Metallic glass, preparation method thereof and mold core for injection molding

Abstract

The invention relates to the technical field of amorphous alloy modification, in particular to metallic glass, a preparation method thereof and a mold core for injection molding. The metallic glass provided by the invention comprises an amorphous alloy base material and a monomolecular layer combined on the surface of the amorphous alloy base material, wherein the material of the monomolecular layer comprises at least one of organic phosphonic acid molecules and organic carboxylic acid molecules. Based on modification of the monomolecular layer, the metal glass can have good surface performance, and the metal glass has good demolding performance when being used in a micro injection molding mold, so that an injection molding product can have a good micro-nano structure.

Description

Technical Field

[0001] This application belongs to the technical field of amorphous alloy modification, and particularly relates to a metallic glass, a preparation method thereof, and a mold core for injection molding. Background Art

[0002] The injection molding process includes key steps such as injection, filling, holding pressure, cooling, and demolding. By precisely controlling these steps, plastic products with high replication quality can be produced. When the molded product has a micro- or nano-scale structure, it is called micro-injection molding. Micro-injection molding is not only a reduction in product size compared to traditional injection molding, but also has significant differences in equipment, mold design, and molding processes.

[0003] Researchers have conducted in-depth studies on the quality of micro-nano structures, focusing on the two processes of filling and demolding. In particular, demolding is the key stage determining the quality of the polymer micro-nano structure in injection molding and has become the focus of research. When the structure is reduced to the micro / nano scale, the surface and interfacial interactions between the polymer and the mold core are significantly enhanced, and some demolding deformations may occur, such as burrs, fractures, and scratches, which will directly affect the performance of micro-injection molding products.

[0004] Metallic glass, also known as amorphous alloy, is an amorphous material with a metallic chemical composition. Among them, bulk metallic glasses (BMGs) are ideal mold materials for preparing micro-nano structures. Due to the lack of microscopic limitations caused by crystal structures in bulk metallic glasses, the volume shrinkage rate is relatively low, isotropic, and it is easy to be processed into sizes and structures that are difficult to obtain with traditional metals. However, in the actual micro-injection molding application of molds, demolding deformation still occurs and needs to be better improved. Summary of the Invention

[0005] The purpose of this application is to provide a metallic glass, a preparation method thereof, and a mold core for injection molding, aiming to solve the technical problem of how to reduce the risk of demolding deformation of the molded product when metallic glass is used in injection molding molds.

[0006] To achieve the above application purpose, the technical solution adopted in this application is as follows: In the first aspect, this application provides a metallic glass, which includes an amorphous alloy substrate and a monolayer combined on the surface of the amorphous alloy substrate, and the material of the monolayer includes at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule.

[0007] In some embodiments, the organic phosphonic acid molecule includes an alkyl phosphonic acid with 4 - 18 carbon atoms; and / or, the organic carboxylic acid molecule includes at least one of an unsaturated acid with 4 - 18 carbon atoms and an alkanoic acid with 4 - 18 carbon atoms.

[0008] In some embodiments, the material of the monolayer is an organic phosphonic acid molecule, and the organic phosphonic acid molecule includes at least one of n-hexylphosphonic acid, n-decylphosphonic acid, n-dodecylphosphonic acid, n-hexadecylphosphonic acid, and n-octadecylphosphonic acid.

[0009] In some embodiments, the amorphous alloy substrate includes at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate, and an iron-based amorphous alloy substrate.

[0010] Second, the present application provides a method for preparing a metallic glass, including: Providing an amorphous alloy substrate and a modification solution, wherein the solute of the modification solution includes at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule; Immersing the amorphous alloy substrate in the modification solution for treatment, and then taking it out for drying treatment to obtain a metallic glass.

[0011] In some embodiments, the organic phosphonic acid molecule includes an alkyl phosphonic acid having 4 to 18 carbon atoms; And / or, the organic carboxylic acid molecule includes at least one of an olefinic acid having 4 to 18 carbon atoms and an alkanoic acid having 4 to 18 carbon atoms; And / or, the amorphous alloy substrate includes at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate, and an iron-based amorphous alloy substrate.

[0012] In some embodiments, the solute concentration in the modification solution is 2 to 8 mmol / L; And / or, the solvent in the modification solution is selected from alcohol solvents.

[0013] In some embodiments, the time of the immersion treatment is 6 to 50 h; And / or, the drying treatment includes natural air drying.

[0014] In some embodiments, before the amorphous alloy substrate is subjected to the immersion treatment, it is first pretreated, and the pretreatment includes: sequentially performing ultrasonic cleaning with an alcohol reagent and water, then ultraviolet ozone treatment, and then sequentially performing ultrasonic cleaning with an alcohol reagent and water.

[0015] Third, the present application provides a mold core for injection molding. The mold core has a microstructured surface, and the material of the mold core is a bulk metallic glass, and the bulk metallic glass includes the metallic glass provided in the first aspect of the present application and / or the metallic glass prepared by the preparation method provided in the second aspect of the present application.

[0016] The metallic glass provided in the first aspect of the present application has a monolayer containing organophosphonic acid molecules and / or organic carboxylic acid molecules modified on the surface of the amorphous alloy substrate. Based on the modification of this monolayer, the metallic glass can have excellent surface properties. Such a metallic glass is used in a micro-injection molding die and has excellent demolding properties, so that the injection-molded product can have excellent micro-nano structures.

[0017] The method for preparing the metallic glass provided in the second aspect of the present application is to soak the amorphous alloy substrate in a solution containing organophosphonic acid molecules and / or organic carboxylic acid molecules. During this process, these organic molecules self-assemble on the surface of the amorphous alloy substrate to form a monolayer, thereby obtaining a surface-modified metallic glass. Such a preparation method is not only simple in process, but also the obtained metallic glass has excellent demolding properties when used in a micro-injection molding die.

