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CN-121988996-A - Boron carbide composite ceramic cutter head and preparation method thereof

CN121988996ACN 121988996 ACN121988996 ACN 121988996ACN-121988996-A

Abstract

The invention discloses a boron carbide composite ceramic tool bit and a preparation method thereof. The boron carbide composite ceramic tool bit comprises a tool bit body and a welding transition body, wherein a boron carbide ceramic skeleton with a three-period minimum curved surface topological structure is arranged inside the tool bit body, metal bonding agents and diamond abrasive particles are filled in three-dimensional communication holes of the skeleton, the welding transition body is a pure metal bonding agent transition layer, and a hard wear-resistant phase is arranged on the outer surface of the combination body. The method comprises the steps of constructing a boron carbide ceramic skeleton with micro-nano flow guide grooves on the surface of a pore through additive manufacturing, depositing an electromagnetic sensitive phase, injecting powder into three-dimensional communicated pores, assembling a blank, applying mechanical oscillation pressure and a high-frequency alternating electromagnetic field at a sintering temperature, utilizing local Joule heat generated by skin effect to induce an in-situ metallurgical reaction to complete densification sintering, and generating a hard surface wear-resistant phase through chemical heat treatment or component in-situ reaction. The invention realizes compact interlocking of the internal structure and improves the service life and welding strength of the cutter head.

Inventors

  • CHEN LIANGYU
  • CHEN TAO
  • QIN XIAOQIAN

Assignees

  • 山东友江智能装备有限公司

Dates

Publication Date
20260508
Application Date
20260305

Claims (10)

