CN116804258B

CN116804258B - Bulk zirconium-based amorphous alloy with high strength and high hardness and preparation method thereof

Info

Publication number: CN116804258B
Application number: CN202311064246.0A
Authority: CN
Inventors: 季晓迪; 徐阳; 刘杰; 师红旗; 汤涛
Original assignee: Nanjing Tech University
Current assignee: Nanjing Tech University
Priority date: 2023-08-23
Filing date: 2023-08-23
Publication date: 2023-10-27
Anticipated expiration: 2043-08-23
Also published as: CN116804258A

Abstract

The invention provides a bulk zirconium-based amorphous alloy with high strength and high hardness and a preparation method thereof, wherein the preparation method comprises the following steps: weighing various metal raw materials according to the chemical general formula of the bulk zirconium-based amorphous alloy, mixing and smelting the various metal raw materials to obtain a metal melt, filling the metal melt into a mold cavity in a vacuum state for die casting molding, and cooling to obtain an amorphous master alloy; and (3) grinding and polishing the surface of the amorphous master alloy to obtain the bulk zirconium-based amorphous alloy. The invention realizes the control of the oxygen content in the alloy by regulating and controlling the element composition in the zirconium-based amorphous alloy, and combines laser irradiation treatment to form a second phase with high hardness and high strength on the surface of the amorphous alloy.

Description

Bulk zirconium-based amorphous alloy with high strength and high hardness and preparation method thereof

Technical Field

The invention belongs to the technical field of amorphous alloy manufacturing, and relates to a bulk zirconium-based amorphous alloy with high strength and high hardness and a preparation method thereof.

Background

Amorphous alloys have structural characteristics similar to glass and are therefore also referred to as metallic glasses. Due to the unique structural characteristics of amorphous alloys, the amorphous alloy exhibits superior magnetic, mechanical, physical and chemical properties compared to conventional crystalline alloys.

The zirconium-based amorphous alloy has a wide supercooled liquid region width, is easy to form an amorphous state, and is one of amorphous systems which are most hopeful to be applied in the engineering field in a large scale. Research on zirconium-based amorphous alloy materials has been developed to a certain extent, and how to prepare the zirconium-based amorphous alloy with high strength and high hardness, so that the zirconium-based amorphous alloy has a larger application range and is always the topic of long-lasting research on amorphous alloy materials.

Although the zirconium-based amorphous alloy has excellent amorphous forming ability, strength and hardness, the amorphous forming ability of the amorphous alloy can be improved by the formulation of the components. However, for most of zirconium-based amorphous alloys, the strength is generally below 2000MPa, and at present, less zirconium-based amorphous alloys with high strength, high hardness, excellent forming capability and low cost are simultaneously satisfied, so that the industrialized application of the zirconium-based amorphous alloys is hindered.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention aims to provide a bulk zirconium-based amorphous alloy with high strength and high hardness and a preparation method thereof, wherein the oxygen content in the alloy is controlled by regulating and controlling the element composition in the zirconium-based amorphous alloy, and a second phase with high hardness and high strength is formed on the surface of the amorphous alloy by combining laser irradiation treatment.

To achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, the method comprising:

weighing various metal raw materials according to the chemical general formula of the bulk zirconium-based amorphous alloy, mixing and smelting the various metal raw materials to obtain a metal melt, filling the metal melt into a mold cavity in a vacuum state for die casting molding, and cooling to obtain an amorphous master alloy; grinding and polishing the surface of the amorphous master alloy to obtain the bulk zirconium-based amorphous alloy;

the chemical general formula of the bulk zirconium-based amorphous alloy is Zr _a Cu _b Al _c Ni _d Ti _e M _f Wherein a, b, c, d, e and f are the atomic ratios of the respective components, 50.ltoreq.a.ltoreq.55, 25.ltoreq.b.ltoreq.30, 8.ltoreq.c.ltoreq.20, 0.1.ltoreq.d.ltoreq. 9,0.1.ltoreq.e.ltoreq.5, 0.1.ltoreq.f.ltoreq.5, a+b+c+d+e+f.ltoreq.100, a may be 50, 51, 52, 53, 54 or 55, b may be 25, 26, 27, 28, 29 or 30, c may be 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20, d may be 0.1, 1, 2, 3, 4, 5, 6, 7, 8 or 9,e may be 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5Or 5, f may be 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5, a+b+c+d+e+f.ltoreq.100, but is not limited to the recited values, other non-recited values within the range of values are equally applicable; m is a rare earth element selected from any one or a combination of at least two of Y, gd and Sc.

The bulk zirconium-based amorphous alloy is sensitive to oxygen elements in the ambient atmosphere, the oxygen elements in the zirconium-based amorphous alloy mainly come from oxygen elements carried by metal raw materials and oxygen elements in the smelting process, the zirconium-based amorphous alloy is easy to absorb oxygen in the smelting process, the oxygen content in the zirconium-based amorphous alloy is increased even if the zirconium-based amorphous alloy is smelted under a vacuum condition, oxides in the zirconium-based amorphous alloy become the core of heterogeneous nucleation, heterogeneous nucleation is induced, the amorphous forming capacity is reduced, and the forming capacity and the mechanical property of the zirconium-based amorphous alloy are further affected. Therefore, the invention prepares the large-block zirconium-based amorphous alloy with high strength and high hardness by compounding basic metal raw materials such as zirconium element, copper element, aluminum element, nickel element, titanium element and the like with rare earth elements and performing melt die casting, and can reduce oxygen element in the amorphous alloy on the basis of ensuring the mechanical property of the zirconium-based amorphous alloy by adding a small amount of rare earth elements.

The rare earth yttrium (Y) has stronger oxygen affinity than zirconium, so that the rare earth yttrium is easier to react with oxygen, thereby effectively eliminating oxygen in a metal melt, having the effect of purifying alloy, and reducing the adverse effect of heterogeneous shape checking on glass forming capability. In addition, the addition of yttrium induces nano crystallization, thereby improving tissue structure, mechanical property and hardness.

By adding a proper amount of rare earth gadolinium (Gd) into the zirconium-based amorphous alloy, the action between small atoms and large atoms among components can be increased, the atomic distance of the zirconium-based amorphous alloy is increased, the short-range ordered region and the atomic arrangement among the atoms of the zirconium-based amorphous alloy are changed, the arrangement density of the atoms in the zirconium-based amorphous alloy is increased, the growth process diffusion of atoms is prevented, and thus the effective crystal nucleation is realized, and the microhardness of the zirconium-based amorphous alloy is improved.

Oxygen in zirconium-based amorphous alloys in the form of ZrO ₂ In the form of a nucleation core or cluster, oxygen becomes more stable in the form of scandium (Sc) after scandium (Sc) is added to the zirconium-based amorphous alloy ₂ O ₃ Exists in addition to Sc ₂ O ₃ And the zirconium-based amorphous alloy is not a core of heterogeneous nucleation. By adding scandium, the stability of the amorphous alloy in the supercooled liquid region is improved so as to prevent the amorphous alloy from being converted into crystals, the glass forming capability of the zirconium-based amorphous alloy is improved, and the maximum amorphous forming size of the amorphous alloy can be remarkably improved by adding a proper amount of scandium.

As a preferable technical scheme of the invention, the smelting process is carried out in a vacuum induction smelting furnace, protective gas is filled in the vacuum induction smelting furnace, a crucible is placed in the vacuum induction smelting furnace, the metal raw material is placed in the crucible, an induction coil is circumferentially arranged on the periphery of the crucible, and alternating current is introduced into the induction coil to generate an alternating magnetic field.

The vacuum degree in the vacuum induction melting furnace is 10 ^-3 -10 ^-1 Pa may be, for example, 0.001Pa, 0.02Pa, 0.03Pa, 0.04Pa, 0.05Pa, 0.06Pa, 0.07Pa, 0.08Pa, 0.09Pa, or 0.1Pa, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

In a preferred embodiment of the present invention, the melting process is to heat the temperature in the vacuum induction melting furnace to a temperature in the range of 1800 to 1900 ℃ at one time, and for example, 1800 ℃, 1810 ℃, 1820 ℃, 1830 ℃, 1840 ℃, 1850 ℃, 1860 ℃, 1870 ℃, 1880 ℃, 1890 ℃ or 1900 ℃, but the melting process is not limited to the above-mentioned values, and other non-mentioned values in the above-mentioned values are applicable.

