A method for manufacturing of ceramic composite based on tungsten carbide

Abstract

The subject of the invention is a method for manufacturing of ceramic composite from a mixture of tungsten carbide (WC) powder and titanium (Ti) powder or a mixture of tungsten carbide (WC) powder and titanium alloy powder, in particular the Ti6A14V alloy, to be used as tool materials intended for the production of mainly cutting knife blades, cutting plates, tips of measuring tools and structural and wearing elements for the manufacturing of elements of machinery, devices and instruments in space technology, armament industry, communications, aerospace, electronics, power engineering, and also for the manufacturing of sports equipment. It is characterized in that the mixture of powders (3) with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide(WC) powder and of 5% to 25%, advantageously 5 wt% of titanium (Ti) powder or a mixture of powders with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide (WC) powder and of 5% to 25%, advantageously 5 wt% of titanium alloy powder, advantageously Ti6A14V alloy, is mechanically ground in a planetary ball mill with a rotational speed in the range of 200 to 500 RPM, advantageously 500 RPM, for a time of 5 minutes to 10 hours, advantageously 5 minutes, when the ratio of weight of the balls to the weight of the powders (3) is in the range of 5:1 to 10:1, advantageously 10:1, and then the obtained mixture of powders (3) is compacted under a pressure of 50 MPa to 100 MPa, advantageously 100 MPa in a tool set, placed in the vacuum chamber of a spark plasma sintering (SPS) device, containing a graphite foil (1) without or with a boron nitride (BN) layer (2) deposited on the internal surface of the foil (1) separating the compacted mixture of the powders (3) and the punches (4) from the die (5), moreover during compacting the mixture (3) is heated at a rate of 500 to 2400°C / min, advantageously 2200°C / min to a sintering temperature of 1850 to 2200°C, advantageously 2000°C, is heat treated at this temperature for a duration of 1 to 15 minutes, advantageously 1 minute, and then cooled to ambient temperature.

Description

[0001] A method for manufacturing of ceramic composite based on tungsten carbide

[0002] The subject of the invention is a method for manufacturing of ceramic composite from a mixture of tungsten carbide (WC) powder and titanium (Ti) powder or a mixture of tungsten carbide (WC) powder and titanium alloy powder, in particular the Ti6A14V alloy, using a high energy ball milling (HEBM) and spark plasma sintering (SPS) method.

[0003] The composite is used in particular for the manufacturing of tool materials intended for cutting knife blades, cutting plates, tips of measuring tools and structural and wearing elements for the manufacturing of elements of machinery, devices and instruments in space technology, armament industry, communications, aerospace, electronics, power engineering, and also for the manufacturing of sports equipment.

[0004] The publication by D. Garbiec, A.M. Laptev, V. Leshchynsky, M. Wisniewska, P. Figiel, A. Biedunkiewicz, P. Siwak, J. Rathel, J. Potschke, M. Herrmann, Spark plasma sintering of WC-Ti powder mixtures and properties of obtained composites (Journal of the European Ceramic Society, January 2022) describes three mixtures of powders, with the following contents: 95 wt% of tungsten carbide and 5 wt% of titanium; 90 wt.% of tungsten carbide and 10 wt% of titanium and 85 wt% of tungsten carbide and 15 wt% of titanium, which then underwent spark plasma sintering. Microstructures and phase compositions of the samples were investigated by electron microscopy method on a measuring and examination station equipped with a scanning electron microscope (SEM). At a titanium content of 5 and 10 wt% in the mixture the samples included WC, W2C and (Wi.xTx)C phases, whereas at the titanium content of 15 wt% in the mixture, the sample additionally contain elemental tungsten as a separate phase. The appearance of elemental tungsten in the form of an additional phase after sintering of the WC-15Ti powders led to a significant reduction in the hardness of the composite. Whereas the best combination of hardness and fracture toughness of the ceramic composites was achieved with 5 wt% titanium in the ceramic mixture.

