Device for forming amorphous film and method for forming same

Abstract

PROBLEM: To provide a large device and a method which is advantageous for forming a large-area amorphous film. SOLUTION: A device of the invention sprays a flame including a particulate material with a spraying machine toward a substrate, melts the material with the flame, and cools the material and flame by cooling gas before they reach the substrate to form an amorphous film. The spraying machine has particulate material spraying ports and flame spraying ports such that the flame including the material has an oblong cross section. Inert gas spraying ports are successively placed on both sides across the ports of the material and flame. Mist spraying ports are successively placed on both sides across the ports for the material, flame and inert gas. A skirt is attached/detached depending on a combustion gas or a film width to restrain film width narrowing and increase of film thickness deviation.

Claims

1. A device for forming amorphous film, which sprays a flame including a particulate material with a spraying machine toward a substrate, melts said particulate material with the flame, and cools said particulate material and said flame before said particulate material and said flame reach the substrate, wherein the spraying machine has a front face provided with a series of particulate material spraying ports and a series of flame spraying ports each placed along a straight line such that said flame including the particulate material has an oblong cross section; a series of spraying ports of an inert gas for rectification and cooling of the flame is placed along said straight line on said front face of the spraying machine, on both sides across all of said series of particulate material spraying ports and said series of flame spraying ports; and a series of spraying ports of a mist for cooling of the flame is placed along said straight line, on both sides across all of said series of particulate material spraying ports, said series of flame spraying ports, and said series of inert gas spraying ports, and the series of particulate material spraying ports is structured by successively disposed particulate material spraying ports, which are symmetrical about a virtual plane located on a center of the spraying machine at right angles to said straight line; and the particulate material is fed to the particulate material spraying ports from a plurality of supply pipes through branched passages, the supply pipes being capable of adjusting each of the particulate material supply and a carriage gas flow rate, the branched passages being symmetrically formed about said virtual plane and having an equal passage length from a common header formed from said supply pipes to each of the particulate material spraying ports, wherein each branched passage of the branched passages is connected to the common header and branches to form additional passages to the particulate material spraying ports in a way such that the particulate material is able to flow from the common header to each particulate supply ports through the same length, wherein said series of spraying ports of the inert gas is configured in a way such that the inert gas is sprayed just outside a flame generated by the series of flame spraying ports from the front face of the spraying machine and wherein said series of spraying ports of the mist are configured in a way such that the mist is sprayed outside the sprayed inert gas, wherein a skirt that is rectangular and extends to a forward position of the spraying machine is provided continuously just outside a position of the flame and the inert gas, said skirt being configured to be able to restrain film width narrowing and increase in film thickness deviation despite the flame having an oblong cross section, and the device or the substrate is able to transfer at a right angle to a longitudinal direction of the oblong cross section of the flame to form a wide and homogenous amorphous film on the substrate at a spraying distance of between 400 mm and 600 mm.

2. The device for forming amorphous film according to claim 1, wherein the series of mist spraying ports is set at an angle such that a sprayed mist approaches said flame; and said angle is able to be changed.

3. The device for forming amorphous film according to claim 2, wherein a spray pressure of said inert gas and a spray pressure of said mist are able to be changed respectively.

4. The device for forming amorphous film according to claim 1, wherein said inert gas and said mist are able to be sprayed so as to cool the flame including the particulate material at a rate of 400,000 to 1,000,000 C./s.

5. The device for forming amorphous film according to claim 1, wherein the series of mist spraying ports is provided as a slit aperture extending along said straight line.

6. The device for forming amorphous film according to claim 1, wherein said flame including the particulate material has a cross section of 150 mm or more in longitudinal length, and said series of inert gas spraying ports and said series of mist spraying ports each formed along said straight line are also 150 mm or more in length.

7. The device for forming amorphous film according to claim 1, wherein the particulate material spraying ports have different sizes.