[0018] The mold core for injection molding provided in the third aspect of the present application can be well used in the injection molding process because its material includes the unique metallic glass of the present application. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is a schematic flow chart of a method for preparing a metallic glass according to an embodiment of the present application; Figure 2 is a diagram of the water contact angle data of the metallic glass modified with different organophosphonic acid molecules according to an embodiment of the present application; Figure 3 is a diagram of the water contact angle data of the metallic glass modified with different organic carboxylic acid molecules according to an embodiment of the present application; Figure 4 is a diagram of the water contact angle data of the metallic glass with different substrates according to an embodiment of the present application; Figure 5 is a detection diagram of a slow wire electrical discharge machining mold core prepared according to an embodiment of the present application; Figure 6 is an appearance diagram of a molded product after micro-injection molding using a mold core prepared according to an embodiment of the present application; Figure 7 is a microscopic morphology diagram of a molded product after micro-injection molding using a mold core modified with different organophosphonic acid molecules according to an embodiment of the present application; Figure 8It is a comparison chart of the replication rates of the molded products after micro - plastic molding using the mold cores modified with different organic phosphonic acid molecules in the embodiments of the present application; Figure 9 It is a comparison chart of the deviations of the molded products after micro - plastic molding using the mold cores modified with different organic phosphonic acid molecules in the embodiments of the present application; Figure 10 It is a microscopic morphology diagram of the molded products after micro - plastic molding using the mold cores modified with different organic carboxylic acid molecules in the embodiments of the present application; Figure 11 It is a comparison chart of the replication rates of the molded products after micro - plastic molding using the mold cores modified with different organic carboxylic acid molecules in the embodiments of the present application; Figure 12 It is a comparison chart of the deviations of the molded products after micro - plastic molding using the mold cores modified with different organic carboxylic acid molecules in the embodiments of the present application. Detailed implementation manners

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0022] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0023] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following (items)" or its similar expressions refer to any combination of these items, including any combination of single (item) or plural items (items).

[0024] It should be understood that in various embodiments of the present application, the magnitude of the sequence numbers of the above - mentioned processes does not mean the sequence of execution. Some or all of the steps can be executed in parallel or sequentially. The execution sequence of each process should be determined by its function and internal logic and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0025] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] In the description of the embodiments of the present application, the weights of the relevant components mentioned not only can refer to the specific contents of each component, but also can represent the proportional relationship between the weights of each component. Therefore, as long as the contents of the relevant components in the description of the embodiments of the present application are scaled up or down proportionally, they are within the scope disclosed in the description of the embodiments of the present application. Specifically, the mass described in the description of the embodiments of the present application can be mass units well-known in the chemical engineering field such as µg, mg, g, kg, etc.

[0027] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0028] Surface modification technology plays a crucial role in the fields of modern materials science and surface engineering, especially in improving the surface properties of materials. The Self-Assembled Monolayers (SAMs) technology has attracted much attention because it can precisely control surface characteristics at the atomic or molecular level. With its nanoscale thickness, highly ordered and stable structure, the self-assembled monolayer can adapt to the adjustability of various stiffness and shape substrate surfaces and has become an excellent solid thin-film lubricating material. Such thin films not only have customizable surface properties, but also can be flexibly designed at the molecular level by adjusting the type of end groups, chain length and molecular structure through a bottom-up design strategy.

[0029] Micro-injection molding is widely used in the preparation of micro-nano structures with high aspect ratios. However, the surface of micro-nano structures with high aspect ratios faces a series of challenges during the preparation process. In particular, the high surface-to-volume ratio leads to enhanced surface effects, excessive and unbalanced demolding forces, making the demolding process not smooth, resulting in inability to demold or deformation, and even damage to the micro-nano structure. When the structure size is reduced to the micron or nano level, microscopic factors including the surface roughness of the mold may significantly affect the adhesion characteristics of the interface between the polymer and the mold core. At the same time, during the injection molding process, the surface effects caused by the size become significant, leading to defects such as necking, warping and deformation of the micro-structure. This makes interface adhesion and friction and wear key factors in the preparation of micro-nano structures. Therefore, the study of the tribological properties of micro-nano structure devices is of great significance for improving the yield and reliability and promoting the high replication rate and high performance of the surface of large-area micro-nano structures with high aspect ratios.

[0030] Based on the difficulties in demolding encountered during the manufacturing process of micro-nano structures, such as the large and uneven demolding forces leading to mold damage or structural deformation, this application designs a metallic glass and a corresponding preparation method, that is, by modifying a hydrophobic monolayer on the surface of an amorphous alloy substrate to form a hydrophobic coating, so as to improve the use performance of the amorphous alloy substrate as a mold core. The specific technical solutions are as follows.

[0031] In a first aspect, an embodiment of this application provides a metallic glass. The metallic glass of the embodiment of this application includes: (1) an amorphous alloy substrate; (2) a monolayer, which is combined on the surface of the amorphous alloy substrate and includes at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule.

[0032] Based on the modification of this monolayer, the metallic glass of the embodiment of this application can have good surface properties. Specifically, it can effectively reduce the surface free energy and make it have good hydrophobicity. Such a metallic glass has good demolding performance when used in a micro-injection molding mold, and thus can make the injection molded product have good micro-nano structures.

[0033] In some embodiments, the organic phosphonic acid in the monolayer refers to a compound in which one or two hydroxyl groups in the (HO) 3 PO molecule are replaced by an alkyl or aryl group. The organic carboxylic acid molecule refers to an organic compound containing a carboxyl group (-COOH). Specifically, the organic phosphonic acid molecules in the monolayer include alkyl phosphonic acids with 4-18 carbon atoms. For example, the alkyl phosphonic acid can be at least one of n-hexylphosphonic acid (HPA), n-decylphosphonic acid (DPA), n-dodecylphosphonic acid (DDPA), n-hexadecylphosphonic acid (HDPA), n-octadecylphosphonic acid (ODPA), etc. The organic carboxylic acid molecules in the monolayer include at least one of alkenoic acids with 4-18 carbon atoms and alkanoic acids with 4-18 carbon atoms. For example, the alkenoic acid can be at least one of 2,4-hexadienoic acid (sorbic acid), 2-octenoic acid, 2-decenoic acid, octadecadienoic acid, etc. And the alkanoic acid can be at least one of n-dodecanoic acid (lauric acid), n-tetradecanoic acid (myristic acid), n-hexadecanoic acid (palmitic acid), etc.

[0034] In some embodiments, only organic phosphonic acid molecules can be selected in the monolayer. For example, the material of the monolayer is organic phosphonic acid molecules, and the organic phosphonic acid molecules include at least one of n-hexylphosphonic acid, n-decylphosphonic acid, n-dodecylphosphonic acid, n-hexadecylphosphonic acid, and n-octadecylphosphonic acid. Further, the organic phosphonic acid molecules include a mixed acid of n-hexylphosphonic acid and n-dodecylphosphonic acid, and the molar ratio of n-hexylphosphonic acid to n-dodecylphosphonic acid can be (4-6):(4-6).

[0035] In some embodiments, the amorphous alloy substrate includes at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate, and an iron-based amorphous alloy substrate.

