.5 to 2.5 parts of HfC; 0.8 to 1.2 parts of rare earth oxide; the preparation method comprises the five key steps of core-shell structure composite powder preparation, high-energy beam melting gradient accumulation, microwave-magnetic field composite field activation, multi-stage pressure plasma sintering and staged variable-rate gradient cooling. And component gradient design is cooperated with a multi-field coupling process. Through collaborative design of a core-shell structure hard phase and a gradient composite phase, and in combination with a multi-field coupling activated sintering and gradient cooling process, the problem of obdurability balance of the non-binding-phase hard alloy is solved, the microstructure stability is optimized, and the comprehensive performance and the process controllability are improved.

The invention relates to a hard alloy micro-texture tool based on discharge plasma pressureless sintering and a preparation method. Comprising the following steps: preparing a micro-texture male die pressing head; wC-Co mixed powder is obtained; the pressure head in the step (1) is adopted to apply 150-180 MPa pressure to the WC-Co mixed powder, the pressure is maintained for 60 min, and a biscuit is obtained after demolding; putting the biscuit into a graphite mold, assembling the mold, carrying out vacuum pressureless sintering on the biscuit, heating to 1300-1400 DEG C at the heating rate of 90-110 DEG C / min, carrying out heat preservation for 10 + / -2 minutes, and then cooling to room temperature along with a furnace to obtain a hard alloy block with a micro-texture on the surface; and the micro-texture surface of the hard alloy block is only polished to be bright. According to the method, thermal damage and fusion edge collapse are thoroughly avoided, and high-precision, namely high geometric fidelity, high efficiency, namely short sintering period and low-cost preparation of the microstructure is realized.

The invention belongs to the field of hard alloy materials, and provides a modified high-performance non-magnetic hard alloy and a preparation process thereof. The surface of a WC particle is chemically plated with a Ni-P-B-Cr-Cu amorphous shell layer, and a binding phase is converted into Ni3P and Ni3B nanophase through two-stage sintering. The WC alloy comprises the following components in parts by weight: 85-95 parts of WC, 12-25 parts of a binding phase and 0.5-1.4 parts of a grain growth inhibitor, the nanophase accounts for 35-50% of the volume of the binding phase and 35-50% of the total volume of the binding phase, and the grain size is 80-125 nm; the average grain size of WC is 0.6-1.0 [mu] m; and the thickness of an interface P enrichment layer is 8-15 nm (the coverage rate is 85-95%). Through interface engineering and controlled crystallization from amorphous to nanocrystalline, the relative magnetic conductivity is 1.001-1.015, the hardness HRA is 90.5-93.0, the strength TRS is 2.2-3.0 GPa, the toughness KWP is 300-450 N / mm, and the magnetic saturation strength is 0.02-0.15 T. The problem of decoupling of the magnetic property and the mechanical property of a traditional non-magnetic hard alloy is solved, and the non-magnetic hard alloy is suitable for magnetic sensitive environments such as semiconductor equipment, precise measurement, MRI tools and oil service logging.

The application relates to the technical field of superhard materials, and discloses a non-magnetic polycrystalline diamond compact as well as a preparation method and application thereof. The non-magnetic polycrystalline diamond compact comprises a nickel-based hard alloy base and a polycrystalline diamond layer combined on the nickel-based hard alloy base; wherein the nickel-based hard alloy base comprises nickel and tungsten carbide, and the polycrystalline diamond layer comprises nickel and diamond micro powder. The non-magnetic polycrystalline diamond compact of the application uses a nickel-based hard alloy base, and the polycrystalline diamond layer uses nickel as a bonding phase, so that the magnetism of the polycrystalline diamond compact is effectively reduced, and the application requirement of a non-magnetic bearing material can be met.

This invention provides a high heat-resistant composite multilayer coating and its preparation method, specifically relating to the field of surface coating technology. The invention discloses a high heat-resistant composite multilayer coating comprising a Cr bonding layer, a Cr1-XAlXN / nc-CrAlN-a-CNX multilayer transition layer 3, and an nc-CrAlN-a-CNX functional layer sequentially coated on a cemented carbide substrate. The Cr1-XAlXN / nc-CrAlN-a-CNX multilayer transition layer and the nc-CrAlN-a-CNX functional layer proposed in this invention not only effectively bond Cr... 1‑X Al X N and CN X The enhanced properties and the composite multilayer structure endow it with excellent wear resistance, thereby achieving good lubrication and wear resistance in high-temperature environments. It significantly expands the high heat resistance of the amorphous carbon-nitrogen layer. At the same time, the transition of CrAl and C content in the composition and the construction method of multilayer support layer effectively improve the film-substrate bonding force between the substrate and the coating, enhance the toughness and load-bearing capacity of the top coating, alleviate the internal stress of the functional layer amorphous carbon layer, and significantly reduce the friction coefficient and wear rate of the amorphous carbon-based solid lubricating coating, thereby greatly improving the overall wear performance.