[0005] The description of the CN 101229976 (A) Chinese patent application demonstrates a method of preparing high-performance WC-MgO nanocomposite material.

[0006] The method of preparing of high-performance WC-MgO composites comprises: 1 — WC and MgO powders with grain size of 1 to 5 pm are mixed according to weight ratio of 4:1 to 20:1; 2 — weight percentage of 0.5 to 5 percent of stearic acid is added so as to prevent powder from bonding to the tank wall and milling balls, thus increasing the yield of the powder, with the ball to material rate being 4:1 to 10:1; 3 — a ball milling tank is cleaned and filled with inert gas, and continuous ball milling is carried out at the rotating speed of 100 to 500 RPM for a time up to 70 hours to obtain WC-MgO nano-composite powder; 4 — the obtained powder is dried, cooled, pressed and formed; 5 — the pressed blank is put into a spark plasma sintering device to carry out sintering at a constant temperature for 3 to 5 minutes.

[0007] The manufactured sintered ceramic has fine grain sizes as well as relatively high hardness and toughness, with a performance similar to the WC-Co composite ceramic, which means that the MgO magnesium oxide successfully replaces the rare and noble cobalt metal (Co). However, this process requires the use of an additive in the form of stearic acid, which mixes with the composite powder parts.

[0008] The Japanese application JP 2014122425 demonstrates a composite powder with a core-outer layer structure, where the core particle material has the formula MaXb, where M is selected from a group consisting of titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, aluminium, magnesium, copper and silicon, and in particular Ti(C,N) titanium carbonitride. The particles have an intermediate layer, containing material composed from, for example, WC, W2C, as well as an outer layer containing cobalt or nickel. Known material may be obtained by treatment in the stream of low-temperature nitrogen plasma. Moreover, in the particle moulding process at least one additive selected from paraffin wax, stearic acid, ethylene bis-stearamide (EBS), polyvinyl alcohol and polyethylene alcohol has to be mixed with the particles before or simultaneously with the moulding.

[0009] The obtained composite powder is characterised by significant particle size (above 1 pm) and the need to use a special additive in the preparation process.

[0010] The publication of the RU 2493938 patent also shows a composite nanopowder containing particles consisting of a core, which consists of layers of titanium carbonitride and titanium nitrate, and a cladding which consists of a layer of nickel, with the following ratio of layers of the core and cladding, wt %: TiCxNy, where 0.28<x<0.70; 0.27<y<0.63; — 24-66; TiN0.6— 30-67; Ni — 4- 9. The method involves feeding a precursor containing titanium nickelide and titanium carbide into a reactor-evaporator chamber, treating in a current of nitrogen plasma at plasma flow rate of 60-100 m / s and at precursor feeding rate of 100-140 g / h, subsequent cooling in a current of nitrogen and trapping the evaporation product on a filter surface, with the precursor containing said components in the following mass ratio TiNi:TiC=25-50:50-75.

[0011] The use of a composite powder as the input material for obtaining of hard tungsten-free alloys requires a high sintering temperature (~1800°C) with a long duration of the process (6-8 h).

[0012] The Polish patent filing PL 421649 demonstrates a method for producing of sintered carbide-based composite for mining tools, which consists of adding Ti3SiC2 powder with a grain size of 3.0 to 5.0 pm in an amount of 5 wt% to 15 wt% to an initial mass containing 85 wt% to 95 wt% of the WC-Co powder with cobalt content of 11 wt%, with an average grain size of the WC-Co powder amounting to 1.5 to 5.0 pm. After initial press moulding, the moulded piece is sintered in a temperature of 1260°C to 1300°C at a pressure of 3 MPa to 100 MPa.

[0013] In this way the tungsten carbide is partially replaced by a triple phase of TiaSiCz type sintered carbide.

