DESC:FORM –2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

LUBRICANT COMPOSITION

Applicant:
BHARAT FORGE LIMITED
an Indian company of
Mundhawa, Pune 411036,
Maharashtra, India

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
FIELD OF INVENTION
[0001] The present invention relates toa lubricant composition. More particularly, the present invention relates to water based lubricant composition. Still more particularly, the present invention relates to a water based lubricant that comprises graphite.
BACKGROUND
[0002] Forging is a process for increasing the density, toughness and strength of metal by grain deformation. It can be performed while the metal is in the hot state or cold. Both processes have advantages and disadvantages. While cold forging upgrades metallurgical properties, hot forging requires the expenditure of less energy and permits greater deformation.
[0003] During forging, the hot metal billets or slugs are usually heated and they are hammered or stamped in a forging die, or the like, to form them into the desired shapes. These dies, which are generally made of extremely hard alloy steel, are nonetheless subject to scoring and heat checking by the hot metal billets, which also have a tendency to be "welded" to the die. This causes rapid wearing and deterioration of these dies, which must then be discarded and replaced.
[0004] Two primary factors which are especially important in forging operations are the rate of production and die life. The dies are very expensive and every precaution, including the choice of proper lubricants, is taken to extend die life. The use of lubricants is to minimize metal pick-up and wear.
[0005] A wide variety of lubricants have been used over a period of time in forgings applications. From operational perspective, oil based lubricants offer minimal cooling capabilities. Further, they have numerous shortcomings. On account of these shortcomings, later in the early 70’s, the trend shifted to water based graphite containing lubricants. Water based graphite containing lubricants are the most commonly used kind of lubricants for forging applications in the industry today.
[0006] Performance of the graphite based lubricants is dictated by nature and form of graphite used in the lubricant composition. Much remains to be desired when it comes to enhancement of ant-friction and anti-wear properties of the presently known water based graphite containing lubricants.
OBJECTS
[0007] Accordingly, it is one of the objects of the present invention to provide a water based graphite containing lubricant with substantially enhanced anti-wear and anti-friction properties. It is another object of the present invention to provide a water based graphite containing lubricant that offers improved mold release properties. It is another object of the present invention to provide lubricants for forging applications that substantially prolong the die-life and boost productivity.
[0008] Other objects and advantages of the present disclosure will be more apparent from the following description which is not intended to limit the scope of the present disclosure.

SUMMARY
[0009] In one aspect of the present invention, there is provided a water-based die lubricant composition in the form of a dispersion. The dispersion comprises:
-three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.4% to 3.4%wt;
-two dimensional graphene particles with a particle size ranging from 3-20 nm in an amount ranging from 0.006 to 0.09% wt; and
-at least one surfactant in an amount ranging from 0.0005 to 0.003% ;
wherein the pH of the dispersion ranges from about 7 to about 8.
[0010] In another aspect, there is provided a method for preparation of water based forging die lubricant composition. The method of the present invention comprises:
preparing a base lubricant by homogenizing 3D graphite particles and diluting in it in a ratio ranging from 1:5 to 1:12;
preparing an inoculate of surface-stabilized 2D graphene particles by dispersing them in de-ionized water with at least one neutral surfactant in an amount raging from 0.0005 to 0.003% at pH ranging from about 7 to about 8 through ultrasonication; and
inoculating the dispersion of surface stabilized nano-particles in the base lubricant to and subjecting the inoculated dispersion to homogenization to obtain a lubricant composition.
[0011] In still another aspect of the present invention there is provided a forging process for metals. The forging process of the present invention comprises applying to forging dies a water based composition having pH ranging from 7 to 8 said composition comprising three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.8% to 3.4%wt; two dimensional graphene particles with a particle size ranging from 3-10 nm in an amount ranging from 0.006 to 0.09% wt and at least one surfactant in an amount ranging from 0.0005 to 0.003% ; and
placing the metal between the dies, closing the dies under pressure, opening the dies and removing the forged metal.
[0012] BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Fig.1 shows Scanning Electron Microscope (SEM) Images of (A & B), shows conventional base lubricant with 1 & 5 KX magnification and (C & D), shows 2D graphene and 3D graphite in the lubricant composition in accordance with the present invention with 1 & 5 KX magnifications.