8. The device for forming amorphous film according to claim 1, wherein the branched passages have different inner diameters.

9. The device for forming amorphous film according to claim 1, wherein the supply pipes, before reaching the common header, are also formed symmetrically about the virtual plane.

10. The device for forming amorphous film according to claim 1, wherein the particulate material is injected uniformly in any part of the cross section of the flame.

11. The device for forming amorphous film according to claim 1, wherein the mist is a water mist that is sprayed in a way such that the amount of oxygen sprayed from the flame spraying ports is 50 to 80% of oxygen requirements for complete combustion.

12. The device for forming amorphous film according to claim 1, wherein the skirt comprises a channel for the series of spraying ports of the mist.

13. The device for forming amorphous film according to claim 1, wherein said series of spraying ports of the mist are configured to spray the mist at an open end of the skirt outside the sprayed inert gas to cool the flame before the flame reaches the substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a device for forming amorphous film 1 according to the invention: FIG. 1(a) is a front view of the device 1 (a cross sectional view taken along line a-a in FIG. 1(b)); FIG. 1(b) is a side view (also showing a flame or the like during film formation); and FIG. 1(c) is a bottom view.

(2) FIG. 2 shows a schematic diagram of branched passages of supply pipes for particulate material in the device of the invention and a graph of a distribution of sprayed amount from each spraying port (outlet port).

(3) FIG. 3 shows photographs and a graph of temperature measurements of the flame sprayed by the device of the invention.

(4) FIG. 4 shows graphs of a flame temperature distribution from the front side of the spraying machine to a spray object.

(5) FIG. 5 shows a graph of a flame temperature distribution from the front side of the spraying machine to the spray object, and a photograph of externals of the sprayed flame or the like.

(6) FIG. 6 is a graph of a flame temperature distribution, when the inert gas is used.

(7) FIG. 7 shows graphs of a temperature distribution of the spray object, when the water mist is used.

(8) FIG. 8 is a photograph of externals of an amorphous alloy thin plate obtained by a production test.

(9) FIG. 9 shows a cross sectional photomicrograph of the amorphous alloy thin plate, and a result of X-ray diffraction profile for the thin plate.

(10) FIG. 10 shows the difference of film width and film thickness deviation between the cases when the spraying machine has no skirt (FIG. 10(a)) and has a skirt (FIG. 10(b)) at the front side thereof.

(11) FIG. 11 shows a conventional device for forming amorphous film.

DESCRIPTION OF EMBODIMENTS

(12) FIG. 1 shows a device for forming amorphous film 1 according to the invention. The device 1 is capable of spraying a flame a about 300 mm in width to achieve an industrial formation of a large-area amorphous film having a corresponding width. Theoretically, according to a powder flame spraying method like the conventional device shown in FIG. 11, the device 1 sprays the flame a including a particulate material to a substrate (not illustrated; placed a downward position in FIG. 1(a) and transferred) with a spraying machine 2, melts the particulate material with the flame a, and cools the particulate material and the flame before they reach the substrate, thereby forming a non-crystalline film.

(13) In detail, the device 1 is structured as follows.

(14) The spraying machine 2 has a front side provided with a series of particulate material spraying ports 11 and a series of flame spraying ports 12, in both series a plurality of ports being disposed at small intervals along a common straight line extending to the longitudinal direction of the spraying machine 2, such that the flame a including the particulate material has an oblong cross section of about 300 mm in longitudinal direction.

(15) Further a series of inert gas (nitrogen gas) spraying ports 13 is provided on both sides across all of the particulate material spraying ports 11 and the flame spraying ports 12, a plurality of ports 13 being also disposed at small intervals along the straight line, for rectification and cooling of the flame a including the particulate material.

(16) On both sides across the spraying machine 2 including the particulate material spraying ports 11, the flame spraying ports 12 and the inert gas spraying ports 13, spraying nozzles 3 of mist (water mist) for cooling of the flame are disposed. The spraying nozzles 3 have a downwardly directed mist spraying port 14. The spraying port 14 is a slit which is continuously open along the straight line.

