Preparation method of high-melting-point and high-entropy alloy spherical powder based on laser additive manufacturing

Abstract

The invention discloses a preparation method of high-melting-point and high-entropy alloy spherical powder based on laser additive manufacturing. The preparation method comprises the steps: randomly selecting powder of five or more from high-melting-point metallic elements including tungsten, titanium, zirconium, hafnium, vanadium, niobium, tantalum and molybdenum, and mixing the powder according to a certain ratio; then, carrying out mechanical alloying by using a high-energy ball mill to obtain single-phase solid solution powder of a high-melting-point and high-entropy alloy; preparing a powder bar material by adopting the forming standard of a hot isostatic pressing process; and finally, preparing laser directly-formed powder by using an electrode induction melting gas atomization process. By using the single-phase solid solution powder of the high-melting-point and high-entropy alloy, formed by using the preparation method, a series of problems of different burnout rates of different elements due to relatively high difference as well as component microscopic segregation and negative eutectic and the like caused by various elements in the laser additive manufacturing and forming processes of the powder of the high-melting-point metallic elements can be solved, and the rapid and precise manufacture of high-temperature-resistant and wear-resistant parts special for the aerospace and hot end parts of high-performance turbine engines can be more effectively realized.

Description

【Technical field】 [0001] The invention relates to the technical field of high-entropy alloys, in particular to a method for preparing spherical powders of high-melting-point high-entropy alloys based on laser additive manufacturing. 【Background technique】 [0002] Multi-principal high-entropy alloys have multiple effects of high entropy, lattice distortion and hysteresis diffusion. The organizational structure is simple solid solution structure and nanostructure, even amorphous structure, so it has high strength, good wear resistance, high Excellent properties such as work hardening, high temperature softening resistance, high temperature oxidation resistance, corrosion resistance and high electrical resistivity or a combination of these excellent properties are unmatched by traditional multi-element alloys; the constituent phases of high melting point high entropy alloys are body-centered cubic Mainly, the alloys of this system tend to have higher strength, and high-entropy...

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Problems solved by technology

[0005] The existing method of laser additive manufacturing to prepare high-melting-point high-entropy alloys mostly adopts the powder ratio of different elements and mixes them evenly with an ordinary ball mill, which is directly used in laser additive manufacturing. This method does not fully consider the burning rate of different elements. Different, the dilution of the matrix and the different proportions of powders of different elements falling into the molten pool during the laser cladding process and other problems of uneven composition content during forming; and this method will inevitably cause The composition microsegregation and negative eutectic will affect the overall performance of the formed parts. Therefore, it is very difficult to directly apply the high melting point metal elemental powder to laser additive manufacturing.

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