Title of Invention

"A PROCESS FOR PREPARATION OF CARBON NANO TUBE(S) COATED CUTTING TOOL(S)"

Abstract A Carbon Nanotube(s) Coated cutting tool(s) and a process for preparation thereof comprising of nano material(s) which is carbon. Further there is provided a process for preparation of carbon nano tube(s) coated cutting tool(s) comprising the steps of coating of catalyst on the surface of cutting tool(s) at a temperature of 10-125°C for a time period of 10-3600 second incorporation of catalyst coated cutting tool loaded quartz boat in a reactor, connecting the reactor to vacuum line to pump down to less than 200 mm Hg incorporation of the gases into the mixing chamber and subsequently in reactor de-oxygenation of the gases followed by removal of moisture and coating of nanomaterial(s) such as carbon nanotube(s) under different conditions such as herein described.
Full Text FIELD OF THE INVENTION
A Carbon Nanotube(s) Coated cutting tool(s) and a process for preparation thereof comprising of nano material(s) which is carbon.
BACKGROUND OF THE INVENTION
Cutting tools is the part of a machine tool, which comes into contact with workpiece and removes material from the workpiece. These are usually made of steel because they need to be tough. However, they also need excellent wear resistance so are often coated with hard ceramics such as titanium carbide (TiC), or boron nitride (BN) etc.
In recent years major development has seen witnessed in the field of hard coatings: the successful deposition of diamond, the hardest material in nature. Diamond is the hardest material, but fracture toughness is very poor. Similarly, high speed steel has highest fracture touchness but its hardness value is very poor. The advantage of diamond coating for carbide cutting tools via CVD process is that they combine the hardness of natural diamond with the strength and relative fracture toughness of high speed steel. The deposition of diamond has stimulated the development of a new class of cutting tools, namely diamond coated WC-Co alloys.
Larsson and Karlsson have applied a thin coating on cutting tool which comprises one or more refractory compound layers; wherein at least one layer includes a hexagonal phase microcrystal h-(Mel, Me2)X, in which Mel is one or more of V, Cr, Nb and Ta, Me2 is one or more of Ti, Zr, Hf, Al and Si, and X is one or more of N, C, O and B; the molar ratio among Mel, Me2, and X is represented by R=X% (Mel%+Me2%), in which R=0.5-l; and X contains O and B less than 30%. (Wear proof thin coating for cutting tool; T. Larsson and L. Karlsson; China; 1857836 A 8th November 2006).
The tools comprise WC hard alloy or TiCN cermet tool bases equipped with (a) ≤1 underlayer(s) of carbide, nitride, carbonitride, carboxide and/or carboxynitride of Ti having total av. thickness 0.5-10 micrometer formed by chem.. vapor deposition and (b) upper alpha Al2O3 layer of av. Thickness 16-30 micrometer formed by chem. vapor deposition and having certain inclined angle distribution defined in the claim. (Surface coated cermet cutting tools with thick alpha - alumina layers showing chipping resistance; A. Honma, a. Hara, and K. Kono; Japan, 2006305687, 9th November 2006).
Trinh et al. have applied a coating on cutting tool. The coating comprises a metal oxide/oxide composite layer comprising of two components with a grain size of 1 - 100 nm, whereby one component contains tegragonal or cubic zirconia and another component comprises of cryst. or amorphous alumina. (Composite coating for cutting tool inserts; D. Trinh, H. Hoegberg, L. Hultman, M. Collin, and I. Reineck, Eur. Pat. 1717347, 2nd November 2006).
Chang et al (Ceramic matrix nanocomposites containing carbon nanotubes for enhanced mechanical behaviour, S. Chang, R.H. Doremus, R.W. Siegel and P.M. Ajayan, US Pat. 6,420293, 16th July 2002) have mixed carbon nanotube in alumina to improve the mechanical
performance of cutting tool. The drawback of this invention is that (1) distribution of nanotube in alumina is not uniform, and (2) loading of carbon nanotube in alumina matrix is limited.
Not a single patent/paper is available, which describes the coating of cutting tool by carbon nanotube(s).
(Figure Remove)
The Fig. 1 shows the performance of various cutting tools. Though the diamond or boron nitride cutting tools are superior with respect to the thermal and wear resistance. But its fracture toughness is too less. In this context carbon nanotube is an ideal candidate to improve its wear and fracture toughness performance due to its outstanding properties i.e., Young's modulus of- 1.25 TPa, tensile strength of-100 GPa, thermal conductivity of 3000 W/mk at 25°C, etc. whereas, the conventional mild steel has a Young's modulus of 0.1 to 0.2 TPa and tensile strength of 2GPa.
OBJECTS OF THE INVENTION
An object of the invention is to provide cutting tool (s) and a method for preparation thereof having improved wear and thermal resistance to the larger extent.