According to the preparation method of the CeO2 and TaC co-doped synergistically reinforced WC-10Co high-temperature application hard alloy, based on a distributed precipitation method, TaC and CeO2 are co-doped in WC-10Co, and compared with traditional ball-milling mixing, the prepared powder is higher in purity; second-phase particles are introduced from the source, uniform distribution of the second-phase particles on the hard alloy matrix is achieved, and stress concentration distribution is reduced; a hard alloy block sintered from the prepared powder is good in hardness and toughness and good in high-temperature thermal stability, when the content of TaC and the content of CeO2 are 0.5 wt% respectively, the hardness and the fracture toughness of a hard alloy composite material reach the maximum, the hardness and the fracture toughness are 2041 HV and 17.91 MPa.m < 1 / 2 > at the normal temperature respectively, the Vickers hardness at the high temperature of 900 DEG C is 723 HV, the hardness and the fracture toughness are greatly improved compared with ball-milling mixed powder, and the hardness and the fracture toughness of the hard alloy composite material are greatly improved. The service life of the hard alloy in a special environment is prolonged, the use cost is reduced, and the application field is expanded.

The invention discloses a chemically enhanced shear thickening polishing solution suitable for a WC-Co alloy and a polishing method, and aims to solve the problem of loss of a Co phase on the surface of the WC-Co alloy in a traditional polishing method. The polishing solution comprises K3 [Fe (CN) 6], KOH, diamond abrasive particles, dispersed phase particles and deionized water, a WC phase and a Co phase of a WC-Co alloy react with [Fe (CN) 6] 3 <-> and OH <-> in the polishing solution respectively, and a soft oxidation film WO3-x and a stable Co3O4 oxidation film are generated on the surface of the alloy. Through the shear thickening effect, the polishing solution forms a particle cluster wrapping the abrasive particles when the relative speed reaches a threshold value, a surface oxidation film is removed through the micro-cutting effect of the diamond abrasive particles, and efficient, high-quality and Co-loss-free WC-Co alloy surface polishing is achieved. The method obviously inhibits the loss of the Co phase at the same time, maintains the hardness and the use performance of the alloy surface, and is especially suitable for precision machining of the hard alloy blade.

The invention belongs to the technical field of alloys, and provides a beta-layer-removed gradient hard alloy and a preparation method thereof. The preparation method comprises the following steps: 1) carrying out compression molding on a nitrogen-free raw material to obtain a pressed blank; the nitrogen-free raw material comprises a mixture and an optional forming agent, and the mixture is composed of WC, Co and alloy carbide; 2, the pressed blank is sequentially subjected to pre-sintering, first oscillation hot-pressing treatment and second oscillation hot-pressing treatment, and the beta-layer-removed gradient hard alloy is obtained.By means of the method, the hard alloy with the low beta-phase residual amount and the high beta-layer-removed thickness uniformity can be obtained.

The invention relates to the technical field of cutting machining, in particular to a lengthened hard alloy spiral cutter strip and cutting equipment thereof, the cutter strip main body of the spiral cutter strip adopts a 60-degree large spiral angle and a lengthened design, so that a cutter provided with the spiral cutter strip can complete machining of a deep hole or a side wall at a time; the cutting force of the cutter can be more axial, and radial vibration in the cutting process is reduced; the cutting equipment comprises a rack and a bracket fixed to the top of the rack, a feeding part is installed on the rack, and a material changing part is fixedly installed on the bracket. The material changing part comprises a material frame fixed to the bracket, a material conveying belt installed at one end of the bottom of the material frame, a material stirring assembly installed in the middle of the material frame and a material clamping assembly used for stopping the material stirring assembly, and the material changing part further comprises an embedding groove, a clamping plate and a clamping positioning assembly. And a target piece on a machining station can be automatically clamped and corrected.

The invention belongs to the technical field of hard alloy surface engineering, and particularly relates to an MT-TiCN gradient coating of a hard alloy cutter and a preparation method of the MT-TiCN gradient coating. The coating sequentially comprises a TiN bottom layer, an MT-TiCN gradient layer, a transition layer and an Al2O3 layer from inside to outside, wherein the C / N atomic proportion of the MT-TiCN gradient layer is in gradient distribution from rich N to rich C in the thickness direction. The coating is prepared through a medium-temperature chemical vapor deposition process, the internal stress of the coating is effectively relieved, and the bonding strength, toughness and wear resistance of the coating and a matrix are remarkably improved.

