GB2620367A

GB2620367A - A method and apparatus for forming blades using a mixture of metals and 2-D materials

Info

Publication number: GB2620367A
Application number: GB2209430.4A
Authority: GB
Inventors: Koncherry Vivek
Original assignee: Graphene Innovations Manchester Ltd
Current assignee: Graphene Innovations Manchester Ltd
Priority date: 2022-06-28
Filing date: 2022-06-28
Publication date: 2024-01-10
Also published as: GB202209430D0

Abstract

A nozzle 100 for mixing a 2d material such as graphene with molten metal comprises an inlet 56 for molten metal, at least one inlet 58 for the 2d material, a deflecting arrangement for deflecting and mixing material as it flows through the nozzle and an outlet disposed downstream of the deflecting arrangement. The deflecting arrangement can comprise either plural deflector plates 102 or at least one helical plate 202 extending from the inner wall 68 of the nozzle. The nozzle can comprise means 400 for vibrating it. Figure 4 shows a nozzle which further comprises a motor driven screw thread mixer 304. Also disclosed is a method of making cutting blades by mixing molten metal and a 2d material in a nozzle, forming slabs and then sheet from the mixture and forming blades from the sheet and a method of forming a turbine blade by mixing molten metal and a 2d material in a nozzle followed by mould casting. The molten metal can be stainless steel, carbon steel, tool steel or titanium alloys and the method used to form razor blades.

Description

I

A METHOD AND APPARATUS FOR FORMING BLADES USING A MIXTURE OF METALS AND

2-D MATERIALS

FIELD

The present invention relates to a method and apparatus for forming a blade. The method involves creating a mixture of a metal with a 2-D material, such as graphene for example, from which blades are subsequently manufactured. In particular, but not exclusively, the method and apparatus provides homogeneous mixing of graphene and a suitable metal such as stainless steel, for the production of blades.

BACKGROUND

Blades such as razor blades are usually formed from metal sheets. Historically, blades for razors have been produced with cutting edges that provide a substrate (such as a ground portion of the edge of the blade) to which a coating is applied. The hard coating may further be coated in a lubricant. In addition, an underlayer may be provided between the ground surface of the blade and the hard coating applied to the blade, to improve bonding between the blade and the hard layer.

Advantages of applying a hard coating to a blade in this way are that the hard coating strengthens the blade edge to reduce its susceptibility to damage through impacts or general wear and may assist in reducing corrosion of the blade. Suitable hard coatings for razor blades may include platinum, Polytetrafluoroethylene (PTFE), chromium, and mixtures involving chromium such as a chromium-carbon mixture or a chromium-platinum mixture, for example. It is also known to apply a layer of graphene to a blade, as described in US11,000,963, for example.

An issue caused by applying hard coatings of these types is that the coating layer(s), including any underlayers and hard layers as described above, may be relatively thick, and so alter the weight and size of the razor blades produced, and therefore alter the cutting properties. Further, requiring steps of applying additional layers of hard coatings to a razor blade increases the manufacturing complexity and lengthens the process.

While razor blades such as those produced for shaving equipment are primarily discussed herein, it should be understood that the methods described and composites resulting from the manufacturing methods, are suitable for producing knife and saw blades, razor wire, axe blades, and any other types of metallic cutting blades. For example, such blades may be used in industrial processes such as forestry and paper production, cutting tools for industrial applications, as well as in kitchenware and medical equipment. In addition, using the described apparatus, objects such as turbine blades may be formed of the composites produced.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a method of manufacturing a blade, including the steps of: providing a molten metal to a mixing nozzle via a main inlet, providing a 2D material to the mixing nozzle via a 2D material inlet, the 2D material preferably being graphene, mixing the molten metal and 2D material using a mixing nozzle, the mixing nozzle providing a mixing volume for creating a mixture of the molten metal and the 2D material, forming slabs of the mixture, processing a slab to form a sheet for forming blades, and forming blades from the sheet.

In at least one embodiment, the method further includes, prior to providing the molten metal to the mixing nozzle, melting recycled or virgin metal, optionally in an arc furnace.

In at least one embodiment, the molten metal is stainless steel.

In at least one embodiment, multiple 2D material inlets may be used to provide the 2D material to the mixing nozzle.

In at least one embodiment, the method further includes, prior to providing the molten metal to the mixing nozzle, providing molten steel to an argon-oxygen decarburisation vessel to create stainless steel, and optionally further including the step of transferring the stainless steel to a ladle furnace to control the temperature and composition of the stainless steel.

In at least one embodiment, mixing the molten metal and 2D material includes controlling a temperature of the mixing volume, and optionally controlling the temperature at between 1300°C and 1600°C, and preferably in the range of 1400°C to 1530°C.

In at least one embodiment, mixing the molten metal and 2D material includes controlling a pressure of the mixing volume, and optionally controlling the pressure at around 0-30 bar pressure, and preferably around 0-20 bar pressure.