Another object of the invention is to provide cutting tool (s) and a method for preparation thereof having dense arrays of well-aligned carbon nanotubes on the cutting tool substrates.
Further object of the invention is to provide cutting tool (s) and a method for preparation thereof which overcomes disadvantages of the prior art.
Still further object of the invention is to provide cutting tool (s) and a method for preparation thereof which is simple and cost effective.
SUMMARY OF THE INVENTION
In the present invention nanomaterial(s) coated cutting tool(s) have been developed.
In another embodiment of the present invention, a technique i.e., simple dip coaiting technique has been used to coat catalyst on the cutting tool surface.
In another embodiment of the present invention, a technique i.e., chemical vapour deposition technique has been used to coat nanomaterial(s) on the cutting tool surface.
In another embodiment of the present invention, the cutting tools are selected from the group comprising of carbides, oxides, nitrides, oxycarbides, oxynitrides, carbonitrides, oxycarbonitrides, carbonates, phosphates and mixtures thereof.
In another embodiment of the present invention, the cutting tools are selected from the group of nanocrystalline ceramic metal carbides of aluminum, titanium, zirconium, magnesium, yttrium, cerium, tungsten and mixture thereof.
In another embodiment of the present invention, the cutting tools are selected from the group comprising of metal oxides, metal carbides, metal nitrides, metal oxycarbides, metal oxynitrides, metal carbonitrides, metal oxycarbonitrides, metal carbonates, metal phosphates and mixtures thereof.
In another embodiment of the present invention, the nanomaterial(s) is carbon.
In another embodiment of the present invention, the carbon nanomaterial(s) is single wall carbon nanotube, multiwall carbon nanotube and mixture thereof.
In another embodiment of the present invention, various compositions of mixed catalysts i.e., combination of any two following metals, i.e., iron (Fe), cobalt {Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), molybdenum (Mo), etc are used to grow carbon nanotube(s) on the surface of cutting tool(s).
In another embodiment, various environments, i.e., inert gas, carbon containing gas, reducing gas, etc are used to get a good and uniform coating of carbon nanotube(s) on the surface of cutting tool(s).
In another embodiment, various mixed environments using inert gas, carbon containing gas, reducing gas, etc are used to get a good and uniform coating of carbon nanotube(s) on the surface of cutting tool(s).
In another embodiment, various compositions of mixed environments using inert gas, carbon containing gas, reducing gas, etc are used to get a good and uniform coating of carbon nanotube(s) on the surface of cutting tool(s).
In another embodiment, different temperatures to crack carbon containing gases are used to get a good and uniform coating of carbon nanotubes on the surface of cutting tools (s).
In another embodiment, different times to crack carbon containing gases are tested to get a good and uniform coating of carbon nanotube(s) on the surface of cutting tool(s).
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS
This invention provides A Carbon Nanotube(s) Coated cutting tool(s) and a process for preparation thereof comprising of nano material(s) which is carbon.
coating of catalyst on the surface of cutting tool(s) at a temperature of 10-125°C for a time period of 10-3600 second
incorporation of catalyst coated cutting tool loaded quartz boat in a reactor,
connecting the reactor to vacuum line to pump down to less than 200 mm Hg
incorporation of the gases into the mixing chamber and subsequently in reactor
de-oxygenation of the gases followed by removal of moisture and
coating of nanomaterial(s) such as carbon nanotube(s) under different conditions such as herein described.
The cutting tool(s) may be selected from the group of nanocrystalline ceramic metal carbides of tungsten, aluminum, titanium, zirconium, magnesium, yttrium, cerium and mixture thereof wherein the cutting tool(s) may be selected from the group comprising of oxides, carbides, nitrides, oxycarbides, oxynitrides, carbonitrides, oxycarbonitrides, carbonates, phosphates and mixtures thereof wherein the cutting tool(s) may be selected from the group comprising of metal oxides, metal carbides, metal nitrides, metal oxycarbides, metal oxynitrides, metal carbonitrides, metal oxycarbonitrides, metal carbonates, metal phosphates and mixtures thereof in which the cutting tool(s) is heated in an atmosphere of air, nitrogen, oxygen, Argon, Hydrogen, CC>2 and mixtures thereof.