As a preferred technical solution of the present invention, the smelting process is divided into three stages, including a first smelting, a second smelting and a third smelting, which are sequentially performed.

The temperature of the first melting is 550 to 600 ℃, and may be 550 ℃, 555 ℃, 560 ℃, 565 ℃, 570 ℃, 575 ℃, 580 ℃, 585 ℃, 590 ℃, 595 ℃, or 600 ℃, for example, but the first melting is not limited to the recited values, and other values not recited in the recited values are equally applicable.

The heating time of the first smelting is 5 to 10s, and may be, for example, 5.0s, 5.5s, 6.0s, 6.5s, 7.0s, 7.5s, 8.0s, 8.5s, 9.0s, 9.5s or 10.0s, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

The second melting temperature may be 1500-1600 ℃, for example 1500 ℃, 1510 ℃, 1520 ℃, 1530 ℃, 1540 ℃, 1550 ℃, 1560 ℃, 1570 ℃, 1580 ℃, 1590 ℃, or 1600 ℃, but is not limited to the recited values, and other non-recited values within the range are equally applicable.

The heating time of the second smelting is 10 to 20s, and may be, for example, 10s, 11s, 12s, 13s, 14s, 15s, 16s, 17s, 18s, 19s or 20s, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

The temperature of the third melting is 1800 to 1900 ℃, and may be 1800 ℃, 1810 ℃, 1820 ℃, 1830 ℃, 1840 ℃, 1850 ℃, 1860 ℃, 1870 ℃, 1880 ℃, 1890 ℃, or 1900 ℃, for example, but is not limited to the values recited, and other values not recited in the range are equally applicable.

The heating time of the third smelting is 10 to 15s, and may be, for example, 10s, 10.5s, 11s, 11.5s, 12s, 12.5s, 13s, 13.5s, 14s, 14.5s or 15s, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

The effective measure for improving the amorphous forming capability of the alloy is to inhibit nucleation and growth of crystals, if heterogeneous nucleation points exist in a metal melt, the stability of supercooled liquid is reduced, and the heterogeneous nucleation of the crystals is induced, so that the forming capability of the amorphous alloy is weakened. The main reason for heterogeneous nuclei is the presence of locally ordered clusters of atoms and fine grains of high Wen Cancun. The invention controls the metal raw material to smelt in stages in different temperature ranges by controlling the magnitude and the power of alternating current, so that the melt forms an amorphous phase rapidly, and the proportion of the amorphous phase can be up to more than 90%.

The first smelting stage aims at softening the metal raw materials, so that the atomic diffusion capacity among the metal raw materials is improved, the disorder degree and the free volume content of a crystalline microstructure in the metal raw materials are increased, the internal stress concentration of the amorphous alloy is effectively relieved after the metal melt is solidified, and therefore, the premature occurrence of cracks and the expansion of the cracks are prevented.

The purpose of the second smelting stage is to initially reduce metastable clusters and the presence of a high Wen Cancun phase while removing oxygen elements from the metal melt. The invention limits the smelting temperature of the second smelting stage to 1500-1600 ℃, and in the smelting temperature range, rare earth elements in the metal raw materials and oxygen elements in the metal melt react to obtain oxides, and meanwhile, protective gas is introduced into the metal melt by matching with an aeration pipeline, so that the oxides float upwards along with dispersed bubbles to be removed.

The purpose of the third smelting stage is to further reduce metastable atom clusters and the existence of high Wen Cancun phase, and simultaneously form amorphous state rapidly, and in the smelting temperature range of 1800-1900 ℃ defined by the invention, along with the rise of the temperature of the metal melt, heterogeneous nuclei generated by refractory impurities in the metal raw material are eliminated, the amorphous forming capability of the alloy is improved, and the prepared zirconium-based amorphous alloy shows good hardness and strength. When the smelting temperature is higher than 1900 ℃, although the influence of heterogeneous nucleation is eliminated, the heat in the metal melt cannot be timely led out due to the limited heat dissipation capacity of the crucible, the cooling rate of the metal melt is influenced, and once the cooling rate is lower than the critical cooling rate of the alloy, crystallization nucleation can be generated, so that a crystalline structure is formed.

As a preferable technical scheme of the invention, a first ultrasonic amplitude transformer is further arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches below the liquid level of the metal melt in the crucible, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, and the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer.

The output power of the first ultrasonic generator is 2.5-3kW, and can be 2.5kW, 2.55kW, 2.6kW, 2.65kW, 2.7kW, 2.75kW, 2.8kW, 2.85kW, 2.9kW, 2.95kW or 3.0kW, for example; the ultrasonic frequency generated is 50-60kHz, and may be, for example, 50kHz, 51kHz, 52kHz, 53kHz, 54kHz, 55kHz, 56kHz, 57kHz, 58kHz, 59kHz or 60kHz, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

According to the invention, ultrasound is applied to the metal melt in the smelting process, and the first ultrasound amplitude transformer is used for introducing the ultrasound into the metal melt in the crucible, so that the generation of heterogeneous nuclei can be effectively inhibited. In addition, alternating current is introduced into the induction coil to generate an alternating magnetic field, so that an electromagnetic stirring effect is achieved on the metal melt in the crucible, the components of the alloy during smelting are more uniform due to the existence of electromagnetic stirring, and crystal nucleus pollution caused by ohmic contact at the bottom of the crucible is reduced, so that purer amorphous state is formed.

As a preferred embodiment of the invention, the first ultrasonic generator applies ultrasonic waves i to the metal melt via the first ultrasonic horn when the melting temperature reaches a temperature in the range 1800-1900 ℃.

As a preferred embodiment of the invention, in the third melting phase, the first ultrasonic generator applies ultrasonic waves i to the metal melt via the first ultrasonic horn.

As a preferable technical scheme of the invention, an aeration pipeline is further arranged at the bottom layer in the crucible, and in the second smelting stage, protective gas is introduced into the metal melt body through the aeration pipeline.

The amount of the shielding gas may be 2.5 to 3.5L/min, for example, 2.5L/min, 2.6L/min, 2.7L/min, 2.8L/min, 2.9L/min, 3.0L/min, 3.1L/min, 3.2L/min, 3.3L/min, 3.4L/min or 3.5L/min, but not limited to the recited values, and other non-recited values within the range of the values are equally applicable.

According to the invention, a small amount of rare earth raw materials are doped in the basic metal raw materials, oxide particles generated by the reaction of the rare earth raw materials and oxygen elements are dispersed in a metal melt, the oxide particles gradually float up to the surface of the metal melt in the melting process, but part of oxide particles with smaller sizes are suspended in the metal melt and cannot be discharged, and the part of oxide particles are used as seed crystals in the amorphous forming process, so that the phenomena of segregation and crystallization of amorphous are induced. According to the invention, the protective gas is introduced into the metal melt, so that the protective gas can be dispersed in the metal melt to form small bubbles, and the small-size oxide particles are driven to float upwards along with the floating of the small bubbles, so that oxygen elements in the zirconium-based amorphous alloy are removed more thoroughly, and the deoxidization and purification requirements are met.

As a preferred embodiment of the present invention, the die casting process includes:

and (3) coating lubricant on the inner surface of the die cavity, injecting the metal melt into the die cavity through high pressure, maintaining the pressure of the die cavity after the metal melt is completely filled in the die cavity, and cooling the die after maintaining the pressure for a period of time until the metal melt is solidified to obtain the amorphous master alloy.

The injection speed of the metal melt is 4-5m/s, and can be, for example, 4.0m/s, 4.1m/s, 4.2m/s, 4.3m/s, 4.4m/s, 4.5m/s, 4.6m/s, 4.7m/s, 4.8m/s, 4.9m/s or 5.0m/s; the injection pressure of the metal melt is 80-110MPa, for example, 80MPa, 85MPa, 90MPa, 95MPa, 100MPa, 105MPa or 110MPa; the dwell time of the mold cavity is 10-15s, for example, 10s, 10.5s, 11s, 11.5s, 12s, 12.5s, 13s, 13.5s, 14s, 14.5s or 15s, but is not limited to the recited values, and other non-recited values within this range are equally applicable.