In at least one embodiment, mixing the molten metal and 2D material includes vibrating the mixing nozzle, and optionally the vibration is at between 10Hz and 10,000Hz and has a mechanical amplitude of between 0.1mm and 1mm.

In at least one embodiment, forming slabs of the mixture includes first forming ingots of the mixture and then cutting the ingots into slabs, and optionally processing a slab by rolling the slab and reducing the temperature to around 1200°C.

In at least one embodiment, processing a slab to form a sheet includes one or more of the following steps: reducing the thickness of the slab using a roughing mill to form a sheet; reducing the thickness of the sheet using a finishing mill; cooling the sheet; rolling the sheet using a down coiler.

In at least one embodiment, forming blades from the sheet includes one or more of the following steps: cutting the sheet to a predetermined blade width; stamping the sheet to form blade blanks; heat-treating the blanks using one or more of the following steps: treating the blanks in a furnace between 1000°C and 1200°C; quenching the blanks in water; chilling the blanks at around -40°C to -60°C; and/or reheating the blanks; grinding and polishing the blanks to form a blade or strip of blades; separating individual blades from the strip of blades.

The present invention also provides a mixing nozzle for use in the method of manufacturing a blade, the mixing nozzle providing: a body including a nozzle wall defining a mixing volume, a main inlet for receiving a flow of molten metal, a 2D material inlet for receiving a flow of a 2D material, a deflector arrangement providing a deflecting surface for deflecting the mixture as it flows through the nozzle, and an outlet disposed downstream of the deflector arrangement.

In at least one embodiment, multiple 2D material inlets are provided by the mixing nozzle.

In at least one embodiment, the deflector arrangement provides multiple deflector plates, each extending from the nozzle wall, spaced around the periphery of the nozzle wall.

In at least one embodiment, each deflector plate extends from the nozzle wall, the deflector plate extending across the mixing volume by at least 50% of a width or a diameter of the mixing volume, and optionally, wherein the deflecting surface is inclined lengthwise of the body.

In at least one embodiment, multiple sets of deflecting plates are provided, each set extending from a respective position around the periphery of the nozzle wall, the deflecting plates of each set extending from positions spaced apart lengthwise of the body, and the respective sets each being offset from the other sets around the periphery of the nozzle wall.

In at least one embodiment, the deflector plates between them extend across the entire cross-sectional area of the mixing volume of the nozzle such that there is no unobstructed straight path between the main inlet and the outlet.

In at least one embodiment, the mixing nozzle provides: multiple main inlets spaced around the periphery of the nozzle wall, and optionally wherein the main inlets are spaced lengthwise of the nozzle wall, and / or multiple 2D material inlets spaced around the periphery of the nozzle wall, and optionally wherein the 2D material inlets are spaced lengthwise of the nozzle wall.

In at least one embodiment, the deflector arrangement provides a continuous deflector plate extending inwardly from the nozzle wall, winding around the periphery of the nozzle wall as it extends lengthwise of the mixing volume, and optionally, wherein the continuous deflector plate has a helical form.

In at least one embodiment, the continuous deflector plate extends around the periphery of the nozzle wall for multiple revolutions.

In at least one embodiment, the continuous deflector plate extends inwardly of the nozzle wall by between 10-50% of the diameter of the mixing volume, and preferably by between 20-35% of the diameter, and optionally, wherein the continuous deflector plate is inclined downwardly radially from the nozzle wall in the direction of the outlet.

In at least one embodiment, the mixing nozzle includes one or more mixers providing a deflector in the form of a screw thread, and a motor configured to drive the mixers so that they rotate within the mixing volume.

In at least one embodiment, two mixers are provided, and the mixers are configured to counter-rotate.

In at least one embodiment, the deflector arrangement lies downstream of the main inlets and the 2D material inlets.

In at least one embodiment, the mixing nozzle includes a vibration collar configured to surround a portion of the body of the nozzle, the vibration collar including a vibration motor for imparting vibration to the nozzle wall, and optionally wherein a layer of heat insulating material is provided between the vibration motor and the portions connected to the body of the nozzle.

In at least one embodiment, the vibration collar provides a cooling arrangement for cooling the vibration motor, and optionally the cooling arrangement provides an inlet for receiving a flow of cooling air and an outlet for exhausting warmed air.

In at least one embodiment, the mixing nozzle provides a heating coil arrangement for controlling a temperature of the mixing volume, and optionally controlling the temperature at between 1300°C and 1600°C, and preferably in the range of 1400°C to 1530°C.

The present invention also provides a blade formed by the methods outlined above, or by using a mixing nozzle as outlined above.

The described methods provide clear benefits since manufacturing a blade according to the described methods means that the usual manufacturing steps of applying one or more layers of coatings to the formed blade are no longer essential. The blades formed according to the method are more resistant to corrosion and less susceptible to wear, and damage through impact, and so provide a longer lifespan than blades manufactured by current state of the art techniques. For both these reasons, the process and resulting blades have environmental benefits, compared to use of current manufacturing techniques since they require fewer processing steps and provide more durable blades resulting in replacements being made less frequently.

