TWI429755B - Silicon-based alloy and manufacturing method thereof - Google Patents

Description

Base alloy and manufacturing method thereof

The present invention relates to a bismuth-based alloy and a method of producing the same, and more particularly to a bismuth-based alloy having high density and fine structure and a method of producing the same.

Niobium-based alloys can be widely used in decorative coatings, optical coatings or wear-resistant coatings. The above coatings are mainly deposited by direct sputtering of argon ions or by reactive sputtering of the desired gas. Functional film. The properties of the bismuth-based alloy (target) used in the above coating technique (for example, the ratio of the crater contained in the bismuth-based alloy or the coarseness of the microstructure) affects the quality of the resulting film.

However, the phase diagram of the ruthenium-based alloy (for example, bismuth-aluminum, bismuth-silver, bismuth-gold, bismuth-tin, or bismuth-zinc) used in the coating is known, and the melting point of bismuth and metal is usually very different. Sex, so it is almost not dissolved.

If a ruthenium-based alloy used as a target is produced by a general smelting casting method, the ruthenium-based alloy is liable to have a large number of shrinkage cavities and a very large microstructure. When the ruthenium-based alloy is used as a target and used in a sputtering process, it is likely to cause abnormal discharge (Arcing), slow sputtering rate, low yield, uneven coating composition, and deterioration of coating quality.

If a ruthenium-based alloy used as a target is produced by a conventional powder metallurgy method, since the difference in melting point between the bismuth and the metal is large and does not solidify at the same time, there is no sinterability in solid state sintering, and it is not easy to obtain a high-density sintering. The ratio of the shrinkage cavities in the alloy, that is, the sintered niobium-based alloy, is too high.

In order to improve the disadvantages in the above-mentioned bismuth-based alloy, in the prior art, the following method is proposed: mixing cerium with metal powder and filling it into an airless sealed container above the liquid phase of the bismuth-based alloy The temperature is subjected to Hot Isostatic Press, and the liquid phase is used to reduce the proportion of craters in the ruthenium-based alloy. However, since the process is carried out in the liquid phase, the Oswald Ripening effect is easily generated, that is, the small particles of the tantalum powder are dissolved in the liquid phase and precipitated on the larger tantalum particles, so that the microstructure of the final tantalum grains is obtained. It becomes coarser than the original powder. Therefore, it is difficult to obtain a finer microstructure and a uniform composition in the final bismuth-based alloy. In addition, equipment that performs heat equalization is expensive, which increases production costs.

Further, in the prior art, a technique of manufacturing a ruthenium-based alloy by means of spray coating is also disclosed. However, the method of spray forming has the disadvantage of low yield, and is liable to cause a large amount of waste of raw materials.

Accordingly, an object of the present invention is to provide a bismuth-based alloy and a method for producing the same, which can avoid the Oswald Ripening effect by hot pressing below the liquid phase formation temperature to form a bismuth-based alloy having high density and fine structure.

According to an embodiment of the present invention, a method of manufacturing a bismuth based alloy is provided. This manufacturing method includes the following steps. Provides raw materials for tantalum and metals. A melting step is performed to melt the raw materials of the above-mentioned niobium and metal to form a niobium-based alloy soup solution. An atomization step is performed to atomize the bismuth-based alloy soup solution to form a bismuth-based alloy powder. A hot pressing step is performed to thermally press the ruthenium-based alloy powder to form a ruthenium-based alloy. Among them, the temperature is 40 ° C below the liquid phase formation temperature of the ruthenium based alloy. The hot pressing step is carried out until the liquid phase formation temperature of the base alloy is 20 ° C and the pressure is 150 MPa (MPa) to 200 MPa.

According to another embodiment of the present invention, in the method for producing a bismuth-based alloy, the atomizing step further comprises performing a spraying step of spraying the bismuth-based alloy soup liquid with a gas.

According to another embodiment of the present invention, the gas pressure is from 1 MPa to 5 MPa, and the gas velocity is from 50 m/s to 100 m/s.

According to still another embodiment of the present invention, a bismuth based alloy is provided. The niobium-based alloy comprises niobium and a metal, wherein the niobium accounts for 50% to 90% by weight, and the actual density of the niobium-based alloy is greater than or equal to 99.5% of the theoretical density of the niobium-based alloy, and in the niobium-based alloy, each In the range of 1 micrometer (mm), the number of interfaces of the crucible with the metal is greater than or equal to 100.