A second ultrasonic amplitude transformer is arranged in the die cavity, one end of the second ultrasonic amplitude transformer is abutted with the outer wall of the die, and the other end of the second ultrasonic amplitude transformer is connected with a second ultrasonic generator.

And in the process from the pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through the second ultrasonic amplitude transformer.

The ultrasonic frequency generated by the second ultrasonic generator is 1.4-1.5kHz, and can be 1.4kHz, 1.41kHz, 1.42kHz, 1.43kHz, 1.44kHz, 1.45kHz, 1.46kHz, 1.47kHz, 1.48kHz, 1.49kHz or 1.5kHz; the single ultrasonic time is 5-8s, and can be 5.0s, 5.5s, 6.0s, 6.5s, 7.0s, 7.5s or 8.0s; the interval between two adjacent ultrasound waves is 10-12s, for example, 10s, 10.2s, 10.4s, 10.6s, 10.8s, 11s, 11.2s, 11.4s, 11.6s, 11.8s or 12s, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

According to the invention, intermittent ultrasonic vibration is applied to the metal melt in the die casting cooling process, on one hand, as the ultrasonic frequency is increased, the vibration amplitude of the die cavity is increased, and the vibration causes the relative speed change between the metal melt and the die cavity to be more severe, so that the metal melt obtains a better micro-forming filling effect, and the improvement of the amorphous micro-forming interface effect is facilitated; on the other hand, along with the increase of ultrasonic frequency, the stress superposition effect and the acoustic softening phenomenon acting on the metal melt are more remarkable, so that the amorphous alloy is internally subjected to plastic deformation, the generated stress field and the alternating stress field generated by ultrasonic vibration are mutually superposed, so that the particles in the amorphous alloy generate oscillation stress and are locally diffused and absorbed, the activity of the metal melt is increased, the local temperature is increased, more new free volume is generated, the viscosity of the metal melt is reduced along with the increase of the free volume concentration, the flowing stress of the metal melt is reduced, the forming capability of the metal melt is higher as the flowing stress of the metal melt is lower, and the bulk zirconium-based amorphous alloy is more favorable to be obtained.

As a preferable technical scheme of the invention, the cooling refers to naturally cooling the die-casting forming piece to room temperature under the air atmosphere and normal pressure environment to obtain the amorphous master alloy.

As a preferable technical scheme of the invention, the cooling is divided into two stages, including a first cooling and a second cooling which are sequentially carried out; wherein the first cooling is performed under a protective atmosphere and a negative pressure environment, and the second cooling is performed under an air atmosphere and a normal pressure environment.

The negative pressure environment of the first cooling is 10 ^-2 -10Pa, which may be for example 0.01Pa, 1Pa, 2Pa, 3Pa, 4Pa, 5Pa, 6Pa, 7Pa, 8Pa, 9Pa or 10Pa; the cooling rate of the first cooling is 50-80K/s, and can be 50K/s, 52K/s, 54K/s, 56K/s, 58K/s, 60K/s, 62K/s, 64K/s, 68K/s, 70K/s, 72K/s, 74K/s, 76K/s, 78K/s or 80K/s; the amorphous master alloy is cooled to 200 to 250 ℃ after the first cooling, and may be 200 ℃, 205 ℃, 210 ℃, 215 ℃, 220 ℃, 225 ℃, 230 ℃, 235 ℃, 240 ℃, 245 ℃, or 250 ℃, for example, but is not limited to the recited values, and other values not recited in the range of values are equally applicable.

The cooling rate of the second cooling is 100-150K/s, for example, 100K/s, 105K/s, 110K/s, 115K/s, 120K/s, 125K/s, 130K/s, 135K/s, 140K/s, 145K/s or 150K/s, but not limited to the recited values, and other non-recited values within the range of values are equally applicable.

The invention controls the temperature of the cooling process to inhibit the nucleation process of the metal melt, thereby uniformly and continuously solidifying the metal melt into solid to obtain the zirconium-based amorphous alloy. The cooling process defined by the invention comprises a first cooling process and a second cooling process, wherein in the first cooling process, the metal melt hardly has oxidation problem because the die cavity is under the protective atmosphere, so that a mode of cooling along with a die can be adopted in the first cooling stage, the cooling rate is kept relatively low until the cooling rate is cooled below the glass transition temperature, and the amorphous alloy with large size can be formed through low-speed cooling. When the temperature is reduced to 200-250 ℃, the zirconium-based amorphous alloy is solidified and formed, and enters a second cooling stage at the moment, the cooling rate of the second cooling stage is higher than that of the first cooling stage, and if the cooling rate of the second cooling stage is too low, a nucleation process is initiated, so that a crystal phase is continuously separated out, and the crystallization volume fraction of the amorphous alloy is continuously increased. The present invention preferably employs water quenching or oil quenching during the second cooling process. The cooling method provided by the invention can ensure that the amorphous phase in the zirconium-based amorphous alloy has a duty ratio of more than 90 percent and the maximum forming size of more than 25 mm.

As a preferred technical scheme of the present invention, the preparation method further comprises: and (3) polishing and polishing the surface of the amorphous master alloy, and then carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy.

According to the invention, by carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere, zirconium nitride and titanium nitride can be introduced into the surface of the amorphous master alloy, and the surface hardness of the zirconium-based amorphous alloy can be further improved by introducing a composite phase of the zirconium nitride and the titanium nitride. In addition, laser is focused on the surface of the amorphous master alloy, so that the surface of the amorphous master alloy is remelted, and the surface roughness of the zirconium-based amorphous alloy is reduced. By changing the technological parameters of laser irradiation, the effective regulation and control of the content of the nitriding phase on the surface of the zirconium-based amorphous alloy can be realized, and further the regulation and control of the surface hardness and the surface roughness can be realized.

The laser irradiation has a laser emission power of 130 to 250W, for example, 130W, 140W, 150W, 160W, 170W, 180W, 190W, 200W, 210W, 220W, 230W, 240W or 250W, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

The spot diameter of the laser beam is 2 to 5mm, and may be, for example, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm or 5.0mm, but is not limited to the recited values, and other values not recited in the range of the values are equally applicable.

The scanning speed of the laser is 280-380mm/min, for example, 280mm/min, 290mm/min, 300mm/min, 310mm/min, 320mm/min, 330mm/min, 340mm/min, 350mm/min, 360mm/min, 370mm/min or 380mm/min, but the scanning speed is not limited to the recited values, and other non-recited values within the range of the values are equally applicable.

The invention particularly limits the laser scanning speed, when the laser scanning speed is within the range of 280-380mm/min, the solidification speed of a remelting pool is relatively high, and a large number of equiaxed dendrites with smaller size exist in a cladding layer formed on the surface of the zirconium-based amorphous alloy, so that the organization combination of the equiaxed dendrites is tight, and the improvement of the mechanical property of the zirconium-based amorphous alloy is facilitated. When the scanning speed is lower than 280mm/min, the laser energy density is too high, the size of a molten pool is increased, the solidification speed is reduced, and the grain growth is increased, so that the mechanical properties of the finally obtained zirconium-based amorphous alloy are affected.

As a preferable technical scheme of the invention, the laser emission power of the laser irradiation is 150-200W.

The scanning speed of the laser is 300-350mm/min.

In a second aspect, the present invention provides a bulk zirconium based amorphous alloy having high strength and high hardness, the bulk zirconium based amorphous alloy being prepared by the method of any one of claims 1 to 13, the bulk zirconium based amorphous alloy having the chemical formula Zr _a Cu _b Al _c Ni _d Ti _e M _f Wherein a, b, c, d, e and f are the atomic proportions of the corresponding components, wherein a is more than or equal to 50 and less than or equal to 55, b is more than or equal to 25 and less than or equal to 30, c is more than or equal to 8 and less than or equal to 20, d is more than or equal to 0.1 and less than or equal to 9,0.1 and less than or equal to 5, f is more than or equal to 0.1 and less than or equal to 5, and a+b+c+d+e+f is more than or equal to 100; m is rare earth element selected from one of Y, gd and Sc.

In a preferred embodiment of the present invention, the maximum forming size of the bulk zirconium based amorphous alloy is 25mm or more, for example, 25mm, 26mm, 27mm, 28mm, 29mm or 30mm, but the present invention is not limited to the above-mentioned values, and other values not shown in the above-mentioned value range are equally applicable.