BRIEF DESCRIPTION OF THE FIGURES

In order that the present disclosure may be more readily understood, preferable embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a diagrammatic view of a method of manufacturing a blade, embodying the present

disclosure;

FIGURE 2A is a cross-sectional illustration of a mixing nozzle according to a first embodiment of the present disclosure, the nozzle providing deflectors in the form of multiple deflector plates extending from a wall of the mixing nozzle; FIGURES 2B and 2C are illustrations of a portion of the mixing volume of the nozzle of FIGURE 2, showing respectively an isometric view of multiple deflector plates, and a top-down view illustrating the cross-sectional area of a portion of the mixing volume, and overlapping deflector plates; FIGURE 3 is a cross-sectional illustration of a mixing nozzle according to a second embodiment of the present disclosure, the nozzle providing a deflector in the form of a continuous deflector plate extending from a wall of the mixing nozzle; FIGURE 4A is a cross-sectional illustration of a mixing nozzle according to a third embodiment of the present disclosure, the nozzle providing a driven deflector disposed within the mixing nozzle; FIGURE 4B is a top-down cross-sectional view through a portion of the mixing nozzle of FIGURE 4A; and FIGURES is a diagrammatic view of a vibrating collar arrangement for use with the mixing nozzles of embodiments of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

With reference to the drawings, we describe a method and apparatus for creating a mixture of metal and a two-dimensional material, particularly for use in manufacturing a blade, and a blade manufactured according to the method. In some embodiments of the technology, a mixture of two or more two-dimensional materials may be used.

Two-dimensional (12D') materials, also referred to by some in the field as "single-layer materials", are crystalline solids consisting of one (or optionally more than one) layer of atoms having a thickness of a few nanometres or less. For example, a single-layer graphene material has a thickness in the order of 0.3 nanometres. Nanoplatelets may be formed of multiple layers, with a thickness of up to 30 nanometres, for example. In some examples a material of up to 100 nanometres thickness may be formed. Electrons in these materials are free to move in the 2D plane, but their restricted motion in the third direction is governed by quantum mechanics. Graphene is an example of such a 2D material. Other 2D materials suitable in the context of the present invention include MXene, and Platinum Diselenide, for example.

In the context of creating a mixture of a metal and 2D material for the purpose of manufacturing a blade, a suitable metal for this purpose is steel (such as stainless steel, for example). Other metals suitable for this purpose include carbon steel, tool steel, alloy steel, and titanium alloys, for example.

Where a metal 2D material is used, suitable 2D metals are those having a significantly higher melting point that the metal (i.e., the stainless steel) used as the base of the composite, so that the 2D material does not melt during the mixing phase.

For the purpose of explaining the examples described herein, we refer to steel as the raw material being used, pre-processed to form stainless steel, and subsequently to the mixture being made with stainless steel and graphene. It should be understood that other materials may be used.

With reference to Figure 1 of the drawings, the manufacturing process starts with a raw material 12 in the form of recycled or virgin steel. The raw material is melted 14 in a furnace (such as an electric arc furnace) at a temperature of around 1400°C to 1800°C, and preferably in the range of 1500°C to 1700°C, and more preferably around 1600°C. The molten metal is then passed into a decarburisation vessel 16 (an argon-oxygen decarburisation vessel, for example) for stainless steel manufacturing.

The molten stainless steel is then transferred into a ladle furnace 18 to maintain the correct composition and temperature, prior to the molten steel being poured into a tundish 20. The tundish 20 provides the mechanism by which the molten metal is fed into the mixing nozzle, as described below.

At this stage, graphene and/or another 2D material and the molten stainless steel (or other metal being used in the process) is mixed 10 to form a composite. By mixing a component such as graphene into the stainless steel at this stage, the composite formed provides advantageous properties for forming a blade subsequently from the mixture. This in turn removes the requirement to coat the formed blade in a hardened coating such as a layer of graphene, for example. Using a graphene and stainless-steel composite has been found to increase ultimate tensile strength of a blade formed of this way by between 17% and 64% depending on the specific properties of the composition, and the hardness by around 25%.

The step of mixing the molten metal and 2D material is indicated at 10 in the appended Figures, and is carried out using a mixing nozzle 100, 200, 300. Suitable mixing nozzles 100, 200, 300 for this purpose are illustrated in Figures 2, 3 and 4 of the drawings, and are described in more detail below.

In general terms, graphene 22 is supplied via a metering system 26 which releases the graphene via a conduit 24 leading to the mixing nozzle 100, 200, 300 at a desired flow rate.

The mixing nozzle 100, 200, 300 is designed such that the molten steel and graphene are mixed homogeneously, without agglomeration. The mixing nozzle 100, 200, 300 provides one or more main inlets 56 for receiving a flow of molten metal. The graphene 22 enters the mixing nozzle 100, 200, 300 via multiple 2D material inlets 58.