(17) As shown in FIG. 1(b), the mist spraying nozzles 3 are provided on the spraying machine 2 via a support member 3a connected to the spraying machine 2. The spraying nozzles 3 are provided on the support member 3a at an inward inclined angle, such that a sprayed mist from either sides of the spraying machine 2 approaches the flame a to cross each other at a forward position of the flame a, and the angle is able to be changed. The inert gas spraying ports 13 are also set at an inward inclined angle, such that the sprayed inert gas b approaches the flame a. However, in order to strengthen cooling effect, usually the mist c is sprayed at a larger angle than the inert gas b so as to enter into the flame a.

(18) The reference numeral 21 in FIG. 1 indicates a supply pipe (three in total) for supplying the particulate material together with carriage gas (nitrogen gas, and the like). The particulate material is fed from the supply pipes 21, disposed through branched passages 26 formed in the spraying machine 2, and sprayed from each material spraying port 11. Each of the reference numerals 22 and 23 indicates supply pipes for oxygen and propane gas as fuel for the flame a respectively. The reference numeral 24 indicates a supply pipe for the inert gas b for rectification and cooling of the flame (a supply pipe for the mist is not illustrated). Each supply per hour through the supply pipes is able to be changed, and each of the inert gas spray pressure and the mist spray pressure is able to be changed. Because the flame a is wide and strong, the sprayed mist is decomposed to generate oxygen. Therefore, in order to avoid oxygen in the flame a becoming excessive, a quantity of oxygen fed to the supply pipe 22 is restricted to 50 to 80% of oxygen requirements for complete combustion of fuel gas.

(19) As described above, the flow and the pressure of each gas, the particulate material and the like, and the spraying angle of the mist c are respectively changed. Therefore, the device 1 enables to appropriately adjust the cooling rate of the flame a. The adjustment is conducted depending on chemical components of the alloy (that is, chemical components of the particulate material) to be sprayed and the like: when spraying metallic glass or the like, slower cooling rate is applied; and when spraying a metal having a high melting point and a narrow temperature range of supercooling, the cooling rate is raised to about 400,000 to 1,000,000 C./s.

(20) Forming an amorphous film on a substrate with the device 1 is conducted by, for example, feeding a belt-like thin substrate to a fixed, horizontal direction and spraying to the surface of the substrate with the device 1 spaced a few hundred mm above the substrate. When the width (or longitudinal) direction of the device 1 is set at right angles to the feeding direction of the substrate, the device 1 is able to efficiently form a large-area amorphous film of about 300 mm in width.

(21) A schematic diagram in FIG. 2 shows the particulate material supply pipes 21 and the branched passages 26 connected thereto in the device 1, regarding one of the three supply pipes. The graph shows a weight of the particulate material recovered at each particulate material spraying port, when the particulate material and carriage gas are fed from upstream. The supply pipes from upstream to the spraying ports have a structure such that the spraying ports are symmetrically disposed on both sides across the center part of the spraying machine, and that the particulate material supplying passages to the spraying ports are the branched passages having an equal length and symmetrically formed on both sides across the center part. Thus, as the graph shows, the particulate material is symmetrically sprayed without deflecting to one side in the longitudinal direction (that is, the right side or the left side). For further homogeneous spraying, a treatment to decrease the inner diameter of the branched passages at the part a and the part b in the schematic diagram are adopted. The result of the treatment is shown in the graph as after treatment, which shows that a variation of spraying amount is eliminated.

(22) Hereinafter, various measurements regarding the device for forming amorphous film according to the invention (device 1 of FIG. 1) are introduced.