[0014] Both tungsten and cobalt are rare and precious metals, which is why there is a need to change the chemical composition of WC-Co type sintered carbides towards lowering the contents of WC and Co and replacing them with other components.

[0015] The solution according to the invention eliminates the problems and disadvantages known from the state of the art.

[0016] The goal of the invention was to develop a method of manufacturing such a ceramic composite which would allow the obtaining of products with high mechanical strength, compressive strength, wear resistance and resistance to high temperatures. The technological process according to the invention, in which high-energy ball milling and plasma spark sintering of a composite powder will enable obtaining a new generation composite tooling material, that is, ceramic composite based on tungsten carbide (WC) manufactured from a mixture of a tungsten carbide (WC) powder and titanium (Ti) powder or a mixture of tungsten carbide (WC) powder and a titanium alloy powder, in particular of the Ti6A14V alloy, characterised by high density, hardness, and fracture toughness. Whereas the structural and wearable material obtained using the method according to the invention from a tungsten carbide (WC) based ceramic composite manufactured from a mixture of tungsten carbide (WC) powder and titanium (Ti) powder or a mixture of a titanium alloy powder, in particular the Ti6A14V alloy, of a WC-Ti, WC-Ti6A14V type with an uniform micro-structure over the entire volume will contribute to reducing the mass of products (elements of machinery and equipment), increasing their hardness and stiffness, strength, resistance to friction wear, fracture toughness and to high temperature.

[0017] Essential feature of the solution according to the invention, which is a method for the manufacturing of ceramic composite from a mixture of tungsten carbide (WC) powder and titanium (Ti) powder or from a mixture of tungsten carbide (WC) powder and titanium alloy powder using a method of high-energy ball milling in a planetary ball mill using milling vessels in the form of bowls and balls, and for obtaining a product from a ceramic composite in the process of spark plasma sintering (SPS) using graphite foil separating the mixture of powders from the upper and lower graphite punch and from the graphite die, consists of a mixture of powders with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide (WC) powder and of 5% to 25%, advantageously 5 wt% of titanium (Ti) powder or a mixture of powders with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide (WC) powder and of 5% to 25%, advantageously 5 wt% of titanium alloy powder, advantageously Ti6A14V alloy, being mechanically ground in a planetary ball mill with a rotational speed in the range of 200 to 500 RPM, advantageously 500 RPM, for a time of 5 minutes to 10 hours, advantageously 5 minutes, when the ratio of weight of the balls to the weight of the powders is in the range of 5:1 to 10:1, advantageously 10:1. The obtained mixture of powders is compacted under a pressure of 50 MPa to 100 MPa, advantageously 100 MPa in a tool set, placed in the vacuum chamber of a spark plasma sintering (SPS) device, containing a graphite foil without or with a boron nitride (BN) layer deposited on the internal surface of the foil separating the compacted mixture of the powders and the punches from the die. During compacting the mixture is heated at a rate of 500 to 2400°C / min, advantageously 2200°C / min to a sintering temperature of 1850 to 2200°C, advantageously 2000°C, is heat treated at this temperature for a duration of 1 to 15 minutes, advantageously 1 minute, and then cooled to ambient temperature.

[0018] It is advantageous when the mixture of powders is ground in planetary ball mills, in which the bowls and balls are manufactured from a material with a hardness above 80 HRA, in particular from a tungsten carbide-cobalt composite.

[0019] It is moreover advantageous if the mixture of powders is ground with an addition of a Process Control Agent (PCA), with a content of 1-5%, <in particular? 5 wt% of the mixture.

