Method for improving plasticity of zirconium-based amorphous alloy and product thereof

Abstract

The invention relates to the technical field of amorphous alloys, and discloses a method for improving plasticity of a zirconium-based amorphous alloy and a product thereof, and the method comprises the following steps: S1, mixing zirconium, nickel, copper and aluminum according to a mass ratio of 62: 12.5: 15.5: 10, and smelting to obtain a master alloy; s2, melting the mother alloy, sucking and casting the mother alloy into a copper mold, and quickly cooling to form an amorphous alloy bar; s3, the amorphous alloy bar is subjected to aging annealing treatment, the aging speed is increased, and then the amorphous alloy bar is cut into 4.5 mm small cylinders; and S4, the amorphous alloy small cylinder is put into a special mold, the upper surface and the lower surface of the small cylinder are treated through ultrasonic equipment, and the zirconium-based amorphous alloy with the room-temperature plasticity improved is obtained. The processing method disclosed by the invention is simple in process requirement, short in processing time and high in repeatability. The compression plasticity of the zirconium-based amorphous alloy which is subjected to aging treatment and then ultrasonic treatment is obviously superior to that of an as-cast zirconium-based amorphous alloy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of amorphous alloys, in particular to a method for improving the plasticity of zirconium-based amorphous alloys and a product thereof. BACKGROUND

[0002] Amorphous alloys (also known as metallic glasses) are a kind of long-range disordered solid substances formed in the process of rapid cooling of liquid melt, which is different from the periodic and symmetrical arrangement of atoms in traditional crystalline metal materials. Amorphous alloys have both metallic and glassy, solid and liquid properties. Since its discovery, amorphous alloys have become a hot topic in the field of condensed matter physics and materials science due to their unique structure and excellent performance. Compared with traditional crystalline materials, amorphous alloys have more excellent physical, chemical and mechanical properties, such as high yield strength, high elastic strain (about 2%), low thermal expansion coefficient, excellent corrosion resistance in acid, alkali and salt, excellent magnetic properties, and superplasticity in the supercooled liquid phase, which makes them have broad application prospects in mechanical, electronic, shipbuilding, aerospace and military fields, and are considered as a new generation of engineering materials after steel and plastic.

[0003] Amorphous alloys are in a metastable state in thermodynamics, and will spontaneously transform to a state with lower energy (stress action or high temperature will accelerate the process) driven by energy difference, i.e. aging (structural relaxation). During this process, the structure is ordered and the performance is changed, especially the deterioration of room temperature deformation ability. This instability of amorphous materials is one of the factors restricting their application.

[0004] "Rejuvenation" or "juvenation" refers to the process of transformation of amorphous alloys from a low-energy state to a high-energy state. In other words, this process is to make the amorphous alloy that has experienced structural relaxation transform to a state close to the liquid structure state, corresponding to an increase in fictive temperature (Tf). As the reverse process of structural relaxation, rejuvenation treatment can effectively improve the energy state of amorphous alloys, introduce more free volume and rheological units, and make amorphous alloys "rejuvenate". Different initial states will also have different effects on the effect of rejuvenation treatment.

[0005] In summary, we use a new method, i.e. aging assisted ultrasonic loading method, to significantly improve the room temperature compression plasticity of amorphous alloys. SUMMARY

[0006] The present application aims to provide a method for improving the plasticity of zirconium-based amorphous alloys and a product thereof. Through the synergistic effect of aging annealing and ultrasonic vibration loading, the room temperature compression plasticity of zirconium-based amorphous alloys is significantly improved, while the amorphous structure is maintained.

[0007] To achieve the above object, the present application provides the following technical solutions. In the first aspect, the present application provides a method for improving plasticity of zirconium-based amorphous alloy, comprising the following steps: S1, zirconium, nickel, copper and aluminum are mixed in a mass ratio of 62:12.5:15.5:10 and smelted into a master alloy; S2, the master alloy is melted and suction cast into a copper mold, and an amorphous alloy rod is formed after rapid cooling; S3, the amorphous alloy rod is subjected to aging annealing treatment to accelerate the aging speed, and then cut into amorphous alloy small cylinders; S4, the amorphous alloy small cylinders are placed in a special mold, and the upper and lower surfaces thereof are subjected to loading treatment by an ultrasonic device.

[0008] Further, in step S2, the master alloy is smelted in a WK series vacuum arc furnace, heated by electric arc in an inert gas protection atmosphere, and the molten master alloy is suctioned into a copper mold with a diameter of 2 mm through gas pressure, and an amorphous alloy rod with a diameter of 2 mm and a length of 80 mm is obtained after cooling.