The catalyst is selected from Group VIII metals comprising of Ni (Nickel), Ru (Ruthenum), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platinum) and/or mixture thereof; Group VIb metals comprising of Cr (Chromium), Mo (Molybdenum) and W (Tungsten) and/or mixture thereof, and mixture of group VIII metals comprising of Ni (Nickel), Ru (Ruthenium), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platinum) and Group VIb metals comprising of Cr (Chromium), Mo (Molybdenum) and W (Tungsten) wherein the catalyst comprising of at least one group VIII metal and at least one group VIb metal in a ratio of one part of Cr or other metal from group VIb and at least 2 or more part of Ni or other metal from group VIII.
The catalyst(s) is/are coated on cutting tool(s) by electroless dip coating process, wherein the oxidizing agents used in dip coating are metal, metal sulfide, metal disulifide, metal halide and metal sulphate in which metals are group VIII metals comprising of Ni, Ru, Rh, Pd, Ir, and group VIb metals comprising of Cr, Mo, W and mixture thereof; reducing agents are group of metal comprising of Na, Mg, Al, Zn, Cu and mixtures thereof, metal hydrides comprising of Na, Mg, Al, Zn, Cu and mixtures thereof, metal hypophosphite comprising of Na, Mg, Al, Zn, Cu and mixtures thereof and chelating agents are comprising of water, carbohydrates, including polysaccharides, organic acids with more than one coordination group lipids, steroids, amino acids and related compounds, peptides, phosphate, nucleotides, tetrapyrrois, ferrioxamines, ionophores, such as gramicidin, monensin, valinomycin, phenolics, 2, 2'-bipyridyldimercaptopropanol, ethylenedioxy-diethylene-dinitrilo-tetraacetic acid, ethylene,glycol-bis(2-aminoethyl)-N,N.N',N"-tetraacetic acid, lonophores-nitrilotrriacetic acid, NTA ortho-Phenanthroline, salicylic acid, triethanolamine, sodium succinate, sodium acetate, ethylene diamine, ethylenediaminetetraacetic acid, dethylenetriaminepentaacetic acid, ethylenedinitrilotetraatic acid, and mixture thereof.
The catalyst(s) is/are coated on cutting tool(s) by electroless dip coating process, wherein the buffer solution used in dip coating is group of weak acid and its salt and mixture thereof in which weak acids comprising of succinic acid, formic acid, acetic acid, tricholoroacetic acid, hydrofluoric acid, hydrocynic acid, hydrogen sulphide, water and group of sodium and/or potassium comprising of succinic acid, formic acid, acetic, trichoroacetic acid, hydrofluoric acid, hydrocynic acid and hydrogen sulphide.
The catalyst(s) is/are coated on cutting tool(s) by electroless dip coating process, wherein the coating of the catalyst is carried out in an environment of nitrogen, argon, helium and mixture thereof and at a temperature of 10-125°C for a time period of 10-3600 second to obtain a thickness of 50-200 nm by dipping the cutting tool(s) in acidic bath provided in a dip-coating
set-up wherein the bath is prepared by dissolving oxidizing agent in de-ionized water, in a ratio of 1:100 to 9:100 which is added with reducing agent, chelating agent and buffer in a ratio of 1:1 to 1:5, 1:1 to 1:10 and 1:0.10 to 1:1 followed by stirring of the mixture to obtain the acidic bath.
The coating of the catalyst may also be carried out by spraying a brown coloured solution on cutting tool(s) wherein the preparation of the solution comprises the steps of:
-dissolving metal nitrate in de-ionized water in a ratio of 1:5 to 1:15 which is added with equal amount of carbonate to obtain a brown coloured solution.
-stirring of the solution so obtained to get a semi solid mass followed by heating the same in an oven at a temperature of 75 to 200°C for a period of 1000 to 86400 seconds.
-heating the resulting mass thus obtained in a furnace at a temperature of 300 to 700°C for a period of 1000 to 7000 seconds followed by cooling down the same to room temperature to obtain a brown coloured mass and
-addition of methyl alcohol with the powder followed by stirring to obtain the solution.
The chemical vapour deposition technique makes use of the gases comprising of carbon containing gas such as group of saturated hydrocarbons, aliphatic hydrocarbons, oxygenated hydrocarbons, aromatic hydrocarbons, alcohols, carbon monoxide and mixture thereof, reducing gas such as group of gases hydrogen, chlorine and mixtures thereof and diluent gas such as group of nitrogen, argon, helium and mixture thereof and the ratio of these gases are 0:100 to 50: 50, 0:5:95 to 60:20:20 and 0:100 to 60:40 between reducing:diluent gases, carbon containing gas:reducing gas:diluent gas, and carbon containing gas:diluent gas respectively.
The nanomaterial(s) is coated at a temperature range of 400 to 900°C in a time period of 10 to 7200 sec, which has a diameter of 1 to 80 nm, wherein at least 20% has a diameter less than 30 nm, and length of 100 to 6000 nm, wherein at least 70% of the carbon nanotubes have diameter less than 10 nm and 40% carbon nanotubes are single wall.
a) Uncoated tungsten carbide cutting tool is shown in Fig. 2. The pattern for the uncoated WC exhibits many peaks, indicating a crystalline structure. Table 1 shows the composition of the bath used for nickel coating, which acts as a catalyst to grow carbon
b) (Figure Remove)

