CN-122007369-A - Mechanical property regulation and control method for die-casting amorphous alloy

CN122007369ACN 122007369 ACN122007369 ACN 122007369ACN-122007369-A

Abstract

The invention relates to the technical field of amorphous alloy preparation and die casting, and provides a die casting amorphous alloy mechanical property regulation method which comprises the steps of S1, placing selected amorphous alloy raw materials into a smelting crucible, S2, constructing a smelting vacuum environment, S3, heating the smelting crucible to enable the amorphous alloy raw materials in the smelting crucible to be molten, S4, pouring amorphous alloy melt into a charging barrel, S5, injecting the amorphous alloy melt in the charging barrel into a cavity of a die casting die, regulating and controlling the shear strain rate of the amorphous alloy melt during die filling by regulating the injection rate, S6, carrying out pressure maintaining solidification on the amorphous alloy melt, and opening the die to obtain an amorphous alloy structural member, S7, processing the amorphous alloy structural member into a standard test size, carrying out mechanical property detection, and screening out technological parameters meeting target performance requirements. The invention can solve the problems of single performance regulation means and high cost of the existing amorphous alloy.

Inventors

LIU LEHUA
HUANG CHUANG
DENG ZHICHENG
HU SIHUA
XIE YURUI
ZHANG WEIWEN
WANG JUAN

Assignees

华南理工大学
深圳领威科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260312

Claims (10)

1. A vacuum die casting device is characterized by comprising a sealed smelting chamber, a smelting crucible and a pouring driving mechanism which are arranged in the smelting chamber, a die casting die, a charging barrel, a injection rod, a vacuum pump set and a die temperature machine, wherein, One end of the charging barrel is communicated with the cavity of the die casting die, and the other end of the charging barrel penetrates through the smelting chamber and is connected with the injection rod; the smelting crucible is arranged on the dumping driving mechanism, and the dumping driving mechanism is used for driving the smelting crucible to overturn so as to pour the melt formed by smelting into the charging barrel; the injection rod is used for injecting the melt in the charging barrel into the cavity of the die-casting die; The die-casting die is used for die-casting and forming the melt injected into the cavity; the vacuum pump set is communicated with the smelting chamber and the die casting die and is used for extracting vacuum; the die temperature machine is connected with the die-casting die and used for preheating the die-casting die.
2. A vacuum die casting apparatus according to claim 1, wherein, The smelting crucible adopts a high-temperature resistant ceramic crucible, wherein the high-temperature resistant ceramic crucible is a fused quartz-alumina composite ceramic crucible, a zirconia ceramic crucible or a yttria ceramic crucible.
3. A method for regulating mechanical properties of die-casting amorphous alloy, characterized in that the amorphous alloy structural member is prepared by using the vacuum die-casting equipment as claimed in claim 1 or 2, and the regulation comprises: S1, placing selected amorphous alloy raw materials into a smelting crucible of vacuum die casting equipment; s2, constructing a smelting vacuum environment in the vacuum die casting equipment, wherein a die casting die of the vacuum die casting equipment is preheated to ensure that the preheating temperature of the die casting die is lower than the glass transition temperature of the amorphous alloy, and the vacuum die casting equipment is subjected to vacuum treatment to ensure that the vacuum die casting equipment reaches the preset vacuum degree; S3, heating the smelting crucible in the vacuum environment with the preset vacuum degree by the vacuum die casting equipment to enable the amorphous alloy raw material in the smelting crucible to be melted into amorphous alloy melt in a molten state; S4, pouring the amorphous alloy melt from the smelting crucible into a charging barrel; s5, under the action of an injection rod, injecting the amorphous alloy melt in the charging barrel into a cavity of the die casting die at a preset injection rate, wherein the shear strain rate of the amorphous alloy melt during filling is regulated and controlled by regulating the injection rate; S6, after the amorphous alloy melt is injected into the cavity in a pressing mode, carrying out pressure maintaining solidification on the amorphous alloy melt, and after the pressure maintaining solidification is finished, opening a die to obtain an amorphous alloy structural member; S7, processing the prepared amorphous alloy structural member into a standard test size for mechanical property detection, and screening out technological parameters meeting target performance requirements according to the detected mechanical property and injection rate corresponding to the mechanical property.
4. The method for controlling mechanical properties of die-cast amorphous alloy according to claim 3, wherein in S5, the shear strain rate of the amorphous alloy melt during the die-casting is controlled by adjusting the injection rate, comprising determining the injection rate according to the corresponding relation between the injection rate and the mechanical properties, The shear strain rate increases with increasing injection rate and decreases with decreasing injection rate.
5. The method for regulating mechanical properties of die-casting amorphous alloy according to claim 4, wherein in S4, the preset injection rate is 0.5-2.5 m/S; The shear strain rate of the amorphous alloy melt during filling is 10 2 ~10 4 s -1 .
6. The method for controlling mechanical properties of die-casting amorphous alloy according to claim 5, wherein when the amorphous alloy structural member is high in hardness, the injection rate is set to 0.5-1.5 m/s; when the amorphous alloy structural member is high in plasticity or toughness, the injection speed is set to be 1.5-2.5 m/s.
7. The method for regulating mechanical properties of die-casting amorphous alloy according to claim 3, wherein in S2, the preheating temperature is 150-250 ℃; The preset vacuum degree is 10 -3 ～10 2 Pa.
8. The method for regulating mechanical properties of die-casting amorphous alloy according to claim 3, wherein in S3, the melting temperature of the amorphous alloy raw material is higher than 100-250 ℃ of the liquidus of the amorphous alloy.
9. The method for regulating mechanical properties of die-casting amorphous alloy according to claim 3, wherein in S4, the pouring rate of the melting crucible is 15-30 degrees/S.
10. The method for regulating mechanical properties of die-casting amorphous alloy according to claim 3, wherein in S5, the pressure of the amorphous alloy melt for pressure-maintaining solidification is 10-300 mpa, and the pressure-maintaining time is 2-10S; The effective thickness of the amorphous alloy structural member is 0.3-2 mm.

