TWI224985B - A method of casting for materials comprising an amorphous alloy matrix structure - Google Patents

Abstract

This invention relates to a method of making amorphous alloy matrix structure materials by centrifugal casting. Particularly, the molten metal was forced into a water-cooled metal mold and solidified under a centrifugal force. In this method, the alloy is first melted via vacuum arc remelting (VAR) or induction skull melting (ISM) under either vacuum or protective atmosphere. The molten metal is then pressed into a water-cooled copper mold and rapidly solidify to form a bulk amorphous matrix. The advantages of this invention are that it can provide not only a high cooling rate but also a method of mass production. As a result, large and/or complicatedly shaped bulk amorphous matrix structure can be easily produced.

Description

1224985 V. Description of the invention (l): -——-:-Fan Yigu, industrial use, day = gold (or metal glass, glass metal) is a type with two or two strength, impact resistance, financial wear and tear, financial Rot surname, low Young's modulus is two u I, some iron-based amorphous alloys have excellent soft magnetic properties. Unexpected materials have been used in transformer coils, golf head strike panels, micro and electrical pinions, optical precision parts, bulletproof materials and 3C products for the people's livelihood. ^ Some researchers have found that amorphous bases are compounded with nanometer precipitation. Tissue structure material has more excellent mechanical properties than pure amorphous phase material and is a material with great potential in the future. For the existing Zr / Ti / Cu / Fe series amorphous alloys with more industrial application value, the molten body still needs to be cooled at a cooling rate of 5 ° C ~ 100 ° C / s to form the amorphous phase, due to the limitation of the existing The manufacturing process has not yet established a quantification capability suitable for complex, large flat or large-size parts, so it remains in the academic research or product development stage. Therefore, it is urgent to develop a special process suitable for quantification. This month is a casting method developed for the energy limitation of the amorphous alloy process of the prior art. The alloy is melted by heating ISM or VAR water-cooled copper crucibles, and the casting process is pressurized with high centrifugal force. According to this technology, it takes about 15 minutes. It can complete one-shot casting. If one-shot casting of multiple cavities is used, and the use of water-cooled copper molds can shorten the mold cooling time, it is a continuous continuous casting process with quantitative capabilities. The centrifugal casting of the present invention has excellent quenching ability, so it can be used to cast all amorphous alloy systems used in the prior art, including active amorphous alloys such as the Zr / Ti system. In this way, it can be used to cast nearly 100% amorphous alloys or amorphous base structural materials with partially crystalline phases.

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/: By heating the amorphous bulk material to an appropriate temperature, the amorphous base is precipitated with nano-particles, and a high-toughness amorphous / nanocrystalline composite structure material ^ is produced, which is an innovative amorphous alloy base structural block. The (plate) material casting method has great potential and industrial utilization value. BACKGROUND OF THE INVENTION Amorphous alloy is a solid but its atomic structure is similar to that of liquid materials. Because it has no long-range regularity, the atomic structure exhibits special properties different from crystalline alloys, such as high mechanical strength and high hardness. , Good corrosion resistance, excellent optical, electrical, magnetic properties and abrasion resistance. Since Klement first synthesized ^ —Si-based amorphous phase by the rapid condensation method in 1960, it was restricted by the formation of amorphous phase and required extremely high cooling rate. Therefore, scholars such as Chen did not apply it until the mid-1970s. Pd4QNi4 () P2 () (1976) and Pd76Cu6Si18 (1978) were made into water-quenching method (Critical Cooling Rate 'Rc) with a water quenching method (CQ). In 1988, Professor Akira Inoue of Tohoku University first discovered that the supercooled liquid region (ΔTχ = Tx-Tg) of Mg-Ln-TM (TM = transition metal) amorphous alloy reached 50K, and the supercooled liquid The zone is defined as the temperature range between the crystallization temperature (Tx) minus the glass transition temperature (Tg). After Inoue taught and synthesized the Mg-Ln-TM bulk amorphous alloy at a very low Rc (critical cooling rate), Special ingredients such as Zr-A and Ni,

Zr-Al-Cu, Zr-Al-Cu-Ni, Zr-Ti-Cu-Ni and (Zr, Hf) -A1-Cu-

Alloys such as Ni have a wide ΔΤχ. Professor William Johnson of California Institute of Technology