  1. 1. The boron carbide composite ceramic tool bit is characterized by comprising a tool bit body and a welding transition body arranged on the top surface of the tool bit body, wherein the tool bit body and the welding transition body are sintered into an integrated structure, and a hard wear-resistant phase is arranged on the outer surface of a sintered combination body of the tool bit body and the welding transition body; The internal supporting framework of the tool bit body is a boron carbide ceramic framework with a three-period minimum curved surface topological structure, metal bonding agents and diamond abrasive grains are filled in three-dimensional communication pores of the boron carbide ceramic framework, the pore size of the three-dimensional communication pores of the boron carbide ceramic framework is larger than the maximum outer diameter of the diamond abrasive grains, the metal bonding agents and the diamond abrasive grains are sintered together in the pores, and metallurgical bonding is formed between the metal bonding agents and the inner walls of the pores of the boron carbide ceramic framework; The welding transition body is a pure metal transition layer without the diamond abrasive particles and the boron carbide ceramic skeleton, and the welding transition body is composed of the metal bonding agent.
  2. 2. The boron carbide composite ceramic tool bit of claim 1, wherein the tool bit body comprises at least two stacked plates arranged in parallel and sintered together, wherein the boron carbide ceramic frameworks with different pore diameter parameters or the diamond abrasive particles with different particle sizes and concentrations are arranged between adjacent stacked plates; the inner wall surface of the pore of the boron carbide ceramic framework is provided with a micro-nano flow guide groove, transition metal carbide nano particles are deposited on the inner surface of the micro-nano flow guide groove, and the transition metal carbide nano particles are used as electromagnetic sensitive phases.
  3. 3. The boron carbide composite ceramic tool bit of claim 1 or 2, wherein the basic component system of the metal bond is a combination of more than three elements of Fe, ni, co, cu, sn, zn, and the volume ratio concentration of the diamond abrasive particles in the tool bit body is controlled to be in the range of 10-80%; The hard wear-resistant phase is a carburized layer and a nitrided layer, or is formed by adding a strong carbide forming element into the metal bonding agent and reacting with the metal bonding agent in the sintering process, wherein the strong carbide forming element is one or a combination of more than one of Fe, al, mg, ag, cr, W, V, si and Ti.
  4. 4. A method for preparing a boron carbide composite ceramic tool bit based on the realization of any one of claims 1-3, comprising the steps of: S100, constructing a boron carbide ceramic skeleton, namely preparing a boron carbide green body with a three-period minimum curved surface topology pore network, processing micro-nano diversion grooves on the inner wall surfaces of pores of the boron carbide green body by utilizing a laser etching technology, depositing transition metal carbide nano particles on the inner surfaces of the micro-nano diversion grooves as electromagnetic sensitive phases, degreasing and solid-phase sintering the boron carbide green body to obtain the boron carbide ceramic skeleton; S200, mixing and cold pressing to obtain composite powder, injecting the composite powder into three-dimensional communication pores of the boron carbide ceramic skeleton for cold pressing to obtain a green body of the tool bit body, and cold pressing the metal binder powder without diamond to obtain a green body of a welding transition body; S300, loading the integral green body of the composite tool bit into a hot-pressing sintering die, placing the integral green body into a closed vacuum sintering chamber, applying mechanical oscillation pressure to the hot-pressing sintering die in a heating environment, simultaneously starting a high-frequency induction coil to apply a high-frequency alternating electromagnetic field, generating local Joule heat at the bottom of the micro-nano diversion trench by utilizing an electromagnetic skin effect, and promoting the metal bonding agent to be melted and to perform in-situ metallurgical reaction with the inner wall of a pore of the boron carbide ceramic skeleton to finish sintering molding; s400, surface hardening treatment and post processing, namely generating a hard wear-resistant phase on the outer surface of the combined body after sintering and forming, and carrying out a grinding procedure on the hard wear-resistant phase on the top of the boron carbide composite ceramic tool bit to expose a metal matrix with the inside formed by a pure metal binder as a welding joint surface.
  5. 5. The method of manufacturing a boron carbide composite ceramic tool bit according to claim 4, wherein in step S100: Establishing a three-dimensional space mathematical model of a three-period minimum curved surface topological lamination, dividing the three-dimensional space mathematical model into a plurality of discrete level intervals along the height direction, respectively assigning different periodic control constants and porosity threshold functions for adjacent level intervals, and constructing a parallel lamination structure with the aperture and the porosity having a stepwise abrupt change on the digital model layer; printing the boron carbide green body according to the three-dimensional space mathematical model by adopting photo-curing three-dimensional printing equipment; Etching the micro-nano diversion trench on the surface of the inner wall of the hole of the boron carbide green body by adopting a femtosecond laser processing platform, wherein the width of the micro-nano diversion trench is controlled between 1 and 10 microns, and the depth is controlled between 5 and 20 microns; And when the transition metal carbide nano particles are deposited on the inner surface of the micro-nano diversion trench, the thickness of the deposited layer is set to be 10-500 nanometers.
  6. 6. The method of manufacturing a boron carbide composite ceramic tool bit according to claim 4, wherein in step S200: Applying mechanical vibration to a cold pressing mold in which the boron carbide ceramic skeleton is placed while injecting the composite powder into the three-dimensional communication pores of the boron carbide ceramic skeleton, the frequency of the mechanical vibration being controlled between 50Hz and 200Hz, and the amplitude being controlled between 0.1mm and 2 mm; when the blank of the cutter head body is pressed, the axial cold pressing pressure applied by the pressing head of the cold press is controlled to be between 50MPa and 200 MPa; when the blank of the welding transition body is pressed, the pressure of cold pressing is controlled between 50MPa and 200 MPa.
  7. 7. The method of manufacturing a boron carbide composite ceramic tool bit according to claim 4, wherein in step S300: Pumping the vacuum degree in the closed vacuum sintering chamber to 0.1Pa to 0.001Pa, and then introducing argon as a protective atmosphere; Heating and controlling the ambient temperature within the closed vacuum sintering chamber to between 600 ℃ and 1100 ℃; The mechanical oscillation pressure applied to the hot-pressed sintering die through the mechanical servo pressure head is formed by superposing a static basic loading pressure and an amplitude parameter of the mechanical oscillation pressure according to a sine rule, wherein the value range of the static basic loading pressure is set to be 20Kg.f/cm < 2 > to 100Kg.f/cm < 2 >, the value range of the amplitude parameter is 5% to 20% of the static basic loading pressure, and the value range of the mechanical oscillation frequency is set to be 10Hz to 50Hz.
  8. 8. The method of manufacturing a boron carbide composite ceramic tool bit according to claim 4, wherein in step S300: The working frequency of the high-frequency alternating electromagnetic field is 10kHz to 500kHz; the high-frequency alternating electromagnetic field generates skin effect in the electromagnetic sensitive phase area at the bottom of the micro-nano diversion trench, and the induced micro-vortex is excited to generate the local joule heat so as to improve the local temperature at the bottom of the micro-nano diversion trench; And adding a strong carbide forming element into the metal binder powder in advance, wherein the strong carbide forming element and the boron carbide ceramic framework are subjected to in-situ metallurgical reaction at the interface of the micro-nano diversion trench under the excitation of local high temperature to generate diboride and carbide grains, and mechanical interlocking is formed in the micro-nano diversion trench.
  9. 9. The method of claim 4, wherein in the step S400, the step of generating the hard wear-resistant phase by chemical heat treatment in an external atmosphere includes: Transferring the boron carbide composite ceramic tool bit after sintering into a high-temperature atmosphere treatment furnace, and controlling the heat preservation time between 1 and 10 hours at the ambient temperature of 600 to 1100 ℃; And introducing a penetrating layer active gas into the high-temperature atmosphere treatment furnace, wherein active carbon atoms or active nitrogen atoms decomposed by the penetrating layer active gas diffuse into the metal bonding agent and chemically react with metal elements in the metal bonding agent on the outer surface to generate the hard wear-resistant phase composed of metal carbide or metal nitride, and the thickness is controlled to be between 0.1 and 0.5 mm.
  10. 10. The method of claim 4, wherein in the step S400, the step of generating the hard wear phase by in situ reaction of the components comprises: Adding a strong carbide-forming element to the metal bond powder at a volume concentration of 0.2% to 60% in the step S200; In the step S300, under the sintering temperature of 600-1100 ℃ and the coupling action of an alternating electromagnetic field, the strong carbide forming element moving to the outer surface of the composite cutter head blank body is contacted with the hot-press sintering die, graphite materials in the hot-press sintering die are used as carbon sources to generate in-situ chemical reaction, and a hard wear-resistant layer formed by hard metal carbide is directly generated on the outer surface of the sintered combination body to be used as the hard wear-resistant phase.