[0036] Second, embodiments of the present application provide a method for preparing a metallic glass for preparing the above-mentioned metallic glass. Specifically, the preparation method of the embodiments of the present application includes: S01: Provide an amorphous alloy substrate and a modification solution, and the solute of the modification solution includes at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule; S02: Immerse the amorphous alloy substrate in the modification solution, then take it out and perform a drying treatment to obtain a metallic glass.

[0037] In the embodiments of the present application, the amorphous alloy substrate is immersed in a solution containing an organic phosphonic acid molecule and / or an organic carboxylic acid molecule, and a monolayer is self-assembled on the surface of the amorphous alloy substrate by these organic molecules, so as to obtain a surface-modified metallic glass. Such a preparation method is not only simple in process, but also the obtained metallic glass has good demolding performance when used in a micro-injection molding die.

[0038] Specifically, the metallic glass obtained by the above preparation method is a bulk metallic glass.

[0039] Raw materials are provided in step S01.

[0040] In some embodiments, the modification solution contains at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule, wherein the organic phosphonic acid molecule includes an alkyl phosphonic acid with 4-18 carbon atoms; the organic carboxylic acid molecule includes at least one of an olefinic acid with 4-18 carbon atoms and an alkanoic acid with 4-18 carbon atoms. The substrate to be modified is an amorphous alloy substrate, including at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate, and an iron-based amorphous alloy substrate.

[0041] In some embodiments, the solute concentration in the modification solution is 2-8 mmol / L, and the total concentration of the organic phosphonic acid molecule and / or the organic carboxylic acid molecule in the modification solution is 2-8 mmol / L. The dispersibility is good within this concentration range, and self-assembly can be well performed on the surface of the amorphous alloy substrate to form a monolayer. Further, the solvent in the modification solution is selected from alcohol solvents, such as ethanol, propanol, etc.

[0042] Step S02 is a self-assembly step.

[0043] In some embodiments, the amorphous alloy substrate is immersed in the modification solution for 6-50 h, for example, the immersion time can be 20-50 h; self-assembly can be fully performed within this time range. The immersion temperature can be room temperature (25-30 °C).

[0044] In some embodiments, after the soaking treatment is completed for self-assembly, natural air drying is further carried out.

[0045] In some embodiments, before the amorphous alloy substrate is subjected to the soaking treatment, a pretreatment is first carried out, and the pretreatment includes: sequentially performing ultrasonic cleaning with an alcohol reagent and water first, then ultraviolet ozone treatment, and then sequentially performing ultrasonic cleaning with an alcohol reagent and water again. This can fully clean the surface of the amorphous alloy substrate, so that the organic molecule self-assembly can be better carried out.

[0046] In some embodiments, the present application uses a room-temperature solution deposition method to prepare a hydrophobic monolayer (such as HPA, DDPA, and mixed HPA-DDPA monolayers) on the surface of an amorphous alloy (such as a Zr-based bulk amorphous alloy). The influence on the experiment is explored by changing different molecular species and amorphous alloy species. The influence of the amorphous alloy substrate on the replication of micro-nano structures is evaluated through a micro-injection experiment, and the hydrophobic properties and surface morphology of the micro-injection products after surface monolayer modification treatment are further analyzed, so as to evaluate the improvement effect of SAMs treatment on the performance of micro-injection products.

[0047] In a third aspect, an embodiment of the present application provides a mold core for injection molding. Specifically, the mold core of the embodiment of the present application has a micro-structured surface, and the material of the mold core is a bulk metallic glass, and the bulk metallic glass includes the metallic glass provided in the first aspect of the embodiment of the present application and / or the metallic glass prepared by the preparation method provided in the second aspect of the embodiment of the present application. Based on the fact that the mold core material includes the unique metallic glass of the present application, it can be well used in the injection molding process.

[0048] Most polymer resins need to go through various process treatments before being formed into final products. These resins are generally processed starting from the molten state, and when the aspect ratio of the micro / nano structure exceeds 1:1, its surface effect will be enhanced, resulting in an accelerated cooling rate. Especially when the surface-to-volume ratio is high, it may cause premature solidification of the melt, thereby preventing the full filling of the micro-nano cavity. This situation may also lead to excessive or uneven demolding force, causing difficulties in the demolding process, and further resulting in problems such as inability to demold, product deformation, or damage to the micro-nano structure. Therefore, reducing the micro-nano scale friction during the molding process has become the focus of research.

[0049] In some embodiments, the present application uses a slow wire electrical discharge machining to process ordered micro-structures as an injection mold core, and explores the influence of injecting bulk amorphous alloys with different anchoring group SAMs, different chain length SAMs, and mixed SAMs. The surface microstructure array of the mold core is characterized by a laser confocal microscope, and the replication quality and morphology of the micro-injection parts are compared. For example, in the embodiment of the present application, Zr 55 Cu 30 Al 10 Ni5 Taking the bulk amorphous alloy mold core as the research object, this paper mainly discusses the effects of organic phosphonic acid SAMs with different carbon chain lengths on the surface properties, injection molding properties and demolding force of the Zr-based bulk amorphous alloy, and explores the effects of the types of SAMs and the types of amorphous alloys on the experiment.

[0050] In some embodiments, HPA SAMs, DDPA SAMs and HPA-DDPA mixed SAMs are adsorbed on the surface of the Zr-based bulk amorphous alloy. The results show that the stacking density order of SAMs is HPA-DDPA SAMs > DDPA SAMs > HPA SAMs. Organic phosphonic acid SAMs can effectively reduce the surface free energy of the Zr-based bulk amorphous alloy and realize the modification from hydrophilic to hydrophobic surface, and the mixed-chain SAMs show the highest water contact angle. With the increase of the carbon chain length, the water contact angle of SAMs increases, and the mixed-chain SAMs show relatively better hydrophobic performance.

[0051] In some embodiments, organic carboxylic acid SAMs of sorbic acid SAMs and myristic acid SAMs are adsorbed on the surface of the Zr-based bulk amorphous alloy. The results show that organic carboxylic acid SAMs can also effectively reduce the surface free energy of the Zr-based bulk amorphous alloy. Although the modification from hydrophilic to hydrophobic surface is weaker, it can still increase its contact angle, and myristic acid SAMs show the highest water contact angle. With the increase of the carbon chain length, the water contact angle of myristic acid SAMs increases, and myristic acid SAMs show relatively better hydrophobic performance.