1224985 V. Description of the invention (3) In 1 993, it was discovered that Zr-Ti-Be-TM alloys can form amorphous alloys with a wide and extremely low critical cooling rate. Two groups of scholars can also use die casting method Or die-casting to produce bulk amorphous materials. Although the bulk amorphous alloy can be successfully prepared by the above method, but after analyzing the manufacturing parameters used, it can be found that there are still defects that require special process design and are not suitable for the quantification of active, complex, or large-sized amorphous alloys. The analysis of the bulk amorphous forming method in the past 10 years is nothing more than (丨) water quenching method. The alloy is placed in a quartz tube, heated and melted, and then quenched directly in water to form a bar. 42) Cold mold spinning method The alloy is placed in a quartz tube and melted by high frequency induction heating, and the molten alloy is injected into the upright rotating copper roller with Ar pressure to form an amorphous foil strip with a thickness of about 30 / zm; (3) made of non-aqueous foil by mechanical alloy method Crystal powder, and then formed by cold equalizing or hot equalizing or rolling; (4) vacuum suction method: melt the alloy by atmospheric pressure and draw the alloy vertically into the metal mold cavity for rapid cold forming; (5) gravity casting Method: Inject molten metal into the metal mold by gravity and quench it; (6) The traditional die-casting method is to dissolve the alloy in a ceramic slump under protective gas in a south frequency manner. The solution is pressed into the metal mold to cool; (7) compression molding method: the alloy is placed in the lower mold to be heated and dissolved by non-consumable electrodes, the lower mold is horizontally moved under the upper mold and aligned with the upper mold, and then press-molded by forging. . The above-mentioned various suitable amorphous block forming methods are not really suitable for the quantitative process 'for producing high-quality and large-sized large amorphous blocks (plates) materials' There are all kinds of amorphous blocks (plates) which are not good for large areas Quantitative problem, 1224985 V. Description of the invention (4) For example, (1) water quenching is more suitable for making amorphous rods without quantification ability; (2) cold mold fusion is only suitable for making amorphous foil strips, not for production Thick material strength; (3) The amorphous powder is formed by cold equalizing or hot equalizing. Due to the need for pressure molding below the crystallization temperature, the shape and process capability are limited. Do not make complex shapes and large sizes. Block (plate) material, which is expensive and not suitable for quantification process; (4) the above method is used to produce amorphous blocks, because the pressure difference is not large, so the complex shape of the casting is likely to cause cold shutting and The formation of local crystallization phenomenon is not suitable for quantification of large-area blocks (plates); (5) Gravity casting method: suitable for casting rods, it is not easy to cast a complete shape for large flat or thin castings; (6) by die casting or compression molding law The production of amorphous blocks can prevent the formation of an air gap layer with low heat transfer efficiency between the mold wall and the solidified layer when the alloy solidifies and shrinks, reducing the heat transfer effect of the mold cavity and the melt, but these two methods still exist. Factors that are not conducive to the formation of the amorphous phase of the active metal. For example, when molten metal with active alloys such as s Zr / Ti series is cast into the copper mold cavity, it is formed by traditional die casting method, and the alloy is applied to the ceramic crucible by high frequency induction melting. Medium melting is not easy to control the cleanliness of the alloy, and at the same time, the active Zr / Ti series alloy will react with the crucible material. Some oxides in the melt are not good for the formation of amorphous phases. They are usually formed by die casting. The alloy melting chamber is protected by a protective atmosphere. When the molten metal solidifies through the flow path ^ into the mold cavity, it is easy to cause local oxidation of the molten metal, so it is not easy to control the quality of the amorphous block (plate) material. Although the compression molding method melts in a vacuum or a protective atmosphere, there is no such problem, but because the alloy is placed in the lower mold and melted, the lower mold water is "moved under the upper mold and aligned with the upper mold. Pressurized by forging