Description

Boron carbide composite ceramic cutter head and preparation method thereof Technical Field The invention relates to the technical field of superhard materials and special ceramic cutters, in particular to a boron carbide composite ceramic cutter head and a preparation method thereof. Background In the fields of stone machining and special alloy cutting, the application of the superhard material tool has important significance for improving the machining efficiency and the surface quality of a workpiece. Boron carbide, a ceramic material with high intrinsic hardness, low density and excellent chemical stability, is often used as a core component or reinforcing phase of cutting tools. In the industry, a powder metallurgy process is generally utilized to mix and sinter boron carbide powder, metal powder and diamond abrasive particles to prepare the composite material tool bit with high wear resistance. Existing boron carbide composite tool bits are typically secured to the surface of a steel substrate by brazing or induction welding in industrial applications. When continuous cutting operations are performed, the cutting head needs to withstand severe mechanical impact and alternating thermal stresses. The cutting tool mainly relies on metal bond to mechanically coat abrasive particles and is directly connected with the base steel material through a bonding agent layer after sintering. However, prior art boron carbide composite tool tips suffer from significant structural reliability drawbacks in practical use. Because the metal bond has limited physical holding force on the diamond abrasive particles, the abrasive particles often fall off due to overlarge stress when processing high-hardness materials such as granite. Meanwhile, because the boron carbide ceramic components and the steel matrix have great differences in thermal expansion coefficient and elastic modulus, the welding interface of the cutter head and the matrix is extremely easy to generate residual thermal stress, and under the action of complex cutting force, the welding joint surface is often peeled off or cracked integrally due to insufficient strength. The coexistence of such lack of internal holding force and unstable external welding directly limits the wide application of boron carbide ceramic materials in high performance cutting tools. Disclosure of Invention The invention aims to provide a boron carbide composite ceramic tool bit and a preparation method thereof, which are used for solving the problems that the existing ceramic tool bit is large in brittleness, difficult to weld with a steel matrix at high strength and the like. The invention provides a boron carbide composite ceramic cutter head, which comprises a cutter head body and a welding transition body arranged on the top surface of the cutter head body. The tool bit body and the welding transition body are sintered into an integrated structure. The hard wear-resistant phase is arranged on the outer surface of the combination body after the sintering of the cutter head body and the welding transition body. The internal supporting framework of the tool bit body is a boron carbide ceramic framework with a three-period minimum curved surface topological configuration. The three-dimensional communicated pores of the boron carbide ceramic framework are internally filled with metal bonding agents and diamond abrasive particles. The pore size of the three-dimensional communicated pores of the boron carbide ceramic framework is larger than the maximum outer diameter of the diamond abrasive particles. The metal bonding agent and the diamond abrasive particles are sintered together in the pores, and the metal bonding agent and the inner walls of the pores of the boron carbide ceramic framework form metallurgical bonding. The welding transition body is a pure metal transition layer without diamond abrasive particles and a boron carbide ceramic skeleton, and is composed of metal bonding agents. The tool bit body includes at least two laminates arranged in parallel and sintered together. Boron carbide ceramic frameworks with different aperture parameters or diamond abrasive particles with different particle sizes and concentrations are arranged between adjacent laminations. The inner wall surface of the pore of the boron carbide ceramic framework is provided with a micro-nano flow guide groove, and transition metal carbide nano particles are deposited on the inner surface of the micro-nano flow guide groove. The transition metal carbide nanoparticles act as an electromagnetic sensitive phase. The basic component system of the metal binding agent is a combination of more than three elements in Fe, ni, co, cu, sn, zn. The volume ratio concentration of diamond abrasive particles in the tool bit body is controlled to be in the range of 10-80%. The hard wear-resistant phase is a carburized layer and a nitrided layer, or is formed by adding a strong carbide forming element into the metal bonding