An advantage of the present invention is that a bismuth-based alloy having high density and fine structure can be formed by hot pressing below the liquid phase formation temperature. When the hot pressing is performed above the liquid phase forming temperature, the flow of the soup is easy to occur, that is, the liquid alloy soup is pressed by the pressure, and it is easy to flow out of the container for accommodating the alloy soup, and in order to avoid the occurrence of the soup phenomenon, Hot pressure equalization is usually required. Compared with the use of the heat equalizing pressure, the present invention can produce a high-density and fine-structured bismuth-based alloy by a general hot pressing apparatus, thereby reducing the equipment cost. In addition, the present invention can reduce the cost of raw material costs compared to the manner of spray coating. Furthermore, since the bismuth-based alloy produced by the present invention has high compactness and fine structure, sputtering of the bismuth-based alloy of the present invention can improve the uniformity of the composition of the coating, that is, improve the quality of the coating, thereby improving Product competitiveness.

Please refer to FIG. 1 , which is a flow chart showing a method of manufacturing a bismuth-based alloy according to an embodiment of the present invention. The method of manufacturing the bismuth based alloy begins at step 102 with the provision of a raw material for bismuth and metal. In this step 102, a metal is selected as desired, and the weight ratio of bismuth to the above metal is adjusted as needed. Wherein, the above metal may be, for example, aluminum, silver, gold, tin, zinc or a ruthenium based alloy of the above materials.

Next, the smelting step 104 is carried out, the raw materials of the prepared bismuth and the metal are placed in a container, and the raw materials of the prepared bismuth and metal are heated to a high temperature to be melted to form a bismuth-based alloy soup solution.

After the smelting step 104, an atomization step 106 is performed to atomize the bismuth-based alloy soup solution to form a bismuth-based alloy powder. For example, in the performing the atomizing step 106, the spraying step is further included, that is, the strontium-based alloy soup is sprayed with a gas to form a bismuth-based alloy powder, or the bismuth-based alloy soup solution is obtained from the smelting container. Dropped to a disc, the bismuth-based alloy soup was formed into a bismuth-based alloy powder by the principle of centrifugal force. The above-described spraying step or the technique of producing alloy powder by using the centrifugal force principle is a technical means commonly used in the field, so the details thereof will not be described herein.

Next, a hot pressing step 108 is performed to thermally pressurize the ruthenium-based alloy powder produced in step 106 to form the desired ruthenium-based alloy. In the hot pressing step 108, the temperature is 40 ° C below the liquid phase formation temperature of the bismuth-based alloy to 20 ° C below the liquid phase formation temperature of the bismuth-based alloy, and the pressure used for the hot pressing is 150 MPa to 200 MPa.

In the present invention, it is below the liquid phase formation temperature of the ruthenium based alloy. The hot pressing step 108 is carried out, so that the ruthenium-based alloy powder can be kept in a solid state during the hot pressing process, so that no flow-through phenomenon occurs and the composition of the finally produced ruthenium-based alloy is not affected. Further, based on the above-mentioned "no flow phenomenon", the hot pressing step 108 can be carried out by a general hot pressing apparatus, thereby reducing the high equipment cost required for the heat equalizing process.

In a particular embodiment, the gas used in the spraying step included in the atomizing step 106 described above may be an inert gas such as nitrogen or argon. Further, in a specific embodiment, the pressure of the gas used in the above-described spraying step is 1 MPa to 5 MPa, and the speed thereof is 50 meters/second (m/s) to 100 m/s.

In a particular embodiment, the hot pressing step 108 is continued for a period of from 1 hour to 3 hours in order to enable the final bismuth-based alloy to have sufficient high density and fine texture.

The compactness of the above-mentioned bismuth-based alloy refers to the porosity in the bismuth-based alloy, which is generally expressed as a percentage of the theoretical density of the bismuth-based alloy produced by the process, which may be referred to as a sintered density. For example, if the actual density of a bismuth-based alloy occupies 99% of its theoretical density and the actual density of another bismuth-based alloy occupies 90% of its theoretical density, it is said that the first one is compared with the second bismuth-based alloy. The bismuth based alloy has better compactness.