The bulk zirconium based amorphous alloy has a hardness of 500HV or more, for example, 500HV, 510HV, 520HV, 530HV, 540HV, 550HV, 560HV, 570HV, 580HV, 590HV or 600HV, but is not limited to the recited values, and other non-recited values within the range are equally applicable.

The bulk zirconium-based amorphous alloy has a tensile strength of 2000MPa or more, for example, 2000MPa, 2100MPa, 2200MPa, 2300MPa, 2400MPa, 2500MPa, 2600MPa, 2700MPa, 2800MPa, 2900MPa, or 3000MPa, but the present invention is not limited to the above-mentioned values, and other values not mentioned in the above-mentioned value range are applicable.

Illustratively, the present invention provides a more preferred method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, comprising the steps of:

(1) Smelting: zirconium particles, copper blocks, high-purity aluminum particles, nickel particles, titanium particles and rare earth yttrium, gadolinium or scandium blocks are selected as raw materials, the purity of the raw materials is not lower than 99.9%, the raw materials are polished, and then ultrasonic cleaning is carried out by acetone or alcohol, wherein Zr is selected as alloy components _a Cu _b Al _c Ni _d Ti _e M _f The method comprises the following steps of weighing the mass of various metal raw materials in atomic percent, mixing the various metal raw materials, putting the mixture into a crucible, putting the crucible into a vacuum induction smelting furnace, filling protective gas into the vacuum induction smelting furnace, and vacuumizing the vacuum induction smelting furnace to 10 percent ^-3 -10 ^-1 Pa；

An induction coil is arranged around the periphery of the crucible, alternating current is introduced into the induction coil around the periphery of the crucible to generate an alternating magnetic field, metal raw materials in the crucible are heated and smelted to form a metal melt, and the metal melt is stirred through the alternating magnetic field;

A first ultrasonic amplitude transformer is arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the position below the liquid level of the metal melt in the crucible, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, and the first ultrasonic generator applies ultrasonic waves to the metal melt through the first ultrasonic amplitude transformer;

the heating smelting process is divided into three stages, including a first smelting, a second smelting and a third smelting, which are sequentially performed:

the temperature of the first smelting is 550-600 ℃, and the heating time of the first smelting is 5-10s;

the temperature of the second smelting is 1500-1600 ℃, and the heating time of the second smelting is 10-20s;

the temperature of the third smelting is 1800-1900 ℃, and the heating time of the third smelting is 10-15s;

an aeration pipeline is arranged at the bottom layer in the crucible, and 2.5-3.5L/min of argon is introduced into the metal melt through the aeration pipeline in the second smelting stage;

in the third smelting stage, the first ultrasonic generator applies ultrasonic with the frequency of 50-60kHz to the metal melt through the first ultrasonic amplitude transformer, and the output power of the first ultrasonic generator is 2.5-3kW;

(2) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt formed in the step (1) into the mold cavity at a speed of 4-5m/s, wherein the injection pressure of the metal melt is 80-110MPa, and maintaining the pressure of the mold cavity for 10-15s after the metal melt is completely filled in the mold cavity;

Subsequently stage cooling the crucible, including sequentially performing a first cooling and a second cooling; wherein the first cooling is performed under a protective atmosphere and a negative pressure environment, and the negative pressure environment of the first cooling is 10 ^-2 -10Pa, the cooling rate of the first cooling is 50-80K/s, and the metal melt is cooled to 200-250 ℃ after the first cooling; the second cooling is carried out in an air atmosphere and an atmospheric pressure environment, and the cooling rate of the second cooling is 100-150K/s; after cooling, the metal melt is completely solidified to form an amorphous master alloy;

in the process from the pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic with the frequency of 1.4-1.5kHz to the metal melt in the die cavity through the second ultrasonic amplitude transformer, wherein the single ultrasonic time is 5-8s, and the interval time between two adjacent ultrasonic times is 10-12s;

(3) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (2), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy; wherein, the emission power of the laser is 150-200W, the spot diameter of the laser is 2-5mm, and the scanning speed of the laser is 300-350mm/min.

Compared with the prior art, the invention has the beneficial effects that:

Oxygen in zirconium-based amorphous alloys in the form of ZrO ₂ In the form of a nucleation core or cluster, oxygen becomes more stable in the form of scandium (Sc) after scandium (Sc) is added to the zirconium-based amorphous alloy ₂ O ₃ Exists in addition to Sc ₂ O ₃ And the zirconium-based amorphous alloy is not a core of heterogeneous nucleation. By adding scandium, the stability of amorphous alloy in supercooled liquid region is improved to prevent transformation to crystal, the glass forming ability of zirconium-based amorphous alloy is improved, and appropriate amount of scandium is addedScandium can significantly increase the maximum amorphous formation size of amorphous alloys.

Drawings

FIG. 1 is an X-ray diffraction chart of the zirconium based amorphous alloys prepared in example 21, example 22 and example 23;

FIG. 2 is a compressed fracture electron micrograph of the zirconium based amorphous alloy prepared in example 21 at room temperature;

FIG. 3 is a compressed fracture electron micrograph of the zirconium based amorphous alloy prepared in example 22 at room temperature;

fig. 4 is a compressed fracture electron microscope photograph of the zirconium-based amorphous alloy prepared in example 23 at room temperature.

Detailed Description

The technical scheme of the application is described in detail below with reference to specific embodiments and attached drawings. The examples described herein are specific embodiments of the present application for illustrating the concept of the present application; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the application in its aspects. In addition to the embodiments described herein, those skilled in the art can adopt other obvious solutions based on the disclosure of the claims and the specification thereof, including those adopting any obvious substitutions and modifications to the embodiments described herein.

Example 1

The embodiment provides a preparation method of a bulk zirconium-based amorphous alloy with high strength and high hardness, which specifically comprises the following steps:

(1) And (3) batching: zirconium particles, copper blocks, high-purity aluminum particles, nickel particles and yttrium blocks are selected as raw materials, the purity of the metal raw materials is not lower than 99.9%, the metal raw materials are polished, ultrasonic cleaning is carried out by acetone or alcohol, and Zr is selected as alloy components ₅₀ Cu ₂₅ Al ₁₅ Ni ₉ Ti _0.1 Y _0.9 Weighing the mass of each metal raw material in atomic percent, mixing each metal raw material and then placing the mixture into a crucible;

(2) Smelting: placing the crucible into a vacuum induction melting furnace, filling argon into the vacuum induction melting furnace, and vacuumizing the vacuum induction melting furnace to 10 ^-3 Pa；

The periphery of the crucible is provided with an induction coil in a surrounding way, alternating current is introduced into the induction coil at the periphery of the crucible to generate an alternating magnetic field, and the mode of smelting the metal raw materials in the crucible is as follows: heating to 1800 ℃ at one time, smelting a metal raw material to form a metal melt, and stirring the metal melt through an alternating magnetic field;

(3) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt in the step (2) into the mold cavity through high pressure, maintaining the pressure of the mold cavity after the metal melt is completely filled in the mold cavity, and naturally cooling the mold to room temperature after maintaining the pressure for a period of time until the metal melt is solidified to obtain amorphous master alloy;

the injection speed of the metal melt is 4m/s, the injection pressure of the metal melt is 80MPa, and the pressure maintaining time of the die cavity is 10s; a second ultrasonic amplitude transformer is arranged in the die cavity, one end of the second ultrasonic amplitude transformer is abutted with the outer wall of the die, and the other end Yu Dier ultrasonic generator is connected; in the process from the beginning of pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through the second ultrasonic amplitude transformer; the ultrasonic frequency generated by the second ultrasonic generator is 1.4kHz, the single ultrasonic time is 5s, and the interval time between two adjacent ultrasonic waves is 12s;

(4) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (3), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy; the laser has the emission power of 130W, the spot diameter of the laser is 3mm, and the scanning speed of the laser is 290mm/min.

The chemical general formula of the prepared bulk zirconium-based amorphous alloy is Zr after measurement ₅₀ Cu ₂₅ Al ₁₅ Ni ₉ Ti _0.1 Y _0.9 Specific parameters of the maximum forming size, hardness and tensile strength are shown in Table 1.