[0052] In some embodiments, HPA-DDPA mixed SAMs are adsorbed on the surface of the Ti-based bulk amorphous alloy and the Fe-based bulk amorphous alloy. The results show that on different base bulk amorphous alloys, HPA-DDPA mixed SAMs can also effectively reduce their surface free energy and realize the modification from hydrophilic to hydrophobic surface.

[0053] In some embodiments, the injection molding results show that organic phosphonic acid SAMs can effectively reduce the surface energy of Zr-based bulk amorphous alloys, thereby reducing the adhesion phenomenon during the demolding process. When injecting without applying SAMs on the mold core surface, defects such as uneven heights, top depressions, and neck constrictions often occur in the micro-columns of the rectangular grid injection molded parts, and their sizes are usually smaller than those of the micro-cavity molds. However, when injecting the Zr-based bulk amorphous alloy mold core adsorbed with SAMs, these injection molded part defects are significantly improved. Each micro-column becomes more uniform in three-dimensional shape, can be accurately replicated, and the replication rate of the shape microstructure of the micro-cavity is increased. In addition, when injecting on the mold core without SAMs treatment, the height and width of the cross-section of the micro-columns of the injection molded parts show negative deviations, that is, the microstructure shrinks and deforms. In contrast, after the mold core surface is treated with organic phosphonic acid SAMs, the height-width deviation of the micro-columns of the injection molded parts gradually decreases, and the width deviation becomes positive after treatment with HPA-DDPA SAMs, showing an expansion deformation of the microstructure.

[0054] In some embodiments, different organic carboxylic acid SAMs, namely sorbic acid SAMs and myristic acid SAMs, are adsorbed on the Zr-based bulk amorphous alloy in this application. The corresponding injection molding results show that organic carboxylic acid SAMs can also reduce the surface energy of Zr-based bulk amorphous alloys and reduce the adhesion phenomenon during the demolding process. When injecting the Zr-based bulk amorphous alloy mold core adsorbed with organic carboxylic acid SAMs, these injection molded part defects are improved. Each micro-column becomes more uniform in three-dimensional shape, and compared with the case where SAMs are not applied on the mold core surface, the injection can be more accurately replicated, and the replication rate of the shape microstructure of the micro-cavity is increased.

[0055] In some embodiments, the injection molding effects of different SAMs on the Zr-based bulk amorphous alloy mold core are studied in a micro-injection device. The mold core is manufactured by slow wire electrical discharge machining technology, and its surface structure is characterized by a laser microscope. The experiments show that SAMs treatment improves the interaction between the mold core and the polymer, and especially HPA-DDPA SAMs are outstanding in enhancing the injection molding effect. At the same time, organic carboxylic acid SAMs also play a role in enhancing the injection molding effect. The injection results show that organic phosphonic acid SAMs can reduce the surface energy of Zr amorphous alloys, reduce demolding adhesion, and improve the uniformity of micro-columns. HPA-DDPA SAMs exhibit excellent wear resistance and maintain high replication quality. The research not only confirms the effectiveness of SAMs in improving surface friction performance and demolding effect, but also provides new ideas for optimizing micro-injection technology.

[0056] In summary, this embodiment of the present application introduces the process of preparing SAMs on the surface of the bulk amorphous alloy mold core and each raw material, and specifically describes and introduces the micro-injection equipment, characterization experimental equipment and principles required for experimental research. Five different SAMs were prepared on the surface of the bulk amorphous alloy mold core, and their main surface characteristics were analyzed. Polypropylene (PP) was selected as the raw material for micro-injection molding experiments, and in-depth research was carried out on the replication filling performance, aspect ratio deviation analysis and wear resistance through the micro-injection molding equipment. The following will be described in conjunction with specific embodiments. Example 1 1. Experimental Materials and Preparation

[0057] 1.1 Materials and Reagents Zr 55 Cu 30 Al 10 Ni 5 Amorphous alloy sheets with a thickness of 1.1 mm (hereinafter referred to as Zr-based bulk amorphous alloy, purchased from Zhongnuo New Materials Technology Co., Ltd.), whose glass transition temperature Tg, crystallization temperature Tx and supercooled liquid region ΔTx are 705 K, 769 K and 64 K respectively. The Zr-based bulk amorphous alloy sheets were cut by wire electrical discharge machining (WEDM-LS, AP250LS, SODICK, Japan) to obtain rectangular thin sheet specimens with a size of 3×5 mm. The solutes used to prepare SAMs are dodecylphosphonic acid (DDPA), hexylphosphonic acid (HPA), 2,4-hexadienoic acid (sorbic acid) and myristic acid (tetradecanoic acid), all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., and the parameters are shown in Table 1.

[0058]

[0059] The cleaning agents and solvents include: absolute ethanol (analytical pure, purchased from Jiangsu Qiangsheng Functional Chemical Co., Ltd.), and primary ultrapure water (purchased from Guangzhou Hewei Medical Technology Co., Ltd.). All chemical reagents were purchased commercially and were not further purified.

[0060] 1.2 Sample Preparation Solution deposition method was used to prepare organophosphonic acid SAMs and organic carboxylic acid SAMs on the Zr-based bulk amorphous alloy respectively. The schematic diagram of the preparation process of organophosphonic acid SAMs is as Figure 1 shown, where Me represents metal elements (including Zr, Cu, Al, Ni, etc.), and R represents an alkyl chain -(CH 2 ) n CH 3 . The preparation process of organic carboxylic acid SAMs is to replace the organophosphonic acid with organic carboxylic acid, and other parameters can be adjusted accordingly.

[0061] The specific steps are as follows: First, pre-treat the Zr-based bulk amorphous alloy. Use anhydrous ethanol and ultrapure water to ultrasonically clean the sample surface for 15 minutes in sequence to remove organic contamination and inorganic impurities on the surface. Then, perform 15-minute UV / ozone treatment through a self-made ultraviolet ozone cleaning instrument to further remove residual organic substances. Finally, ultrasonically clean the sample surface with anhydrous ethanol and ultrapure water again for 15 minutes in sequence to avoid residue of pollutants. In the experiment, the bare Zr-based bulk amorphous alloy was also pre-treated as above. The solute powders were dried at a constant temperature of 80 °C for 1 hour in a vacuum drying oven (DZF-6050AB, Shanghai Kuntian Laboratory Instrument Co., Ltd., China) to remove moisture. Using anhydrous ethanol as the solvent, prepare DDPA solutions, HPA solutions, HPA-DDPA mixed solutions (mixing ratio molar is 1:1), sorbic acid solutions, and myristic acid solutions with a concentration of 5 mmol / L. Then immerse the Zr-based bulk amorphous alloy in five different solutions at room temperature for 6 - 48 hours respectively. After taking out, use primary ultrapure water to remove the residual solution on the surface and let it air dry naturally in a dust-free environment. 2. Micro-injection molding equipment

[0062] In this experiment, a micro-injection molding machine from Babyplast Company in Italy, model BABYPLAST-6-10P, was used. The detailed parameters of the equipment are listed in Table 2.