Fig. 2: Uncoated tungsten carbide cutting tool
Temperature plays a major role during catalyst coating. In order to find out the effective temperature, the coating was carried out over a range of temperature i.e., 50 to 90°C for 15 minutes, at pH of 9 and stabilizer concentration of 25g/L. The XRD graph (Fig. 3) shows that the intensity of peak increases as the temperature is raised. In Ni coated samples, two prominent peaks common to the six patterns appear at 20 values of 31.2° and 44.5°, and characteristic of NiP; and Ni respectively. The peaks at 31.2° and 44.5° correspond to (110) and (111) reflections. But at 90°C the quality of coating is not good due to problems in maintaining pH. Hence, the optimum temperature is ~ 80°C. Below 80°C, the reaction takes considerable time to start coating and the coating is also very slow. The composition was calculated from EDAX and shown in Fig. 4. The wt% of nickel was plotted against temperature in Fig. 5, which shows that as the temperature increases, the coating rate increases. SEM images are shown in Fig. 6, which shows 80°C is the optimum temperature for nickel coating.
(Figure Remove)Fig. 5: Deposition of Nickel (wt %) as a function of temperature of bath



Fig. 6: SEM images of Mi-coated samples with different bath temperatures:(a) as received, (b)50°C, (c) 60°C, (d) 70°C, (e) 80°C and (f) 90°C.
Among the other process variables, the pH of the bath is one of the most important parameters as it considerably influences the thickness and quality of Ni-P coating on the substrate. The XRD patterns of the electroless Ni-coated samples for pH 7,8,9,10 and 11 are shown in Fig, (7). The EDAX is shown in Fig. 8 for pH 9 and 11. At higher pH, the rate of reaction is fast but the quality deteriorates and the action of the stabilizing agent is also affected (Fig. 9).