[0020] The use of the solution presented in the invention enables the following technical and utility effects:

[0021] - the ability to manufacture a ceramic composite from a mixture of tungsten carbide (WC) and titanium (Ti) powders or a mixture of tungsten carbide (WC) and titanium alloy powders, in particular a Ti6A14V alloy powder with a density over 99% of theoretical density, hardness over 2000 HV10 and fracture toughness over 7 MPa-m1 / 2, which form a new generation of tooling, structural materials, intended to be used for cutting tools and for parts and elements of machinery with very high hardness, fracture toughness and stiffness, which must meet the continuously increasing expectations of the armaments, aerospace, electronics, computer, automotive, biomedical and other industries;

[0022] - obtaining a new tooling and structural material from a mixture of powders: tungsten carbide-titanium (WC-Ti) or tungsten carbide-titanium alloy (WC- Ti6A14V), where both titanium (Ti) and titanium alloy (Ti6A14V) successfully replace cobalt (Co), which is toxic, allergenic and harmful to living organisms, with similar physical and mechanical properties to the commonly used tungsten carbide-cobalt (WC-Co) composite;

[0023] - a method for the manufacturing of composite using high-energy ball milling and spark plasma sintering (SPS) according to the invention will result in obtaining a composite material with a required uniform microstructure, without excessive, uncontrolled grain growth, and with unique technological properties, safe for the health of living organisms and for the environment;

[0024] - the selection of the spark plasma (SPS) process parameters according to the invention has a direct influence on the voltage of the pulsed current. These parameters include the heating rate from 500 to 2400°C, advantageously 2200°C and the ratio of pulse duration to the duration of the interval between pulses. Obtaining a higher voltage (above 5 V) than standard (3 V) causes an increase in the number of electric spark discharges generated between the compacted powder particles at the initial stage of sintering and an increase in the temperature at the surface of these particles, enabling the cleaning of the particle surface from oxides and absorbed gasses by vaporizing them, and what is most important, it initiates and intensifies diffusion phenomenon at a much lower temperature, which in combination with the increased pressure from 50 MPa to 100 MPa, advantageously 100 MPa, enables obtaining from the mixture of tungsten carbide-titanium (WC-Ti) powders or tungsten carbide-titanium alloy (WC-Ti6A14V) powders a tooling material with porosity lower than 5%, high hardness and high fracture toughness, in a shorter duration process;

[0025] - lowering the porosity has an advantageous impact on increasing the impact strength of sintered materials, which is essential in the case of a tooling material obtained from a mixture of WC-Ti and WC-Ti6A14V powders;

[0026] - the use of tools of high-strength graphite in a spark plasma sintering device and optimisation of the tools’ dimensions using a computer-aided technique of modelling of physical phenomena, the finite element method (FEM), will contribute to lowering the resistance of the tooling system, and as a consequence to increasing the degree of consolidation of the powder material and obtaining of sintered elements with a density approximating the theoretical maximum.

[0027] The subject of the invention was presented in more detail in example implementations and in a drawing, which presents the tooling set — the layout of tools in an axial cross-section — for the manufacturing of products from a powder material using the spark plasma sintering (SPS) method.

[0028] Example 1

[0029] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium (Ti) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 500 RPM, for a duration of 5 minutes, where the ratio of the weight of the balls to the weight of the powders 3 is 10:1. The obtained mixture of powders 3 is pressed and sintered in a tooling set, containing a graphite foil 1 covered on the internal surface with a layer of boron nitride (BN) 2, which provides electrical insulation between the sintered mixture of powders 3 and punches 4 and the die 5. The tooling set is placed in the vacuum chamber of the spark plasma sintering (SPS) device, where the compacting process is conducted under a pressure of 100 MPa. During compacting the mixture 3 is heated at a rate of 2200°C / min to a sintering temperature of 2000°C, is heat treated at this temperature for a duration of 1 minute, and then cooled to ambient temperature.

[0030] Example 2

[0031] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 1.

[0032] Example 3

[0033] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium (Ti) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 200 RPM, for a duration of 10 hours, where the ratio of the weight of the balls to the weight of the powders 3 is 5:1. The obtained mixture of powders 3 is pressed and sintered, in the same manner as in the example 1, with the change that the process is conducted in an SPS device under a pressure of 50 MPa. During compacting the mixture 3 is heated at a rate of 500°C / min to a sintering temperature of 1850°C, is heat treated at this temperature for a duration of 15 minutes and cooled to ambient temperature. Example 4

[0034] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 3.

