Preparation method of low-density refractory high-entropy alloy cladding layer for laser cladding

Abstract

The invention discloses a preparation method of a low-density refractory high-entropy alloy cladding layer for laser cladding, the high-entropy alloy is composed of powder of six metal elements of Ti, Al, Mo, Nb, Cr and Zr, the high-entropy alloy is calculated according to the proportion, the mass of each component is accurately weighed, the components are fully and uniformly mixed by using a ball milling technology, the mixture is uniformly pressed on the surface of a base material, and the high-entropy alloy cladding layer is prepared. After drying, a cladding layer can be obtained through laser cladding processing, wherein a matrix material is TC4 (Ti6-Al4-V); after the high-entropy alloy powder is subjected to laser cladding, a cladding layer has good macroscopic morphology, has the characteristics of fine structure, no crack and high bonding strength between the cladding layer and a base material, and has relatively high microhardness. The high-entropy alloy shows a plurality of structure and performance characteristics different from those of traditional alloy, and belongs to the field of materials with academic value and aerospace application potential.

Description

technical field [0001] The invention belongs to the technical field of titanium alloy surface modification, and in particular relates to a method for preparing a low-density refractory high-entropy alloy cladding layer for laser cladding. Background technique [0002] Traditional alloy design methods are based on one element, and then add other elements to improve the performance of the alloy, such as iron-based, nickel-based and titanium-based alloys. In 2004, a Taiwan scholar proposed the design concept of high-entropy alloy for the first time. The alloy is composed of 5 or more elements, and the atomic percentage of each element is 5%-35%. High-entropy alloys do not form complex multi-phase alloy compounds in the crystal structure, but simple solid solutions of BCC and FCC structures, and even easily produce nanophase and disordered amorphous phases, and have good thermal stability, extremely High hardness, room temperature strength and good plastic deformation ability, ...

AI Technical Summary

Problems solved by technology

[0003] The failure of titanium and titanium alloy parts mostly begins on the surface of the part or its surface layer. The coating that can be prepared by traditional surface modification technology is usually thin (<100μm), the microstructure is poor in compactness, and the bonding strength with the substrate is not high. , cannot give titanium alloys excellent long-term service conditions

Some researchers have used electrochemical deposition and magnetron sputtering to prepare high-entropy alloy cladding layers, but they cannot meet high-strength applications. Laser cladding has high heating and cooling rates and has little thermal impact on the substrate. The grains of the cladding layer are fine and evenly distributed in the matrix. The cladding layer and the matrix are metallurgically bonded with high bonding strength. The thickness of the cladding layer can reach up to several millimeters, and the powder that can be used as the cladding layer has a wide range, so through Appropriate alloy ratio design to obtain a high-entropy alloy cladding layer with excellent performance is of great significance for the development of high-entropy alloys in practical applications

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