Fig. 8: EDAX characteristics of Ni-coated samples: (a) pH=9, (b) pH11
Fig. 9: Deposition of Nickel (wt %) as a function of pH
Coating time is another important variable during coating of nickel on substrate. To find out the optimum coating time, experiment was carried out for 30 minutes with an increment of 5 minutes. The intensity of the peak corresponding to the Ni and the coating thickness increases with the increase in the coating time (Fig 10). The nickel% was calculated from EDAX analysis (Fig. 11) and plotted against time in Fig 12. But the suitable time for Ni coating would be somewhere between 15-20 minutes since the thick coating won't be cracked easily to Ni nanoparticles which is necessary for the growth of CNT. Fig. 13 shows SEM micrograph.(Figure Remove)Fig. 14 shows the SEM micrograph of as-received tungsten carbide and Fig. 15 (a-t) shows the SEM micrographs of nickel-coated tungsten carbide plated at 80°C for different times under PH-8.5. From these figures it is observed that the coatings are uniform and continuous in the range of nanometer. It can be found that with increasing coating time of the bath solution the coating thickness increases. However, SEM images of the 20 minutes Ni coating showed uniform grain size and almost all nanoparticles were spread discretely on WC without aggregation. With increasing coating time, some grains coalesced forming larger Ni grains, resulting in a wide distribution of grain sizes. This suggests that the grains with large diameters do not act as nucleation seeds for CNTs preparation. From the Fig. 16 it is obvious that the nickel content goes on increasing with increasing coating time. Simultaneously, phosphorus content also increases with increasing time.
Fig. 18: XRD graphs of CNTs coated tungsten carbide cutting tool.
The carbon nanotube coated cutting tools were characterized extensively using SEM. Fig. 19 shows the CNTs grown at 750°C for 20 min by decomposition of C2H2 via CVD on nickel coated tungsten carbide. It has been shown that, growth of CNTs was clearly observed on 20 mins nickel coated tungsten carbide. These CNTs have diameters in the range of 1-170 nm and the length of CNTs is up to several micrometers. It can be found that the product contains very little impurity and the nanotubes are made up of tangled bundles. In the SEM images, all of the catalyst surfaces within the observed field are fully covered with these carbon materials. It demonstrates that the synthesis method is preferable to obtain large scale production.

Fig.19: SEM micrographs of CNT coated tungsten carbide cutting tool
g.20: Raman spectrum of CNT coated tungsten carbide
Fig. 20 shows a Raman spectrum of CNT coated tungsten carbide cutting tool. The spectrum shows mainly two Raman bands: one is D band and other is G band. The D band indicates disordered features in graphite sheets and the G band indicates the original graphitic structure. Thus the value of ID/IG can express the graphitization of carbon materials. The lower the value is, higher is the degree of graphitization. In this Fig. 20, the D band is observed at 1350cm"1 and G band is observed at 1590cm"1. The D band in the Raman spectra are strong in intensity, whereas G-band are weak due to presence of amorphous carbon with carbon nanotubes.
Surface roughness of as received, nickel coated and carbon nanotube coated cutting tool was measured by surface profilometer and the results are given in Table 3. It shows that the surface roughness increases after CNT coating.

The increase of surface roughness in cutting tool is due to the high density of carbon nanotubes on the surface of cutting tool as shown in Figs. 19 and 21.
The nanomaterials coated cutting tool is used to machine the steel workpiece. It is observed from SEM studies that nanomaterials clearly survived after machining operation as shown in Fig 22.