[0035] Example 5

[0036] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium (Ti) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 200 RPM, for 10 hours, where the ratio of the weight of the balls to the weight of the powders 3 is 5.T. The obtained mixture of powders 3 is pressed and sintered, in the same manner as in the example 1, with the change that the process is conducted in an SPS device under a pressure of 50 MPa. During compacting the mixture 3 is heated at a rate of 2400°C / min to a sintering temperature of 2200°C, is heat treated at this temperature for a duration of 15 minutes and cooled to ambient temperature.

[0037] Example 6

[0038] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 5.

[0039] The ceramic tungsten carbide-titanium (WC-Ti) composite obtained using the method according to the invention, the technological process of which is presented in examples 1-6, is characterised by the following properties: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium powder and over 1000 IT TO for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is also a material that is safe for living organisms and for the environment.

[0040] Example 7

[0041] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium alloy (Ti6A14V) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 500 RPM, for a duration of 5 minutes, where the ratio of the weight of the balls to the weight of the powder 3 is 10:1. The obtained mixture of powders 3 is pressed and sintered in a tooling set, containing a graphite foil 1 covered on the internal surface with a layer of boron nitride (BN) 2, which provides electrical insulation between the sintered mixture of powders 3 and punches 4 and the die 5. The tooling set is placed in the vacuum chamber of the spark plasma sintering (SPS) device, where the compacting process is conducted under a pressure of 100 MPa. During compacting the mixture 3 is heated at a rate of 2200°C / min to a sintering temperature of 2000°C, is heat treated at this temperature for a duration of 1 minute, and then cooled to ambient temperature.

[0042] Example 8

[0043] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 7.

[0044] Example 9

[0045] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium alloy (TiA14V) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 200 RPM, for 10 hours, where the ratio of the weight of the balls to the weight of the powders 3 is 5:1. The obtained mixture of powders 3 is pressed and sintered, in the same manner as in the example 7, with the change that the process is conducted in an SPS device under a pressure of 50 MPa. During compacting the mixture 3 is heated at a rate of 500°C / min to a sintering temperature of 1850°C, is heat treated at this temperature for a duration of 15 minutes and cooled to ambient temperature.

[0046] Example 10

[0047] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 9.

[0048] Example 11

[0049] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% titanium alloy (TiA14V) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 200 RPM, for 10 hours, where the ratio of the weight of the balls to the weight of the powders 3 is 5:1. The obtained mixture of powders 3 is pressed and sintered, in the same manner as in the example 7, with the change that the process is conducted in an SPS device under a pressure of 50 MPa. During compacting the mixture 3 is heated at a rate of 2400°C / min to a sintering temperature of 2200°C, is heat treated at this temperature for a duration of 15 minutes and cooled to ambient temperature.

[0050] Example 12

[0051] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 11.

[0052] The ceramic tungsten carbide-titanium alloy (WC-Ti6A14V) composite obtained using the method according to the invention, the technological process of which is presented in the examples 7-12, is characterised with the following properties: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium alloy powder and over 1000 HV10 for a composite with a 25 wt% content of titanium alloy powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is also a material that is safe for living organisms and for the environment.

[0053] Example 13

[0054] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 1, 3, 5, where the bowls and balls are manufactured from a material with a hardness above 80 HRA, in particular from a tungsten carbide-cobalt composite.

[0055] Example 14

[0056] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 2, 4, 6, where the bowls and balls are manufactured from a material with a hardness above 80 HRA, in particular from a tungsten carbide-cobalt composite.

[0057] The ceramic tungsten carbide-titanium (WC-Ti) composite obtained using the method according to the invention, the technological process of which is presented in the examples 13 and 14, is characterised by: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium powder and over 1000 HV10 for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is a material that is safe for living organisms and for the environment.

