CN-122007412-A - High-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder

CN122007412ACN 122007412 ACN122007412 ACN 122007412ACN-122007412-A

Abstract

A high-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder belongs to the technical field of laser cladding materials, and comprises a ceramic core, tiC-WC composite ceramic particles formed by TiC and WC through mechanical alloying, a refractory high-entropy alloy transition layer coated outside the ceramic core, wherein the refractory high-entropy alloy transition layer comprises TiZrNbTaMo high-entropy alloy, a ductile high-entropy alloy outer layer coated outside the refractory high-entropy alloy transition layer comprises FeCoCrNiAlx high-entropy alloy, wherein x=0.3-0.7, a gradient interface structure with continuously changing components is arranged between the refractory high-entropy alloy transition layer and the ductile high-entropy alloy outer layer, the synergistic wear-resisting effect of a ceramic reinforcing phase is realized through TiC-WC composite ceramic core design, the problem of physical property mismatch between ceramics and a metal matrix is effectively solved through the design of a refractory-ductile high-entropy alloy double-layer coating structure and the gradient interface is combined, and the internal stress and crack sensitivity of the cladding layer are remarkably reduced.

Inventors

WANG GE
Leng Xinyang
YANG HUI
TANG BIAO
ZHAO HANQING
HE XIN

Assignees

佳木斯大学

Dates

Publication Date: 20260512
Application Date: 20260306

Claims (10)

1. The high-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder is characterized by comprising the following components: A ceramic core, tiC-WC composite ceramic particles formed by mechanically alloying TiC and WC; the refractory high-entropy alloy transition layer is coated outside the ceramic core and comprises TiZrNbTaMo series high-entropy alloy; The high-entropy alloy coating is coated outside the refractory high-entropy alloy transition layer, and comprises FeCoCrNiAl x high-entropy alloy, wherein x=0.3-0.7; Wherein, a gradient interface structure with continuously changing components is arranged between the refractory high-entropy alloy transition layer and the ductile high-entropy alloy outer layer.
2. The composite powder of claim 1, wherein the gradient interface structure has a thickness of 1-5 microns, and the concentration of Fe, co, ni elements in the structure continuously decreases from the outer layer to the transition layer, and the concentration of Ti, mo elements continuously decreases from the transition layer to the outer layer.
3. The composite powder of claim 1, wherein the molar ratio of Fe, co, cr, ni elements in the ductile high-entropy alloy outer layer is 1:1:1:1, and the molar ratio of al elements to any one of the elements is (0.3-0.7): 1.
4. The composite powder of claim 1, wherein the mass ratio of TiC to WC in the ceramic core is 6:4 to 8:2.
5. The composite powder of claim 1, wherein Ti, zr, nb, ta, mo elements in the refractory high-entropy alloy transition layer are equimolar ratio configured.
6. The composite powder of claim 1, prepared by the steps of: preparing TiC-WC composite ceramic core particles by a high-energy ball milling method; coating a refractory high-entropy alloy transition layer and a tough high-entropy alloy outer layer on the surface of the ceramic core in sequence by adopting a mechanical fusion method to form a pre-powder; and (3) carrying out heat treatment on the pre-prepared powder under the protection of vacuum or inert gas, wherein the heat treatment temperature is 800-1200 ℃, and the heat preservation time is 1-4 hours, so as to promote inter-layer element interdiffusion and form the gradient interface structure.
7. A method of laser cladding a composite powder according to any one of claims 1-5, comprising: Conveying the composite powder to the surface of a substrate to be clad; Cladding is carried out by adopting laser beams under protective atmosphere, the laser power is 2-5kW, and the scanning speed is 5-20mm/s; The gradient interface structure of the composite powder can effectively relieve thermal stress in the cladding process and inhibit crack generation.
8. A laser cladding coating, characterized in that the coating is prepared from the composite powder of any one of claims 1-5 through a laser cladding process, the coating comprises uniformly distributed TiC-WC composite ceramic reinforcing phases, and the reinforcing phases are metallurgically bonded with a high-entropy alloy matrix through a gradient interface.
9. The laser cladding coating according to claim 8, wherein the coating has a room temperature microhardness of not less than 800 HV and a hardness retention of not less than 70% at 800 ℃.
10. Use of a laser cladding coating according to claim 8 or 9, wherein the coating is used for the preparation of aerospace engine blades, nuclear reactor structural parts or metallurgical roll wear protection layers.