Fig. 22: SEM micrographs of CNT coated tungsten carbide cutting tool after machining operation
Example A
The coating of nanomaterials i.e., carbon nanotubes is conducted in a simple tubular reactor placed horizontally. This reactor had a quartz tube of 84 cm length with outer diameter of 10 mm and inside diameter of 100 mm. It was constructed in such a way that the cutting tool could be easily inserted and removed from the reactor. The reactor was heated in a three zone
tubular furnace. A proportional temperature controller controls the furnace temperature in each zone. The temperature was kept around 500 to 900°C in the mid zone of furnace to facilitate the decomposition of precursor gases. The inlet and outlet temperatures were maintained at 300-600°C. Nitrogen, helium, argon, chlorine, hydrogen, methane, ethane, propane, carbon dioxide, ethylene, acetylene and mixtures of it are used as precursor gases. Each gas has its own function. Acetylene/methane/ethylene/propane/carbon dioxide/ethane acts as a source of carbon, hydrogen/chlorine acts as a reducing gas and nitrogen/helium/argon acts as a carrier gas and also provides the inert atmosphere inside the reactor. The coating of catalyst i.e., iron (Fe), cobalt (Co), nickel (Ni), ruthenium (Ru), rhodium (Rh), palladium (Pd), iridium (Ir), platinum (Pt) chromium (Cr), molybdenum (Mo), etc on cutting tool is done by the conventional dip ci>aiing soi-^cl-xvct spraying technique. The cutting tool is dipped in a bath containing nickel sulphate (NiSO4.6H2O, source of nickel), sodium hypophosphite (Nal^PC^.HjO, reducing agent), ammonium chloride (NH4CI, complexing agent), tri-sodium citrate (Na3C6H5O7.2H2O, stabilizer), ammonium hydroxide (NP^OH, pH adjustment). The catalyst coated cutting tool entered in the middle zone of the reactor. The reactor was connected to a vacuum line and then pumped down to less than 200 mm Hg. This process was continued 10 times till it is free of oxygen. In the next step the temperature of reactor was increased in between 400 to 600°C in an inert atmosphere. The rate of inert gas flow was kept constant at 120 ml/min. After 5 to 10 minutes reducing gas was allowed to flow at the rate of 5 to 25 ml/min for 10 to 30 minutes. The gases entered in the reactor through three different non-return valves. The flow rates of gases were measured by rotometers. Gases are first deoxygenated by passing them through an alkaline pyrogallol solution, con sulphuric acid, calcium chloride, potasioum hydroxide, and subsequently moisture is removed by passing them through a silica gel bed. The gases are mixed before entering into the reactor. The water circulation arrangement is made at inlet and exit of the reactors tube to keep the temperature at desired level. Water is also used as a coolant in the condenser. Any condensable in the reactor effluent is collected in a liquid collector where as noncondensables are sent to the exit flow, which is recorded by the pressure indicator dial and then vented to the atmosphere. The different conditions are used in each run to grow carbon nanotubes. The nanomaterials coated cutting tool is characterized by XRD, EDAX , SEM, surface profilometer, etc.
(Figure Remove)The catalyst coated cutting tool is placed inside the reactor for coating of nanomaterials, i.e., carbon nanotube. The experimental condition is same as mentioned in Example A.
Advantages
1. Carbon nanotube(s) coating for cutting tools via chemical vapour deposition process
results in the outstanding properties of carbon nanotube(s) i.e., Young's modulus of
1.25 TPa, tensile strength of-100 GPa, thermal conductivity of 3000 W/mk at 25°C,
etc.
2. Improvement in the thermal conductivity because of the presence of carbon nanotube.
As a result, heat generation during cutting can escape from surface, making it suitable
for applications where the coating surface can reach high temperatures.
3. Uniform coating of nanomaterials i.e., carbon nanotubes on the surface of cutting tool.
4. Variation in the density of carbon nanotubes on the surface of cutting tool from a low
value i.e., 1 vol% to to a high values i.e., 30 vol%.
5. Absorption of lot of mechanical energy during machining of material, as the cutting
tool is coated with carbon nanotubes, which indirectly improves the life of cutting
tools.
6. Mixing of carbon nanotubes into the nanocrystalline ceramic matrix is not required.
7. Sintering is not required in the proposed process which in turn reduces the processing cost.
Applications
The nanomaterials i.e., carbon nanotube coated cutting tool can be used to machine steel, stainless steel, cast iron, all cast iron, super alloys, powder metals, aluminium alloys, non ferrous alloys and non metals, plastics, precious metal, lead alloys, copper, etc.
It is to be noted that the formulation of the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant formulations are intended to be within the scope of the present invention which is further set forth under the following claims:-