[0058] Example 15

[0059] The mixture of powders 3, with a contents of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 7, 9, 11, where the bowls and balls are manufactured from a material with a hardness above 80 HRA, in particular from a tungsten carbide-cobalt composite.

[0060] Example 16 The mixture of powders 3, with a contents of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 8, 10, 12, where the bowls and balls are manufactured from a material with a hardness above 80 HRA, in particular from a tungsten carbide-cobalt composite.

[0061] The ceramic tungsten carbide-titanium alloy (WC-Ti6A14V) composite obtained using the method according to the invention, the technological process of which is presented in the examples 15 and 16, is characterised by: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with, a 5 wt% content of titanium alloy powder and over 1000 HV10 for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is a material that is safe for living organisms and for the environment.

[0062] Example 17

[0063] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 1, 3, 5 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0064] Example 18

[0065] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 1, 3, 5 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture.

[0066] Example 19

[0067] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 1, 3, 5, 13 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0068] Example 20

[0069] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 1, 3, 5, 13 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture. Example 21

[0070] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified inthe examples: 2, 4, 6, 14 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0071] Example 22

[0072] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 2, 4, 6, 14 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture.

[0073] Example 23

[0074] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 2, 4, 6 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0075] Example 24

[0076] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 2, 4, 6 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture.

[0077] The ceramic tungsten carbide-titanium (WC-Ti) composite obtained using the method according to the invention, the technological process of which is presented in examples 17-24, is characterised with the following properties: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium powder and over 1000 HV10 for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is a material that is safe for living organisms and for the environment.

[0078] Example 25

[0079] The mixture of powders 3, with a contents of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 7, 9, 11 with an addition of a Process Control Agent (PCA) with a contents of 5 wt% of the mixture. Example 26

[0080] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 7, 9, 11 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture.

[0081] Example 27

[0082] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 7, 9, 11, 15 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0083] Example 28

[0084] The mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 5 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 7, 9, 11, 15 with an addition of a Process Control Agent (PCA) with a content of 1 wt% of the mixture.

[0085] Example 29

[0086] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 8, 10, 12, 16 with an addition of a Process Control Agent (PCA) with a content of 5 wt% of the mixture.

[0087] Example 30

[0088] The mixture of powders 3, with a contents of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 8, 10, 12, 16 with an addition of a Process Control Agent (PCA) with a contents of 1 wt% of the mixture.

[0089] Example 31

[0090] The mixture of powders 3, with a contents of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 8, 10, 12 with an addition of a Process Control Agent (PCA) with a contents of 5 wt% of the mixture. Example 32

[0091] The mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium alloy (Ti6A14V) powder is ground with high energy ball milling in a planetary ball mill, as specified in the examples: 8, 10, 12 with an addition of a Process Control Agent (PC A) with a content of 1 wt% of the mixture.

[0092] The ceramic tungsten carbide-titanium alloy (WC-Ti6A14V) composite obtained using the method according to the invention, the technological process of which is presented in examples 25-32, is characterised by: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium alloy powder and over 1000 HV10 for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-m1 / 2, porosity lower than 5%, and is a material that is safe for living organisms and for the environment.

[0093] Example 33

[0094] A mixture of powders 3, with a content of 95 wt% of tungsten carbide (WC) powder and 10 wt% titanium (Ti) powder is ground using high energy ball milling method in a planetary ball mill with a speed of 200 RPM, for a duration of 5 hours, where the ratio of the weight of the balls to the weight of the powders 3 is 5:1. The obtained mixture of powders 3 is pressed and sintered, in the same manner as in example 1, with the change that the process is compacting the conducted in an SPS device under a pressure of 100 MPa. During compacting the mixture 3 is heated at a rate of 2400°C / min to a sintering temperature of 2200°C, is heat treated at this temperature for a duration of 1 minute and cooled to ambient temperature.