Example 2

(1) And (3) batching: as in example 1;

(2) Smelting: basically, the embodiment 1 is different in that the mode of melting the metal raw material, specifically, the process of heating and melting the metal raw material in the crucible is divided into three stages, including a first melting, a second melting and a third melting, which are sequentially performed, specifically, as follows:

the temperature of the first smelting is 550 ℃, and the heating time of the first smelting is 10s;

the temperature of the second smelting is 1500 ℃, and the heating time of the second smelting is 20s;

The temperature of the third smelting is 1800 ℃, and the heating time of the third smelting is 15s;

(3) And (3) die casting: as in example 1;

(4) And (3) irradiation: as in example 1.

The chemical general formula of the prepared bulk zirconium-based amorphous alloy is Zr after measurement ₅₀ Cu ₂₅ Al ₁₅ Ni ₉ Ti _0.1 Y _0.9 The maximum forming size, hardness and specific parameters of tensile strength of the prepared bulk zirconium-based amorphous alloy are shown in Table 1.

Example 3

(1) And (3) batching: as in example 1;

(2) Smelting: basically the same as the embodiment 1, the difference is that a first ultrasonic amplitude transformer is also arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the crucible below the liquid level of the metal melt, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, when the smelting temperature reaches 1800 ℃, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer, wherein the output power of the first ultrasonic generator is 2.5kW, and the generated ultrasonic frequency is 60kHz;

(3) And (3) die casting: as in example 1;

(4) And (3) irradiation: as in example 1.

Example 4

(1) And (3) batching: same as in example 2;

(2) Smelting: basically the same as the embodiment 2, the difference is that a first ultrasonic amplitude transformer is also arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the crucible below the liquid level of the metal melt, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, in the third smelting stage, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer, wherein the output power of the first ultrasonic generator is 2.5kW, and the generated ultrasonic frequency is 60kHz;

(3) And (3) die casting: same as in example 2;

(4) And (3) irradiation: as in example 2.

Example 5

(1) And (3) batching: same as in example 4;

(2) Smelting: basically the same as in example 4, except that an aeration line is further provided at the inner bottom layer of the crucible, and in the second smelting stage, a shielding gas is introduced into the metal melt through the aeration line, wherein the introduction amount of the shielding gas is 2.5L/min;

(3) And (3) die casting: same as in example 4;

(4) And (3) irradiation: same as in example 4.

Example 6

(1) And (3) batching: zirconium particles, copper blocks, high-purity aluminum particles, nickel particles and yttrium blocks are selected as raw materials, the purity of the metal raw materials is not lower than 99.9%, the metal raw materials are polished, ultrasonic cleaning is carried out by acetone or alcohol, and Zr is selected as alloy components ₅₀ Cu ₂₅ Al ₂₀ Ni _0.1 Ti _4.8 Gd _0.1 Weighing the mass of each metal raw material in atomic percent, mixing each metal raw material and then placing the mixture into a crucible;

(2) Smelting: placing the crucible into a vacuum induction melting furnace, filling argon into the vacuum induction melting furnace, and vacuumizing the vacuum induction melting furnace to 10 ^-2 Pa；

The periphery of the crucible is provided with an induction coil in a surrounding way, alternating current is introduced into the induction coil at the periphery of the crucible to generate an alternating magnetic field, and the mode of smelting the metal raw materials in the crucible is as follows: heating to 1850 ℃ at one time, smelting a metal raw material to form a metal melt, and stirring the metal melt through an alternating magnetic field;

(3) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt in the step (2) into the mold cavity through high pressure, maintaining the pressure of the mold cavity after the metal melt is completely filled in the mold cavity, and cooling the mold in sections until the metal melt is solidified after the pressure is maintained for a period of time to obtain amorphous master alloy;

the injection speed of the metal melt is 5m/s, the injection pressure of the metal melt is 100MPa, and the pressure maintaining time of the die cavity is 15s; one end of the second ultrasonic amplitude transformer is arranged in the die cavity and is abutted with the outer wall of the die, and the other end Yu Dier ultrasonic generator is connected; in the process from the beginning of pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through the second ultrasonic amplitude transformer; the ultrasonic frequency generated by the second ultrasonic generator is 1.4kHz, the single ultrasonic time is 7s, and the interval time between two adjacent ultrasonic waves is 12s;

The staged cooling comprises a first cooling and a second cooling which are sequentially carried out; wherein the first cooling is performed under an argon atmosphere and a negative pressure environment, and the second cooling is performed under an air atmosphere and a normal pressure environment; the negative pressure environment of the first cooling is 10Pa, the cooling rate is 80K/s, and the amorphous master alloy is cooled to 250 ℃ after the first cooling; the cooling rate of the second cooling is 150K/s;

(4) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (3), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy; the laser has the emission power of 150W, the spot diameter of 2mm and the scanning speed of 300mm/min.

The chemical general formula of the prepared bulk zirconium-based amorphous alloy is Zr after measurement ₅₀ Cu ₂₅ Al ₂₀ Ni _0.1 Ti _4.8 Gd _0.1 The maximum forming size, hardness and specific parameters of tensile strength of the prepared bulk zirconium-based amorphous alloy are shown in Table 1.

Example 7

(1) And (3) batching: same as in example 6;

(2) Smelting: basically, the same manner as in example 6 is different in that the manner of melting the metal raw material, specifically, the process of heating and melting the metal raw material in the crucible is divided into three stages including the first melting, the second melting and the third melting which are sequentially performed, specifically, as follows:

the temperature of the first smelting is 560 ℃, and the heating time of the first smelting is 5s;

the temperature of the second smelting is 1530 ℃, and the heating time of the second smelting is 10s;

the temperature of the third smelting is 1850 ℃, and the heating time of the third smelting is 13s;

(3) And (3) die casting: same as in example 6;

(4) And (3) irradiation: same as in example 6.

Example 8

(1) And (3) batching: same as in example 6;

(2) Smelting: basically the same as the embodiment 6, the difference is that a first ultrasonic amplitude transformer is also arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the crucible below the liquid level of the metal melt, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, when the smelting temperature reaches 1800 ℃, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 55kHz;

(3) And (3) die casting: same as in example 6;

(4) And (3) irradiation: same as in example 6.

Example 9

(1) And (3) batching: same as in example 7;

(2) Smelting: basically the same as in example 7, the difference is that a first ultrasonic horn is also provided in the crucible, one end of the first ultrasonic horn extends below the liquid level of the metal melt in the crucible, the other end is connected with a first ultrasonic generator, in the third smelting stage, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic horn, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 55kHz;

(3) And (3) die casting: same as in example 7;

(4) And (3) irradiation: same as in example 7.

Example 10

(1) And (3) batching: same as in example 9;

(2) Smelting: basically the same as in example 9, except that an aeration line is further provided at the inner bottom layer of the crucible, and in the second smelting stage, a shielding gas is introduced into the metal melt through the aeration line, wherein the introduction amount of the shielding gas is 3.5L/min;

(3) And (3) die casting: same as in example 9;

(4) And (3) irradiation: same as in example 9.

Example 11

(1) And (3) batching: zirconium particles, copper blocks, high-purity aluminum particles, nickel particles and scandium blocks are selected as raw materials, the purity of the metal raw materials is not lower than 99.9 percent, the metal raw materials are ultrasonically cleaned by acetone or alcohol after oxide skin is polished, and Zr is selected as alloy components ₅₄ Cu ₂₆ Al ₈ Ni ₂ Ti ₅ Sc ₅ Weighing the mass of each metal raw material in atomic percent, mixing each metal raw material and then placing the mixture into a crucible;

(2) Smelting: placing the crucible into a vacuum induction melting furnace, filling argon into the vacuum induction melting furnace, and vacuumizing the vacuum induction melting furnace to 10 ^-1 Pa；

The periphery of the crucible is provided with an induction coil in a surrounding way, alternating current is introduced into the induction coil at the periphery of the crucible to generate an alternating magnetic field, and the mode of smelting the metal raw materials in the crucible is as follows: heating to 1900 ℃ at one time, smelting a metal raw material to form a metal melt, and stirring the metal melt through an alternating magnetic field;

(3) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt into the mold cavity by high pressure, maintaining the pressure of the mold cavity after the metal melt is completely filled in the mold cavity, and cooling the mold in stages after maintaining the pressure for a period of time until the metal melt is solidified to obtain the amorphous master alloy;

the injection speed of the metal melt is 4.5m/s, the injection pressure is 110MPa, and the pressure maintaining time of the die cavity is 12s; a second ultrasonic amplitude transformer is arranged in the die cavity, one end of the second ultrasonic amplitude transformer is abutted with the outer wall of the die, and the other end of the second ultrasonic amplitude transformer is connected with a second ultrasonic generator; in the process from the beginning of pressure maintaining of the die cavity to the complete solidification of the metal melt, a second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through a second ultrasonic amplitude transformer; the ultrasonic frequency generated by the second ultrasonic generator is 1.5kHz, the single ultrasonic time is 5s, and the interval time between two adjacent ultrasonic waves is 10s;

The staged cooling comprises a first cooling and a second cooling which are sequentially carried out; wherein the first cooling is performed under an argon atmosphere and a negative pressure environment, and the second cooling is performed under an air atmosphere and a normal pressure environment; the negative pressure environment of the first cooling is 10 ^-1 Pa, cooling rate is 70K/s, and cooling the amorphous master alloy to 230 ℃ after first cooling; the cooling rate of the second cooling is 120K/s;

(4) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (3), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain a large block of zirconium-based amorphous alloy with high strength and high hardness; the laser has the emission power of 220W, the spot diameter of 2mm and the scanning speed of 380mm/min.