[0063]

[0064] The cooling system of the micro-injection molding machine uses a Shenzhen Dijia AC-02A chiller, with a compression power of 1.5 kW, a water tank capacity of 38 L, a cooling air volume of 2500 cubic meters per hour, a water pump power of 0.55 kW, a chilled water flow rate of 1.5 cubic meters per hour, and a maximum cooling water pump pressure of 4 kg. This system consists of a water tank and a water pump, circulating cold water through water pipes to effectively control the pressure oil and mold temperature of the injection molding machine, ensuring the normal operation of the machine while preventing overheating. 3. Test equipment in the surface test of amorphous alloy

[0065] 3.1. X-ray diffractometer (XRD) Use a Bruker D8-AA25 X-ray diffractometer to detect the amorphous state and internal crystallization state of the bare and wire-cut Zr-based bulk amorphous alloy. The incident range of this instrument is from 20° to 80°, the step size is 0.02°, and the Cu-Kα ray wavelength λ = 1.5418 is used.

[0066] 3.2. Laser confocal microscope The filling performance of rectangular grid microstructures in micro-injection molding was detected using a laser confocal microscope (KEYENCE, VK-50, Japan). To study the influence of different SAMs on the micro-injection molding process more deeply, the filling performance and height-width deviation of the microstructures of the molded plastic parts were further investigated.

[0067] 3.3、Water contact angle measuring instrument The wettability of the bare board and different SAMs surfaces was characterized and calculated by the solid-liquid contact angle of ultrapure water at room temperature using a fully automatic high-temperature water contact angle measuring instrument (DSA100S, KRUSS, Germany). Each sample was measured at least five times repeatedly.

[0068] 3.4、Other experimental instruments (1)Vacuum drying oven: In this study, a vacuum drying oven of model DZF-6050B produced by Wohong Experimental Instrument Co., Ltd. was used to dry the materials used.

[0069] (2)Electronic balance scale: The electronic balance used in this article is a domestic model HZY-A200, which is mainly used in the experiments of preparing different SAMs content ratios. 4、Test results Effect of organophosphonic acid SAMs on the contact angle of Zr-based BMGs

[0070] Zr-based bulk amorphous alloys with different organophosphonic acid SAMs coatings were prepared by the solution deposition method. The surface water contact angles of the bare board and Zr-based bulk amorphous alloys with different organophosphonic acid SAMs are as Figure 2 shown. The results show that the water contact angle on the bare board surface is 60.1°, indicating that the bare board surface has obvious hydrophilicity. However, after immersing the bare board in the organophosphonic acid solution for 6 hours, the water contact angles increased to 83° for HPA SAMs, 93° for DDPA SAMs, and 104.1° for HPA-DDPA SAMs, respectively. Therefore, it is proved that the adsorption of HPA, DDPA, and HPA-DDPA molecules on the bare board surface is realized, and these three SAMs can effectively reduce the surface free energy of Zr-based bulk amorphous alloys, modifying the surface of Zr-based bulk amorphous alloys from a hydrophilic surface to a hydrophobic surface.

[0071] Among the three different SAMs, the water contact angle of the mixed HPA-DDPA SAMs is the largest, followed by the DDPA SAMs, and the water contact angle of the HPA SAMs is the smallest. This is because the water contact angle is significantly affected by the packing density of phosphonic acid molecules. As the packing density increases, the surface free energy decreases and the water contact angle increases. In addition, for pure SAMs, the longer the molecular chain, the higher the packing density. Therefore, the packing density and water contact angle of the DDPA SAMs with long chains are higher than those of the HPA SAMs with short chains. For the mixed HPA-DDPA SAMs, since the molecules of different lengths do not phase-separate and have the same head anchoring groups, their adsorption does not have an obvious preferential order. The short HPA molecules can insert into the pores between the long DDPA molecules, which makes the mixed HPA-DDPA SAMs have a higher packing density than the pure SAMs. At the same time, the increase in packing density also increases the orderliness of the SAMs and reduces the poor packing. Therefore, the mixed HPA-DDPA SAMs have the highest packing density and water contact angle. Effect of Organic Carboxylic Acid SAMs on the Contact Angle of Zr-Based BMGs

[0072] Zr-based bulk amorphous alloys with different organic carboxylic acid SAMs coatings were prepared by solution deposition method. The surface water contact angles of the bare plate and the Zr-based bulk amorphous alloys with different organic carboxylic acid SAMs are as Figure 3 shown. The results show that the water contact angle on the bare plate surface is 60.1°, indicating that the bare plate surface has obvious hydrophilicity. However, after immersing the bare plate in the organic carboxylic acid solution for 6 hours, the water contact angles increased to 61.7° for sorbic acid SAMs and 72.4° for myristic acid SAMs, respectively. Therefore, sorbic acid and myristic acid molecules were adsorbed on the bare plate surface. Although the surface of the Zr-based bulk amorphous alloy was modified from a hydrophilic surface to a hydrophobic surface weakly, the contact angle performance was still improved. Among the two different SAMs, the water contact angle of the myristic acid SAMs is the largest, while the water contact angle of the sorbic acid SAMs is the smallest. Effect of Organic Phosphonic Acid SAMs on the Contact Angle of Ti-Based and Fe-Based Bulk Amorphous Alloys

[0073] Comparing the influence on the wetting properties of different base bulk amorphous alloys, and using Ti 20 Zr 20 Hf 20 Be 20 Ni 20 amorphous alloy plates (hereinafter referred to as Ti-based bulk amorphous alloys) and Fe 69 B 23 Nb 4 Y 4Amorphous alloy sheet (hereinafter referred to as Fe-based bulk amorphous alloy), and the Fe-based bulk amorphous alloy and the Ti-based bulk amorphous alloy are modified according to the above method.