In embodiments of the described technology, a vibration collar 400 is provided (as illustrated in Figure 5 of the drawings), configured to contact a portion of the mixing nozzle 100, 200, 300 so as to assist with the mixing of the molten metal and graphene, and reduce or avoid the inlets 58 becoming blocked while in use. The mixing nozzle 100, 200, 300 provides one or more deflectors for dispersing and mixing the molten metal and graphene as they pass through the body of the nozzle 100, 200, 300. These deflectors may take various forms, as described in more detail below.

Heat is applied to the body of the vessel providing the nozzle 100, 200, 300, so that as the mixture passes through the nozzle it is kept at or around a desired temperature to enable to the composite mixture to remain in a molten state enabling it to flow to a mould 28 downstream of the nozzle 100, 200, 300. A standard heating coil is used, at or around a portion of a body 62 of the nozzle 100, 200, 300, in a heating zone 60, as is known in the art. This maintains the temperature of the mixture at between 1300°C and 1600°C, and preferably in the range of 1400°C to 1530°C. The vessel in which the mixing takes place is at a pressure of around 0-30 bar pressure, and preferably around 0-20 bar pressure. The vessel and nozzle 100, 200, 300 may be formed of any suitable material as is generally known in the art, such as steel, provided with a suitable refractory lining such as a ceramic lining.

Following the mixing step 10, the procedure for producing a blade using the molten metal mixture follows the approach generally known in the art, as would typically be applied to molten steel, for

example.

The molten mixture flows into a mould 28 to produce a desired shape of cast material as is known in the art. The cast material, also known as ingots, is made continuously before the ingots are cut into slabs 30. The slabs are then passed onto a rolling mill 34. At this stage, the temperature of the slabs is preferably maintained at up to 1200°C, and preferably around 1200°C. The slabs are transported to a roughing mill 36 followed by a finishing mill 38 where the thickness of the slabs is reduced as desired. Cooling 40 is carried out to achieve the final thickness of the sheets before storing these in the form of a coil. The coil is produced by winding in a down-coiler 42.

The coil of stainless-steel metal sheet is then transferred in the blade manufacturing process, where it is slit into strips with the desired width 44. A stamping process 46 is then carried out on the strips to produce blanks consisting of dull-edged blades.

The blanks are then heat-treated 48. The heat treatment typically takes place in four stages, in order to harden the metal by restructuring the molecules. As an example, in a first step of heat treatment, the blanks are treated in a furnace at between 1000°C and 1200°C, and preferably at or around 1100°C, for a short period of time (between 20 and 60 seconds, and preferably around 30 seconds). This heating step is followed by a quenching step, where the blanks are quenched in water (preferably in water at or around 30°C to 40°C) -or the blanks may be quenched by spraying them with water.

The blanks are subsequently chilled at around -40°C to -60°C, and preferably at or around -50°C, which makes the blanks brittle, and finally, a heating step is carried out for around 20 seconds which is sufficient to restore a degree of flexibility to the blanks (i.e. to return the blanks to a temperature at which they can be worked into blades). Once this heat treatment is completed, the blanks are formed into blades 50 by grinding and polishing.

Typically, three-step grinding 52 of the hard blanks is carried out to create two sharp edges, in which the contour of the blade is sharpened to produce two sharp edges, followed by a polishing step to remove any burrs created by the grinding steps.

Optionally, at this point, an additional coating such as lubricant or the like may be applied. The blades may then be separated 54 into individual blades. Alternatively, the blades may be left as a strip, joined to one another, which may make it more efficient to store and transport the blades in large volumes, for example.

Looking now at the mixing nozzle 100, 200, 300 design in detail, we look at a first embodiment as shown in Figure 2A of the drawings.

The mixing nozzle 100 provides a body 62 including one or more nozzle walls 68, defining a mixing volume 64, the body 62 being provided with a main inlet 56 for receiving a flow of molten metal, and one or more 2D material inlets 58 for receiving a flow of graphene (or another suitable 2D material). In the embodiment shown, the body 62 is substantially cylindrical; in other embodiments the body may have a different profile.

Preferably, multiple 2D material inlets 58 are provided. In embodiments, the 2D material inlets 58 are spaced from each other around a periphery of the body 62 of the mixing nozzle 100. In embodiments, the 2D material inlets 58 are spaced from each other lengthwise of the body 62 of the mixing nozzle 100. Each 2D material inlet 58 is positioned so that a central axis of the inlet forms an angle a with a central axis X of the body 62 (i.e., that axis being aligned with the general direction in which the molten steel flows through the mixing volume 64) of between 10° and 60°, preferably between 25° and 45°, and more preferably still at around 30° to 40°.

