High-entropy alloy powder for additive remanufacturing and preparation method thereof

Abstract

The invention discloses a high-entropy alloy powder for additive remanufacturing and a preparation method thereof, wherein the atomic expression of the high-entropy alloy powder is Al 0.4 Co Cu 0.6 NiSi 0.2, and the particle size range is 50 to 150 micron. The preparation method comprises the following steps: sequentially putting block materials of each metal into a vacuum induction melting furnace according to the atomic percentage from the low melting point to the high melting point for vacuum induction melting, and then adopting an air atomization rapid solidification technology to preparethe high-entropy alloy powder. According to the invention, a high-entropy alloy formula free of Fe elements and rare metals is obtained through a large number of experimental designs, and combining with the air atomization rapid solidification technology, the high-entropy alloy powder is prepared. The prepared high-entropy alloy powder is relatively uniform in structural components, high in sphericity, good in fluidity, relatively low in oxygen content, high in powder yield rate and good in quality; and has a simple solid solution phase structure of "fcc plus trace bcc", and is high in microhardness, so that is appliable to the field of high-entropy alloy additive remanufacturing forming.

Description

technical field [0001] The invention belongs to the technical field of high-entropy alloy additive remanufacturing, and in particular relates to a high-entropy alloy powder for additive remanufacturing and a preparation method thereof. Background technique [0002] High entropy alloy is a kind of high mixed entropy alloy with multiple principal elements, which has excellent comprehensive properties such as high strength, high hardness, good plasticity, excellent wear resistance and corrosion resistance, good thermal stability and high oxidation resistance. performance. [0003] At present, relatively more research is still on the application of high-entropy alloys in coating preparation, and in recent years, research on the application of high-entropy alloys in additive remanufacturing has also gradually increased. [0004] However, the current high-entropy alloy powders used for additive remanufacturing are basically pure metal powders mixed mechanically. Due to the differ...

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Problems solved by technology

[0004] However, the current high-entropy alloy powders used for additive remanufacturing are basically pure metal powders mixed mechanically. Due to the differences in physical properties such as the melting point of different metal powders, some powders in the formed structural parts / layers will not be Melting or partial melting will lead to defects such as uneven structure, serious composition segregation, and low solid solubility, which will affect its comprehensive performance

[0005] In addition, most of the existing high-entropy alloy powders contain Fe and / or rare metals

[0006] For high-entropy alloy powders containing rare metals, the cost is high due to the high price of rare metals, which is not suitable for large-scale industrial applications, and most high-entropy alloys containing rare metals have poor plasticity and are not suitable for additive remanufacturing (see Document 1)

[0007] For high-entropy alloy powders containing Fe elements, AlCoCrFeNi or CoCrFeMnNi series are mainly studied at present. When these two series are used for additive remanufacturing, most of the mechanical strength is not ideal under the condition of ensuring plasticity (see literature 2 and ref. 3)

[0008] For the high-entropy alloy powder containing Fe element, there is still a problem: in the process of additive remanufacturing, due to the solid solution diffusion between elements, the elements in the high-entropy alloy will solid dissolve into the matrix, and the elements in the matrix will also solidify. Dissolved into high-entropy alloys, and the Fe matrix is ​​the most commonly used matrix in additive remanufacturing. If the designed high-entropy alloy contains Fe elements, it will change the composition of the high-entropy alloy at the bonding interface and even cause phase transformation, resulting in high-entropy alloys. The overall performance of the alloy is greatly affected

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