CN110102751B

CN110102751B - Plasma preparation technology for metal particle oxidation resistant layer

Info

Publication number: CN110102751B
Application number: CN201910313155.3A
Authority: CN
Inventors: 邓龙江; 郭阳; 简贤; 张丽; 尹良君; 谢建良
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2019-04-18
Filing date: 2019-04-18
Publication date: 2021-04-30
Anticipated expiration: 2039-04-18
Also published as: CN110102751A

Abstract

The invention relates to a plasma preparation technology for an anti-oxidation layer of metal particles. The specific process includes: oxidizing metal particles at high temperature in the air to obtain a precursor material; subjecting the precursor material to plasma treatment to form a 200-600 nm thick stably attached metal particle. The high temperature anti-oxidation gradient ceramic structure on the particle surface; wherein, the air pressure of the plasma treatment is 50-150Pa, the temperature is 500-900°C, the power is 300-500W, the single reaction time is 20s-60s, and the interval time is 20-40s , the number of reactions is 20 to 40 times. The gradient ceramic layer formed by the invention can effectively reduce the transmission channel between the FSA and the oxidizing atmosphere, and improve the anti-oxidation and anti-corrosion properties of the FSA; It has high bonding strength, which greatly improves the matching of the thermal expansion coefficient between the high temperature resistant oxidation layer and the substrate.

Description

Plasma preparation technology for metal particle oxidation resistant layer

Technical Field

The invention relates to a plasma preparation technology of an oxidation resistant layer of metal particles, in particular to a plasma technology for preparing a layer of gradient ceramic structure with good oxidation resistance on the surface of metal particles.

Background

The zero-valent metal particle material is widely applied to the fields of national defense and military industry, mechanical microelectronics, optical devices, biomedical treatment, chemical energy and the like. However, the zero-valent metal particulate material which is not subjected to surface treatment has the defects of poor oxidation resistance, easy corrosion and the like. CN105385987A discloses a method for preparing a high-temperature oxidation resistant layer on the surface of metal tungsten, which mainly comprises the steps of embedding metal tungsten with a clean surface into a molybdenum impregnation agent, carrying out heat treatment in an inert atmosphere to obtain a semi-finished product with a tungsten-molybdenum solid solution layer on the surface of the metal tungsten, then embedding the semi-finished product into a silicon impregnation agent after carrying out heat treatment in nitrogen, and carrying out hot processing in the inert atmosphere to obtain a finished product with a W-Mo-N-Si series high-temperature oxidation resistant layer on the surface of the metal tungsten. However, the preparation process is complex, the production cost is high, the thermal matching between the coating and the substrate is poor, the structure and the phase state of the coating are difficult to control, and the high-temperature service life of the metal tungsten is directly influenced. Patent application No. CN1452453 proposes a method for forming an anti-oxidation layer by ultraviolet irradiation, which comprises first covering the surface of the coating film of the original conductive main body with silver colloid, then coating the surface of the silver colloid with PU (polyurethane) containing UV initiator, and finally irradiating with ultraviolet rays to generate cross-polymerization reaction between PU and initiator to form an anti-oxidation PU layer firmly attached to the surface of the silver colloid. The preparation process also has the problem that the thermal expansion coefficients of the coating and the substrate are difficult to match.

Disclosure of Invention

The invention aims to provide a plasma preparation technology of a metal particle oxidation resistant layer, aiming at the defects of easy corrosion, poor oxidation resistance and difficult matching of the thermal expansion coefficients of the oxidation resistant layer and a matrix of a metal particle material in the background technology. According to the invention, a layer of corrosion-resistant and high-temperature oxidation-resistant gradient ceramic structure with the thickness of 200-600 nm and stably attached to the surface of the metal particles is obtained on the surface of the metal particles.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the plasma preparation technology of the metal particle oxidation resistant layer is characterized by comprising the following steps of:

oxidizing the metal particles in air at a high temperature to obtain a precursor material, wherein the oxidation temperature is 500-900 ℃, and the oxidation time is 1-15 h;

performing plasma treatment on the precursor material to form a high-temperature oxidation-resistant gradient ceramic structure with the thickness of 200-600 nm, namely an oxidation-resistant layer, which is stably attached to the surface of the metal particles; wherein the pressure of the plasma treatment is 50-150 Pa, the temperature is 500-900 ℃, the plasma power is 300-500W, the single reaction time is 20-60 s, the interval time is 20-40 s, and the reaction times are 20-40.