[0014] Figure 2 shows a die scan of a newly manufactured unused blocker bottom without any wear and tear for reference
[0015] Figure 3 shows a die scan of blocker bottom after 2500 runs using the base lubricant. The wear pattern was found out to be 86%.
[0016] Figure 4 shows a die scan of blocker bottom after 2500 runs using the lubricant composition of the present invention. The die wear pattern was found to be 68%. (Decrease of18%)
DESCRIPTION
[0017] The terms and phrases as indicated in quotation marks (“ ”) in this section are intended to have the meaning ascribed to them in this ‘Definitions’ section applied to them throughout this document, including in the claims, unless clearly indicated otherwise in context.
[0018] The term “Forging Applications” means all types of forging applications including hot forging, cold Forging and warm forging irrespective of the type of metal involved in the forging process.
[0019] The term “Two dimensional graphene” or “2D graphene” in the context of the present specification refers to carbonaceous graphene nano-material with a particle size ranging between 3-10 nm.The term “Three dimensional graphite” or “3D graphite” in the context of the present specification refers to graphite with a particle size ranging between 30 to 50µm.
[0020] The base lubricant in the context of the present invention means a water based graphite containing lubricant that comprises 3D graphite particles having particle size ranging from 30µm to 50 µm.The term “surface modification/stabilization” means, optimizing surface charges on 2D graphene particles to enhance their stability and maintain them in the de-agglomerated state when they are inoculated in the base lubricant.
[0021] In one aspect, there is provided a water-based lubricant composition for forging applications comprising a combination of 3D graphite and 2D graphene nano-particles.
[0022] In one embodiment, the water based lubricant composition of the present invention further comprises sodium based compounds, at least one dialkali metal salt of a dicarboxylic acid.
[0023] Particle size of 3D graphite as employed in the lubricant composition of the present invention typically ranges between 20 to 90µm and 50 to 70µm preferably between 30to 50µm.Typically, the proportion of the three dimensional graphite in the lubricant composition of the present invention ranges from 2.2% wt to 3.6% wt, preferably ranging from 2.4%wt to 3.4%wt.

[0024] The 2D nano-sized graphene particlesmay be either particles with large surface area or individual 2D projected nano-structured lattice with the FCC face lattice.The carbonaceous graphene nano-particles as employed in the composition of the present invention are further characterized by average lateral size varying from about 5 to about 10 microns and surface area ranging from about 250 to300 m2/g.
[0025] The two-dimensional graphene particles possess unique friction and wear properties on account of their impressive tribological behavior, high chemical inertness, extreme strength, and easy shear capability on their densely packed and atomically smoothsurfaces.
[0026] Graphene based nano-particles (2D structure) with varied particle sizes are available. Depending upon the particle size range, they exhibit different properties.In general, nano-particles greater than 100 nm tend to be very hard, while those with particle size less than 10 nm tend to be soft.
[0027] The soft graphene nano-particles tend to have hexagonal surface and they offer increased vertical and horizontal co-efficient of friction and enhanced lubrication.Further, their sharp edges favor the geometry and behavior in liquid under the horizontal flow mechanism.
[0028] Typically, the particle size of 2 D graphene employed in the lubricant composition of the present invention varies between 3 to 10nm. Typically, the proportion of 2D graphene particles in the lubricant composition of the present invention varies from 0.006 to 0.09%wt.
[0029] Graphite is stable allotrope carbon under standard condition with larger particle size molecule. When it comes in contact with 2 D carbonaceous nano- materials with lesser particle size, it leads to bi-polar transition effect due to ballistic transport of charges to large quantum oscillations in the carbonaceous graphene material. Further, 2D graphene particles have characteristically very large surface area and when they are combined with 3 D graphite particles as such, they tend to aggregate thereby adversely affecting the lubricating properties of the resulting lubricant composition.
[0030] To avoid this, the present invention employs surface modified 2 D graphene particles treated with a solvent at pH ranging from about 7 to about 8; preferably; ranging from about 7 to about 7.5. Typically, deionized water is used as the solvent to prepare a dispersing medium. In one embodiment, the pH of the lubricant composition of the present invention is about 7.2. Surfactant employed for surface-treatment of 2D graphene particles, is typically selected from the group consisting of anionic and neutral surfactants. Typically, the surfactant is selected from the group consisting of Lauryl Glucoside, polyethelene glycol, CTAB(Cetyltrimethylammonium bromide), SDBS (Sodium Dodecyl Benzene Sulphonate) and Triton X-100 (OctylphenolEthoxylate). In an exemplary embodiment, Triton X-100 (OctylphenolEthoxylate) is used as the surfactant.