An initial stage of mixing takes place within the mixing volume 64 as the graphene enters the volume via the 2D material inlets 58, and the molten metal and 2D material flow together within the shared mixing volume 64. Material flowing through the body 62 moves generally lengthwise of the body 62, between the main inlet 56 and an outlet 66 formed downstream of the mixing volume 64.

The nozzle 100 provides a deflector arrangement in the form of multiple deflector plates 102, lying downstream of the 2D material inlets 58 in the direction of flow. Each deflector plate 102 extends across a portion of the mixing volume 64, from the nozzle walls 68, to deflect any material passing through the mixing volume 64 coming into contact with a surface of the deflector plate 102. More specifically, the nozzle walls 68 define a cross-sectional area of the body 62 of the nozzle 100, which is generally round / circular when the nozzle 100 has a substantially cylindrical shape. Each deflector plate 102 extends from a nozzle wall 68 across a portion of the cross-sectional area: preferably covering at least half of the cross-sectional area. In other words, in plan view -looking down the central axis X of the nozzle -each deflector plate 102 covers more than 50% of the cross-sectional area of the mixing volume.

With reference to Figures 2B and 2C, the nozzle 100 is described in more detail. In embodiments, and as illustrated, the nozzle 100 provides multiple deflector plates 102 which are grouped into two or more sets 102a, 102b. Each set comprises one or more deflector plates 102a, 102b, extending from the nozzle wall 68, across the cross-sectional area of the body 62 of the nozzle 100, so as to provide a deflecting surface 104a, 104b in the direction facing the oncoming flow of material through the nozzle 100. The deflector plates 102a, 102b, and their deflecting surfaces 104a, 104b between them extend across the entire cross-sectional area of the mixing volume 64 of the nozzle 100, such that there is no unobstructed straight path between the main inlet 56 of the nozzle 100 and the outlet 66. Material flowing through the nozzle 100 must follow a tortuous path before reaching the outlet 66, encouraging mixing of the molten metal and the 2D material within the mixing volume 64.

Figure 2B illustrates the deflector plates 102a, 102b extending outwards from the nozzle wall 68 from a proximal edge adjoining the nozzle wall 68, to a distal edge 106a, 106b. In embodiment wherein the nozzle wall 68 is cylindrical, the distal edge 106a, 106b forms a chord across the mixing volume 64. The deflector plates 102a, 102b are inclined lengthwise of the nozzle body 62, so that the distal edge 106a, 106b of each plate lies closer than most of the proximal edge to the outlet 66 of the nozzle 100. In this way, material impacting the deflecting surfaces 104a, 104b of the plates maintains its movement in the direction of the outlet 66 (which is preferable to a deflecting surface lying in the plane perpendicular to the direction of flow which would more significantly reduce flow rate).

Two or more sets of deflecting plates 102a, 102b are provided, each set extending from a respective position on the periphery of the nozzle wall 68. Where two sets are provided, as shown, the sets are preferably set on opposing sides of the nozzle wall 68, spaced 180° apart around the periphery. In other embodiments, other numbers of sets may be provided, where for n sets, those sets are each spaced (360/n)0 apart around the periphery. The deflecting plates 102a, 102b belonging to a set are spaced lengthwise of the nozzle 100 in the direction of flow, and offset lengthwise from the other sets of plates. In this way, the deflector plates 102a, 102b of the different sets alternate along the length of the nozzle 100, so that material flowing through the nozzle 100 impacts a deflecting surface 104a of a first set, followed by a deflecting surface 104b of a second set, etc., to create a cascading effect.

Figure 20 illustrates that the deflector plates 102a, 102b each extend more than halfway across the width/diameter of the body 62, so that the deflecting surfaces 104a, 104b overlap when viewed in there is no clear straight path between the deflector plates 102a, 102b, such that material flowing through the nozzle 100 contacts multiple deflecting surfaces 104a, 104b on its route to the outlet 66.

In other words, in this embodiment, the mixture flows across the deflecting surfaces 104a, 104b and over the distal edges 106a, 106b, in sequence, so as to provide a cascading effect as the mixture flows from one plate down to the next plate, until it reaches the outlet 66.

With reference to Figure 5, the vibration collar 400 provides a collar arrangement 410 configured to surround a portion of the body 62 of the nozzle 100, 200, 300. The collar 400 includes a vibration unit 418 that provides a vibration motor 406 (connected to a power source which is not illustrated), and a cooling arrangement. Preferably, the collar arrangement 410 contacts the body 62 at a position adjacent the 2D material inlets 58. The effect of the vibration on the nozzle 100 is to aid the mixing of the graphene with the molten metal, and to encourage the materials to flow continuously to avoid clogging or blocking of the 2D material inlets 58, for example.

Preferably, the vibration motor 406 vibrates at between 10Hz and 10,000Hz, causing a vibration of mechanical amplitude between around 0.1mm and 1mm.