Further, the metal particles include, but are not limited to, zero valence particles such as FeCo, fesai, and the like.

Further, the high-temperature oxidation-resistant gradient ceramic structure on the surface of the metal particles comprises 2-4 layers of gradient ceramic layers.

The invention has the beneficial effects that:

the plasma preparation technology for the metal particle oxidation resisting layer provided by the invention utilizes in-situ oxidation on the surface of FSA (FeSiAl) to generate a disordered oxidation layer, and further converts the disordered oxidation layer into a brand-new gradient ceramic layer with excellent oxidation resistance and corrosion resistance through a plasma technology. The gradient ceramic layer formed by the technology can effectively reduce a transmission channel between the FSA and the oxidizing atmosphere, and improve the oxidation resistance and corrosion resistance of the FSA; compared with the traditional oxidation resistant coating, the gradient ceramic grown in situ has higher bonding strength with metal particles, so that the matching of the high-temperature resistant oxidation resistant layer and the thermal expansion coefficient of the matrix is greatly improved. The method has the advantages of simple process, low cost, controllable reaction process, high yield and great utilization value and development prospect.

Drawings

FIG. 1 is a cross-sectional back-scattered electron image of a gradient ceramic/FSA composite structure (FSA @ GCLs) obtained in step 2 of example 1;

FIG. 2 is an SEM image of the gradient ceramic/FSA composite structure obtained in examples 1-4; wherein (a) is example 2, (b) is example 3, (c) is example 4, and (d) is example 1;

FIG. 3 is an XRD pattern of the gradient ceramic/FSA composite structure obtained in example 1;

FIG. 4 is a TG curve (a) and a second stage onset temperature (b) of the gradient ceramic/FSA composite structure obtained in example 1.

Detailed Description

The technical scheme of the invention is detailed below by combining the accompanying drawings and the embodiment.

A plasma preparation technology of a metal particle oxidation resistant layer comprises the following steps:

weighing certain mass of FeSiAl (FSA) metal particles, and oxidizing the FeSiAl (FSA) metal particles in air at a high temperature to obtain a precursor material, wherein the oxidizing temperature is 500-900 ℃, and the oxidizing time is 1-15 h;

subjecting the precursor material to plasma treatment, and subjecting the surface of the precursor material to plasma etching, scouring, self-organization reconstruction and other processes to form a layer of high-temperature oxidation-resistant gradient ceramic structure with the thickness of 200-600 nm, wherein the high-temperature oxidation-resistant gradient ceramic structure is stably attached to the surface of metal particles, namely an oxidation resistant layer; the specific process is as follows: placing the precursor material in a reaction furnace in an inert gas atmosphere, wherein the pressure in the reaction furnace is 50-150 Pa, the temperature is 500-900 ℃, the plasma power is 300-500W, the single reaction time is 20-60 s, the interval time is 20-40 s, and the reaction times are 20-40 times; and after the reaction is finished, naturally cooling to room temperature, and taking out to obtain a high-temperature oxidation-resistant gradient ceramic structure, namely an oxidation-resistant layer, with the thickness of 200-600 nm, stably attached to the surface of the metal particles.

Example 1

The preparation method of the high-temperature-resistant oxidation-resistant gradient ceramic/FSA composite structure comprises the following steps:

step 1, weighing 50g of micron-sized FeSiAl (FSA) metal particles, and oxidizing the metal particles at high temperature in air to obtain a precursor material, wherein the oxidation temperature is 700 ℃ and the oxidation time is 10 hours;

step 2, processing the precursor material (FSA @ CLs) obtained in the step 1 by a plasma preparation technology; the method specifically comprises the following steps: placing the precursor material obtained in the step (1) in a CVD furnace in an argon atmosphere, and carrying out multiple plasma reactions under the conditions that the pressure in the furnace is 95Pa, the temperature is 850 ℃ and the plasma power is 450W, wherein the single reaction time is 60s, the two-time reaction interval time is 20s, and the reaction times are 20 times; and after the reaction is finished, naturally cooling to room temperature, and taking out a product to obtain the gradient ceramic/FSA composite structure (FSA @ GCLs).

FIG. 1 is a cross-sectional back-scattered electron image of a gradient ceramic/FSA composite structure (FSA @ GCLs) obtained in step 2 of example 1; as can be seen from FIG. 1, the composite structure obtained in example 1 has a gradient distribution of the FSA surface ceramic layer, with a thickness of about 400nm to 500 nm.