[0031] Surfactant lowers the advancing contact angle, aids in displacing air phase at the surface, and replaces it with a liquid phase. Further, it also aids in dispersing these composites into liquid vehicles and also helps to ensure better adherence. The resulting homogeneous and stable dispersion of 2 D nano-particles improves the interactions of 2 D graphene particles with 3D graphite particles. Further, it also avoids any aggregation. Still further, the surface modified 2D graphene particles exhibit better stability in fluids.
[0032] The blend of 3D graphite and 2D graphene in the lubricant composition of the present invention forms a thin film contact and an elasto-hydro-dynamic (EHD) contact by mechanical entrapment. Such contact with die surface helps in better sliding effect by this friction model.
[0033] Typically, the total solid content of the lubricant composition of the present invention ranges from2.4% to 3.4%wt.
[0034] Apart from the combination 2D graphene and 3D graphite particles, the composition of the present invention comprisesother ingredients that improve the lubricating properties of the composition. These include at least one sodium based compound selected from the group consisting of sodium pentaborate and sodium molybdate and a combination thereof.
[0035] Further, the lubricant composition of the present invention may comprise at least one di-alkali metal salt of a dicarboxylic acid selected from the group consisting of phthalic acid, orthophthalic acid, isophthalic acid and terephthalic acid. In one of the embodiments, dipotassium terephthalate is used.
[0036] The collective proportion of sodium based compounds may range from about 0.4%wt to 0.6%wt while the proportion of dialkali metal salts of di-carboxylic acids may range from 0.2% to 0.5%wt.
[0037] The lubricant composition of the present invention may further comprise at least one additive selected from a group that includes but is not limited to wetting agent, stabilizing agent, anti-bacterial agent, dispersants, rheology modifiers, biocides, corrosion inhibitors, extreme pressure additives, antifoaming agents, and mixtures thereof containing additional ingredients.
[0038] The lubricant composition of the present invention comprises 2D graphene particles dispersed throughout the bulk of the solids in the composition predominantly comprising 3 D graphite particles without any aggregation. The inventors conducted several experiments to assess the impact of pH, particle size of graphene as well as graphite particles and their concentrations on the stability of lubricant composition and its lubricating properties.
[0039] As regards particle size, it has been observed that combination of 3D graphite particles having particle size ranging between 30 to 50 nm along with 2 D graphene with a particle size ranging between 3 to 10 nm at their respective concentrations as provided herein above not only ensures better stability but it also results in enhanced lubricating properties.
[0040] In another aspect of the present invention, there is provided a method of preparation of the lubricant composition of the present invention. It comprises the following steps:
• preparing a base lubricant by homogenizing 3Dgraphite particles in de-ionized water with one or more additives and diluting resulting homogenized base lubricant in deionized water in proportion ranging from 1:5 to 1:12;
• preparing an inoculate of surface-stabilized 2D graphene particles by dispersing them in de-ionized water with at least one surfactant in an amount ranging from 0.0005 to 0.003%wtat pH ranging from about 7 to about 8 through ultra-sonication; and
• inoculating the dispersion of surface stabilized nano-particles in the base lubricant under continuous stirring to obtain a stable lubricant composition without any aggregates.
[0041] In one embodiment of the invention, the method step of preparing a base lubricant further comprises adding sodium based compounds, a dialkali metal salt of dicarboxylic acids along with 3D graphite particles in de-ionized water.
[0042] Surface potential of the 2D graphene nano-particles is altered by changes in solution pH. During surface stabilization, pH is adjusted in such a manner that the desired particle size ranging from 3nm to 10 nm is maintained without formation of any aggregates in the composition.
[0043] In a further aspect of the present invention, there is provided a method for forging a metallic component that employs the lubricant composition of the present invention. The lubricant composition of the present invention is applied to the dies through sprays without diluting.
[0044] The lubricant composition of the present invention can be employed for a wide variety of forging processes including cold forging as well as hot forging at higher temperatures ranging from 700 to 1300oC. It is suitable for forging processes for various metals that include iron, aluminum and the like.