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Type, which causes the entire process to take too long to operate, which can easily cause the alloy to melt and add directly to the lower mold. The temperature rise in the cavity part of the product will indirectly reduce the cavity part. The formed shape is more suitable for making amorphous blocks (plates) with simple shapes. Due to the heterogeneous nucleation opportunities in the major amorphous block (plate) manufacturing processes today, the chilling capacity of the lower molds is indirectly limited, so it is limited. Less development potential. Although the above-mentioned defects can be made up to 10mm, the shape is complicated and the progress is slow. For manufacturing methods, vacuum. The molten metal is solidified and formed into a complex amorphous form

Alloys such as Zr-Al-Ni-Cu or Ti-Zr-Cu-Ni-B are made of rods with a diameter larger than the diameter. However, due to the limitation of quantification and area capacity, the application and development of amorphous alloys are lacking. The invention uses a centrifugal casting or a protective atmosphere to melt, solidify, and solidify the alloy into a water-cooled mold, and presses a strong centrifugal force to pressurize a molding method that has a quantification ability and can produce large-sized, quality alloy base structural materials. . Summary of the Invention

The invention is a method for forming an amorphous alloy base structural material by centrifugal casting, which is characterized in that a molten metal liquid is injected into a water-cooled metal mold by centrifugal force and solidified. The centrifugal casting of the present invention is to complete the entire process of melting, casting, and rapid solidification of the alloy in a vacuum chamber. After the alloy is melted by heating, it is poured into a high-speed centrifugal mold, and the metal is hydraulically injected into the mold cavity with high centrifugal force to rapidly condense. Forming. The heat source used in the present invention can melt the alloy into a liquid state and melt

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The heating method of the molten metal temperature is higher than the dazzling point, and the molten metal liquid can be continuously heated, providing enough heat to prevent the molten metal from solidifying before casting. It can completely re-melt the nucleus in the molten metal liquid at excessive temperature, and avoid heterogeneous nucleation. Or heterogeneous nucleation opportunities to obtain all amorphous structures or high-rate amorphous base structure blocks (plates). Generally used heating methods can be Plasma melting, Electron beam melting, Resistance heating, Vacuum arc remelting, or Induction shell melting. skuU melting) method or vacuum induction melting method (Inductioon fflelting). The hanging pot used for various heating methods can be graphite, ceramic or shell copper crucible heating method. For the melting of Zr / Ti / Cu-based active alloys, water-cooled copper crucibles can be used to obtain higher purity metal melts, and the reaction of molten metals with snail materials can also be avoided. Especially, the alloys are melted by induction shell melting. Heating and melting under vacuum or inert milk can easily heat the molten alloy body above the melting point above 50 ° C. It can cast complex large flat blocks (plates) to reduce the incompleteness or cold connection of the finished product due to low pouring temperature. It can also effectively suppress the occurrence of heterogeneous nucleation or heterogeneous nucleation opportunities in the crucible or during the casting process of the high-temperature molten alloy, which is beneficial to the formation of amorphous phases. It is also difficult to react with the alloy due to the use of non-consumable water-cooled copper. It is a very suitable melting process for alloys with high activity. The centrifugal casting of the present invention adopts a horizontal centrifugal casting method, and the centrifugal rotation speed is at least 50 rpm or more. Higher speed can obtain greater pressurizing capacity, which can fill the metal cavity completely in the mold instantly. It is suitable for casting complex or large-area block (plate) material. It can effectively avoid the cold welding of the casting.