In addition, the fine structure of the above-mentioned bismuth-based alloy is used to evaluate the uniformity of the distribution of bismuth and other metals in the bismuth-based alloy produced by the process, and the metallographic structure of the bismuth-based alloy is usually observed by a scanning electron microscope (SEM). And quantitative metallographic analysis to evaluate the uniformity of the distribution of niobium and other metals in the microstructure of niobium-based alloys. For example, the average number of interfaces between bismuth and metal in the range of 1 micrometer (mm) (can be called "average 矽 / The number of metal interfaces") was used to evaluate the uniformity of the bismuth based alloy.

In a particular embodiment, when the duration of the hot pressing step 108 is from 1 hour to 3 hours as described above, the actual density of the resulting bismuth-based alloy is greater than or equal to 99.5% of the theoretical density of the bismuth-based alloy. Further, in the above-mentioned bismuth-based alloy, the number of interfaces of bismuth and metal is greater than or equal to 100 per 1 mm. It is emphasized here that in the present invention, the presence of impurities at a specific level is allowed.

In a particular embodiment, wherein the percentage by weight of bismuth is from 50% to 90%. In a specific embodiment, in order to allow the ruthenium contained in the ruthenium-based alloy to be sufficiently mixed with other metals, the above-described smelting step 104 is carried out at a temperature of 1500 ° C to 1700 ° C.

The present invention is more specifically described by the following examples and comparative examples, but the scope of the present invention is not limited by the examples and comparative examples.

Example

First, the pure niobium block and the pure aluminum block are blended so that the weight percentage of niobium is 70%. Next, the raw materials of the prepared crucible and aluminum are placed in a crucible of a vacuum induction melting spray milling apparatus, and heated to 1600 ° C to melt the crucible and the aluminum block to form a niobium-aluminum alloy soup solution. After the above melting step is completed, the molten strontium-aluminum alloy soup flowing from the bottom of the crucible is sprayed with an inert gas, and the bismuth-aluminum alloy soup is rapidly atomized into metal droplets, and after solidification, it has a fine structure, and The weight percentage of niobium is 70% of niobium-aluminum alloy powder. Then, the above-mentioned bismuth-aluminum alloy powder is collected, placed in a hot-pressing mold capable of high temperature and high pressure, and the temperature is raised to 550 ° C (the liquid phase formation temperature of the bismuth-aluminum alloy is about 580 ° C) to 175 MPa. The pressure was hot pressed for 2 hours. After the sintered body of the aluminum alloy is cooled, it is taken out of the furnace, The Kimidd method was used to measure the density, and the metallographic structure was observed by SEM backscattering image. The degree of detail of the microstructure was evaluated by quantitative metallographic analysis. The above SEM backscattered image is shown in Annex 1, and its compactness and fineness of the structure are as shown in Table 1 below, wherein the sintered density is 99.9%, and the average 矽/aluminum interface number is 126/mm.

Comparative Example 1

In Comparative Example 1, the step of preparing the bismuth-aluminum alloy is similar to the steps of the above examples, wherein the difference is that in Comparative Example 1, the liquid phase formation temperature is greater than 矽-aluminum alloy at 600 ° C, and 50 MPa. The pressure is hot pressed. As a result, a serious flow of soup occurs, resulting in an inaccurate composition of the final bismuth-aluminum alloy.

Comparative Example 2

In Comparative Example 2, the steps of preparing the bismuth-aluminum alloy were similar to those of the above examples, with the difference that in the comparative example 2, the hot pressing was performed at a pressure of 50 MPa (the temperature and time of the hot pressing and the examples) the same). The compactness of the bismuth-aluminum alloy of this comparative example and the degree of fineness of the structure are also described in the following Table 1, in which the sintered density is only about 71%, and there is no effect of sintering densification, and high-density quality requirements cannot be achieved.

Comparative Example 3

In Comparative Example 3, the steps of preparing the bismuth-aluminum alloy were similar to those of the above examples, with the difference that the comparative example used a hot homogenization process to first place the atomized bismuth-aluminum alloy powder on In the stainless steel tank, the stainless steel tank is evacuated and the stainless steel tank is sealed by welding. Next, the stainless steel can was placed in a heat equalizing furnace at a temperature greater than 600 ° C of the liquid phase formation temperature of the bismuth-aluminum alloy (the pressure and time of the hot pressing were the same as in the examples). This contrast The SEM backscatter image of the bismuth-aluminum alloy produced by the example is attached as Annex 2, and its compactness and fineness of the structure are described in Table 1 below, where the sintered density is 99.9%, but the average 矽/aluminum interface number It is only 75 pieces/mm, which is smaller than the average 矽/aluminum interface number of the above embodiment, that is, the degree of detail of the structure of the comparative example is inferior to that of the above embodiment.