[0045] Without bound by theories and/or assumptions, the combination of 3D graphite and 2D graphene structure creates a mending effect on the surface of the structure that compensates for loss of mass during friction. Additionally, interaction of nano-particle on the surface also forms a protective layer which enhances the anti-frictional property.
[0046] The lubricant composition of the present invention boosts the productivity of forging by at least 15%, preferably by at least 30%. It may be applied to a mold by known coating techniques that include spraying, sprinkling, and application by a brush. Typically, the die life is enhanced by at least 15 to 30% when it is compared with the life of a die employed in a conventional forging process that employs known water based graphite containing lubricant.
[0047] The following examples are given by way of illustration only and therefore should not be constructed to limit the scope of the present invention.
[0048] EXAMPLES
EXAMPLE -1
Base Lubricant
[0049] Commercially available water based lubricant Delta Forge FF 5503DTMcomprising 3D graphite synthetic particles having particle size ranging from 30 to 50 µm, sodium molybdate, sodium pentaborate and di-potassium terephthalate(Carbon, Sodium and potassium in a proportion of 70%, 4% and 3% respectively) was used for the preparation of a base lubricant.
[0050] The commercially available lubricant was analyzed to test the particle size of the 3D graphite particles. (The SpectroLNF Q200 (LNF-Q200) while the viscosity was measured by VISCOMETER(Digital Cone Viscometer, CPD 2000,Chem-Tech Lab,Pune). The samples of thin film of lubricant was mounted on a stub of metal with adhesive coated with 40-60 nm of metal such as gold/palladium under a Scanning Electron Microscope (SEM,JOEL-T330,Joel.,Co-Ltd.,KCTI, Bharat Forge, Pune) at 5KV. The surface morphology and elemental composition by EDAX were scanned.
[0051] Total solid content of the 3D graphite particles was measured using moisture analyzer MB35 (OHAUS), Bharat Forge, KCTI.
[0052] Density: ca. 1170 kg/m3; Solid Content: 33 %; Viscosity: ca. 900mPa.s
[0053] Moisture Content: 72 %; pH : 8 and Particle size : 30-50 µm.
[0054] The commercially available dispersion with above specifications was allowed to mix with de-ionized water at the dilution ration of 1:10, in the blending tank and the resulting diluted mixture was homogenized by stirring for 30 to 45 minutes using magnetic heavy rotor blades at rpm 15,000 to 20,000 rpm (IKA Stirrer RW 15000, heavy rotor).
[0055] The diluted dispersion as prepared by the above process was dispensed onto the surface of the dies by manualspraying systems, which were timed with the stroke of the forging press.This lubricant mixture was sprayed uniformly at every 5 seconds per stroke.The forging operation was carried out at temperature 150-200°C and subjected to a pressure of 2500 Tons for forging the connecting rods using blocker dies and the process was repeated for 2500 cycles. The material of the connecting rods was H13 with Hardness HRC 48-52.
[0056] After 2500 cycles, the die wear pattern was assessed using Faro edge arm, USA, high performance contact/non-contact probe measurement system, with highest accuracy of 3D measurement of wear pattern. This system seamlessly scanned the diverse surface materials regardless to contrast. A magnetic mount kit present in the system allowed the Arm to be fixed on any ferrous base consisting of Dia 150 mm magnetic mount. Hex wrench was provided by FARO and the output data datawas analyzed using the CAM 2 Q software by FARO. 3D scan by- Faro-edge instrument reveals no significant improvement in the die wear pattern estimated around 88% as shown in Fig.3.
[0057] first through ultra-sonication using the ultrasonic bath for 10 minutes followed by the probe sonication (PCI ANALYTICS PVT. LTD., Model PKS - 750F Frequency (KHZ): 20, Power (W): 750) for around 20 minutes.
[0058] The 2D graphite nano-particles employed in the preparation were characterized by following specifications: density : about 0.25g/cc, average thickness ranging from and surface area ranging from about 250 to 300 m2/g.
Example 2A: Lubricant Composition with 2D Graphene size between 40 to 50 nm using Triton X 100 as a surfactant.
[0059] The two dimensional graphene with an average particle size of 40 to 50nm and a concentration of 0.006% was dispersed in 500 ml of deionized water by ultrasonication method with the help of 0.001% of non-anionic surfactant agentTriton-X-100), (Octyl-phenol-ethoxylate), Sigma Aldrich, Germany to avoid agglomeration, with pH 7.5.