[0074] HPA-DDPA SAMs coated Ti-based, Fe-based and Zr-based bulk amorphous alloys were prepared by solution deposition. The surface water contact angles of bare plate and HPA-DDPA SAMs coated Ti-based, Fe-based and Zr-based bulk amorphous alloys are shown in Figure 2. Figure 4 As shown in the figure. As can be seen from the figure, the water contact angles on the surfaces of Ti-based, Fe-based and Zr-based bulk bare boards are 78.6°, 75.0° and 60.1°, respectively, which indicates that the surfaces of Ti-based, Fe-based and Zr-based bulk bare boards are all significantly hydrophilic. However, after the bare boards were immersed in the HPA-DDPA phosphonic acid solution for 6 hours, the water contact angles increased to 89.5° for Ti-based bulk, 91.3° for Fe-based bulk and 101.4° for Zr-based bulk, respectively, and the corresponding increase ratios were approximately 13.9%, 21.7% and 68.7%. Therefore, this experiment achieved the adsorption of HPA-DDPA molecules on the surfaces of Ti-based, Fe-based and Zr-based bulk bare boards, and this SAMs can modify the surfaces of different bulk amorphous alloys from hydrophilic surfaces to hydrophobic surfaces. Among the three different bulk amorphous alloys, the Zr-based bulk amorphous alloy has the largest water contact angle ratio, followed by the Fe-based bulk amorphous alloy, while the Ti-based bulk amorphous alloy has the smallest water contact angle ratio, which shows that the SAMs coating is also effective for the wetting properties of other non-Zr-based bulk amorphous alloys. Example 2 1. Core surface morphology and process parameters

[0075] Wire-cut EDM (WEDM-LS) is widely used because it does not apply mechanical forces to the workpiece and electrode when machining difficult-to-machine materials. Compared with other machining methods, WEDM-LS is completely immersed in an oil environment, which can not only isolate oxygen but also remove heat in time to prevent BMG from crystallizing and oxidizing during machining. This technology is particularly suitable for machining Zr-based bulk amorphous alloy mold cores. During the machining of the mold core of WEDM-LS (AP250LS, Sodick, Japan), a brass wire with a diameter of 100μm is used to discharge the Zr-based bulk amorphous alloy substrate according to a preset trajectory. The pulse current is turned on for 60 milliseconds and off for 40 milliseconds in one cycle. The use of oil-based dielectric fluid can create an environment without external air, which can prevent external oxygen from interfering with the machined surface and effectively remove the debris generated during the machining process.

[0076] like Figure 5It is a prepared Zr-based bulk amorphous alloy mold core. Among them, (a) is the prism array microstructure. By controlling the movement trajectory of the wire electrode, a Zr-based bulk metallic glass (BMG) mold core with a surface having a prism array microstructure was successfully processed. A laser confocal microscope was used to finely measure a single prism manufactured. Its width and height are 112.3 ± 0.72 μm and 281.7 ± 0.46 μm respectively, the aspect ratio of the prism is 2.5:1, and the spacing between adjacent prisms is 195.4 ± 0.91 μm. Such acceptable errors in dimensions are likely due to the release of residual stress in the amorphous alloy mold core after the electroforming process, which in turn leads to the shrinkage of the microcavity. In the enlarged image, namely Figure 5 In (b), submicron-sized discharge pits caused by spark discharge corrosion are observed on the surface of the mold core. After measurement, the surface roughness Ra of the upper surface and the lower surface of the microstructure are 0.89 μm and 1.73 μm respectively. This difference in surface roughness between the upper and lower surfaces may be due to the structural limitations of the cylindrical wire electrode and the effect of discharge concentration, resulting in relatively lower surface quality of the lower surface. The XRD results of the Zr-based bulk amorphous alloy are shown in (d) of the figure. A broad diffraction peak can be found at about 37.4 °C, which confirms its completely amorphous nature, and it still remains completely amorphous after slow wire electrical discharge machining. Figure 5 (c) of Figure 5 is the three-dimensional solid diagram of the mold core. The micron columns of the insert will be replicated into a rectangular grid microstructure. The specific dimensions of the mold core are shown in Figure 5 (e).

[0077] Furthermore, PP was selected as the raw material, and experiments were carried out using a Babyplast micro-injection molding machine. The research method used the single-factor analysis method, keeping the molding process parameters unchanged, including melt temperature, injection speed, injection pressure, etc. The detailed parameters are listed in Table 3. In this experiment, the effects of five different SAMs-adsorbed Zr-based bulk amorphous alloy mold cores on the demolding force and injection molding effect were analyzed. 5 - 20 samples were selected from each batch of injection molded parts for analysis. The injection molded samples are shown in Figure 6 . Under each group of experimental conditions, after ensuring the stable operation of the injection molding machine, 5 molded standard samples were selected for morphological structure analysis under a laser confocal microscope. 2. Research on the micro-injection molding effect of SAMs

[0079] 2.1. Influence of organophosphonic acid SAMs on injection molding quality The PP injection molded products after the first demolding were selected and observed under a laser confocal microscope for the microstructure. The influence of the amorphous alloy mold core modified with organophosphonic acid SAMs on the demolding effect was illustrated by the three-dimensional morphology of the matrix array microstructure. The two-dimensional cross-section of a rectangular grid microstructure was intercepted and analyzed for replication quality, and in Figure 7Its two-dimensional profile is shown in [Figure 0]. It should be noted that for the same sample, at least three positions are intercepted, and the most representative two-dimensional profile is selected for analysis. It can be seen that when the amorphous alloy mold core is not modified with SAMs, the width of the micro-columns of the micro-injection molded PP sample is relatively small, and most of the micro-columns are not fully replicated. However, after the alkylphosphonic acid SAMs are deposited on the surface of the amorphous alloy, the micro-injection molding of the PP sample is carried out using the modified mold core, and the morphology and fullness of the micro-columns are significantly improved. Therefore, the micro-structure of the mold core can be well replicated and successfully demolded from the amorphous alloy mold core.

[0080] To quantitatively analyze the demolding quality, the deviation percentages of the height and width of the micro-column cross-section are defined to describe the deviation between the cross-section of the injection-molded micro-structure and the micro-cavity in the amorphous alloy mold core. The calculation formula is as follows:

[0081] where , and represent the replication rate of the micro-structure on the part surface, the cross-sectional area of the micro-columns of the injection-molded part, and the cross-sectional area of the micro-columns of the mold core, respectively.