[0095] Example 34

[0096] The prepared mixture of powders 3, with a content of 75 wt% of tungsten carbide (WC) powder and 25 wt% of titanium (Ti) powder is subjected to a high energy ball milling and spark plasma sintering process, as specified in the example 33.

[0097] The ceramic tungsten carbide-titanium (WC-Ti) composite obtained using the method according to the invention, the technological process of which is presented in the examples 33 and 34, is characterised with the following properties: density over 99% of the theoretical density, hardness over 2000 HV10 for a composite with a 5 wt% content of titanium powder and over 1000 HV10 for a composite with a 25 wt% content of titanium powder, fracture toughness over 7 MPa-mI / 2, porosity lower than 5%, and is also a material that is safe for living organisms and for the environment. Comparable results were obtained for the mechanical properties of the composite with the results obtained in examples 1-6.

[0098] Example 35

[0099] A method for manufacturing of a tungsten carbide based ceramic composite in the same manner as in the examples 1-35, though the tooling set for spark plasma sintering contains a graphite foil without a boron nitride (BN) layer.

[0100] Comparable results of the mechanical properties of the composite were obtained.

[0101] The detailed descriptions of the technological process of manufacturing the tungsten carbide based ceramic composite, according to the invention are not restricted solely to the presented example implementations and to specify the method of manufacturing of the composite with the patent claims.

[0102] The described examples may be subjected to many modifications, adaptations or equivalent implementations as a part of the character of the technical solution according to the invention and obtaining no less advantageous technical effects.

Claims

Claims1. A method for the manufacturing of ceramic composite from a mixture of tungsten carbide (WC) powder and titanium (Ti) powder or a mixture of of tungsten carbide (WC) and titanium alloy powder using a method of high- energy ball milling in a planetary ball mill using milling vessels in the form of bowls and balls, and for obtaining a product from a ceramic composite in the process of spark plasma sintering (SPS) using graphite foil separating the mixture of powders from the upper and lower graphite punch and from the graphite die, characterized in that the mixture of powders (3) with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide(WC) powder and of 5% to 25%, advantageously 5 wt% of titanium (Ti) powder or a mixture of powders (3) with a content of 75% to 95%, advantageously 95 wt% of tungsten carbide (WC) powder and of 5% to 25%, advantageously 5 wt% of titanium alloy powder, advantageously Ti6A14V alloy, is mechanically ground in a planetary ball mill with a rotational speed in the range of 200 to 500 RPM, advantageously 500 RPM, for a time of 5 minutes to 10 hours, advantageously 5 minutes, when the ratio of weight of the balls to the weight of the powders (3) is in the range of 5:1 to 10:1, advantageously 10:1, and then the obtained mixture of powders (3) is compacted under a pressure of 50 MPa to 100 MPa, advantageously 100 MPa in a tool set, placed in the vacuum chamber of a spark plasma sintering (SPS) device, containing a graphite foil (1) without or with a boron nitride (BN) layer (2) deposited on the internal surface of the foil (1) separating the compacted mixture of the powders (3) and the punches (4) from the die (5), moreover during compacting the mixture (3) is heated at a rate of 500 to 2400°C / min, advantageously 2200°C / min to a sintering temperature of 1850 to 2200°C, advantageously 2000°C, is heat treated at this temperature for a duration of 1 to 15 minutes, advantageously 1 minute, and then cooled to ambient temperature.

2. A method according to claim 1 characterized in that the mixture of powders (3) is ground in planetary ball mills, in which the bowls and balls are manufactured from a material with a hardness above 80 HRA, advantageously from a tungsten carbide-cobalt composite.

3. A method according to claim 1 or 2, characterized in that the mixture of powders (3) is ground with an addition of a Process Control Agent (PCA), with a content of 1-5%, in particular 5 wt% of the mixture (3).

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