The present disclosure relates to the technical field of powder metallurgy, especially to a coarse grain cemented carbide and a preparation method thereof. Pseudo particles in coarse grain tungsten carbide are removed by pretreating process. Broken of the coarse grain tungsten carbide in traditional wet milling is avoid by solid-liquid stirring, spay granulating and surface covering, which also guarantee the uniform distribution of PEG and cobalt salt. Transformation from cobalt salt to cobalt is safely and effectively guaranteed by performing two sintering stages with different atmosphere and temperature to obtain a WC—Co mixture material. By performing spark plasma sintering process, the precipitation of nano fine grain tungsten carbide guarantees regrowth of defect occurred in pretreating process. The coarse grain cemented carbide with the average grain size of WC above 10 μm, the uniform cobalt phase distribution and be bending strength not less than 2200 MPa is prepared.

Provided is a cemented carbide composition having a hard phase made of tungsten carbide (WC) as a first hard phase component and at least one second hard phase component selected from the group consisting of tantalum carbide (TaC), niobium carbide (NbC), and mixtures thereof, and a binder phase made of at least one binder component selected from the group consisting of cobalt (Co), nickel (Ni), and mixtures thereof. Also provided is a cemented carbide composition having a hard phase made of WC as a hard phase, NbC as an anti-galling phase, and TaC as a toughness improver, and a binder phase made of at least one binder component selected from the group consisting of Co, Ni, and mixtures thereof. Associated methods of producing the cemented carbide compositions and tools incorporating the same are additionally contemplated.

The invention relates to a core-shell structure whisker toughened hard alloy. The core-shell structure whisker toughened hard alloy comprises a hard alloy matrix and a core-shell structure whisker, the core-shell structure whisker comprises a tungsten core part and an outer tungsten carbide shell layer. According to the core-shell structure whisker toughened hard alloy provided by the invention, the core-shell structure whiskers are added into the hard alloy, and the obdurability of the hard alloy is improved by utilizing the obdurability of the tungsten core part; the outer tungsten carbide shell layer is utilized, the hardness of the whisker is improved, the carbon content of a hard alloy system can be balanced in the sintering process, the wettability between the whisker and a hard alloy matrix is improved, sintering densification is promoted, and the interface bonding force between the whisker and the hard alloy matrix is improved. And finally, the strength and toughness of the hard alloy are improved on the premise of not obviously reducing the hardness of the hard alloy.

The invention provides a preparation method of a hard alloy material based on a high-entropy alloy bonding phase, and relates to the field of hard alloy materials, and the preparation method comprises the steps of S1, tungsten carbide powder pretreatment, S2, preparation of a WC-coated TiN core-shell structure, S3, in-situ synthesis of an interface wetting agent (Ti, Zr, Mo) CN, S4, wet high-energy ball milling and mixing, and S5, preparation of the hard alloy material. According to the hard alloy material prepared through the method, the limitation that traditional cobalt serves as a bonding phase is overcome, interface bonding between the high-entropy alloy and a tungsten carbide matrix is remarkably improved, abnormal growth of crystal grains is inhibited, generation of a brittle phase is avoided, and the hardness, toughness and high-temperature stability of the hard alloy material are remarkably improved.

A cutting tool includes a substrate at least partially coated with a coating. The substrate is a cemented carbide, cermet or ceramic. The coating includes a layer of Ti(C,N), a layer of Al2O3 and there between a bonding layer. The Ti(C,N) layer is composed of columnar grains, wherein an average grain size D422 of the Ti(C,N) layer is 25-50 nm, and wherein the Ti(C,N) layer includes a portion B1 that is adjacent to the bonding layer. An average grain size of the Ti(C,N) grains in portion B1 is larger than the average grain size D422 in the whole Ti(C,N) layer. In the portion B1 of Ti(C,N) layer the Ti(C,N) grains has an average grain size of 140-300 nm.

The invention provides a multi-zone gradient hard alloy material, and relates to the field of hard alloy materials, the multi-zone gradient hard alloy material comprises a drill tip zone, a transition zone and a drill handle zone from the outer layer to the inner layer, the drill tip zone comprises AlTiN, TiCN, ZrC, SiC-B4C composite particles, TaC and Mo2C, the transition zone comprises WC, Co, ZrC, nanoparticles, NbC and carbon nanotubes, and the drill handle zone comprises WC, Co, Ni and ZrC. Through gradient structure design, interface stress concentration in the sintering process is effectively reduced, the hardness and wear resistance of the material are improved, so that the overall crack resistance and service stability of the structure are improved, the service life of the structure is prolonged, and the material is suitable for the field of complex impact loads such as mine drilling and geological survey.