WE CLAIM;
1. A process for preparation of carbon nano tube(s) coated cutting
tool(s) comprising the steps of:
- coating of catalyst on the surface of cutting tool(s) at a' temperature of 10-125°C for a time period of 10-3600 second
- incorporation of catalyst coated cutting tool loaded quartz boat in a reactor,
- connecting the reactor to vacuum line to pump down to less than 200 mm Hg
- incorporation of the gases into the mixing chamber and subsequently in reactor
- de-oxygenation of the gases followed by removal of moisture and
- coating of nanomaterial(s) such as carbon nanotube(s) under different conditions such as herein described.
2. The process for preparation as claimed in claim 1, wherein the cutting tools(s) may be selected from the group of nanocrystalline ceramic metal carbides of tungsten, aluminum, titanium, zirconium, magnesium, yttrium, cerium and mixture thereof and the cutting tool(s) may be selected from the group comprising of oxides, carbides, nitrides, oxycarbides, oxynitrides, carbonitrides, oxycarbonitrdes, carbonates, phosphates and mixtures thereof wherein the cutting tool(s) may be selected from the group comprising of metal oxides, metal carbides, metal nitrides, metal oxycarbides, metal oxynitrides, metal carbonitrides, metal oxycarbonitrides, metal carbonates, metal phosphates and mixtures thereof in which the cutting tool(s) is heated in an atmosphere of air, nitrogen, oxygen, Argon, Hydrogen, C02, and mixtures thereof.

3. The process as claimed in claim 1, wherein the catalyst is selected from Group VIII metals comprising of Ni (Nickel), Ru (Ruthenum), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platium) and/or mixture thereof; Group VIb metals comprising of Cr (Chromium), Mo (Molybdenum) and W (Tungsten) and/or mixture thereof, and mixture of group VIII metals comprising of Ni (Nickel), Ru (Ruthenium), Rh (Rhodium), Pd (Palladium), Ir (Iridium) and Pt (Platinum) and Group VIb metals comprising of Cr (Chromium), Mo (Molybdenum) and W (Tungsten) wherein the catalyst comprising of at least one group VIII metal and at least one group VIb metal in a ratio of one part of Cr or other metal from group VIb and at least 2 or more part of Ni or other metal from group VIII.
4. The process claimed in claim 3 wherein the said catalyst(s) are coated on cutting tool(s) by electroless dip coating process, the oxidizing agents used in dip coating are selected from metal, metal sulfide, metal disulifide, metal halide and metal sulphate in which metals are group VIII metals comprising of Ni, Ru, Rh, Pd, Ir, and group VIb metals comprising of Cr, Mo, W and mixture thereof-reducing agents are group of metal comprising of Na, Mg, Al, Zn,. Cu and mixtures thereof, metal hydrides comprising of Na, Mg, Al, Zn, Cu and mixtures thereof, metal hypophosphite comprising of Na, Mg, Al, Zn, Cu and mixtures thereof and chelating agents are comprising of water, carbohydrates, including polysaccharides, organic acids with more than one coordination group lipids, steroids, amino acids and related compounds, peptides, phosphate, nucleotides, tetrapyroois, ferrioxamines, ionophores, such as gramicidin, monensin, valinomycin, phenolics, 2, 2'-bipyridyldimercaptopropanol,
5. ethylenedioxy-diethylene-dinitrilo-tetraacetic acid, ethylene,glycol-bis(2-aminoethyl)-N,N.N',-tetraacetic acid, lonophores-nitrilotrriacetic acid, NTA ortho-Phenanthroline, salicyclic acid, triethanolamine, sodium succinate, sodium acetate, ethylene diamine, ethylenediaminetetraacetic acid, dethylenetriaminepentaacetic acid, ethylenedinitrilotetraatic acid, and mixture thereof.
5. The process as claimed in claim 3 wherein the said catalyst(s) are coated on cutting tool(s) by electroless dip coating process, wherein the buffer solution used in dip coating is group of weak acid and its salt and mixture thereof in which weak acids comprising of succinic acid, formic acid, acetic acid, tricholoroacetic acid, hydrofluoric acid, hydrocynic acid, hydrogen sulphide, water and group of sodium and/or potassium comprising of succinic acid, formic acid, acetic, trichloroacetic acid, hydrofluoric acid, hydrocynic acid and hydrogen sulphide.