The chemical general formula of the prepared bulk zirconium-based amorphous alloy is Zr after measurement ₅₄ Cu ₂₆ Al ₈ Ni ₂ Ti ₅ Sc _5， The maximum forming size, hardness and specific parameters of tensile strength of the prepared bulk zirconium-based amorphous alloy are shown in Table 1.

Example 12

(1) And (3) batching: same as in example 11;

(2) Smelting: basically, the same manner as in example 11 is different in that the manner of melting the metal raw material, specifically, the process of heating and melting the metal raw material in the crucible is divided into three stages including the first melting, the second melting and the third melting which are sequentially performed, specifically, as follows:

the temperature of the first smelting is 600 ℃, and the heating time of the first smelting is 8s;

the temperature of the second smelting is 1600 ℃, and the heating time of the second smelting is 15s;

the temperature of the third smelting is 1900 ℃, and the heating time of the third smelting is 10s;

(3) And (3) die casting: same as in example 11;

(4) And (3) irradiation: same as in example 11.

Example 13

(1) And (3) batching: same as in example 11;

(2) Smelting: basically the same as the embodiment 11, the difference is that a first ultrasonic amplitude transformer is also arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the crucible below the liquid level of the metal melt, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, when the smelting temperature reaches 1900 ℃, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 60kHz;

(3) And (3) die casting: same as in example 11;

(4) And (3) irradiation: same as in example 11.

Example 14

(1) And (3) batching: same as in example 12;

(2) Smelting: basically the same as in example 12, the difference is that a first ultrasonic horn is also provided in the crucible, one end of the first ultrasonic horn extends below the liquid level of the metal melt in the crucible, the other end is connected with a first ultrasonic generator, in the third smelting stage, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic horn, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 60kHz;

(3) And (3) die casting: same as in example 12;

(4) And (3) irradiation: same as in example 12.

Example 15

(1) And (3) batching: same as in example 14;

(2) Smelting: basically the same as in example 14, except that an aeration line is further provided at the inner bottom layer of the crucible, argon gas is introduced into the metal melt through the aeration line in the second melting stage, wherein the introduction amount of the argon gas is 3.0L/min;

(3) And (3) die casting: same as in example 14;

(4) And (3) irradiation: same as in example 14.

The chemical general formula of the prepared bulk zirconium-based amorphous alloy is Zr after measurement ₅₄ Cu ₂₆ Al ₈ Ni ₂ Ti ₅ Sc ₅ The maximum forming size, hardness and specific parameters of tensile strength of the prepared bulk zirconium-based amorphous alloy are shown in Table 1.

Example 16

The periphery of the crucible is provided with an induction coil in a surrounding way, alternating current is introduced into the induction coil at the periphery of the crucible to generate an alternating magnetic field, and the mode of smelting the metal raw materials in the crucible is as follows: heating to 1840 ℃ at one time, smelting a metal raw material to form a metal melt, and stirring the metal melt through an alternating magnetic field;

(3) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt into the mold cavity by high pressure, maintaining the pressure of the mold cavity after the metal melt is completely filled in the mold cavity, and naturally cooling the mold after maintaining the pressure for a period of time until the metal melt is solidified to obtain the amorphous master alloy;

the injection speed of the metal melt is 4m/s, the injection pressure is 110MPa, and the pressure maintaining time of the die cavity is 10s; a second ultrasonic amplitude transformer is arranged in the die cavity, one end of the second ultrasonic amplitude transformer is abutted with the outer wall of the die, and the other end of the second ultrasonic amplitude transformer is connected with a second ultrasonic generator; in the process from the beginning of pressure maintaining of the die cavity to the complete solidification of the metal melt, a second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through a second ultrasonic amplitude transformer; the ultrasonic frequency generated by the second ultrasonic generator is 1.42kHz, the single ultrasonic time is 6s, and the interval time between two adjacent ultrasonic waves is 10s;

(4) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (3), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain a large block of zirconium-based amorphous alloy with high strength and high hardness; the laser has the emission power of 160W, the spot diameter of 3mm and the scanning speed of 300mm/min.

Example 17

(1) And (3) batching: same as in example 16;

(2) Smelting: basically, the same manner as in example 16 is different in that the manner of melting the metal raw material, specifically, the process of heating and melting the metal raw material in the crucible is divided into three stages including sequentially performing the first melting, the second melting and the third melting, specifically, as follows:

the temperature of the first smelting is 600 ℃, and the heating time of the first smelting is 5s;

(3) And (3) die casting: same as in example 16;

(4) And (3) irradiation: same as in example 16.

Example 18

(1) And (3) batching: same as in example 16;

(2) Smelting: basically the same as the embodiment 16, the difference is that a first ultrasonic amplitude transformer is also arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the crucible below the liquid level of the metal melt, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, when the smelting temperature reaches 1800 ℃, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 50kHz;

(3) And (3) die casting: same as in example 16;

(4) And (3) irradiation: same as in example 16.

Example 19

(1) And (3) batching: same as in example 17;

(2) Smelting: basically the same as in example 17, the difference is that a first ultrasonic horn is also provided in the crucible, one end of the first ultrasonic horn extends below the liquid level of the metal melt in the crucible, the other end is connected with a first ultrasonic generator, in a third smelting stage, the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic horn, wherein the output power of the first ultrasonic generator is 3kW, and the generated ultrasonic frequency is 50kHz;

(3) And (3) die casting: same as in example 17;

(4) And (3) irradiation: same as in example 17.

Example 20

(1) And (3) batching: same as in example 19;

(2) Smelting: basically the same as in example 19, except that an aeration line is further provided at the inner bottom layer of the crucible, argon gas is introduced into the metal melt through the aeration line in the second melting stage, wherein the introduction amount of the argon gas is 3.5L/min;

(3) And (3) die casting: same as in example 19;

(4) And (3) irradiation: same as in example 19.

Example 21

(1) And (3) batching: zirconium particles, copper blocks, high-purity aluminum particles, nickel particles and yttrium blocks are selected as raw materials, the purity of the metal raw materials is not lower than 99.9%, the metal raw materials are polished, ultrasonic cleaning is carried out by acetone or alcohol, and Zr is selected as alloy components ₅₀ Cu ₂₅ Al ₁₅ Ni ₉ Ti _0.1 Y _0.9 The mass of each metal raw material is weighed, each metal raw material is mixed and then is put into a crucible,

(2) Smelting: placing the crucible into a vacuum induction melting furnace, filling argon into the vacuum melting furnace, and vacuumizing the vacuum induction melting furnace to 10 ^-3 Pa；

Introducing alternating current into an induction coil at the periphery of the crucible to generate an alternating magnetic field, heating and smelting metal raw materials in the crucible to form a metal melt, and stirring the metal melt through the alternating magnetic field;

in the second smelting stage, 2.5L/min of argon is introduced into the metal melt through an aeration pipeline;

in the third smelting stage, the first ultrasonic generator applies ultrasonic with the frequency of 50kHz to the metal melt through the first ultrasonic amplitude transformer, and the output power of the first ultrasonic generator is 2.5kW;

(3) And (3) die casting: coating lubricant on the inner surface of the mold cavity, injecting the metal melt formed in the step (1) into the mold cavity at a speed of 4m/s, wherein the injection pressure of the metal melt is 80MPa, and maintaining the pressure of the mold cavity for 15s after the metal melt completely fills the mold cavity;

Subsequently stage cooling the crucible, including sequentially performing a first cooling and a second cooling; wherein the first cooling is performed under argon atmosphere and under negative pressure, and the negative pressure of the first cooling is 10 ^-2 Pa, the cooling rate of the first cooling is 50K/s, and the metal melt is cooled to 200 ℃ after the first cooling; the second cooling is carried out under the air atmosphere and the normal pressure environment, and the cooling rate of the second cooling is 100K/s; after cooling, the metal melt is completely solidified to form an amorphous master alloy;

in the process from the beginning of pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic with the frequency of 1.4kHz to the metal melt in the die cavity through the second ultrasonic amplitude transformer, wherein the single ultrasonic time is 8s, and the interval time between two adjacent ultrasonic times is 12s;

(4) And (3) irradiation: polishing and polishing the surface of the amorphous master alloy obtained in the step (2), and carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy; the laser has the emission power of 150W, the spot diameter of 2mm and the scanning speed of 350mm/min.