Description

High-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder Technical Field The invention belongs to the technical field of laser cladding materials, and particularly relates to high-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder and a working method thereof. Background As an advanced surface engineering technology, the laser cladding technology can remarkably improve the performances of wear resistance, corrosion resistance, high temperature resistance and the like of the surface of a workpiece by cladding high-performance alloy powder on the surface of a substrate, and has wide application prospects in the fields of equipment remanufacturing, aerospace, nuclear power and the like. Conventional laser cladding materials have used mainly mechanical mixtures of single ceramic particles (e.g., WC, tiC, cr 3C2, etc.) with metal or alloy powders. However, this simple physical mixing presents the following technical challenges in the laser cladding process: the wettability of the ceramic phase and the metal matrix is poor, and the interface bonding strength is low; The thermal expansion coefficients of the ceramic phase and the metal matrix are greatly different, and huge thermal stress is generated in the rapid heating and cooling processes, so that cracks are initiated and expanded; Ceramic phases are unevenly distributed in a molten pool and are easy to be biased or dissolved, so that the enhancement effect is affected; The performance limitation of a single ceramic phase is difficult to meet the comprehensive performance requirement under complex working conditions. In recent years, the high-entropy alloy is taken as a novel multi-principal element alloy material, and has excellent mechanical property, corrosion resistance and high-temperature stability due to unique high-entropy effect, lattice distortion effect, slow diffusion effect and cocktail effect. The combination of high entropy alloys with ceramics is a current research hotspot. Attempts have been made in the prior art to coat ceramic particles with high entropy alloys, but the following disadvantages remain: with a single ceramic phase, the performance improvement is limited; the coating layer is single-component high-entropy alloy, and the problem of abrupt change of physical properties between the ceramic and the metal matrix cannot be effectively solved; the interface bonding strength is insufficient, and interface failure is easy to occur under extreme working conditions. Therefore, a novel laser cladding composite powder capable of effectively solving the problems is developed, and the novel laser cladding composite powder has important theoretical significance and practical application value. Disclosure of Invention In order to overcome some of the problems mentioned in the background above, the present invention provides a high-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder, so as to at least partially solve the above problems. According to the technical scheme of the invention, the high-entropy alloy coated TiC-WC core-shell structure laser cladding composite powder comprises the following components: A ceramic core, tiC-WC composite ceramic particles formed by mechanically alloying TiC and WC; the refractory high-entropy alloy transition layer is coated outside the ceramic core and comprises TiZrNbTaMo series high-entropy alloy; The high-entropy alloy coating is coated outside the refractory high-entropy alloy transition layer, and comprises FeCoCrNiAl x high-entropy alloy, wherein x=0.3-0.7; Wherein, a gradient interface structure with continuously changing components is arranged between the refractory high-entropy alloy transition layer and the ductile high-entropy alloy outer layer. Preferably, the thickness of the gradient interface structure is 1-5 micrometers, and the concentration of Fe, co and Ni elements in the structure continuously decreases from the outer layer to the transition layer, and the concentration of Ti and Mo elements continuously decreases from the transition layer to the outer layer. Preferably, in the toughness high-entropy alloy outer layer, the molar ratio of Fe, co, cr, ni elements is 1:1:1:1, and the molar ratio of Al elements to any one element is (0.3-0.7): 1. Preferably, the ceramic core has a mass ratio of TiC to WC of 6:4 to 8:2. Preferably, ti, zr, nb, ta, mo elements in the refractory high-entropy alloy transition layer are configured in an equimolar ratio. Preferably, it is characterized by being prepared by the following steps: preparing TiC-WC composite ceramic core particles by a high-energy ball milling method; coating a refractory high-entropy alloy transition layer and a tough high-entropy alloy outer layer on the surface of the ceramic core in sequence by adopting a mechanical fusion method to form a pre-powder; and (3) carrying out heat treatment on the pre-prepared powder under the protection of vacuu