[0060] The two dimensional graphene (2D) with an average size of 40 to 50nm were evaluated using zeta potential measurements and steady shear rheological measurements to assess stability as a function of pH. For zeta potential measurements, a dilute dispersion of the material was made up in deionised water ready for analysis using a Malvern Zetasizer Nano ZS in conjunction with an MPT2 auto-titrator. The titrator was set up with 0.25M and 0.025M HCl to titrate from the start/sample pH to an end pH of 1.0 and record 3 repeat zeta potential measurements at 10 equally spaced pH intervals across the range. The surface charges and size of the nanoparticle were measured in the dispersed solution measured using KINEXUS SERIES Malvern series software.
[0061] All tests were performed at a temperature of 25ºC.
[0062] The mixture was non-uniform and agglomeration was observed either due to large particle size or variation in concentration of nano particles. Since the inoculate of the two D graphene particles was not found to be stable it could not be used for doping the base lubricant.
[0063] A sample of nano-composites was subjected to characterization.
The following features were noted.
Particle Size-40 to 50nm
pH-7.5
Total Nano-particle deposition -0.006
Formation of Agglomeration in the composites/Particles Settling due to larger particle size.
Example 2B :Lubricant Composition with 2D Graphene size between 3 to 10 nm using Sodium dodecyl benzene sulfonate (SDBS)
[0064] The two dimensional graphene with an average particle size of 3 to 10nm and a concentration of 0.06% was dispersed in 500 ml of de-ionized water by ultrasonication method with the help of 0.001% ofanionic surfactant Sodium dodecylbenzenesulfonate(SDBS), Merck, Bangalore, Indiato avoid agglomeration, with the optimum pH condition of 8.0. The mixture was non-uniform and agglomeration was observed either due to variation of pH conditions or the surfactant charge. Thus, this lubricant composition was not suitable for the forging application.
[0065] A sample of nano-composites was subject to characterization. The following features were noted.
Particle Size-3 to 10nm
pH- 8
Total Nano-particle deposition -0.06%
Solution: Not suitable for forging/blending because of agglomeration.
EXAMPLE 3A
[0066] The two dimensional graphene with an average particle size of 3 to 10nm and a concentration of 0.06% was dispersed in 500 ml of deionized water by ultrasonication method with the help of 0.001% ofcationic surfactant agent cetyl tri-methyl ammonium bromide (CTAB), Merck, Bangalore, India to avoid agglomeration, at pH 8. The mixture was non-uniform and agglomeration was observed either due to surfactant or variation in pH conditions. Thus, this lubricant composition was not suitable for the forging application.
[0067] A sample of nano-composites was subject to characterization. The following features were noted.Particle Size-3 to 10nm; pH- 8; Total Nanoparticle deposition -0.06%. Formation of Agglomeration in the composites/Precipitation due to pH variation.Absence of uniform thick paste in the composite lubricant/even though with lesser nano-particle size.Solution not suitable for forging application.

EXAMPLE 3B
[0068] The two dimensional graphene with an average particle size of 3 to 10nm and a concentration of 0.06% was dispersed in 500 ml of deionized water by ultrasonication method with the help of 0.001% of anionic surfactant agent sodium dodecyl benzene sulphonate(SDBS), Merck, Bangalore, India to avoid agglomeration, with the optimum pH condition of 8.0. The mixture was non-uniform and agglomeration was observed either due to surfactant or variation in concentration of nano-particles. Thus, this lubricant composition was not suitable for the forging application.
[0069] A sample of nano-composites was subjected to characterization. The following features were noted.Particle Size-3 to 10m; Viscosity- 930m.Pa s; pH- 8.0
Die Wear Pattern Analysis-No Improvement
Productivity Count-Increase –No Improvement
Total Nano-particle deposition -0.06%
Formation of Agglomeration in the composites/Particles Settling
As a result, this inoculate was not found suitable for mixing it in the base lubricant.
EXAMPLE 3C
[0070] The two dimensional graphene with an average particle size of 3 to 10nm and a concentration of 0.06% was dispersed in 500 ml of deionized water by ultrasonication method with the help of 0.001% of neutral non-anionic surfactant Triton X-100 (octyl-phenol-ethoxylate),Sigma Aldrich, Germany to avoid agglomeration, at pH of 7.2.