Example 22

The present embodiment provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from embodiment 21 in that the laser power employed in step (4) is adjusted to 130W, and other process parameters and operation steps are exactly the same as those of embodiment 21.

Example 23

The present example provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from example 21 in that the laser power employed in step (4) is adjusted to 250W, and other process parameters and operation steps are exactly the same as example 21.

Example 24

The present example provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from example 21 in that the laser scanning speed employed in step (4) is adjusted to 280mm/min, and other process parameters and operation steps are identical to those of example 21.

Example 25

The present example provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from example 21 in that the laser scanning speed employed in step (4) is adjusted to 380mm/min, and other process parameters and operation steps are identical to those of example 21.

Example 26

The present embodiment provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from embodiment 21 in that the cooling process in step (3) includes only one stage, i.e., the second cooling, the first cooling is not performed, and other process parameters and operation steps are exactly the same as those of embodiment 21.

Example 27

The present embodiment provides a method for preparing a bulk zirconium based amorphous alloy having high strength and high hardness, which is different from embodiment 21 in that the application of ultrasound to the metal melt during the die casting process of step (3) is omitted, and other process parameters and operation steps are exactly the same as those of embodiment 21.

The alloy materials prepared in example 21, example 22 and example 23 were scanned using an X-ray diffractometer (XRD). An X-ray diffractometer (XRD) is a material analysis instrument that analyzes a crystal structure, a lattice constant, crystal defects, and internal stress of a material using a diffraction phenomenon of X-rays in a crystal. The X-ray diffraction spectrum of crystalline alloys is generally sharp diffraction peaks of varying intensities, whereas the diffraction curve of a typical amorphous phase is an amorphous diffuse scattering peak that is dispersed at a specific angle.

The specific detection process comprises the following steps: the alloy samples prepared in example 21, example 22 and example 23 were cut into lmm thick sheets on a diamond microtome, the surfaces were sanded and leveled, then were ultrasonically cleaned, the crystal orientation structure was scanned using a DMAX-2400X-ray diffractometer, and a Cu target was used for scanning, K.alpha. radiation was used for scanning, the scanning angle was 20-80 °, the scanning speed was 4 °/min, the step size was 0.02 °, the operating voltage and operating current were 40kV and 120mA, respectively, and the X-ray diffraction pattern as shown in FIG. 1 was obtained by XRD scanning.

As can be seen from the X-ray diffraction pattern shown in FIG. 1, no obvious crystallization peak appears in the X-ray pattern of the zirconium-based amorphous alloy prepared in example 21, indicating that the zirconium-based amorphous alloy prepared in example 21 is of a completely amorphous structure. The size of a molten pool formed on the surface of the zirconium-based amorphous alloy is increased in a reasonable laser energy density range, and the remelting temperature gradually enters a liquid phase region in the irradiation process, so that a short-range ordered structure of heterogeneous nuclei can be promoted to be melted, and the amorphous forming capability of the zirconium-based amorphous alloy is improved.

In the X-ray diffraction patterns of example 22 and example 23, the alloy samples showed dispersed amorphous diffuse scattering peaks between 30 and 50 degrees, indicating the crystal structures in the alloy materials prepared in example 22 and example 23. Wherein diffraction peaks corresponding to sharp crystalline phases appear in diffuse scattering peaks of the alloy material prepared in example 22 are calibrated as CuZr ₂ Crystalline phase, niZr ₂ A crystal phase and an AlZr crystal phase, which indicates that a large number of crystals are present in the zirconium-based amorphous alloy prepared in example 22. The diffuse scattering peak of the alloy material prepared in example 23 shows a small amount of sharp crystal diffraction peak, which is marked as CuZr ₂ A crystal phase and an AlZr crystal phase, which indicates that a small amount of crystals appear in the zirconium-based amorphous alloy prepared in example 23.

The mechanical property of the amorphous alloy is one of important performance indexes in engineering application, and the mechanical property of the amorphous alloy is characterized by adopting an axial compression experiment.

The specific test process comprises the following steps: the two end surfaces of the alloy samples prepared in example 21, example 22 and example 23 are sanded to ensure that the two end surfaces are parallel to each other, the polished alloy samples are placed on a pressurizing platform of a universal mechanical testing machine, axial pressure is applied to the end surfaces of the samples until the alloy samples are broken, static loading load is set to 1000N, and electron microscope scanning is performed on the fracture of the joint Jin Shiyang, so that electron microscope photographs shown in fig. 2, 3 and 4 are obtained.

Fig. 2 is an electron microscope photograph of the alloy sample prepared in example 21, it can be seen from fig. 2 that the fracture of the alloy sample is river-shaped, a vein-shaped shear band appears, the vein is a typical morphology of an amorphous alloy, the density and the softness of the vein directly reflect the strength and the plasticity of the alloy material, and the denser the vein, the stronger the mechanical property of the whole alloy material, so that as can be seen from fig. 2, the alloy sample prepared in example 21 has higher strength and plasticity.

Fig. 3 is an electron micrograph of the alloy sample prepared in example 22, and it can be seen from fig. 3 that most of the regions in the figure are distributed with scattered fine venation lines, and ridge-shaped lamellar regions which are broken along the expansion of the main shear band appear, and the characteristics of cleavage and breaking in crystalline materials are presented, which indicate that the alloy sample has a crystal orientation structure at this time, and the strength and plasticity of the alloy sample at this time are lower.

Fig. 4 is an electron micrograph of the alloy sample prepared in example 23, and it can be seen from fig. 4 that the fracture morphology in the drawing is relatively flat, and is a typical brittle fracture, and the strength and plasticity of the alloy sample are the lowest.

The maximum forming size, hardness and tensile strength of the zirconium based amorphous alloys prepared in examples 1 to 27 were measured and the test results are shown in table 1.

TABLE 1

As can be seen from the test data provided in Table 1, the maximum forming dimensions of the alloy samples prepared in examples 1 to 27 are not less than 25mm, the hardness is not less than 500HV, and the tensile strength is not less than 2000MPa.

Examples 1-5 it can be seen from a comparison that example 2 adds staged smelting based on example 1, example 3 adds sonication to the smelting process based on example 1, example 4 adds sonication to the third smelting stage based on example 2, and example 5 adds aeration to the second smelting stage based on example 4.

From the test data provided in examples 1-5, it can be seen that the hardness and tensile strength of the alloy samples prepared in example 2 are higher than those of example 1, the hardness and tensile strength of the alloy samples prepared in example 4 are higher than those of example 2, and the hardness and tensile strength of the alloy samples prepared in example 5 are higher than those of example 3. It can be found that the hardness and tensile strength of the alloy sample can be improved by staged smelting, because the oxygen content in the metal melt can be further reduced by staged smelting, and the metastable atomic clusters and the existence of high Wen Cancun phase are reduced, thereby being beneficial to improving the mechanical properties of the amorphous alloy.

Further, the combination of staged melting and ultrasonic treatment can further improve the hardness and tensile strength of the alloy sample, because the ultrasonic waves are introduced into the metal melt in the crucible through the first ultrasonic amplitude transformer, the generation of heterogeneous nuclei can be effectively inhibited, and the components of the alloy during melting are more uniform.