[0009] Further, in step S3, the annealing treatment is carried out in a vacuum environment, specifically including: sealing the amorphous alloy rod in a quartz tube, and raising the temperature to 380℃ at a temperature rising rate of 12℃ / min in a box furnace, and naturally cooling after keeping warm for 10 hours.

[0010] Further, in step S3, the amorphous alloy small cylinder is a cylinder with a diameter of 2 mm and a height of 4.5 mm.

[0011] Further, in step S4, the special mold has an inner diameter of 3 mm, the trigger pressure of ultrasonic loading is 22N, and the ultrasonic energy is 100J.

[0012] Further, in step S4, the ultrasonic device uses an ultrasonic punch with a diameter of 10 mm to load the amorphous alloy small cylinder.

[0013] Further, in step S4, the sample size after ultrasonic treatment is a cylinder with a diameter of 2 mm and a height of 4.5 mm.

[0014] In the second aspect, the present application provides a high-strength and high-plasticity Zr 62 Cu 15.5 Ni 12.5 Al 10 amorphous alloy, which is obtained by the method for improving plasticity of zirconium-based amorphous alloy.

[0015] Further, the Zr 62 Cu 15.5 Ni 12.5 Al10 The compression plasticity of the amorphous alloy is superior to that of a cast state and a zirconium-based amorphous alloy directly subjected to ultrasonic vibration loading, and the alloy remains in an amorphous state.

[0016] Based on the technical solution, the embodiment of the present application can at least produce the following technical effects: The method for improving the plasticity of the zirconium-based amorphous alloy provided by the present application uses zirconium, nickel, copper and aluminum as raw materials, accelerates the structural relaxation process of the amorphous alloy through aging annealing treatment, promotes the local rearrangement of atoms, eliminates part of internal stress, and forms a more stable metastable structure. However, pure aging will lead to a decrease in free volume and a decrease in rheological unit density, thereby deteriorating plasticity. The high-frequency mechanical vibration of ultrasonic vibration loading applies energy to the amorphous alloy, induces local shear deformation and atomic rearrangement. This process introduces new free volume and activates rheological units, so that the alloy is transformed from a low-energy state to a high-energy state, effectively offsetting the over-aging effect brought by the aging annealing. The dynamic loading of the ultrasonic punch can also form a uniform stress distribution in the amorphous matrix, avoiding local brittle fracture. The combination of aging annealing and ultrasonic loading forms a unique process path of “aging first and rejuvenation later”. The aging treatment provides a uniform structural basis for the alloy, while the ultrasonic loading restores and improves the free volume density through energy input, and finally realizes a significant improvement in plasticity while retaining the amorphous state. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to the structures shown in the drawings without creative labor for those skilled in the art.

[0018] Figure 1 is a stress-strain curve diagram of the zirconium-based amorphous alloy processing method of the present application; Figure 2 is a stress-strain curve comparison diagram of the zirconium-based amorphous alloy of the present application; Figure 3 is an X-ray diffraction diagram of the zirconium-based amorphous alloy of the present application; Figure 4 is a DSC curve diagram of the zirconium-based amorphous alloy of the present application; Figure 5 is a fracture morphology diagram of the zirconium-based amorphous alloy of the present application. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the protection scope of the present application. In addition, the technical solutions in each embodiment can be combined with each other, but the combination of the technical solutions should be based on the fact that a person of ordinary skill in the art can realize the combination, and when the combination of the technical solutions appears contradictory or unachievable, it should be considered that the combination of the technical solutions does not exist and is not within the protection scope of the present application.

[0020] The object of the present application is achieved by the following technical solutions. The method for improving the plasticity of a zirconium-based amorphous alloy comprises the following steps. S1, mixing zirconium, nickel, copper and aluminum according to a mass ratio of 62:12.5:15.5:10 and smelting the mixture into a master alloy; The structure shape of the master alloy can be, but is not limited to, a block shape, a rod shape and the like.

[0021] In an optional embodiment, the specific operation of the step S1 is as follows. According to the principle of high melting point first and low melting point last, the zirconium, nickel, copper and aluminum are stacked in the copper cavity of a vacuum arc furnace (for example, a WK series vacuum arc furnace), a mechanical pump is used to vacuumize the arc furnace, after the low vacuum of 5 Pa or below is reached, the arc furnace molecular pump is opened to vacuumize again, and the high vacuum of 3×10 -3 Pa is reached.