In embodiments of the technology, the collar arrangement 410 is configured to surround a portion of the body 62 so as to grip the walls 68 of the body, to transfer vibration to the walls 68 from the vibration motor 406. In embodiments of the technology, the collar arrangement 410 is constructed of tungsten carbide, which is suitable due to its high durability and high melting point. Other suitable durable materials may be used.

Vibration is transmitted from the vibration unit 418 to the collar arrangement 410 via a connector 416. Layers of heat insulating material 408 are provided between the vibration motor 406 and the connector 416 to avoid excessive heat transfer between the connector 416 and the motor, to avoid the vibration motor 406 overheating. The heat insulating material 408 may comprise glass, a ceramic such as NextelTM, Kapton TM polymide film, tetrafluoroethylene, or any other suitable heat-insulator.

In embodiments, the vibration collar 400 further provides a cooling circuit, having an inlet 404 for receiving a flow of cooling air 402, and an outlet 414 for exhausting warmed air 412. The cooling circuit passes through and/or around the vibration unit 418 so as to transfer heat away from the vibration motor 406.

In a second embodiment, with reference to Figure 3 of the drawings, the mixing nozzle 200 provides the same general layout as the nozzle 100 of Figure 2, having a body 62 including one or more nozzle walls 68, defining a mixing volume 64. As before, the body 62 is provided with a main inlet 56 for receiving a flow of molten metal, and one or more 2D material inlets 58 for receiving a flow of graphene (or another suitable 2D material). In the embodiment shown in Figure 3, the body 62 is substantially cylindrical; in other embodiments the body may have a different profile.

The difference between the mixing nozzle 200 of the present embodiment with that of Figure 2, is that the multiple deflector plates 102 of the previous embodiment are replaced with a continuous deflector plate 202 wound around the periphery of the nozzle wall 68. The continuous deflector plate 202 lies substantially downstream of the 2D material inlets 58 in the direction of flow; although, in embodiments, the plate may begin at a position aligned with or in the region of the 2D material inlets 58 (as illustrated in Figure 3).

In embodiments of the technology, the continuous deflector plate 202 has a helical form, and winds around the internal surface of the nozzle wall 68 for at least one complete rotation. In some embodiments, the continuous deflector plate 202 has a wave-like form, such that it wraps around the nozzle wall in a non-uniform spiral arrangement. In preferred embodiments, the continuous deflector plate 202 winds around the nozzle wall 68 for multiple revolutions (each revolution comprising a 360° winding). Preferably, as shown the continuous deflector plate 202 winds around the nozzle wall for three or more rotations.

In some embodiments of the technology, multiple continuous deflector plates 202 are provided, each of which wraps around the nozzle wall 68. The continuous deflector plates 202 may be offset from one another so as to provide a double-helix structure, for example.

The continuous deflector plate 202 extends inwardly of the nozzle wall 68, into the mixing volume 64, to deflect material passing through the mixing volume 64 coming into contact with a deflecting surface 204 of the plate 202. In embodiments, the continuous deflector plate 202 extends inwardly of the nozzle wall 68 by between 10-50% of the diameter of the mixing volume 64, and more preferably by between 20-35% of the diameter.

The continuous deflector plate 202 extends outwards from the nozzle wall 68 from a proximal edge adjoining the nozzle wall 68, to a distal edge spaced from the nozzle wall 68. The continuous deflector plate 202 may be inclined lengthwise of the nozzle body 62, so that the distal edge of the plate lies closer than the proximal edge to the outlet 66 of the nozzle 200. In other words, it is inclined downwardly radially from the nozzle wall 68 in the direction of the outlet 66. In this way, material impacting the deflecting surface 204 of the plate maintains its movement in the direction of the outlet 66 so as not to significantly reduce flow rate.

While in this embodiment the deflecting surface 204 does not extend across the entire cross-sectional area of the mixing volume 64, the turbulence caused by the molten mixture impacting the deflecting surface 204 causes the deflected mixture to move inwardly of the mixing volume 64 and consequently come into contact and mix with the mixture flowing through the central portion of the mixing volume. In this way, complete mixing is achieved, resulting in a homogeneous mixture.

In a third embodiment, with reference to Figure 4A of the drawings, the mixing nozzle 300 provides a similar layout to the previously described nozzles 100, 200. The differences in this case are that rather than having an open first end defining a main inlet for receiving a flow of molten metal, instead, one or main inlets 56 are provided in the walls 62 of the nozzle 300, each receiving a flow of molten metal. As before, one or more 2D material inlets 58 are provided downstream of the main inlets 56, for receiving a flow of graphene (or another suitable 2D material).

In this third embodiment, two or more screw-like mixers 304 are provided within the mixing volume defined within the nozzle 300. By screw-like, we mean that the deflectors are formed in the configuration of a screw thread. Preferably, two mixers 304 are provided. These mixers 304 are each disposed lengthwise of the nozzle, extending from a position close to the main inlets 56 at a first end of the nozzle towards an outlet 66 defined at the opposite second end of the nozzle 300.