Furthermore, the hardness and the tensile strength of the alloy sample can be further improved by combining staged smelting, ultrasonic treatment and aeration treatment, and the method is beneficial to reducing the oxygen content in the metal melt because the oxide in the metal melt can be helped to float out quickly by introducing argon into the melt.

As can be seen from the test data of examples 21, 22 and 23, the hardness and tensile strength of the alloy samples prepared in examples 22 and 23 are smaller than those of example 21, and as can be seen by combining the XRD patterns provided in fig. 1, the laser power used in example 22 is too low, resulting in the alloy still containing a large number of crystal crystals, while the laser power in example 23 is too high, and there are still a small number of crystals in the alloy, thereby resulting in insufficient improvement of the mechanical properties of the alloy material.

From the test data of example 21, example 24 and example 25, it can be seen that the hardness and tensile strength of the alloy samples prepared in example 24 and example 25 are smaller than those of example 21, which indicates that the laser scanning speed also affects the hardness and tensile strength of the alloy material, and that too high or too low laser power can lead to a decrease in mechanical properties of the alloy material.

As can be seen from the test data of examples 21 and 26, the hardness and tensile strength of the alloy samples prepared in example 26 are smaller than those of example 21, because the nucleation process of the metal melt is completely inhibited by using staged cooling in example 21, so that the zirconium-based amorphous alloy is obtained by uniformly and continuously solidifying into solid, the amorphous phase accounts for more than 90%, and the mechanical properties of the amorphous alloy are improved.

From the test data of example 21 and example 27, it can be seen that the hardness and tensile strength of the alloy samples prepared in example 27 are smaller than those of example 21, because the ultrasonic wave is applied to the metal melt during the die casting cooling process in step (3) of example 21, so that the metal melt obtains better micro-forming filling effect, and the metal melt is also facilitated to generate more free volume, and is further facilitated to obtain the zirconium-based amorphous alloy with high mechanical properties.

The applicant declares that the above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be apparent to those skilled in the art that any changes or substitutions that are easily conceivable within the technical scope of the present invention disclosed by the present invention fall within the scope of the present invention and the disclosure.

Claims

1. A method for preparing a bulk zirconium-based amorphous alloy having high strength and high hardness, the method comprising:

The chemical general formula of the bulk zirconium-based amorphous alloy is Zr _a Cu _b Al _c Ni _d Ti _e M _f Wherein a, b, c, d, e and f are the atomic proportions of the corresponding components, a is more than or equal to 50 and less than or equal to 55, b is more than or equal to 25 and less than or equal to 30, c is more than or equal to 8 and less than or equal to 20, d is more than or equal to 0.1 and less than or equal to 9,0.1 and less than or equal to 5, f is more than or equal to 0.1 and less than or equal to 5, and a+b+c+d+e+f is more than or equal to 100; m is a rare earth element selected from any one or a combination of at least two of Y, gd and Sc;

the smelting process is carried out in a vacuum induction smelting furnace, protective gas is filled into the vacuum induction smelting furnace, a crucible is placed in the vacuum induction smelting furnace, the metal raw material is placed in the crucible, an induction coil is circumferentially arranged on the periphery of the crucible, and alternating current is introduced into the induction coil to generate an alternating magnetic field;

the vacuum degree in the vacuum induction melting furnace is 10 ^-3 -10 ^-1 Pa；

A first ultrasonic amplitude transformer is further arranged in the crucible, one end of the first ultrasonic amplitude transformer stretches into the position below the liquid level of the metal melt in the crucible, the other end of the first ultrasonic amplitude transformer is connected with a first ultrasonic generator, and the first ultrasonic generator applies ultrasonic I to the metal melt through the first ultrasonic amplitude transformer;

the output power of the first ultrasonic generator is 2.5-3kW, and the generated ultrasonic frequency is 50-60kHz;

Applying ultrasound I to the metal melt by the first ultrasonic horn when the melting temperature reaches a range of 1800-1900 ℃;

the die casting process includes:

coating lubricant on the inner surface of the mold cavity, injecting the metal melt into the mold cavity by high pressure, maintaining the pressure of the mold cavity after the metal melt is completely filled in the mold cavity, and cooling the mold after maintaining the pressure for a period of time until the metal melt is solidified to obtain the amorphous master alloy;

the injection speed of the metal melt is 4-5m/s, the injection pressure of the metal melt is 80-110MPa, and the pressure maintaining time of the die cavity is 10-15s;

a second ultrasonic amplitude transformer is arranged in the die cavity, one end of the second ultrasonic amplitude transformer is abutted with the outer wall of the die, and the other end of the second ultrasonic amplitude transformer is connected with a second ultrasonic generator;

in the process from the pressure maintaining of the die cavity to the complete solidification of the metal melt, the second ultrasonic generator intermittently applies ultrasonic II to the metal melt in the die cavity through the second ultrasonic amplitude transformer;

the ultrasonic frequency generated by the second ultrasonic generator is 1.4-1.5kHz, the single ultrasonic time is 5-8s, and the interval time between two adjacent ultrasonic waves is 10-12s; the cooling is divided into two stages, including a first cooling and a second cooling which are sequentially carried out; wherein the first cooling is performed under a protective atmosphere and a negative pressure environment, and the second cooling is performed under an air atmosphere and a normal pressure environment;

The negative pressure environment of the first cooling is 10 ^-2 -10Pa, wherein the cooling rate of the first cooling is 50-80K/s, and the amorphous master alloy is cooled to 200-250 ℃ after the first cooling;

the cooling rate of the second cooling is 100-150K/s;

the preparation method further comprises the following steps: polishing and polishing the surface of the amorphous master alloy, and then carrying out laser irradiation on the surface of the amorphous master alloy in a nitrogen atmosphere to obtain the bulk zirconium-based amorphous alloy;

the laser emission power of the laser irradiation is 130-250W;

the diameter of the light spot of the laser is 2-5mm;

the scanning speed of the laser is 280-380mm/min.

2. The method of claim 1, wherein the smelting process involves heating the temperature in the vacuum induction melting furnace to a temperature in the range of 1800-1900 ℃ at one time.

3. The method of claim 1, wherein the smelting process is divided into three stages, including a first smelting, a second smelting, and a third smelting, which are sequentially performed;

The temperature of the third smelting is 1800-1900 ℃, and the heating time of the third smelting is 10-15s.

4. The method of producing according to claim 3 wherein in the third melting stage, the first ultrasonic generator applies ultrasonic waves i to the metal melt through the first ultrasonic horn.

5. The production method according to claim 3, wherein an aeration line is further provided at an inner bottom layer of the crucible, and a shielding gas is introduced into the metal melt through the aeration line in the second melting stage;

the ventilation amount of the protective gas is 2.5-3.5L/min.

6. The method according to claim 1, wherein the cooling means naturally cooling the die-cast molding to room temperature under an air atmosphere and an atmospheric pressure environment to obtain the amorphous master alloy.

7. The method according to claim 1, wherein the laser irradiation has a laser emission power of 150 to 200W;

the scanning speed of the laser is 300-350mm/min.

8. A bulk zirconium-based amorphous alloy with high strength and high hardness, which is characterized in that the bulk zirconium-based amorphous alloy is prepared by the preparation method of any one of claims 1 to 7, and the chemical formula of the bulk zirconium-based amorphous alloy is Zr _a Cu _b Al _c Ni _d Ti _e M _f Wherein a, b, c, d, e and f are the atomic proportions of the corresponding components, wherein a is more than or equal to 50 and less than or equal to 55, b is more than or equal to 25 and less than or equal to 30, c is more than or equal to 8 and less than or equal to 20, d is more than or equal to 0.1 and less than or equal to 9,0.1 and less than or equal to 5, f is more than or equal to 0.1 and less than or equal to 5, and a+b+c+d+e+f is more than or equal to 100; m is rare earth element selected from one of Y, gd and Sc.

9. The bulk zirconium based amorphous alloy of claim 8, wherein the maximum forming dimension of the bulk zirconium based amorphous alloy is greater than or equal to 25mm;

the hardness of the bulk zirconium-based amorphous alloy is more than or equal to 500HV;

the tensile strength of the bulk zirconium-based amorphous alloy is more than or equal to 2000MPa.