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1224985 V. Description of the invention (8) [Example 1]: (ISM heating and melting process) Master alloy ingot melting: Vacuum arc melting furnace (yacuum Arc Reme 11 in ng 'VAR) is used to dissolve each furnace at about 600. Grams, pure wrong (99%), pure aluminum (99 · 9%), pure nickel (99%), pure copper (99.5%) or Al-2% Sc alloy (99 · 9%) according to weight percentage After being vacuumed to PiO-sTorr in a water-cooled copper hanging pot, it is melted in a high argon atmosphere. In order to make the alloy completely homogeneous, the molten material is solidified and then re-melted. This is repeated at least seven times. Complete & 5, 11 () 1 ^ 5 (: 113 () (&1;%) mother alloy ingot melting. Amorphous alloy sheet casting: (1) Centrifugal mold: The upper and lower molds of the centrifugal mold are made of oxygen-free copper with excellent thermal conductivity. The size of each mold cavity is 4 plates with a size of 50mm * 100mm * 3mm. (2) Melting and casting · Take Zr55Al1GNi5Cu3G (at%) alloy cunning weight and weigh about 3000 grams, and place it in an ISM vacuum furnace induction water-cooled copper crucible. After evacuating to 1.0 × * 10-3 Torr, the vacuum degree was adjusted to 1 · ΪΜΟ—Τογγ by passing high argon, and the alloy was melted by electric power. After about 2 minutes of melting and heating, it is quickly cast into a 200rpm high-speed copper mold in 1 second, and the plate is taken out after solidification and cooling after about 15 minutes. In order to understand whether the bound plate is an amorphous alloy, this The example uses X-ray diffraction structure analysis for preliminary identification. The results are shown in the X-ray diffraction pattern of the plate sample shown in the first figure. From the diffraction pattern, it can be seen that most of them are amorphous bases and only small. Some crystal diffraction peaks appear. Although the metal mold used in this experiment is a low-speed and water-free device, the mold is made of a large volume of copper material. At low speed, sufficient forming centrifugal force can be obtained and heat absorption can be achieved instantly. ability. ,

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The results of the thermal analysis of the amorphous alloy sheet are shown in the second figure. The Tg and Tx (Qn set) are 693 · 43K and 773 · 02K, respectively. From these two temperatures, ΔΤχ is about 80K. Crystalline alloys have a wide supercooled liquid sad interval 'This temperature interval is generally used to measure the stability of the glass phase when the temperature exceeds the glass transition temperature Tg. The larger the ATx value, the better the thermal stability of the supercooled liquid vessel. , The easier it is to form in the supercooled liquid region, for example, the superplastic forming method of precision molds can be used to make amorphous alloy plates into parts with special shapes.

[Example 2]: (VAR heating and melting process) The melting process of the master alloy ingot is the same as that of Example 1. Casting of amorphous alloy sheet: (j) Centrifugal mold: The upper and lower molds of the centrifugal mold are made of oxygen-free copper with excellent thermal conductivity. There are circulating water cooling pipes in the upper and lower copper molds. The maximum size of 4 mold cavities is 50mm * 100mm * 3mm. (2) Dissolution casting:

Zr55Al1GNi5Cu3. (At%) The master alloy ingot weighs about 600 grams and is placed in a water-cooled copper crucible in a var furnace. It is evacuated with a mechanical pump and a diffusion pump to 5.0 · 1.05 Torr. The vacuum degree is adjusted to uwpToR, and the alloy is melted by heating. After the alloy is completely melted and continuously heated for about 2.5 minutes,

Quickly cast κ150〇Γρι in a high-speed water-cooled copper mold in 0.5 seconds in about 0.5 seconds. After solidification and cooling, the plate was taken out. The diffraction analysis results of the test piece x-ray structure are shown in the third figure. From the X-ray diffraction pattern, it can be seen that most of them are amorphous, and only a small number of crystalline diffraction peaks appear. The thermal analysis results of the test strip after the 11 ^ diffraction analysis are shown in the fourth figure, and the Tg and Tx (on set) are 709.3K and 799K, respectively. From these two temperatures, the ΔΤχ approx. for

1224985 V. Description of the invention (10) 89 · 7K. The plate produced by this method can obtain a wide supercooled liquid area, which shows that the supercooled liquid produced by this method has good thermal stability. Take a 3mm thick test piece made in the method of Example 2 and take about 10mm X 1 Omm square test piece at an appropriate position. After grinding the surface layer of the test piece in the thickness direction by 1.5mm, use 1% hydrofluoric acid etching solution to test the test piece. After being etched for 1 second, the metallographic structure was observed under an optical microscope. As shown in the fifth figure, the test piece was a composite structure with a microcrystalline phase base and a small amount of 10 / zm or less.