The mixers 304 are driven by a motor 302 disposed at an end of the nozzle 300. The mixers 304 are thermally insulated from the motor 302 by a layer of insulating material 310, to avoid heat within the mixing volume defined within the nozzle 300 transferring to the motor 302, potentially damaging the motor 302. The mixers 304 each provide one or more deflectors 306 defining a deflecting surface 308 facing towards the first end of the nozzle, so as to deflect the incoming mixture as it flows through the nozzle 300. In embodiments, and as illustrated, each mixer 304 provides a single deflector 306 shaped like a screw-thread, wrapping around the mixer 304 along its length.

The deflecting surfaces 308 extend outwardly from a central core of the mixer 304.

As can be seen in Figure 4B of the drawings, a wall 312 defining the mixing volume conforms closely to the shape of the mixers 304. In other words, the deflectors 306 surrounding the mixers 304 extend outwardly from their respective central cores to a point adjacent to the wall 312, so that substantially all of the molten mixture passing through the nozzle 300 is subject to mixing through contact with the deflectors 306 or the swirling motion caused by the deflectors 306. Preferably, and as shown, the deflectors 306 of the two (or more) mixers 304 overlap each other in top-down profile, such that substantially all of the cross-sectional area through the nozzle 300 (i.e., in the plane normal to the general direction of flow through the nozzle 300) is covered by the mixers 304 and their deflectors 306, so that no molten material bypasses the mixers 304.

Where two mixers 304 are used, they may be counter-rotated, so that one is driven clockwise and the other anticlockwise by the motor 302. This system induces a pressure suitable for providing homogeneous mixing of the ingredients.

In embodiments of the technology, the motor 302 is a DC motor. Preferably the mixers 304 are driven by the motor 302 at a rate of between 20 RPM and 100 RPM, and preferably at around 50 RPM.

Using the mixing nozzles according to the embodiments described, graphene and other suitable 2D materials may be incorporated into metals such as stainless steel without agglomeration. The addition of graphene into metal acts as a microscopic tebari, or reinforcement, to increase the hardness and strength of the resulting metal. In this way, the resulting material has the properties desired in blade production -it has increased durability and improved wear resistance compared to traditional materials.

The incorporation of graphene prevents or reduces corrosion of the resulting blades, and provides inherent lubrication, a desired property in particular for razor blades. In this way, we eliminate the requirement for multiple layers of additional coatings to be applied to the blades during the process of manufacturing the blades.

Where the apparatus is used for manufacturing other objects such as turbine blades, for example, alternative steps may follow the step of mixing the molten metal with the 2D material(s). For example, the output of the nozzle 100, 200, 300 may flow to a mould for forming suitably-shaped turbine blades. Such a method will eliminate requirements for machining large volumes of metal to achieve the desired shape, thus reducing material wastage and machining time.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The invention may also broadly consist in the parts, elements, steps, examples and/or features referred to or indicated in the specification individually or collectively in any and all combinations of two or more said parts, elements, steps, examples and/or features. In particular, one or more features in any of the embodiments described herein may be combined with one or more features from any other embodiment(s) described herein.

Protection may be sought for any features disclosed in any one or more published documents referenced herein in combination with the present disclosure.

Although certain example embodiments of the invention have been described, the scope of the appended claims is not intended to be limited solely to these embodiments. The claims are to be construed literally, purposively, and/or to encompass equivalents.