[0082] Through Figure 7 the multi-dimensional perspective shown, the three-dimensional surface morphology of the injection-molded rectangular grid micro-structure and its corresponding two-dimensional cross-sectional view are observed after PP is injection-molded on the bare board and the Zr-based amorphous alloy surface treated with different self-assembled monolayers. Figure 7The injection molded parts of (a), (b), (c), and (d) therein respectively represent the microstructures formed on the surfaces treated with bare board, HPA SAMs, DDPA SAMs, and HPA-DDPA SAMs. By observing the two-dimensional cross-section of the rectangular grid microstructure under the bare board condition, it can be seen that its surface morphological structure exhibits significant injection molding defects compared with the injection molded parts treated with SAMs. This may be due to the higher surface energy caused by not performing any surface treatment, which triggers the shrinkage of the polymer. In addition, a significant reduction in the microcolumn height can be observed in the two-dimensional cross-section, which may be caused by the shrinkage during the demolding process. The injection molded parts of Zr-based amorphous alloy injection molded with HPASAMs show more smooth microstructure characteristics, and the height of its microcolumns increases relative to the bare board treatment. This indicates that the use of HPA helps to reduce the friction between the polymer and the mold, thereby reducing the microstructure deformation during demolding. For the injection molded parts of Zr-based amorphous alloy mold core injection molded with DDPA SAMs, the height and width of its rectangular grid microstructure are similar to those of the injection molded parts treated with HPA SAMs, but the height change is more gentle and the overall morphology is more complete. This shows that DDPA SAMs exhibit significant effects in maintaining the dimensional stability of the microstructure and have significant advantages in reducing the friction between the polymer and the mold. The injection molded parts of Zr-based amorphous alloy mold core injection molded with HPA-DDPA SAMs show extremely precise and consistent microstructure characteristics in the three-dimensional topography map, and its two-dimensional cross-section also shows the smallest height and width deviations, achieving the best structure replication effect. This shows that the hybrid chain SAMs can effectively provide high-quality surface protection by combining the advantages of single SAMs and relying on a higher packing density, maintaining the dimensional stability of the microstructure during the demolding process, thus verifying the effectiveness of organophosphonic acid SAMs in optimizing the surface friction performance of amorphous alloys.

[0083] Figure 8 It shows the change in the replication rate of the microstructure of polypropylene (PP) material injection molded parts when using a bare board, HPA SAMs, DDPA SAMs, and HPA-DDPA SAMs as the mold core while other molding process parameters are fixed. The combination shows that compared with the bare board, the replication rate of the microcolumns of the injection molded parts treated with self-assembled monolayers has increased, and the increase is most significant for the HPA-DDPASAMs hybrid chain SAMs. When HPA SAMs, DDPA SAMs, and HPA-DDPASAMs are adsorbed on the surface of the mold core respectively, the replication rate of the rectangular grid microstructure of PP increases from 67.4% to 74.5%, 76.5%, and 81.6% respectively, and the corresponding increase ratios are approximately 7.1%, 9.1%, and 14.2%.

[0084] The main reason for this phenomenon can be attributed to the dominant role of capillary force on hydrophilic surfaces during the adhesion process. Since capillary force is the main force affecting adhesion and is particularly strong on hydrophilic surfaces, the friction performance of hydrophilic surfaces is lower than that of hydrophobic surfaces. In this case, the friction coefficient of the bare board surface is higher than that of the surface treated with phosphonic acid SAMs, which in turn affects the replication rate of the microstructure. In addition, the mixed-chain SAMs of HPA-DDPA have a higher packing density and stronger order compared to the single-chain HPA and DDPA, which weakens the van der Waals interaction per unit area, thereby reducing the interaction between the inner wall of the mold core and PP. This weakened interaction promotes the fluidity of the melt in the cavity, ultimately enhancing the replication performance of the microstructure.

[0085] To quantify the demolding quality, the percentage deviation is defined to describe the dimensional difference between the injection-molded structure and the mold core. The calculation formula is as follows:

[0086] where 、 and are the percentage deviation in width, the average width of the microstructure, and the width of the mold core, respectively;

[0087] where 、 and are the percentage deviation in height, the average height of the microstructure, and the height of the mold core, respectively.

[0088] In the application, the dimensional deviation of the injection-molded rectangular grid microstructure relative to the Zr-based bulk amorphous alloy mold core has been quantified, and the specific data are shown as Figure 9 indicated. For the micro-column profile, the height deviation generally shows a negative value, which indicates that the micro-columns of the injection-molded parts fail to achieve complete replication after demolding from the amorphous alloy mold core under all experimental conditions. When HPA SAMs, DDPA SAMs, and HPA-DDPA SAMs are deposited on the surface of the mold core respectively, the height deviation of the micro-column profile of the injection-molded parts gradually decreases, from -26.8%, -21%, -19.9% to -15.8% respectively. This change is attributed to the fact that SAMs endow the mold core with better anti-adhesion performance by reducing its surface energy. This improved anti-adhesion performance is beneficial to enhancing the fluidity of the melt in the cavity, thereby achieving a smaller height deviation.

[0089] In the case where no self-assembled coating is adsorbed on the mold core surface, the width deviation of the microstructure is -5.9%, indicating shrinkage deformation. However, when HPA SAMs, DDPA SAMs, and HPA-DDPA SAM are deposited on the mold core surface, the width deviation of the microcolumn profile gradually decreases, dropping to -4.3%, -1.2%, and 0.2% respectively. The width deviation of HPA-DDPA SAMs changes from negative to positive, indicating that the rectangular grid microstructure undergoes shrinkage deformation rather than expansion deformation. The main reason for this phenomenon is the relatively small van der Waals interaction force, which weakens the adhesion and friction between the polymer and the mold core during demolding, ensuring the morphological difference of the rectangular grid microstructure.

[0090] Considering the dimensional deviations of the mold core and the microstructure comprehensively, it is found that the PP rectangular grid microstructure formed by bare-board injection molding shows the worst height and width deviations. Therefore, it can be inferred that the surface free energy of the mold core is the key factor affecting the replication quality.

[0091] 2.2 Influence of Organic Carboxylic Acid SAMs on Injection Molding Quality The PP injection-molded products after the first demolding were selected and observed by a laser confocal microscope to study the microstructure. The influence of the amorphous alloy mold core modified with organic carboxylic acid SAMs on the demolding effect was illustrated by the three-dimensional morphology of the matrix array microstructure. The two-dimensional cross-section of a rectangular grid microstructure was intercepted and its replication quality was analyzed, and its two-dimensional contour is shown in Figure 10 It should be noted that for the same sample, at least 3 positions were intercepted, and the most representative two-dimensional contour was selected for analysis. It can be seen that when the amorphous alloy mold core is not modified with SAMs, the width of the microcolumns of the micro-injection molded PP samples is relatively small, and most of the microcolumns are not fully replicated. However, after the organic carboxylic acid SAMs are deposited on the surface of the amorphous alloy, when the modified mold core is used for micro-injection molding of PP samples, the morphology and fullness of the microcolumns are still improved. Therefore, the microstructure of the mold core can be well replicated and successfully demolded from the amorphous alloy mold core.