6. The process as claimed in claim 3, wherein the said catalyst(s) are coated on cutting tools(s) by electroless dip coating process, wherein the coating of the catalyst is carried out in an environment of nitrogen, argon, helium and mixture thereof and at a temperature of 10-125°C for a time period of 10-3600 second to obtain a thickness of 50-200 nm by dipping the cutting tool(s) in acidic bath provided in a dip-coating set-up wherein the bath is prepared by dissolving oxidizing agent in de-ionized water, in a ratio of 1:100 to 9:100 which is added with reducing agent, chelating agent and buffer in a ratio of 1:1 to 1:5 1:1 to 1:10 and 1:0.10 to 1:1 followed by stirring of the mixture to obtain the acidic bath.
7. The process as claimed in claim 1, wherein the coating of the catalyst may also be carried out by spraying a brown coloured solution on cutting tool(s) wherein the preparation of the solution comprises the steps of:
-dissolving metal nitrate in de-ionized water in a ratio of 1:5 to 1:15 which is added with equal amount of carbonate to obtain a brown coloured solution.
-stirring of the solution so obtained to get a semi solid mass followed by heating the same in an oven at a temperature of 75 to 200°C for a period of 1000 to 86400 seconds.
-heating the resulting mass thus obtained in a furnace at a temperature of 300 to 700°C for a period of 1000 to 7000 seconds followed by cooling down the same to room temperature to obtain a brown coloured mass and
-addition of methyl alcohol with the powder followed by stirring to obtain the solution.
8. The process as claimed in claim 1, wherein the chemical vapour deposition technique makes use of the gases comprising of carbon containing gas such as group of saturated hydrocarbons, aliphatic hydrocarbons, oxygenated hydrocarbons, aromatic hydrocarbons, alcohols, carbon monoxide and mixture thereof, reducing gas such as group of gases hydrogen, chlorine and mixtures thereof and diluent gas such as group of nitrogen, argon, helium and mixture thereof and the ratio of these gases are 0:100 to 50, 0:5:95 to 60:20:20 and 0:100 to 60:40 between reducing:diluent gases, carbon containing gas:reducing gas:diluent gas, and carbon containing gas:diluent gas respectively.

9. The process as claimed in claim 1, wherein the nanomaterial(s) is coated at a temperature range of 400 to 900°C in a time period of 10 to 7200 sec, which has a diameter of 1 to 80 nm, wherein at least 20% has a diameter less than 30 nm, and length of 100 to 6000 nm, wherein at least 70% of the carbon nanotubes have diameter less than 10 nm and 40% carbon nanotubes are single wall.

Documents:

735-del-2007-Abstract-(02-11-2012).pdf

735-DEL-2007-Abstract-(20-06-2012).pdf

735-del-2007-abstract.pdf

735-del-2007-Claims-(02-11-2012).pdf

735-DEL-2007-Claims-(20-06-2012).pdf

735-del-2007-claims.pdf

735-DEL-2007-Correspondence Others-(20-06-2012).pdf

735-del-2007-Correspondence-Others-(02-11-2012).pdf

735-del-2007-correspondence-others.pdf

735-DEL-2007-Description (Complete)-(20-06-2012).pdf

735-del-2007-description (complete).pdf

735-DEL-2007-Drawings-(20-06-2012).pdf

735-del-2007-form-1.pdf

735-del-2007-form-2.pdf

735-DEL-2007-GPA-(20-06-2012).pdf


Patent Number 257845
Indian Patent Application Number 735/DEL/2007
PG Journal Number 46/2013
Publication Date 15-Nov-2013
Grant Date 12-Nov-2013
Date of Filing 30-Mar-2007
Name of Patentee INDIAN INSTITUTE OF TECHNOLOGY
Applicant Address KANPUR,KANPUR-208016,(U.P.)INDIA
Inventors:
# Inventor's Name Inventor's Address
1 KAMAL KRISHNA KAR MECHANICAL ENGINEERING AND MATERIALS SCIENCE PROGRAMME MATERIALS SCIENCE PROGRAMME,INDIAN INSTITUTE OF TECHNOLOGY KANPUR, KANPUR-208016,U.P.INDIA
2 ARIFUL RAHAMAN MECHANICAL ENGINEERING AND MATERIALS SCIENCE PROGRAMME MATERIALS SCIENCE PROGRAMME,INDIAN INSTITUTE OF TECHNOLOGY KANPUR, KANPUR-208016,U.P.INDIA
PCT International Classification Number C23C14/24
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA