WO2013087040A1

WO2013087040A1 - Method of manufacturing amorphous alloy article

Info

Publication number: WO2013087040A1
Application number: PCT/CN2012/086773
Authority: WO
Inventors: Qing Gong; Bingzhong TANG; Faliang Zhang
Original assignee: Shenzhen Byd Auto R&D Company Limited; Byd Company Limited
Priority date: 2011-12-15
Filing date: 2012-12-17
Publication date: 2013-06-20
Also published as: CN102433518A

Abstract

A method of manufacturing an amorphous alloy article is provided. The method comprises steps of: placing a prefabricated member made of a predetermined material having a different property from that of an amorphous alloy into a mold, in which the predetermined material is dissolvable in a predetermined solution; casting a fusant of the amorphous alloy into the mold such that the prefabricated member and the amorphous alloy are joined to form a semifinished product, in which a part of the prefabricated member is exposed out of the amorphous alloy; and placing the semifinished product into the predetermined solution to dissolve the prefabricated member.

Description

METHOD OF MANUFACTURING AMORPHOUS ALLOY ARTICLE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and benefits of Chinese Patent Application Serial No. 201110421219.5, filed with the State Intellectual Property Office of P. R. China on December 15, 2011, the entire contents of which are incorporated herein by reference.

FIELD

The present disclosure relates to a field of amorphous alloy, and more particularly to method of manufacturing an amorphous alloy article.

BACKGROUND

An amorphous alloy is also referred as metal glass. Due to a special atomic disordered arrangement structure, the amorphous alloy has excellent physical properties and chemical properties, such as high yield strength, high hardness, hyperelasticity (high elastic limit), high abrasion resistance and high corrosion resistance, different from the conventional crystal metal material. Therefore, the amorphous alloy is considered to be a new generation of structural material which is developed rapidly.

The amorphous alloy, especially a bulk amorphous alloy, has a glass state property and a large supercooled liquid region, therefore, it has an excellent flowability and formability. However, once the amorphous alloy is molded, the secondary molding and the secondary processing thereof are very hard to perform due to its relatively high hardness and metastable microstructure. For example, the hardness of zirconium based amorphous alloy and copper based amorphous alloy may be larger than 5GPa (Vickers hardness), and the hardness of iron based amorphous alloy or nickel based amorphous alloy may be up to 8GPa. Therefore, it is difficult to manufacture relatively complicated amorphous alloy articles, and it is difficult to design and apply the amorphous alloy because of the physical and chemical properties thereof.

Meanwhile, in order to meet the requirements of excellent flowability and the relatively higher cooling rate of the amorphous alloy, a metal mold is often used to form the amorphous alloy article. However, the forming using the metal mold requires a suitable demoulding structure to facilitate the production. It is difficult to design the demoulding structure for the article having a complicated structure, therefore, a subsequent machining is needed, thus increasing the manufacturing cost, especially for the amorphous alloy having high hardness.

Although a lost wax casting is a better choice for manufacturing the complicated parts, its processing accuracy is lower than that of the metal mold forming.

SUMMARY

The present disclosure is directed to solve at least one of the problems existing in the prior art.

Accordingly, a method of manufacturing an amorphous alloy article is provided, which has at least one advantage of simplicity, high efficiency and low cost.

According to embodiments of the present disclosure, a method of manufacturing an amorphous alloy article is provided. The method comprises steps of: placing a prefabricated member made of a predetermined material having a different property from that of an amorphous alloy into a mold, in which the predetermined material is dissolvable in a predetermined solution; casting a fusant of the amorphous alloy into the mold such that the prefabricated member and the amorphous alloy are joined to form a semifinished product, in which a part of the prefabricated member is exposed out of the amorphous alloy; and placing the semifinished product into the predetermined solution to dissolve the prefabricated member.

With the method of manufacturing the amorphous alloy article according to embodiments of the present disclosure, by preparing the prefabricated member having a complicated structure, planting the prefabricated member in the amorphous alloy member via casting, and dissolving the prefabricated member, the amorphous alloy article, having a complicated structure/shape inverse of that of the part of the prefabricated member in the amorphous alloy, may be obtained, which is difficult to make by means of the conventional metal mold forming method.

Additional aspects and advantages of the embodiments of the present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the disclosure will become apparent and more readily appreciated from the following descriptions taken in conjunction with the drawings in which: Fig. 1 is a flow chart of a method of manufacturing an amorphous alloy article according to an embodiment of the present disclosure;

Fig. 2a is a schematic view of a semifinished product formed by joining an amorphous alloy and a prefabricated member according to an embodiment of the present disclosure;

Fig. 2b is a schematic view of the amorphous alloy article obtained from the semifinished product in Fig. 2a; and

Fig. 3 is a schematic view of the semifinished product formed by joining the amorphous alloy and the prefabricated member according to another embodiment of the present disclosure. DETAILED DESCRIPTION

Embodiments of the present disclosure will be described in detail in the following descriptions, examples of which are shown in the accompanying drawings, in which the same or similar elements and elements having same or similar functions are denoted by like reference numerals throughout the descriptions. The embodiments described herein with reference to the accompanying drawings are explanatory and illustrative, which are used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure.

The method of manufacturing an amorphous alloy article according to embodiments of the present disclosure will be described with reference to Fig. 1.

The method of manufacturing an amorphous alloy article according to embodiment of the present disclosure mainly comprises steps of: providing a prefabricated member having a predetermined structure/shape and made of a predetermined material having a different property from that of an amorphous alloy, forming a semifinished product by joining the prefabricated member and an amorphous alloy, and dissolving the prefabricated member of the semifinished product by to obtain the amorphous alloy article having a structure inverse of that of the part of the prefabricated member in the amorphous alloy during forming the semifinished product.

In the present disclosure, the term "predetermined material" refers to a material having a property and/or characteristic (material and/or chemical property) different from that of the amorphous alloy to be joined therewith, such that the prefabricated member will be dissolved and the amorphous alloy will not be dissolved when the semifinished product in a predetermined solution. It should be understood that the predetermined material may be a plastic material, a metal material or another amorphous alloy having different composition from the amorphous alloy to be joined with the predetermined material, as long as the predetermined material can be dissolved and the amorphous alloy will not be dissolved when the semifinished product formed by joining the prefabricated member and an amorphous alloy is placed into the predetermined solution.

It should be understood that the method of manufacturing the amorphous alloy article according to embodiments of the present disclosure may be suitable for manufacturing an article of any amorphous alloy, and more particularly of an amorphous alloy having a high corrosion resistance or has a passivation property in a predetermined solution.

The zirconium based amorphous alloy is preferable, because it has good formability, high corrosion resistance and passivation property. More preferably, the zirconium based amorphous alloy may have a formula of Zr_aCubAl_cNidM_e , where M is one or more elements selected from the group consisting of Fe, Co, Mn, Cr, Ti, Hf, Ta, Nb, C and rare earth elements; and where a, b, c, d, and e is an atomic percentage of the respective elements, and 40=¾a^:¾70, lS^b^S, S^c^ 15, 5 s≡ds≡ 15, 0=¾e=¾5, and a+b+c+d+e=100.

The above zirconium based amorphous alloy may contain impurity elements, and an atomic percentage of the impurity elements is not greater than 2%.

In particular, the method of manufacturing the amorphous alloy article according to embodiments of the present disclosure comprises the following steps a) to c):

Step a): the prefabricated member having a predetermined shape and made of the predetermined material having a different property from that of the amorphous alloy is placed into a mold, in which the predetermined material is dissolvable in a predetermined solution.

Particularly, the prefabricated member made of the predetermined material having a different property from that of the amorphous alloy and having a predetermined shape is prepared. To this end, according to a particular structure/shape formed in the amorphous alloy article, a part of the prefabricated member which will be planted in the amorphous alloy during casting/molding is manufactured to have a structure/shape inverse of the particular structure/shape.

With regard to the material of the prefabricated member, it has a better chemical activity and a better dissolving property in the predetermined solution compared to the amorphous alloy, so that it is advantageous for removing the prefabricate member by disposing the semifinished product in the predetermined solution subsequently. Based on this, preferably, the prefabricated member has a dissolving rate of at least 100 times greater than that of the amorphous alloy in the predetermined solution.

In addition, if the prefabricated member has a high temperature stability, a melting damage or a serious deformation would not happen during forming the semifinished product. Therefore, a material having a high temperature stability, such as a metal material having a high melting point or a plastic having a low thermal conductivity, is preferably selected to manufacture the prefabricated member. Thus, in view of high temperature stability, cost and processing complexity, the predetermined material of the prefabricated member may preferably be selected from a group consisting of a plastic, an aluminum alloy, a copper alloy, a magnesium alloy, a zinc alloy, a black metal, and any combination thereof.

If a metal is used to manufacture the prefabricated member, the melting point of the metal is preferably higher than 400 ^°C . If a plastic material is used to manufacture the prefabricated member, the thermal conductivity of the plastic material is preferably less than 1 w/mk.

Furthermore, even if the melting point of the plastic material used is low (generally ranging from about 120^°C to about 270 ^°C), but the thermal conductivity thereof is very small (the thermal conductivity of the plastic material generally ranges from 0.1 w/mk to 10 w/mk, and the thermal conductivity of the metal material generally ranges from 10 w/mk to 100 w/mk), therefore, a tiny portion of a surface of the prefabricated member of plastic material is melt when the plastic material is contacted with amorphous alloy fusant, without melting and serious deformation of the entire prefabricated member. The heat of the fusant of the amorphous alloy is mainly taken away by the metal mold. Therefore, when the requirement for the accuracy or the surface accuracy of the structure formed in the amorphous alloy article is high, the prefabricated member may be preferably made of a metal. W hen the cost should be low and the requirement for the accuracy or the surface accuracy of the structure formed in the amorphous alloy article is low, the prefabricated member may be preferably made of a plastic material.

There is no particular requirement for the shape/structure of the prefabricated member. Considering that it is hard to manufacture the amorphous alloy article with a groove having a negative draft angle by the metal mold casting method, the prefabricated member may preferably have a dovetail shape (as shown by reference number 1 in Fig. 2a), so that by removing the prefabricated member (particularly, the part of the prefabricated member in the amorphous alloy), the amorphous alloy article with the dovetail groove having the negative draft angle is obtained (as shown in Fig. 2b).

Furthermore, since it is hard to process the amorphous alloy to have a threaded hole due to the high hardness and strength thereof, preferably, the prefabricated member may be a screw (as shown in Fig. 3) such that the amorphous alloy article having a threaded hole may be formed. In the present disclosure, it is understood that the screw has a shape/structure inverse of that of the threaded hole.

Furthermore, there is no particular limitation on the method of forming the prefabricated member, and any known method may be utilized according to the particular shape and material of the prefabricated member.

Step b): the fusant of the amorphous alloy is poured/cast into the mold, such that the prefabricated member and the amorphous alloy are joined to form a semifinished product, in which a part of the prefabricated member is exposed out of the amorphous alloy.

According to some embodiments, the whole prefabricated member may be in the amorphous alloy and exposed out of the surface of the semifinished product, that is, the amorphous alloy does not enclose the prefabricated member. Alternatively, a part of the prefabricated member is inserted into the amorphous alloy and the other part of the prefabricated member is located outside of the amorphous alloy.

Particularly, the prefabricated member is placed and positioned within the mold. A suitable amorphous alloy is melt, and the fusant of the amorphous alloy is cast into the mold inwhich the fixed prefabricated member is disposed, and a part of the prefabricated member is exposed out of the amorphous alloy.

There is no particular limitation on the casting method of the amorphous alloy. For example, a general known die casting device may be used to perform the casting operation.

Therefore, the semifinished product is formed. Because the amorphous alloy has an excellent flowability and copy property, the fusant of the amorphous alloy may wrap up a part of the prefabricated member such that a structure inverse of that of the part of the prefabricated member wrapped up by the amorphous alloy is formed in the amorphous alloy.

Step c): the semifinished product is taken out of the mold and immerged into a predetermined solution to dissolve the prefabricated member.

When the prefabricated member is made of the plastic material, it may be removed by dissolving with an organic solvent. For example, the prefabricated member may be made of an ABS plastic, and the ABS plastic may be removed by dissolving with an ethyl acetate.

When the prefabricated member is made of at least one selected from the copper alloy, the magnesium alloy, the zinc alloy and the black metal, it may be removed by dissolving with a strong acid solution (such as a concentrated nitric acid, a concentrated sulfuric acid and a nitrohydrochloric acid ).

When the prefabricated member is made of the aluminum alloy which is dissolvable in both the strong acid and a strong alkali such as a sodium hydroxide and a potassium hydroxide, it may be removed by dissolving with the strong acid solution or the strong alkali solution.

There is no particular limitation on the concentration of the predetermined solution, as long as the prefabricated member can be dissolved therein.

Finally, the semifinished product without the prefabricated member is taken out of the predetermined solution to obtain the amorphous alloy article.

Therefore, the amorphous alloy article with a required structure is manufactured.

The examples of the present disclosure will be described below.

Example 1

In the present example, a copper alloy C3604 is selected as the predetermined material of the prefabricated member, a HNO₃ solution with a concentration of 7mol/L is selected as the predetermined solution, and the amorphous alloy has the formula of Zr5₂AlioCu3oNi₇.

Firstly, the copper alloy is processed to be a copper alloy screw 10 with a suitable size (as shown in Fig. 3), and then the copper alloy screw 10 is placed and positioned within the mold.

Next, the amorphous alloy having the formula of Zr5₂AlioCu3oNi₇ is melted and cast into the mold with the fixed copper alloy screw 10 therein by means of the die casting device. As shown in Fig.3, the semifinished product made of the copper alloy screw 10 (the prefabricated member) and the amorphous alloy 20 is obtained.

Finally, the semifinished product is taken out of the mold and placed into the HNO₃ solution with the concentration of 7mol/L for 30 minutes. After dissolving the copper alloy screw 10, the amorphous alloy article is taken out of the HNO₃ solution and washed to obtain the amorphous alloy article with the threaded hole.

It is known that the threaded structure (the threaded hole) is hard to form directly by the mold.

Further, because the hardness of the amorphous alloy is up to 5GPa and the strength of the amorphous alloy is up to 2000MPa, it is hard to form the threaded structure in the amorphous alloy by machining method such as drilling and threading after the amorphous alloy is cured, and the machining method needs a hard cutting tool (even a tungsten steel tool) which is expensive. In addition, the lifetime of the cutting tool will be very short, thus increasing the manufacturing cost highly and decreasing a manufacturing efficiency.

With the method of manufacturing the amorphous alloy article according to embodiments of the present disclosure, the screw of copper alloy is manufactured, and then a part of the screw of copper alloy is implanted into the amorphous alloy via molding to form the threaded hole in the amorphous alloy, and finally the amorphous alloy having the threaded hole may obtained by dissolving the copper alloy screw.

The screw of copper alloy has a better dissolving property in the HN0₃ solution with the concentration of 7mol/L (the dissolving rate of the copper alloy screw is 5186mm/a, and the dissolving rate of the amorphous alloy is only 0.02mm/a) and a better chemical activity than the amorphous alloy, so that the screw of copper alloy is dissolved rapidly by the HNO₃ solution with the concentration of 7mol/L, but the amorphous alloy is not dissolved and corroded apparently due to the excellent corrosion resistance thereof, thus ensuring the stability of the appearance and size of the amorphous alloy article. Furthermore, the screw of copper alloy has a high temperature stability (the melting point of the copper alloy is about 1000^°C , and the molding temperature of the amorphous alloy ranges from about 600 ^°C to about 700 ^°C), when the fusant of the amorphous alloy is cast into the mold, the melting damage and the serious deformation would not happen to the copper alloy screw, thus ensuring the stability of the threaded structure of screw of copper alloy during molding.

Example 2

In the present example, ABS plastic is selected as the predetermined material of the prefabricated member, ethyl acetate is selected as the predetermined solution, and the amorphous alloy has the formula of Zr5₂AlioCu3oNi₇.

Firstly, the ABS plastic is processed to be the screw 10 with a suitable size (as shown in Fig.

3), and then the plastic screw 10 is placed and positioned within the mold.

Then, the amorphous alloy having the formula of Zr₅₂AlioCu₃oNi₇ is melted and cast into the mold with the fixed screw 10 therein by means of the die casting device. As shown in Fig.3, the semifinished product made of the Screw 10 of ABS plastic (which acts as the prefabricated member) and the amorphous alloy 20 is obtained.

Next, the semifinished product is taken out of the mold and immerged into the ethyl acetate for 30 minutes. After dissolving the screw 10 of ABS plastic, the amorphous alloy article is taken out and washed to obtain the amorphous alloy article with the threaded hole.

The screw 10 of ABS plastic has a better dissolving property in the ethyl acetate than the amorphous alloy, so that the ABS plastic screw is dissolved rapidly by the ethyl acetate, but the amorphous alloy is not dissolved and corroded due to the excellent chemical stability thereof, thus ensuring the stability of the appearance and size of the amorphous alloy article.

Furthermore, the screw 10 of ABS plastic has a lower thermal conductivity which is one magnitude lower than that of the amorphous alloy, when the fusant of the amorphous alloy is cast into the mold, the melting damage would not happen to the screw because the heat of the fusant of the amorphous alloy is mainly absorbed by the mold, thus ensuring the stability of the threaded structure of the plastic screw during molding.

The method of manufacturing the amorphous alloy article according to the above embodiments of the present disclosure can used to form the threaded hole in the amorphous alloy article with relatively low cost and sufficient accuracy and strength of the threaded hole. Further, it is easy to manufacture the amorphous alloy article having the negative draft angel which is difficult to form by the conventional casting method. In other words, with the method of embodiments of the present disclosure, the amorphous alloy article having a complicated structure such as a threaded hole and a dovetail groove can be manufactured.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that changes, alternatives, and modifications may be made in the embodiments without departing from spirit and principles of the disclosure. Such changes, alternatives, and modifications all fall into the scope of the claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A method of manufacturing an amorphous alloy article, comprising steps of:

placing a prefabricated member made of a predetermined material having a different property from that of an amorphous alloy into a mold, in which the predetermined material is dissolvable in a predetermined solution;

casting a fusant of the amorphous alloy into the mold such that the prefabricated member and the amorphous alloy are joined to form a semifinished product, in which a part of the prefabricated member is exposed out of the amorphous alloy; and

placing the semifinished product into the predetermined solution to dissolve the prefabricated member.

2. The method according to claim 1, wherein the amorphous alloy has a formula of Zr_aCubAl_cNidM_e, where M is one or more elements selected from the group consisting of Fe, Co, Mn, Cr, Ti, Hf, Ta, Nb, C and rare earth elements; and where a, b, c, d, and e is an atomic percentage of the respective elements, and 40=¾a^:¾70, lS^b^S, 5 ^c^= 15, 5 ^d^= 15, 0^c^5, and a+b+c+d+e=100.

3. The method according to claim 2, wherein the amorphous alloy contains impurity elements, and wherein an atomic percentage of the impurity elements is not greater than 2%.

4. The method according to claim 2, wherein the prefabricated member has a dissolving rate of at least 100 times greater than that of the amorphous alloy in the predetermined solution.

5. The method according to claim 4, wherein the predetermined material is selected from a group consisting of a plastic material, an aluminum alloy, a copper alloy, a magnesium alloy, a zinc alloy, a black metal, and any combination thereof.

6. The method according to claim 5, wherein the predetermined material is a plastic having a thermal conductivity of less than 1 w/mk, and the predetermined solution contains an organic solvent.

7. The method according to claim 6, wherein the predetermined material is an ABS plastic, and the predetermined solution contains ethyl acetate.

8. The method according to claim 5, wherein the predetermined material is selected from a group consisting of an aluminum alloy, a copper alloy, a magnesium alloy, a zinc alloy, a black metal, and any combination thereof, and the predetermined solution contains a strong acid solution.

9. The method according to claim 5, wherein the predetermined material is an aluminum alloy, and the predetermined solution contains a strong alkali solution.

10. The method according to claim 1, wherein the prefabricated member has a dovetail shape such that the amorphous alloy article has a negative draft angle.

11. The method according to claim 1 , wherein the prefabricated member is a screw such that the amorphous alloy article has a threaded hole.