[0071] A stable dispersion was obtained as an inoculateand it was found suitable for preparing the nano-doped lubricant composition in accordance with the present invention.Formation of stable uniform inoculate is as shown in Fig. 1D
[0072] The inoculate was used for doping the base lubricant to prepare a final nano-doped lubricant composition in accordance with the present invention. The nano-particles and the base lubricant with the 200 Liters of base lubricant in the overhead rotating tank containing 3D graphite particles with an average size 3-50 µm and allowed to stir for 45 minutes to obtain uniform mixture. The resulting composition was a non-polluting and non-hazardous water based nano lubricant for the forging application at 2500 T LMZ press, BHARAT FORGE.
[0073] The resulting composition was applied to the die in the same manner as mentioned in example 1. The dies was used for 2500 cycles and the die wear pattern was analyzed by 3D scan FORO-EDGE after 2500 cycles and the relative improvement in die wear pattern vis a vis the die wear pattern observed with base lubricant while using the die wear pattern of unused brand new die as shown in Figure 2 as reference for zero wear pattern was measured.
[0074] The results were as follows: Die Wear Pattern Analysis-It was observed that the extent of wear decreased 18% which corresponds to an estimated improvement in productivity count by about 20-25%.
[0075] Analysis of Die wear Pattern:
Type of Die – Blocker
Type of component – Connecting Rods
Material of the component- H13, Hardness -48-52HRC
Cycles completed – 2500 / die
Pressure – 2500 Tons Press
Temperature – 150-200°C
Die Wear Pattern- FARO-EDGE ARM, USA- 3D scan measurement of wear pattern- 68 % after 2500 cyclesas shown in Fig. 4
The comparative results from all the above examples are provided herein below in Table 1.
Die Lubricant used Proportion of Graphene Particle size of Graphene pH Aggregation Moldreleasability Die wear
Base Lubricant(BL)
Example 1 Nil Nil 8 Nil Slow release of the billet. No substantial improvement in die wear pattern by base lubricant Die life
2500 cycles
Die wear percentage
88%
BL+ Graphene
Example 2A
Triton-X 100
0.006% 40 to 50nm 7.5 Yes due to variation of pH Not suitable for forging application Not suitable for forging due to agglomeration
BL+ Graphene
Example 2B 0.06% 3-10 nm 8 Yes due to variation of pH Not suitable for forging application Not suitable for forging due to agglomeration
BL+ Graphene
3A
0.06% 3-10 nm 8 Yes Not suitable for forging application Not suitable for forging due to agglomeration
BL+ Graphene
Example 3B
0.06 % 3-10 nm 8 Yes Not suitable for forging application Not suitable for forging due to agglomeration
BL+ Graphene
Example 3C
0.06% 3-10 nm 7.2 Nil Quick release of the billet from the die, helps in efficiency due to ball bearing effect of nano lubricant. die wear pattern improved significantly by 20% determined by 3D scanning analyser.
[0076] Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
[0077] The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
[0078] While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
[0079] We claim:
1. A water-based die lubricant composition in the form of a dispersion; said dispersion comprising:
-three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.4% to 3.4%wt;
-two dimensional graphene particles with a particle size ranging from 3-20 nm in an amount ranging from 0.006 to 0.09% wt; and
-at least one surfactant in an amount ranging from 0.0005 to 0.003% ,wherein the pH of the dispersion ranges from about 7to about 8.
2. A water based die lubricant composition as claimed in claim 1, wherein the particle size of the two dimensional graphene particles ranges from 3nm to 10 nm.
3. A water-based forging die lubricant composition as claimed in claim 1, further comprising at least one sodium based compound selected from the group consisting of sodium pentaborate and sodium molybdate and a combination thereof in an amount ranging from 0.4 to0.6%.
4. A water-based forging die lubricant composition as claimed in claim 2, further comprising dipotassium terephthalate in an amount ranging from 0.2 to 0.5%.
5. A water-based forging die lubricant composition as claimed in claim 1, wherein the amount of two dimensional graphene particles in the composition ranges from 0.006 to 0.09 %.
6. A water-based forging die lubricant composition as claimed in claim 1, wherein the surfactant is at least one neutral surfactant selected from the group consisting of Lauryl Glucoside, polyethelene glycol and Triton X-100.