The finished product of the ZhsAligNigCu3〇 (at%) alloy centrifugally scaled (1500rpm) plate by VAR dissolving method is shown in the sixth figure. The finished product size is 50mm X 100mm X 3mm (thick). The shape of the cast plate is complete. , And the surface brightness is good. [Comparative Example 1] (I) Amorphous, its process is as follows, the high-passing example _, two methods of heating and melting continue to add, whether the plate is amorphous step identification, base, but the liquid-casting casts a complete alloy in the traditional way Gravity casting production: Vacuum the mechanical pump and diffusion pump to 5.0 * 10-3 Torr purity argon to adjust the vacuum to 1.7 * 1〇-1 Torr, and use the actual Zr55Al10Ni5Cu3. 300 g of master alloy ingot was heated and smelted in water-cooled copper with VAR. After the alloy was completely dissolved for about 2.5 minutes, it was quickly cast in water-cooled copper molds within 0.5 seconds. The size was 50 mm. * 100 mm * 3 mm. In order to understand that the casted plate is an alloy, this comparative example uses X-ray diffraction structure analysis as the initial result. As shown in the seventh figure, it can be seen from the diffraction pattern that the part is amorphous and there is a high proportion of crystalline phase. With gravity casting, the metal process has no pressurizing force, so it is not easy to shape for large flat or thin castings, and its development is limited.

Page 15 1224985 V. Description of the invention (11) In summary, the present invention is a centrifugal casting method of amorphous alloy base structural material. The alloy is melted, cast, and solidified in a vacuum or in a protective atmosphere. In a water-cooled mold, solidifying and forming under the pressure of a strong centrifugal force is a forming method that has quantification ability and can produce large-sized, complex shapes and amorphous alloy base structural blocks (plates). Compared with the gravity casting method of the comparative example, the centrifugal casting method can obtain a higher proportion of amorphous phase in the plate made by centrifugal casting, especially using a water-cooled copper mold with centrifugal casting, and VAR or ISM water-cooled copper crucibles for molten tungsten casting. It can be used to cast highly active alloys such as Ti / Zr, and this method is used to make amorphous alloy base structure materials. It is the first creation and has great industrial use value. It is in good faith that it meets the requirements of the invention patent application. Before the application, it did not appear in any publications and public use, so the application was made in accordance with the patent law. & 定 #

Page 16 1224985 Brief description of the diagram The first picture: X-ray diffraction pattern of Zr55 A l1 () Ni5Cu3 () alloy centrifugally fabricated (200rpm) plate sample by ISM melting and washing. The second picture: DSC thermal analysis chart of 21 * 55 eight 110? ^ 5 (: 113 () alloy centrifugal casting (200 rpm) plate casting with 181! Melting. The third picture: Zr55Al1 () casting with VAR melting X-ray diffraction pattern of Ni5Cu3 (1 alloy centrifugally cast (150 rpm) plate sample. Fourth figure: DSC thermal analysis chart of Zr55Al10Ni5Cu3 () alloy centrifugally cast (1500 rpm) plate sample dissolved and washed with VAR. Fifth image: Zr55Al10Ni5Cu3 () alloy centrifugal casting (1 50 Or pm) sheet metallographic structure is cast by VAR. Sixth image: 21 * 55 person 1101 ^ 5〇113 () alloy is dissolved and washed with ¥ person 1? Centrifugal casting (1,500 rpm) sheet of the solid finished product. Figure 7: X-ray diffraction pattern of Zr55Al1QNi5Cu3Q alloy gravity cast sheet sample cast by VAR melting.

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Claims (1)

^ 24985 _Please patent scope l A casting method of amorphous precious alloy base structural material, which is a method of injecting molten metal liquid into a water-cooled metal mold by centrifugal force. ^ 'Formation of a critical cooling rate in the amorphous phase, rapid solidification forming, and its manufacturing process Including: (1) Placing the alloy ingot in a crucible and melting the alloy ingot by heating or induction heating in a vacuum or a protective gas; (2) Pouring molten gold between 50 rpm and above the metal cooled by water in advance The inner mold of the mold is continuously centrifugally pressurized and cooled with water until the alloy is solidified. 2. The casting method according to item 丨 of the patent application scope, wherein the metal mold is made of copper metal with a thermal conductivity coefficient. Wood use 3. For example, the gate of the patent application No. 丨. Charm; core 1 belongs to the mold and the contact surface of at least one side is provided with a water-cooled flow path device. 4. If the casting method of item 1 of the patent scope is requested, wherein the non-crystalline and soft-feeling σ, the basic bamboo γ < non-Japanese-Japanese quality base in the amorphous structure material is at least 3 〇% or more