TW202323540A - High-entropy alloys with high-temperature strengths - Google Patents

Abstract

The present invention discloses high-entropy alloys with high-temperature strengths. The high-entropy alloys are constituted by mixing at least seven metal elements being selected from a group of high-melting metal elements consisting of aluminum (Al), nickel (Ni), cobalt (Co), chromium (Cr), niobium (Nb), molybdenum (Mo) and tungsten (W) to have superior mechanical properties at a high temperature as well as to achieve the best efficacy of high hardness, high strength, wear resistance, high temperature resistance and corrosion resistance.

Description

high-temperature-strength high-entropy alloy

The present invention relates to a high-entropy alloy with high-temperature strength, especially a high-entropy alloy added with high-melting-point metal elements to provide a high-entropy alloy with better mechanical properties at high temperatures.

According to traditional resistance welding, there are disadvantages such as low stability, high welding temperature and welding spatter, so that the industry turns to the friction stir spot welding technology with higher stability.

In addition to high stability, Friction Stir Spot Welding has low welding temperature, reduces deformation and shrinkage, does not produce spatter, and has higher strength at welding points. The best prospect is that it can be widely used Used in aerospace, automotive, and other industrial fields. Spot welding of high-strength steel for automobiles accounts for about NT$3 billion, spot welding tools account for about 50% of the spot welding process, and the output value is 1.5 billion yuan, with great market potential.

At present, the commercially available tungsten steel plated with diamond knives is used as a spot welding mixing tool for high-strength steel. The knives will shrink due to carbonization and cracking due to high temperature. Therefore, the welding of high-melting point metals due to high-temperature wear of the mixing knives is an urgent need for the industry. One of the problems solved.

Therefore, some people in the industry further use high-entropy alloys to perform, and high-entropy alloys are alloys formed by refining five or more metals of equal or approximately equal amounts, such as Taiwan Patent Publication No. I395336, which has a multi-element high-entropy Optoelectronic semiconductors of alloy oxides, conductors, insulators and design methods thereof, Announcement No. I378899, a photoelectric semiconductor composed of multiple high-entropy alloy oxides and its manufacturing method, or Announcement No. I674334, a method of manufacturing high-entropy alloy coatings.

There is also Chinese patent CN113151725A, a method for enhancing the wear resistance of refractory high-entropy alloys, including: using a vacuum arc melting furnace to mix and smelt the metal elements Ti, Zr, V, Nb, and Al after proportioning weighing and ultrasonic cleaning to obtain TiZrV0 .5Nb0.5Alx refractory high-entropy alloy ingot; using flip casting equipment to cast the alloy solution into a plate-shaped water-cooled copper mold to obtain a plate-shaped alloy; put the cast plate-shaped alloy into a heat treatment furnace and pass in an inert protective gas. Homogenization annealing treatment at 1100°C; the addition of Al element reduces the density of the refractory high-entropy alloy on the one hand, and promotes the precipitation of intermetallic compounds on the other hand, which significantly improves the hardness and wear resistance of the refractory high-entropy alloy.

Or Chinese patent CN113061763A a kind of high-entropy alloy and preparation method thereof, comprising: using elements including Zr, Ti, also including at least one of W, Ta, Hf, V, Cr, Co, Ni, Fe, Mn, Cu and Al The high-entropy alloy spherical powder is prepared from the high-entropy alloy raw material; the high-entropy alloy spherical powder is formed by a laser additive manufacturing process to obtain a high-entropy alloy, wherein the powder carrier gas used in the laser additive manufacturing process is argon oxygen mixed composition. Through the preparation method provided by the invention, high-entropy alloys containing ordered oxygen complexes can be prepared, and due to the different oxygen supply methods used to form ordered oxygen complexes, the distribution of oxides in the prepared high-entropy alloys is more uniform , to further improve the mechanical properties and radiation resistance of high-entropy alloys.