(23) FIG. 3 shows a result of temperature measurement of the flame sprayed by the device of the invention. Each photograph of FIG. 3 shows a sprayed flame, and in test 2 and test 3, the mist (water mist for cooling the flame) is sprayed together with the flame. The horizontal axis of the graph shows the sprayed distance from the front side of the spraying machine. The flame temperature is measured at sprayed distances of 750 mm in test 1, 150 mm, 250 mm and 350 mm in test 2, and 350 mm and 450 mm in test 3 for comparison. The graph shows a temperature distribution of the sprayed gas based on the temperature measurements. The sprayed gas temperature exceeded 1,200 C. at the sprayed distances of 750 mm in test 1, 150 mm in test 2, and 350 mm in test 3. In test 2 and test 3, the sprayed gas was cooled down to 100 C. as a result of cooling. But, since the water mist spray pressure and the mist spraying angle were changed, forms and temperature distributions of the sprayed gas assume a different aspect. The sprayed length, in which the temperature declined from 1,200 to 100 C., was 100 mm in test 3. Because the gas was sprayed at the rate from 30 to 100 m/s, it is found that the cooling rate of the sprayed gas was 300,000 to 1,000,000 C./s in this case.

(24) FIG. 4 shows a distribution of the flame temperature between the front side of the spraying machine and the spray object. The both graphs show a comparison of temperatures at the sprayed distances from the front side of the spraying machine of 300 mm, 350 mm, 400 mm, 450 mm, 500 mm, 550 mm and 600 mm. Condition for spraying was changed from 50 Nm.sup.3/h of oxygen flow to 68 Nm.sup.3/h of oxygen flow. Both graphs show a temperature distribution of the sprayed gas on a straight line parallel to the front side of the spraying machine. In the case of the oxygen flow of 50 Nm.sup.3/h, the temperature near the center was about 1,000 C. at the sprayed distance of 300 mm, while in the case of the oxygen flow of 68 Nm.sup.3/h, the temperature at the center was as high as the spray object melts (1,200 C. or more) at the sprayed distance of 350 mm, and was about 700 C. at the sprayed distance of 400 mm. The graphs clearly show that the temperature of the sprayed gas gradually declines depending on the distance.

(25) FIG. 5 shows a temperature distribution of the flame between the front side of the spraying machine and the spray object, and an appearance photograph of the flame. In the photograph, the sprayed distance of 0 mm indicates the front side of the spraying machine. The graph shows a comparison at the sprayed distances from the front side of 550 mm, 600 mm, 650 mm, 700 mm, 750 mm and 800 mm. The graph shows the temperature distribution of the sprayed gas on a straight line parallel to the front side of the spraying machine. It is found that at the sprayed distance of 550 mm, the temperature distribution is in a range from 550 to 600 C., almost homogeneous, however, as the distance becomes larger, the sprayed gas temperature becomes lower and the temperature range becomes larger.

(26) FIG. 6 shows a temperature distribution of the flame at the sprayed distance of 500 mm, when the inert gas (for rectification and cooling of the flame) is nitrogen gas. Under a fixed spray condition, the spray pressure of the inert gas was changed for comparison. As a result of changing the spray pressure of the inert gas, the flow rate was 360 Nm.sup.3/h and 180 Nm.sup.3/h. The graph shows a temperature distribution of the sprayed gas on a straight line parallel to the front side of the spraying machine. It is found that the change of the inert gas spray pressure adjusted the cooling strength to have an effect on the sprayed gas temperature distribution by 50 to 100 C. in this case.

(27) FIG. 7 shows a temperature distribution of the spray object at the sprayed distance of 400 mm, when the mist (for cooling the flame) is water mist. Under a fixed spray condition, the spray pressure of water mist was changed for comparison. The spray object was a surface of a thin plate substrate, and the particulate material was 80Ni-20Cr. As a result of changing the water mist pressure, the upstream water mist flow rate alone was changed to 4 l/m, 6 l/m and 8 l/m, or the downstream water mist flow rate alone was changed to 8 l/m, 10 l/m and 12 l/m. Both graphs show a temperature at a part where the sprayed gas hit on the thin plate substrate. It is found that the change of the water mist spray pressure adjusted the cooling strength to have an effect on the temperature of the thin plate substrate by 30 to 60 C. to the maximum for every 2 l/m.