[0022] The argon protection gas is introduced into the copper cavity of the vacuum arc furnace, the arc gun is moved, the titanium ingot is burned with a current of 120 A to absorb oxygen and ensure that there is no oxygen in the reaction furnace. The current is aimed at the copper cavity, the arc current is adjusted to 200 A to 300 A, and the zirconium, nickel, copper and aluminum are uniformly fused together to form the master alloy.

[0023] S2, melting the master alloy and suction casting into a copper mold to form an amorphous alloy rod after rapid cooling; In an optional embodiment, the specific operation of the step S2 is as follows. The master alloy is stacked in the copper cavity of the WK series vacuum arc furnace, the arc furnace is vacuumized to 5 Pa or below by a mechanical pump, and then the arc furnace molecular pump is opened to vacuumize to the high vacuum of 3×10 -3Pa, then argon gas is introduced to protect the arc gun, the arc gun is moved, and the titanium ingot is burned with an oxygen absorption of 120 A to ensure that there is no oxygen in the reaction furnace. The current is directed to the copper cavity, the arc current is adjusted to 200-300 A, and after the raw materials are uniformly fused together, the suction casting button is pressed to suction cast the amorphous alloy rod. The diameter, length, etc. of the amorphous alloy rod obtained above can be determined according to the forming mold, such as a diameter of 2 mm, etc.

[0024] Alternatively, the length of the amorphous alloy rod can be 80 mm, and the diameter can be 2 mm.

[0025] S3, annealing the above amorphous alloy rod to accelerate the aging speed, and then cutting into a 4.5 mm small column.

[0026] In this step S3, the amorphous alloy rod is first sealed into a quartz tube by a tube sealing machine. The suction-cast zirconium-based amorphous alloy rod is loaded into a test tube, the test tube is placed on the tube sealing machine at an inclination angle of 15° and rotated at 10 revolutions per minute, and then the test tube is pumped to a vacuum of 5 Pa by a mechanical pump. After that, the test tube is sealed with a quartz plug by using a water-fuel hydrogen-oxygen machine with a hydrogen flow rate of 200 L / H to 300 L / H.

[0027] Then the sealed quartz tube is placed in a KF1200 box furnace and heated to 380℃ at a heating rate of 12℃ / min, and held for 10 hours. After that, the quartz tube is taken out of the box furnace and placed in the air for cooling. After the quartz tube and the amorphous alloy rod are completely cooled, the amorphous alloy rod is taken out.

[0028] The amorphous alloy rod after heat treatment is cut into small columns by a slow saw.

[0029] Alternatively, the length of the amorphous alloy small column can be 4.5 mm, and the diameter can be 2 mm.

[0030] S4, the amorphous alloy small column is placed in a special mold, and the upper and lower surfaces of the small column are treated by using an ultrasonic device.

[0031] The amorphous alloy initial sample is a cylinder with a diameter of 2 mm and a height of 4.5 mm.

[0032] The cross sections of both ends of the amorphous alloy small column are polished to be parallel. Then it is placed in a specially designed ultrasonic mold with an inner diameter of 3 mm and made of stainless steel. A 10 mm diameter ultrasonic punch is used to load and treat the amorphous alloy small column with ultrasonic waves.

[0033] The ultrasonic energy used is 100 J, and the trigger pressure is 22 N.

[0034] Preferably, in step S4, the sample size after ultrasonic treatment is a cylinder with a diameter of 2 mm and a height of 4.5 mm.

[0035] Further, the processing method of the present embodiment produces a zirconium-based amorphous alloy with a composition of Zr 62 Cu 15.5 Ni 12.5 Al 10 .

[0036] The processing method of the present application can improve the plasticity of the zirconium-based amorphous alloy.

[0037] Performance verification and testing: Figure 1 is the stress-strain curve of the zirconium-based amorphous alloy during the processing. Macroscopic compression tests were performed using a Zwick Z050 testing machine at a strain rate of 5 x 10 - 4 s -1 . At least three independent samples were compressed to ensure the reliability of the data. The test sample was a cylinder with a length-diameter ratio of 2:1, with a length of 4.0 mm and a diameter of 2.0 mm. As can be seen from the graph, the plasticity of the zirconium-based amorphous alloy after aging treatment disappears, and the plasticity is restored after ultrasonic loading treatment and exceeds that of the as-cast state.