The invention relates to the technical field of metal cutting tools, in particular to a novel spiral groove hard alloy reaming tool and an efficient chip removal structure thereof.The novel spiral groove hard alloy reaming tool comprises a reamer and a main cutting edge arranged at the bottom of the reamer, a cutting set is arranged on the lower portion of the reamer and comprises a first chip removal groove and a second chip removal groove, and the first chip removal groove and the second chip removal groove are formed around the surface of the reamer; the size of the first chip groove is larger than that of the second chip groove. Wherein the edge is lower than the auxiliary cutting edge, and an inclined plane included angle alpha used for assisting chippings to slide into the second chip groove is formed between the auxiliary cutting edge and the edge; the auxiliary cutting edge is flush with the surface of the reamer and is flush with the two ends of the main cutting edge, through the design of the included angle alpha between the edge of the first chip discharging groove and the auxiliary cutting edge and the cooperation of the stepped structure that the edge is lower than the auxiliary cutting edge, the retention space of chips in a transition area is thoroughly eliminated, spiral scratches caused by chip scraping of a traditional cutter are avoided, and the service life of the reamer is prolonged. And a high-precision reference surface is provided for subsequent tapping.

The embodiment of the invention provides a preparation method of an anti-erosion gradient coating. The preparation method comprises the steps that a to-be-repaired area on the surface of a workpiece is subjected to cleaning and sand blasting treatment; the first powder, the second powder and the third powder are sequentially sprayed to the to-be-repaired area through the high velocity oxy-fuel spraying technology, and the gradient coating is prepared; the first powder, the second powder and the third powder all comprise hard alloy powder and base material powder made of the same material as the workpiece, the content of the hard alloy powder in the first powder is smaller than that of the hard alloy powder in the second powder, and the content of the hard alloy powder in the second powder is smaller than that of the hard alloy powder in the third powder; and after the workpiece is sprayed and naturally cooled, the surface of the sprayed workpiece is subjected to protection treatment. According to the method, the anti-erosion coating (gradient coating) can be prepared on the basis of hypersonic flame spraying. And under the action of the gradient coating, a compact coating with smaller tensile stress can be obtained, and the properties of erosion resistance, water erosion resistance and the like of the workpiece are improved.

The invention discloses intelligent hard alloy bar manufacturing surface treatment equipment, and relates to the technical field of intelligent hard alloy bar manufacturing surface treatment. The intelligent hard alloy bar manufacturing surface treatment equipment comprises a machine table and expansion pieces, the expansion pieces are arranged on the two sides of the machine table, motors are fixedly installed on the surfaces of the expansion pieces on the two sides, and clamping plates are fixedly installed at the output ends of the motors on the two sides; the motor and the telescopic device are electrically connected with the machine table, the machine table is communicated with a power source, a plurality of telescopic rods are arranged on the surface of the machine table, elastic pieces are arranged between the fixed ends and the free ends of the telescopic rods, notches are formed in the surfaces of the free ends and the output ends of the telescopic rods, and an arc plate is fixedly installed at the free end of each telescopic rod. By arranging the arc plate, the hard alloy metal bar does not need to be fixed through drilling holes in the two sides, machining procedures are reduced, the integrity of the bar is prevented from being damaged, meanwhile, additional two-side treatment does not need to be conducted on the polished bar, the machining efficiency is greatly improved, and material losses are reduced.

The utility model discloses a high capacity ball mill hard alloy inner container integral compression moulding mould, the inner container comprises a shell and a bottom plate, the shell comprises a small cylindrical surface, a small conical surface, a large conical surface and a large cylindrical surface which are sequentially connected from top to bottom, the bottom plate is arranged at the bottom of the large cylindrical surface, and the mould is an assembled mould. Comprising a square core shaft and four inner molds attached to the four side faces of the square core shaft, and after the four inner molds are spliced to the four side faces of the square core shaft, the outer side faces of the four inner molds are matched with the shell in shape. According to the utility model, the square core shaft is combined with the four-petal inner mold, so that the mold can be conveniently mounted and demolded.