[0092] The deviation between the cross-section of the injection-molded microstructure and the microcavity in the amorphous alloy mold core is described by formula (1).

[0093] Through Figure 10 the multi-dimensional perspectives shown, the three-dimensional surface morphology and the corresponding two-dimensional cross-sectional views of the injection-molded rectangular grid microstructure of PP after injection molding on the bare board and the Zr-based amorphous alloy surface treated with different self-assembled monolayers were observed. Figure 10The injection molded parts of (a), (b), and (c) represent the microstructures formed on the surfaces treated with bare board, sorbic acid SAMs, and myristic acid SAMs, respectively. It can be seen that the surface morphological structure of the two-dimensional cross-section of the rectangular grid microstructure under the bare board condition shows significant injection molding defects compared with the injection molded parts treated with SAMs. Then, the injection molded parts of Zr-based amorphous alloy injection molded with sorbic acid SAMs show relatively smooth microstructure characteristics, and the height of its micro-columns increases slightly compared with the bare board treatment. This indicates that the use of sorbic acid and phosphonic acid SAMs also helps to reduce the friction between the polymer and the mold, thereby reducing the microstructure deformation during demolding. Secondly, for the injection molded parts of Zr-based amorphous alloy mold cores treated with myristic acid SAMs, the height of its rectangular grid microstructure is similar to that of the injection molded parts treated with HPA SAMs, and its width is improved compared with the injection molded parts treated with HPA SAMs. This indicates that myristic acid SAMs show effectiveness in maintaining the dimensional stability of the microstructure and have advantages in reducing the friction between the polymer and the mold, thus verifying the effectiveness of carboxylic acid SAMs in optimizing the surface friction properties of amorphous alloys.

[0094] Figure 11 shows the change in the replication rate of the microstructure of polypropylene (PP) material injection molded parts when using a bare board, sorbic acid SAMs, and myristic acid SAMs as the mold core while other molding process parameters are fixed. Combining Figure 10 It can be clearly seen that compared with the bare board, the replication rate of the micro-columns of all injection molded parts treated with self-assembled monolayers has increased. When sorbic acid SAMs and myristic acid SAMs are adsorbed on the surface of the mold core respectively, the replication rate of the rectangular grid microstructure of PP increases from 67.4% to 70.7% and 71.5% respectively, and the corresponding increase ratios are approximately 3.3% and 4.1%.

[0095] Formulas (2) and (3) are used to quantify the demolding quality, and the percentage deviation is defined to describe the dimensional difference between the injection molded structure and the mold core. In this experiment, the dimensional deviation of the injection molded parts of the rectangular grid microstructure relative to the Zr-based bulk amorphous alloy mold core has been quantified, and the specific data is as Figure 12 shown. When sorbic acid SAMs and myristic acid SAMs are deposited on the surface of the mold core respectively, the height deviation of the micro-column profile of the injection molded part decreases slightly, from -26.8% to -25.5% and -24.1% respectively. When no self-assembled coating is adsorbed on the surface of the mold core, the width deviation of the microstructure is -5.9%, indicating shrinkage deformation. However, when sorbic acid SAMs and myristic acid SAMs are deposited on the surface of the mold core, the width deviation of the micro-column profile gradually decreases, to -2.2% and -1.4% respectively.

[0096] Considering the dimensional deviations of the mold core and the microstructures comprehensively, the microstructures of the mold core adsorbed with organic carboxylic acid SAMs are improved compared to those of the mold core without the self-assembled coating adsorbed. It can be shown that the organic carboxylic acid SAMs can improve the injection molding effect.

[0097] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A metallic glass, characterized in that: The metallic glass comprises an amorphous alloy substrate and a monomolecular layer bonded to the surface of the amorphous alloy substrate, wherein the material of the monomolecular layer comprises at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule.

2. The metallic glass according to claim 1, wherein: The organic phosphonic acid molecule includes an alkylphosphonic acid having 4 to 18 carbon atoms; And / or, the organic carboxylic acid molecule includes at least one of olefinic acid having 4-18 carbon atoms and alkanoic acid having 4-18 carbon atoms.

3. The metallic glass according to claim 1, wherein: The material of the monomolecular layer is an organic phosphonic acid molecule, and the organic phosphonic acid molecule includes at least one of n-hexylphosphonic acid, n-decylphosphonic acid, n-dodecylphosphonic acid, n-hexadecylphosphonic acid, and n-octadecylphosphonic acid.

4. The metallic glass according to any one of claims 1 to 3, characterized in that: The amorphous alloy substrate includes at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate and an iron-based amorphous alloy substrate.

5. A method for preparing metallic glass, characterized in that: include: Providing an amorphous alloy substrate and a modification solution, wherein the solute of the modification solution includes at least one of an organic phosphonic acid molecule and an organic carboxylic acid molecule; The amorphous alloy substrate is immersed in the modification solution, and then taken out and dried to obtain metallic glass.

6. The method for preparing metallic glass according to claim 5, characterized in that: The organic phosphonic acid molecule includes an alkylphosphonic acid having 4 to 18 carbon atoms; and / or, the organic carboxylic acid molecule comprises at least one of an olefinic acid having 4 to 18 carbon atoms and an alkanoic acid having 4 to 18 carbon atoms; And / or, the amorphous alloy substrate includes at least one of a zirconium-based amorphous alloy substrate, a titanium-based amorphous alloy substrate and an iron-based amorphous alloy substrate.

7. The method for preparing metallic glass according to claim 5, characterized in that: The solute concentration in the modification solution is 2-8 mmol / L; And / or, the solvent in the modification solution is selected from alcohol solvents.

8. The method for preparing metallic glass according to claim 5, characterized in that: The soaking time is 6-50h; And / or, the drying process includes natural air drying.

9. The method for preparing metallic glass according to any one of claims 5 to 8, characterized in that: The amorphous alloy substrate is pretreated before being immersed, and the pretreatment includes: firstly ultrasonic cleaning with alcohol reagent and water in sequence, then ultraviolet ozone treatment, and then ultrasonic cleaning with alcohol reagent and water in sequence.

10. A mold core for injection molding, characterized in that: The mold core has a microstructure surface, and the material of the mold core is bulk metallic glass, which includes the metallic glass described in any one of claims 1 to 4 and / or metallic glass prepared by the method for preparing the metallic glass described in any one of claims 5 to 9.

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