7. A water-based forging die lubricant composition as claimed in claim 1, wherein the pH of the composition ranges from 7 to 8.
8. A method for preparation of water based forging die lubricant composition, said method comprising:
• preparing a base lubricant by homogenizing 3D graphite particles and diluting in it in a ratio ranging from 1:5 to 1:12;
• preparing an inoculate of surface-stabilized 2D graphene particles by dispersing them in de-ionized water with at least one neutral surfactant in an amount ranging from 0.0005 to 0.003% at pH ranging from about 7 to about 8 through ultrasonication; and
• inoculating the dispersion of surface stabilized nano-particles in the base lubricant to and subjecting the inoculated dispersion to homogenization to obtain a lubricant composition.
9. A method of preparation of water based forging die lubricant composition as claimed in claim 8, wherein the 3D graphite particles are homogenized along with sodium pentaborate, sodium molybdate and dipotassium terephthalate.
10. A forging process for metals comprising applying to forging dies a water based composition having pH ranging from 7 to8said composition comprising three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.8% to 3.4%wt; two dimensional graphene particles with a particle size ranging from 3-10 nm in an amount ranging from 0.006 to 0.09% wt and at least one surfactant in an amount ranging from 0.0005 to 0.003% ; and
placing the metal between the dies, closing the dies under pressure, opening the dies and removing the forged metal.

Dated this 29th November, 2016

PATANKAR PRASHANT R
Applicant’s Patent Agent
IN/PA-1833

,CLAIMS:We claim:
1. A water-based die lubricant composition in the form of a dispersion; said dispersion comprising:
-three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.4% to 3.4%wt;
-two dimensional graphene particles with a particle size ranging from 3-20 nm in an amount ranging from 0.006 to 0.09% wt; and
-at least one surfactant in an amount ranging from 0.0005 to 0.003% ,wherein the pH of the dispersion ranges from about 7to about 8.
2. A water based die lubricant composition as claimed in claim 1, wherein the particle size of the two dimensional graphene particles ranges from 3nm to 10 nm.
3. A water-based forging die lubricant composition as claimed in claim 1, further comprising at least one sodium based compound selected from the group consisting of sodium pentaborate and sodium molybdate and a combination thereof in an amount ranging from 0.4 to0.6%.
4. A water-based forging die lubricant composition as claimed in claim 2, further comprising dipotassium terephthalate in an amount ranging from 0.2 to 0.5%.
5. A water-based forging die lubricant composition as claimed in claim 1, wherein the amount of two dimensional graphene particles in the composition ranges from 0.006 to 0.09 %.
6. A water-based forging die lubricant composition as claimed in claim 1, wherein the surfactant is at least one neutral surfactant selected from the group consisting of Lauryl Glucoside, polyethelene glycol and Triton X-100.
7. A water-based forging die lubricant composition as claimed in claim 1, wherein the pH of the composition ranges from 7 to 8.
8. A method for preparation of water based forging die lubricant composition, said method comprising:
• preparing a base lubricant by homogenizing 3D graphite particles and diluting in it in a ratio ranging from 1:5 to 1:12;
• preparing an inoculate of surface-stabilized 2D graphene particles by dispersing them in de-ionized water with at least one neutral surfactant in an amount ranging from 0.0005 to 0.003% at pH ranging from about 7 to about 8 through ultrasonication; and
• inoculating the dispersion of surface stabilized nano-particles in the base lubricant to and subjecting the inoculated dispersion to homogenization to obtain a lubricant composition.
9. A method of preparation of water based forging die lubricant composition as claimed in claim 8, wherein the 3D graphite particles are homogenized along with sodium pentaborate, sodium molybdate and dipotassium terephthalate.
10. A forging process for metals comprising applying to forging dies a water based composition having pH ranging from 7 to8said composition comprising three dimensional graphite particles with a particle size ranging from 30 to 50 µm in an amount ranging from 2.8% to 3.4%wt; two dimensional graphene particles with a particle size ranging from 3-10 nm in an amount ranging from 0.006 to 0.09% wt and at least one surfactant in an amount ranging from 0.0005 to 0.003% ; and
placing the metal between the dies, closing the dies under pressure, opening the dies and removing the forged metal.

Dated this 29th November, 2016

PATANKAR PRASHANT R
Applicant’s Patent Agent
IN/PA-1833