Example 2

This example is different from example 1 in that:

step 2, when the precursor material (FSA @ CLs) obtained in step 1 is processed by a plasma preparation technology, the specific process is as follows: placing the precursor material obtained in the step (1) in a CVD furnace in an argon atmosphere, and carrying out multiple plasma reactions under the conditions that the pressure in the furnace is 95Pa, the temperature is 750 ℃ and the plasma power is 450W, wherein the single reaction time is 40s, the two-time reaction interval time is 20s, and the reaction times are 20 times; and after the reaction is finished, naturally cooling to room temperature, and taking out a product to obtain the gradient ceramic/FSA composite structure (FSA @ GCLs).

Example 3

This example is different from example 1 in that:

step 2, when the precursor material (FSA @ CLs) obtained in step 1 is processed by a plasma preparation technology, the specific process is as follows: placing the precursor material obtained in the step (1) in a CVD furnace in an argon atmosphere, and carrying out multiple plasma reactions under the conditions that the pressure in the furnace is 95Pa, the temperature is 800 ℃ and the plasma power is 450W, wherein the single reaction time is 40s, the two-time reaction interval time is 20s, and the reaction times are 20 times; and after the reaction is finished, naturally cooling to room temperature, and taking out a product to obtain the gradient ceramic/FSA composite structure (FSA @ GCLs).

Example 4

This example is different from example 1 in that:

step 2, when the precursor material (FSA @ CLs) obtained in step 1 is processed by a plasma preparation technology, the specific process is as follows: placing the precursor material obtained in the step (1) in a CVD furnace in an argon atmosphere, and carrying out multiple plasma reactions under the conditions that the pressure in the furnace is 95Pa, the temperature is 850 ℃ and the plasma power is 450W, wherein the single reaction time is 40s, the two-time reaction interval time is 20s, and the reaction times are 20 times; and after the reaction is finished, naturally cooling to room temperature, and taking out a product to obtain the gradient ceramic/FSA composite structure (FSA @ GCLs).

FIG. 2 is an SEM image of the gradient ceramic/FSA composite structure obtained in examples 1-4; wherein (a) is example 2, (b) is example 3, (c) is example 4, and (d) is example 1; as can be seen from fig. 2, the surface of the particles in example 2 had a few cracks, the surface of the particles in example 3 had no cracks, the surface of the particles in example 4 had white particles, and the white particles on the surface of the particles in example 1 had a significantly larger size than those on the surface of the particles in example 4.

FIG. 3 is an XRD pattern of the gradient ceramic/FSA composite structure obtained in example 1(FSA @ GCLs); as can be seen from FIG. 3, the main diffraction peaks of FSA, FSA @ CLs and FSA @ GCLs are FSA, and a small amount of Al appears simultaneously₂O₃And Fe₂O₃This indicates that FSA produces Fe upon oxidation₂O₃The FSA @ CLs is processed by a plasma induction technology to generate Al₂O₃It has also been demonstrated that high temperature oxidation and plasma induction techniques do not affect or alter the intrinsic properties of the FSA.

FIG. 4 is a TG curve (a) and second stage onset temperature (b) for the gradient ceramic/FSA composite structure obtained in example 1(FSA @ GCLs). As can be seen in FIG. 4a, the oxidation of FSA, FSA @ CLs and FSA @ GCLs can be divided into two stages: solid oxidation and liquid oxidation. As can be seen from FIG. 4b, the second stage onset temperature of FSA @ GCLs is significantly increased by more than 120 ℃ over FSA.

Claims

1. The preparation method of the plasma of the metal particle oxidation resistant layer is characterized by comprising the following steps:

oxidizing the metal particles in air at a high temperature to obtain a precursor material, wherein the oxidation temperature is 500-900 ℃, and the oxidation time is 1-15 h; the metal particles are FeCo or FeSiAl;

performing plasma treatment on the precursor material to form a high-temperature oxidation-resistant gradient ceramic structure, namely an oxidation-resistant layer, with the thickness of 200-600 nm, wherein the high-temperature oxidation-resistant gradient ceramic structure is attached to the surface of the metal particles; wherein the pressure of the plasma treatment is 50-150 Pa, the temperature is 500-900 ℃, the plasma power is 300-500W, the single reaction time is 20-60 s, the interval time is 20-40 s, and the reaction times are 20-40.

2. The method for preparing the plasma of the anti-oxidation layer of the metal particles as claimed in claim 1, wherein the high-temperature anti-oxidation gradient ceramic structure on the surface of the metal particles comprises 2-4 gradient ceramic layers.