The invention provides a manufacturing method of a hard alloy for a hard rock cutting pick, which relates to the field of alloy preparation and comprises the following steps: step 1, preparing raw material powder for preparing the hard alloy for the hard rock cutting pick according to the proportion of raw materials; 2, mixing the raw material powder in the step 1 to obtain mixed powder; 3, putting the mixed powder obtained in the step 2 into a lower mold, and pressing on a press machine to obtain a pressed blank; step 4, sintering: primary sintering: putting the pressed green body into a first sintering furnace, and sintering at a first preset temperature; secondary sintering: putting the green body subjected to primary sintering into a second sintering furnace, and sintering at a second preset temperature; and 5, the hard alloy block obtained after secondary sintering is subjected to finish machining treatment according to the design size of the hard alloy part of the hard rock cutting tooth. According to the method, double-temperature-zone sintering is conducted, impurities / stress is removed through primary sintering (protective atmosphere), and grain growth is precisely regulated and controlled through secondary sintering (vacuum).

The invention belongs to the technical field of hard alloy sintering, and particularly relates to a sintering stack with controllable insertion strip height and a system and method for controlling magnetic performance fluctuation of a hard alloy bar. The sintering stack with the controllable inserting strip height comprises a plurality of sintering boats and a plurality of inserting strip sets. The sintering boats and the insertion strip groups are alternately arranged; and the minimum height difference of the insertion strips among the plurality of insertion strip groups is 1-2mm. According to the sintering stack with the height-controllable inserting strips, the height of the sintering boat can be set in a gradient mode through the multiple sets of inserting strips with different heights according to the carbon atmosphere concentration, airflow and temperature distribution in a sintering furnace, the gradient distribution of a temperature field and the carbon atmosphere in the sintering furnace is effectively compensated, the carbon atmosphere and temperature distribution in the hard alloy sintering process is controlled, and the sintering efficiency is improved. The method can greatly reduce the fluctuation of magnetic properties of hard alloy bar products, reduce the difference of physical properties of the hard alloy bar products sintered in the same furnace, improve the consistency of various physical properties of the sintered hard alloy, and improve the stability of the service life of the hard alloy products.

The present invention relates to a method for preparing a polycrystalline diamond composite sheet. The method comprises the following steps: soaking diamond particles of primary and secondary sizes in strong acid and alkali, and repeatedly washing with pure water; sandblasting a cemented carbide substrate; mixing the primary and secondary diamond particles in a mixer; placing the mixed diamond particles and cemented carbide substrate in a high-temperature resistant metal cup; placing a composite block in the metal cup, and placing the metal cup in a six-sided top press; and performing three-stage high-pressure and two-stage high-temperature sintering. The first stage is high-pressure, cold pressurization to 6.5-8.2 GPa, maintained for 30-60 seconds; the second stage is high-pressure and simultaneous heating, sintering at a pressure of 6-8 GPa, a temperature of 1490-1580°C, maintained for 300-600 seconds; and the third stage is high-pressure and simultaneous heating, pressure of 5.0-6.0 GPa, a temperature of 1150-1250°C, maintained for 150-200 seconds. The pressure and temperature are then reduced to normal pressure and room temperature to obtain a polycrystalline diamond composite sheet blank. After sintering, fine particles are evenly distributed around coarse particles.

The application discloses a kind of hard alloy cutter materials for deep hole machining, the cutter material is composed of the following weight percentage components: tungsten carbide: 75%~85%, wherein 0.2~0.4 μm superfine tungsten carbide particles account for 60%~80%, 0.4~0.8 μm tungsten carbide particles account for 20%~40%; Cobalt: 10%~15% titanium carbide: 2%~5%; Tantalum carbide: 1%~3%; Niobium carbide: 0.5%~2%; Vanadium carbide: 0.3%~1.0%; Chromium carbide: 0.2%~0.8%; Rare earth element: Y2O3 Or La2O3: 0.1%~0.5%. The application breaks through the bottleneck of high temperature wear, insufficient strength and short service life of traditional hard alloy in deep hole machining through three-dimensional innovation of component design, structure control and surface strengthening, and provides an efficient solution for precision deep hole machining of high hardness materials.

The invention belongs to the technical field of alloys, and particularly provides a gradient hard alloy and a preparation method thereof.The preparation method comprises the steps that (1) a mixture is provided, specifically, the mixture is composed of WC, Co and an additive, and the additive comprises titanium-containing nitride and optional alloy carbide; (2) carrying out sintering treatment on the mixture; the sintering treatment process comprises the following steps: in a first stage, under a vacuum condition, raising the temperature to a sintering temperature of 1200-1400 DEG C and preserving heat; and in the second stage, under the sintering temperature, the oscillation pressure with the median value of 250-400 MPa is applied, and heat preservation is carried out. According to the preparation method, the thickness uniformity of the debeta phase in the hard alloy can be improved, and cubic phase residues in the hard alloy can be effectively reduced.