Claims

CLAIMS1. A method of manufacturing a blade, including the steps of: providing a molten metal to a mixing nozzle via a main inlet, providing a 2D material to the mixing nozzle via a 2D material inlet, the 2D material preferably being graphene, mixing the molten metal and 2D material using a mixing nozzle, the mixing nozzle providing a mixing volume for creating a mixture of the molten metal and the 2D material, forming slabs of the mixture, processing a slab to form a sheet for forming blades, and forming blades from the sheet.
2. A method according to claim 1, further including, prior to providing the molten metal to the mixing nozzle, melting recycled or virgin metal, optionally in an arc furnace.
3 A method according to claim 1 or claim 2, wherein the molten metal is stainless steel.
4. A method according to claim 3, further including prior to providing the molten metal to the mixing nozzle, providing molten steel to an argon-oxygen decarburisation vessel to create stainless steel, and optionally further including the step of transferring the stainless steel to a ladle furnace to control the temperature and composition of the stainless steel.
5. A method according to any one of the preceding claims, wherein mixing the molten metal and 2D material includes controlling a temperature of the mixing volume, and optionally controlling the temperature at between 1300°C and 1600°C, and preferably in the range of 1400°C to 1530°C.
6. A method according to any one of the preceding claims, wherein mixing the molten metal and 2D material includes controlling a pressure of the mixing volume, and optionally controlling the pressure at around 0-30 bar pressure, and preferably around 0-20 bar pressure.
7. A method according to any one of the preceding claims, wherein mixing the molten metal and 2D material includes vibrating the mixing nozzle, and optionally the vibration is between 10Hz and 10,000Hz with a mechanical amplitude of between 0.1mm and lmm.
8. A method according to any one of the preceding claims, wherein forming slabs of the mixture includes first forming ingots of the mixture and then cutting the ingots into slabs, and optionally processing a slab by rolling the slab and reducing the temperature to around 1200°C.
9. A method according to any one of the preceding claims, wherein processing a slab to form a sheet includes one or more of the following steps: reducing the thickness of the slab using a roughing mill to form a sheet; reducing the thickness of the sheet using a finishing mill; cooling the sheet; rolling the sheet using a down coiler.
10. A method according to any one of the preceding claims, wherein forming blades from the sheet includes one or more of the following steps: cutting the sheet to a predetermined blade width; stamping the sheet to form blade blanks; heat-treating the blanks using one or more of the following steps: treating the blanks in a furnace between 1000°C and 1200°C; quenching the blanks in water; chilling the blanks at around -40°C to -60°C; and/or reheating the blanks; grinding and polishing the blanks to form a blade or strip of blades; separating individual blades from the strip of blades.
11. A mixing nozzle for use in the method of any one of claims Ito 10, the mixing nozzle providing: a body including a nozzle wall defining a mixing volume, a main inlet for receiving a flow of molten metal, a 2D material inlet for receiving a flow of a 2D material, a deflector arrangement providing a deflecting surface for deflecting the mixture as it flows through the nozzle, and an outlet disposed downstream of the deflector arrangement.
12. A mixing nozzle according to claim 11, wherein the deflector arrangement provides multiple deflector plates, each extending from the nozzle wall, spaced around the periphery of the nozzle wall.
13. A mixing nozzle according to claim 12, wherein each deflector plate extends from the nozzle wall, the deflector plate extending across the mixing volume by at least 50% of a width or a diameter of the mixing volume, and optionally, wherein the deflecting surface is inclined lengthwise of the body.
14. A mixing nozzle according to claim 12 or claim 13, wherein multiple sets of deflecting plates are provided, each set extending from a respective position around the periphery of the nozzle wall, the deflecting plates of each set extending from positions spaced apart lengthwise of the body, and the respective sets each being offset from the other sets around the periphery of the nozzle wall.
15. A mixing nozzle according to any one of claims 12 to 14, wherein the deflector plates between them extend across the entire cross-sectional area of the mixing volume of the nozzle such that there is no unobstructed straight path between the main inlet and the outlet.
16. A mixing nozzle according to any one of claims 11 to 15, providing: multiple main inlets spaced around the periphery of the nozzle wall, and optionally wherein the main inlets are spaced lengthwise of the nozzle wall, and! or multiple 2D material inlets spaced around the periphery of the nozzle wall, and optionally wherein the 2D material inlets are spaced lengthwise of the nozzle wall.
17. A mixing nozzle according to claim 11, wherein the deflector arrangement provides a continuous deflector plate extending inwardly from the nozzle wall, winding around the periphery of the nozzle wall as it extends lengthwise of the mixing volume, and optionally, wherein the continuous deflector plate has a helical form.
18. A mixing nozzle according to claim 17, wherein the continuous deflector plate extends around the periphery of the nozzle wall for multiple revolutions, and preferably has a non-uniform wave-like configuration.
19. A mixing nozzle according to claim 17 or claim 18, wherein the continuous deflector plate extends inwardly of the nozzle wall by between 10-50% of the diameter of the mixing volume, and preferably by between 20-35% of the diameter, and optionally, wherein the continuous deflector plate is inclined downwardly radially from the nozzle wall in the direction of the outlet.
20. A mixing nozzle according to claim 11, further including one or more mixers providing a deflector in the form of a screw thread, and a motor configured to drive the mixers so that they rotate within the mixing volume.
21. A mixing nozzle according to claim 20, wherein two mixers are provided and the mixers are configured to counter-rotate.
22. A mixing nozzle according to any one of claims 11 to 21, wherein the deflector arrangement lies downstream of the main inlets and the 2D material inlets.
23. A mixing nozzle according to any one of claims 11 to 22, further including a vibration collar configured to surround a portion of the body of the nozzle, the vibration collar including a vibration motor for imparting vibration to the nozzle wall, and optionally wherein a layer of heat insulating material is provided between the vibration motor and the portions connected to the body of the nozzle.
24. A mixing nozzle according to claim 23, wherein the vibration collar provides a cooling arrangement for cooling the vibration motor, and optionally the cooling arrangement provides an inlet for receiving a flow of cooling air and an outlet for exhausting warmed air.
25. A mixing nozzle according to any one of claims 11 to 24, further providing a heating coil arrangement for controlling a temperature of the mixing volume, and optionally controlling the temperature at between 1300°C and 1600°C, and preferably in the range of 1400°C to 1530°C.
26. A blade formed by the method according to any one of claims 1 to 10, or by using a mixing nozzle according to any one of claims 11 to 25.