Description

Mechanical property regulation and control method for die-casting amorphous alloy Technical Field The invention relates to the technical field of amorphous alloy preparation and die-casting molding, in particular to a method for regulating and controlling mechanical properties of die-casting amorphous alloy. Background Amorphous alloy (also called metallic glass) has extremely high yield strength, high hardness, excellent elastic limit and corrosion resistance due to the long-range disordered structure of atomic arrangement, and has great application potential in the fields of consumer electronics hinges, precision mechanical transmission parts, medical appliances and the like. However, amorphous alloys generally exhibit macroscopic brittleness at room temperature, lacking plastic deformability, which greatly limits their reliability as critical structural components. Therefore, how to improve the plasticity of the plastic material while maintaining the high strength, or flexibly adjust and control the 'strong-tough' matching relation according to different application scenes is always the research and development focus of the field. In order to regulate the mechanical properties of amorphous alloys, the current industry and academia mainly adopt conventional technical paths such as changing alloy components, cryogenic cycle treatment, annealing heat treatment or mechanical pre-deformation, but the methods have obvious limitations. Specifically, component regulation belongs to a static mode of 'one component corresponds to one property', and if the product property requirement is changed, master alloys with different proportions must be remelted, so that the stock cost of raw materials is greatly increased, and the production line can also be caused to frequently clean a crucible and a charging barrel, so that the production efficiency is seriously reduced. The cryogenic cycle treatment can induce internal stress through cold and hot cycles to increase free volume, but takes very long time and high liquid nitrogen energy consumption as an offline post-treatment procedure, and the treatment effect on large-size or complex special-shaped die castings is also often uneven. Annealing typically causes structural relaxation of the amorphous alloy, annihilating the free volume, and while increasing hardness, tends to cause further embrittlement of the material. And for complex precise thin-wall parts formed by die casting, even load is difficult to apply, and the workpiece is extremely easy to damage. Vacuum die casting is used as a main flow process for realizing near-net forming of an amorphous alloy precise structural member, and has the advantages of high-speed filling and high-pressure solidification. However, the optimization of the existing die casting process mainly focuses on the level of forming quality, namely, macroscopic defects such as air holes, cold insulation and the like are eliminated by optimizing thermodynamic parameters such as the temperature of a die, the smelting temperature or the vacuum degree, and the potential of the dynamic parameter such as injection rate on the regulation and control of the intrinsic microstructure of the material is ignored to a great extent. In fact, amorphous alloys are thermodynamically metastable materials, whose properties are highly sensitive to shear history. During die casting, the melt flows through the gate and cavity at high velocity in a very short time, and undergoes severe shear deformation of up to 10 3~105 s-1. The shearing spring effect in the rheological process can theoretically change the free volume content and the atomic cluster structure in the material, and is a natural and intense rheological modification means. In view of this, there is a need in the art for a new method that does not require changes in alloy composition nor the addition of post-treatment equipment. Disclosure of Invention In view of the above problems, the present invention aims to provide a method for adjusting and controlling mechanical properties of die-casting amorphous alloy, so as to solve the problems of single means and high cost of the existing amorphous alloy. The invention uses the characteristics of high-speed mold filling and high-pressure solidification in the high-vacuum die casting process, and applies a high shearing action in the die casting mold filling stage to apply a severe disturbance to the amorphous melt under the deep supercooling condition. The shear strain rate is changed by regulating the injection rate, so that the internal structure relaxation behavior of the amorphous alloy is controlled, and the macroscopic mechanical properties (such as hardness, yield strength and the like) of the amorphous alloy are effectively regulated by reserving free volumes of different degrees. The above object is achieved by the embodiments of the following technical solutions: In a first aspect, the invention provides a vacuum die casting apparatus comprising a