And Chinese patent CN113046615A a kind of high-entropy alloy with high-strength HCP phase and its preparation method, it is characterized in that: adopt high-purity metal powder Co, Cr, Fe, Ni, Ta, Nb as raw material, first elemental powder is in a certain proportion in high-energy After mechanical mixing in a ball mill, put it into a vacuum drying oven for drying, and then use powder plasma arc additive manufacturing technology to obtain high-entropy alloys by layer-by-layer accumulation.

Although the above-mentioned prior patents are all about the composition and process technology of high-entropy alloys, they cannot achieve the high hardness, high strength, wear resistance, high temperature resistance and Corrosion resistance function.

The reason is that, in view of this, the inventor has been adhering to many years of rich design and development and actual production experience in this related industry, and then researched and improved, hoping to add high-melting point metal elements to the high-entropy alloy (HEA) components for making stirring knives, so that it can It has good mechanical properties at high temperature, and a high-entropy alloy with high-temperature strength is specially provided in order to achieve better practical value.

The main purpose of the present invention is to provide a high-entropy alloy with high-temperature strength, especially a high-entropy alloy added with high-melting point metal elements to provide a high-entropy alloy with better mechanical properties at high temperatures.

The main purpose and effect of the high-temperature-strength high-entropy alloy of the present invention are achieved by the following specific technical means:

It contains at least seven metal elements, wherein the at least seven metal elements are selected from aluminum (Al), nickel (Ni), cobalt (Co), chromium (Cr), niobium (Nb), molybdenum (Mo) The high melting point metal element group composed of tungsten and tungsten (W) allows it to have good mechanical properties at high temperatures, so as to achieve high hardness, high strength, wear resistance, high temperature resistance and corrosion resistance.

A preferred embodiment of the high-temperature strength high-entropy alloy of the present invention, wherein the high-entropy alloy includes aluminum (Al) with an atomic percentage of 5.00-15.00 at%, nickel (Ni) with an atomic percentage of 30.00-40.00 at%, Cobalt (Co) at 20.00~30.00at%, Chromium (Cr) at 5.00~15.00at%, Niobium (Nb) at 5.00~15.00at%, 1.00~5.00at% at% molybdenum (Mo), and tungsten (W) with an atomic percentage of 5.00~15.00 at%.

A preferred embodiment of the high-entropy alloy with high-temperature strength of the present invention, wherein the high-entropy alloy can be used for casting or lamination.

A preferred embodiment of the high-entropy alloy with high-temperature strength in the present invention, wherein the powder particle size range of the high-entropy alloy for laser lamination manufacturing is 20-45 μm.

A preferred embodiment of the high-entropy alloy with high-temperature strength in the present invention, wherein the powder particle size range of the high-entropy alloy used for electron beam lamination is 50-100 μm.

In order to have a more complete and clear disclosure of the technical content used in the present invention, the purpose of the invention and the effects achieved, it will be described in detail below, and please also refer to the disclosed drawings and drawing numbers:

First, the high-entropy alloy with high-temperature strength of the present invention is mainly selected from aluminum (Al) at 5.00-15.00 at%, nickel (Ni) at 30.00-40.00 at%, cobalt (Ni) at 20.00-30.00 at%. Co), 5.00~15.00at% chromium (Cr), 5.00~15.00at% niobium (Nb), 1.00~5.00at% molybdenum (Mo), and 5.00~15.00at% tungsten (W); the above metals The melting points of elements are listed in the table below: Aluminum (Al) Nickel (Ni) Cobalt (Co) Chromium (Cr) Niobium (Nb) Molybdenum (Mo) Tungsten (W) Element melting point (℃) 660 1455 1495 1907 2477 2623 3422 Composition ratio (at%) 5~15 30~40 20~30 5~15 5~15 1~5 5~10

The following is an example to illustrate the process method of high-entropy alloy [one of the feasible processes]: First, the above-mentioned metal elements are smelted and mixed. Inert Gas Atomization), the above-mentioned metal elements (alloy raw materials) are melted in an inert atmosphere by using a cycle induction furnace, so that the oxygen increase of these alloys is kept at a minimum, and the inert gas ( _N2 or Ar) Shock, atomize, and break the molten soup into tiny droplets, and then solidify into spherical alloy powders. The powders are observed by particle size analysis, composition analysis, and electron microscope. Afterwards, these classified spherical alloy powders are manufactured by laser lamination (SLM, Selective Laser Melting), and the fine spherical alloy powders are fused together with a high-power fiber laser, and thin layers are constructed layer by layer. , repeating the construction layer by layer until the construction is completed. Here, in the above lamination process, the parameter conditions can be set according to the product, such as E=50-125 J/mm ³ , E=75-165 J/mm ³ , and finally Finished products can be tested for microstructure and mechanical properties.