[0038] Figure 2 is the stress-strain comparison curve of the zirconium-based amorphous alloy with different ultrasonic processing methods. Macroscopic compression tests were performed using a Zwick Z050 testing machine at a strain rate of 5 x 10 -4 -1 s. At least three independent samples were compressed to ensure the reliability of the data. The test sample was a cylinder with a length-diameter ratio of 2:1, with a length of 4.0 mm and a diameter of 2.0 mm. As can be seen from the graph, the plasticity of the zirconium-based amorphous alloy treated by aging-assisted ultrasonic vibration loading is better than that of the as-cast state and the zirconium-based amorphous alloy treated by direct ultrasonic treatment.

[0039] Figure 3 is the X-ray diffraction pattern of the zirconium-based amorphous alloy. The XRD curve was obtained by CuKα radiation (XRD, Rigaku MiniFlex 600) to verify the amorphous characteristics before and after processing. As can be seen from the graph, the zirconium-based amorphous alloy after annealing-assisted ultrasonic loading treatment still maintains good amorphous state.

[0040] Figure 4 is the DSC curve of the zirconium-based amorphous alloy of the present application. Differential scanning calorimetry (DSC, PerkinElmer DSC-8000) was used to measure the glass performance of the sample at a heating rate of 20 K / min, and the DSC curve of the zirconium-based amorphous alloy was obtained. As can be seen from the graph, the aging-assisted ultrasonic loading method of the present application can effectively rejuvenate the aged amorphous alloy.

[0041] Figure 5Figure 1 is a fracture morphology diagram of a zirconium-based amorphous alloy of the present application. As shown in the diagram, the fracture morphology of the as-cast zirconium-based amorphous alloy is the typical vein-like fracture morphology of amorphous alloys, and the vein-like fracture morphology basically disappears after aging treatment; and the vein-like fracture morphology appears again after ultrasonic treatment.

[0042] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method of improving the ductility of a zirconium-based amorphous alloy, characterized by, The method comprises the following steps: S1, mixing zirconium, nickel, copper and aluminum in a mass ratio of 62:12.5:15.5:10 and smelting into a master alloy; S2, after melting the master alloy, suction casting into a copper mold, and after rapid cooling, forming an amorphous alloy rod; S3, aging annealing treatment is performed on the amorphous alloy rod to accelerate the aging speed, and then cutting into an amorphous alloy small cylinder; S4, placing the amorphous alloy small cylinder into a special mold and loading the upper and lower surfaces thereof through an ultrasonic device.

2. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S2, the master alloy is smelted in a WK series vacuum arc furnace, heated by electric arc in an inert gas protection atmosphere, and the molten master alloy is suctioned into a copper mold with a diameter of 2mm through gas pressure, and after cooling, an amorphous alloy rod with a diameter of 2mm and a length of 80mm is obtained.

3. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S3, the annealing treatment is performed in a vacuum environment, specifically including: sealing the amorphous alloy rod in a quartz tube, and raising the temperature to 380℃ at a temperature rising rate of 12℃ / min in a box furnace, and after keeping warm for 10 hours, naturally cooling.

4. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S3, the amorphous alloy small cylinder is a cylinder with a diameter of 2mm and a height of 4.5mm.

5. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S4, the inner diameter of the special mold is 3mm, the trigger pressure of ultrasonic loading is 22N, and the ultrasonic energy is 100J.

6. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S4, the ultrasonic device adopts an ultrasonic punch with a diameter of 10mm to load the amorphous alloy small cylinder.

7. The method of increasing the ductility of a zirconium-based amorphous alloy of claim 1, wherein, In step S4, the sample size after ultrasonic treatment is a cylinder with a diameter of 2mm and a height of 4.5mm.

8. A high strength-to-plasticity Zr 62 Cu 15.5 Ni 12.5 Al 10 Amorphous alloy characterized by, The method is obtained by the method for improving the plasticity of zirconium-based amorphous alloy according to any one of claims 1-7. The method is obtained by the method for improving the plasticity of zirconium-based amorphous alloy according to any one of claims 1-7.

9. The high strength-to-plasticity Zr of claim 8 62 Cu 15.5 Ni 12.5 Al 10 An amorphous alloy, characterized by, The Zr 62 Cu 15.5 Ni 12.5 Al 10 Compressive plasticity of the amorphous alloys is superior to that of as-cast and directly ultrasonic vibration loaded zirconium-based amorphous alloys, which both remain amorphous alloys.

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