(28) The aforementioned terms upstream and downstream are defined to be upstream side or downstream side along the feeding direction of the substrate as the spray object in the device of the invention (the substrate transferred relative to the device of the invention).

EXAMPLE

(29) Hereinafter, the test production of an amorphous alloy thin plate conducted by utilizing the device of FIG. 1 is described. In the test, a rolling mill and the like were also used as mentioned below.

(30) (1) Test Method

(31) A rapid quenching transition control spraying machine (the device for forming amorphous film shown in FIG. 1) is used to product an amorphous alloy thin plate of 300 m in thickness and 300 mm in width. The production test was conducted by a rapid quenching transition control spraying machine provided on a test rolling mill. A test condition of the rapid quenching transition control spraying machine is shown in Table 1. The amorphous alloy thin plate was produced by heating the surface of the thin plate substrate to 400 C. in temperature before spraying an amorphous alloy, melting 64.5Ni-10Cr-7.5Mo-18B powder, spraying from the rapid quenching transition control spraying machine to form an amorphous alloy film, keeping the film in a temperature range of plastic flow (300 to 520 C.), while removing an inner hole and rolling to flatten the surface of the film, and then peeling off the film from the substrate.

(32) TABLE-US-00001 TABLE 1 Table 1 Test condition for producing amorphous alloy thin plate Condition Alloy powder supply (g/s) 30 of large- Propane gas flow rate (m.sup.3/h) 34 size Oxygen flow rate (m.sup.3/h) 120 rapid Rectifying nitrogen flow rate (m.sup.3/h) 400 quenching Sprayed distance to the thin plate substrate (mm) 600 transition Angle of upstream water mist () 9 control Flow rate of upstream water mist (l/min) 4 spraying Angle of downstream water mist () 9 Flow rate of downstream water mist (l/min) 4

(33) (2) Test Result

(34) The appearance of the amorphous alloy thin plate obtained by the production test is shown in FIG. 8. The obtained amorphous alloy thin plate was a successive belt of 400 m in thickness, 300 mm in width and 4,000 mm in length. The cross section of thus obtained amorphous alloy thin plate and the X-ray diffraction profile result are shown in FIG. 9.

(35) In the aforementioned rapid quenching transition control spraying machine (the device 1 for forming amorphous film shown in FIG. 1), depending on the flow rate of combustion gas or the size of the formed film or the like, the flame a and the inert gas b are occasionally desired to come in contact with air in a smaller area. Specifically, the spraying machine 2 is desirable to have a front part provided with a skirt having a rectangular, hollow cross section and placed around, extending forward all of the flame spraying ports 12 and the inert gas spraying ports 13, which is indicated by the referring numeral 6 in FIG. 10(b).

(36) When the skirt 6 is provided on the front part of the spraying machine 2 so as to surround just outside the flame a and the inert gas b, the frame a is allowed to come in contact with air in a smaller area, thereby restraining the formed film from width narrowing and increase of a film thickness deviation (see Table 2), in comparison to the case without a skirt 6 (FIG. 10(a)).

(37) TABLE-US-00002 TABLE 2 Table 2 Difference in film width and film thickness deviation depending on the presence or absence of the skirt No Skirt Skirt Film width (mm) 120 to 170 260 to 300 Film thickness deviation (m) 80 to 120 30 to 80

DESCRIPTION OF LETTERS OR NUMERALS

(38) 1 Device for forming amorphous film

(39) 2 Spraying machine

(40) 3 Mist spraying nozzle

(41) 6 Skirt

(42) 11 Particulate material spraying ports

(43) 12 Flame spraying ports

(44) 13 Inert gas spraying ports

(45) 14 Mist spraying port