Compare the hardness of the finished product made of the high-temperature-strength high-entropy alloy of the present invention with literature and commercially available high-entropy alloys at room temperature. Please refer to the first figure, except for the high-temperature-strength high-entropy alloy of the present invention. In addition, comparing TiZrNbHfTa, TiZrNbWMo, AlCoCrFeNiSi, AlCoCrCuFeNi and Inconel 718 and other groups, the chart shows that the hardness of the high-temperature strength high-entropy alloy (CoCrNbNiW) of the present invention (CoCrNbNiW) at room temperature is 872.6HV higher than other groups.

Please refer to the second figure, which is a schematic diagram comparing the hardness curves of the present invention with literature and commercially available high-entropy alloys at high temperatures between room temperature and 1000°C. In the figure, except for the high-temperature-strength high-entropy alloy of the present invention, Comparing groups such as SLM-HIP, SLM-AlCoCrFeNiSi, SLM-AlCoCrCuFeNi, SLM-Inconel 718, arc melting A100Co1.5CrFeNi1.5T10, arc melting A102Co1.5CrFeNi1.5T10 and SKH51, it is shown in the chart that the present invention has high temperature The room temperature hardness of the high-strength high-entropy alloy (CoCrNbNiW) is 872.6 HV, and the high-temperature hardness at 1000 °C is close to 400 HV, which is significantly higher than that of the literature entropy alloys and commercial high-entropy alloys.

In addition, the preferred embodiment of the high-entropy alloy with high-temperature strength in the present invention, wherein the high-entropy alloy can be used for casting or laminated manufacturing; the powder particle size range of the high-entropy alloy for laser laminated manufacturing is 20-45 μm . The powder particle size range of the high-entropy alloy used for electron beam lamination is 50-100 μm.

However, the above-mentioned embodiments or drawings do not limit the product structure or usage of the present invention, and any appropriate changes or modifications by those with ordinary knowledge in the technical field shall be considered as not departing from the patent scope of the present invention.

To sum up, the embodiment of the present invention can indeed achieve the expected use effect, and the specific structure disclosed by it has not only never been seen in similar products, nor has it been disclosed before the application, and it has fully complied with the provisions of the Patent Law In accordance with the requirements, it is very convenient to file an application for a patent for invention in accordance with the law, and sincerely ask for the review and approval of the patent.

none

The first picture: a schematic diagram comparing the hardness of the present invention with literature and commercially available high-entropy alloys at room temperature.

The second figure: a schematic diagram comparing the hardness curves of the present invention with literature and commercially available high-entropy alloys at high temperatures between room temperature and 1000°C.

Claims (4)

A high-entropy alloy with high-temperature strength, which is mainly composed of at least seven metal elements with high melting point characteristics, and the high-entropy alloy includes: 5.00~15.00at% aluminum (Al), 30.00~40.00at% nickel (Ni), 20.00~30.00at% cobalt (Co), 5.00~15.00at% chromium (Cr), 5.00~15.00at% Niobium (Nb), 1.00~5.00at% molybdenum (Mo), and 5.00~15.00at% tungsten (W). The high-entropy alloy with high-temperature strength as described in Claim 1, wherein the high-entropy alloy can be used for casting or laminated manufacturing. The high-entropy alloy with high-temperature strength as described in Claim 2, wherein the powder particle size range of the high-entropy alloy used for laser lamination manufacturing is 20-45 μm. The high-entropy alloy with high-temperature strength as described in Claim 2, wherein the powder particle size range of the high-entropy alloy used for electron beam lamination is 50-100 μm.

Images