Comparative Example 4

The niobium-aluminum alloy was prepared by a conventional smelting casting method, and the pure niobium block and the pure aluminum block were blended according to 70% by weight of the niobium in the above embodiment. Next, the prepared raw materials of aluminum and aluminum were placed in an induction melting furnace for melting, and casting was carried out at 1600 °C. The SEM backscatter image of the bismuth-aluminum alloy produced by this comparative example is shown in Annex 3, and the compactness and fineness of the structure are described in Table 1 below, wherein the sintered density is 99.5%, but the average 矽/aluminum The number of interfaces is only 17/mm, which is much smaller than the average 矽/aluminum interface number of the above embodiments, that is, the degree of detail of the tissue of the comparative example is inferior to that of the above embodiment.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. Fan The scope defined in the patent application scope is subject to the definition of patent application.

100‧‧‧Manufacturing method of bismuth based alloy

102‧‧‧Steps

104‧‧‧Smelting steps

106‧‧‧Atomization step

108‧‧‧ hot pressing step

In order to have a better understanding of the ideas of this creation, please refer to the above detailed description and the corresponding drawings. It is emphasized that, in accordance with the standard of the industry, the various features in the drawings are not to scale. In fact, the dimensions of the various features may be arbitrarily enlarged or reduced in order to clearly illustrate the above embodiments. The relevant schema description is as follows.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a flow chart showing a method of manufacturing a bismuth-based alloy according to an embodiment of the present invention.

100‧‧‧Manufacturing method of bismuth based alloy

102‧‧‧Steps

104‧‧‧Smelting steps

106‧‧‧Atomization step

108‧‧‧ hot pressing step

Claims (10)

A method for manufacturing a bismuth-based alloy, comprising: providing a raw material of a bismuth and a metal; performing a smelting step, melting the bismuth and the raw material of the metal to form a bismuth-based alloy soup solution; performing an atomization step, atomizing The bismuth-based alloy soup solution to form a bismuth-based alloy powder; and performing a hot pressing step of hot pressing the bismuth-based alloy powder to form the bismuth-based alloy, wherein the temperature is the liquid phase formation of the bismuth-based alloy The hot pressing step is carried out at 40 ° C below the temperature to 20 ° C below the liquid phase formation temperature of the ruthenium based alloy and at a pressure of from 150 MPa to 200 MPa. The method for producing a ruthenium-based alloy according to claim 1, wherein the hot pressing step lasts for 1 hour to 3 hours. The method for producing a ruthenium-based alloy according to claim 2, wherein the actual density of the ruthenium-based alloy is greater than or equal to 99.5% of the theoretical density of the ruthenium-based alloy, and in the range of 1 micrometer in the ruthenium-based alloy The number of interfaces between the crucible and the metal is greater than or equal to 100. The method for producing a ruthenium-based alloy according to claim 1, wherein the metal is selected from the group consisting of aluminum, silver, gold, tin, zinc or a ruthenium-based alloy of the above materials. The method for producing a ruthenium-based alloy according to claim 1, wherein the atomizing step further comprises performing a spraying step of spraying the bismuth-based alloy soup with a gas. The method for producing a ruthenium-based alloy according to claim 5, wherein the gas system is an inert gas, and the inert gas is nitrogen or argon. The method for producing a ruthenium-based alloy according to claim 5, wherein the gas is subjected to a pressure of 1 MPa to 5 MPa, and the gas is at a speed of 50 MPa to 100 MPa. Metrics per second. The method for producing a niobium-based alloy according to claim 1, wherein the niobium accounts for 50% to 90% by weight. The method for producing a ruthenium-based alloy according to claim 1, wherein the smelting step is carried out at a temperature of 1500 ° C to 1700 ° C. A bismuth-based alloy consisting essentially of a bismuth and a metal, wherein the bismuth is 50% to 90% by weight, and the actual density of the bismuth-based alloy is greater than or equal to 99.5 of the theoretical density of the bismuth-based alloy. %, and in the bismuth-based alloy, the number of interfaces of the ruthenium to the metal is greater than or equal to 100 per 1 micrometer, and the metal is selected from the group consisting of aluminum, silver, gold, tin, zinc or the above materials. A group of bismuth based alloys.