阅读说明：本技术 电泳沉积制备高附着力纳米铝热剂涂层的方法及其涂层 (Method for preparing high-adhesion nano thermite coating by electrophoretic deposition and coating prepared by method ) 是由 张代雄 于 2020-07-27 设计创作，主要内容包括：本发明提供一种电泳沉积制备高附着力纳米铝热剂涂层的方法及其涂层,采用油相合成法即十八胺与硝酸盐合成制备MO<Sub>x</Sub>纳米粒子,MO<Sub>x</Sub>纳米粒子再与纳米铝粉混合,分散于有机溶液中,加入分散剂形成悬浮液,利用电泳沉积法获得纳米铝热剂Al-MO<Sub>x</Sub>涂层。本发明通过构筑具有良好附着力的纳米铝热剂Al-MO<Sub>x</Sub>涂层,解决当前EPD法制备Al-MO<Sub>x</Sub>含能涂层与基底附着力差、容易大面积脱落、因环境失效的难题,为发展快速制备适应于复杂储运环境、具有高能量输出的实用型火工品器件提供普适性策略。本发明纳米合成工艺条件简单,涂层组装速度快,适合工业成产,可广泛的应用于国防军工、微电机系统等众多领域,市场应用前景好。(The invention provides a method for preparing a high-adhesion nano thermite coating by electrophoretic deposition and a coating thereof, wherein an oil phase synthesis method, namely synthesizing octadecylamine and nitrate to prepare MO x Nanoparticles, MO x Mixing the nano particles with nano aluminum powder, dispersing the mixture in an organic solution, adding a dispersing agent to form a suspension, and obtaining a nano thermite Al-MO by an electrophoretic deposition method x And (4) coating. The invention constructs the nano thermite Al-MO with good adhesive force x The coating solves the problem of Al-MO prepared by the current EPD method x Poor adhesion of energetic coatings to substratesThe device is easy to fall off in a large area and fails due to the environment, and a universal strategy is provided for developing and rapidly preparing a practical initiating explosive device which is suitable for a complex storage and transportation environment and has high energy output. The nano-synthesis process has simple conditions and high coating assembling speed, is suitable for industrial production, can be widely applied to various fields such as national defense and military industry, micromotor systems and the like, and has good market application prospect.)

1. The method for preparing the high-adhesion nano thermite coating by electrophoretic deposition is characterized in that an oil phase synthesis method is adopted to prepare metal oxide MO_xNanoparticles, MO_xMixing the nano particles with nano aluminum powder, dispersing the mixture in an organic solution, adding a dispersing agent to form a suspension, and obtaining the nano thermite coating by using an electrophoretic deposition method.

2. The method for preparing the high-adhesion nano thermite coating by electrophoretic deposition according to claim 1, comprising the following steps:

(1) heating octadecylamine to be molten, heating to 120-250 ℃, and adding MO_xNitrate corresponding to nano particles is stirred at high temperature to prepare MO_xCentrifugally collecting the nano particles for later use;

(2) polishing and washing the cathode and anode electrode plates, and then placing the cathode and anode electrode plates in a vacuum drying oven for drying for later use;

(3) mixing nano aluminum powder and MO obtained in step (1)_xSequentially adding the nano particles into the dispersion liquid according to the weight ratio of 10: 1-1: 10, adding a proper amount of dispersing agent into the dispersion liquid, wherein the total concentration range of the solid powder is 1.0-20.0 g/L, and performing ultrasonic dispersion to form stable suspension;

(4) fixing cathode and anode plates, vertically inserting into uniformly dispersed suspension, performing electrophoretic deposition with an external electric field of 50-200Vcm^-1After 5-30 minutes, obtaining a deposition film on the cathode plate;

(5) and drying the deposition film obtained by electrophoretic deposition.

3. The method of claim 1, wherein the MO is a high adhesion nano thermite coating_xM is one of Fe, Co, Ni, Cu and Zn.

4. The method for preparing the high-adhesion nano thermite coating by electrophoretic deposition according to claim 1, wherein the mass ratio of octadecylamine to nitrate in the step (1) is 40: 1-10: 1, the synthesis reaction temperature is 120-250 ℃, and the synthesis reaction time is 10-180 minutes.

5. The method for preparing the high-adhesion nano thermite coating by electrophoretic deposition according to claim 1, wherein the dispersion liquid in the step (3) is selected from isopropanol, ethanol, or a mixture of ethanol and acetylacetone according to a volume ratio of 1: 1; the dispersant is polyethyleneimine, nitric acid or hydrochloric acid.

6. Nano thermite coating obtained according to the preparation process of any one of claims 1 to 5.

Technical Field

The invention relates to the technical field of coatings, in particular to a method for preparing a high-adhesion nano thermite coating by electrophoretic deposition and a coating prepared by the method.

Background

Thermite (Al-MO)_x)，Is prepared from Al and Metal Oxide (MO)_xE.g. Fe₂O₃、CuO、Co₃O₄NiO, etc.) can be triggered by external energy to cause thermite reaction (2 xAl +3 MO)_x＝x Al₂O₃+3M + Q) releases a large amount of heat, and has unique and important application value in the national defense and military industry field due to the excellent heat release performance and deflagration performance. With the increasing demand for miniaturization and intelligence of weaponry in the 21 st century, the realization of the assembly of energetic materials in Micro-Electro-mechanical systems (MEMS) devices in the form of coatings is an urgent need for improving the energy output of igniters and thrusters. Al-MO compared to organic energetic materials_xThe higher triggering temperature leads the storage, transportation and use safety of the coating to be higher, and the assembly and preparation of the coating become the focus of attention of scholars at home and abroad.

Nano thermite (Al-MO)_x) The coating has good adhesive force with the device substrate, is not easy to fall off in complex storage, transportation and use environments, and is one of the prerequisites that the energy-containing device can meet the practical application. Commonly used energetic material coating techniques include magnetron sputtering, electron beam sputtering, thermal evaporation, electrospinning, etc., which generally result in energetic coatings with good adhesion to device substrates, but also suffer from expensive equipment, complex operation, poor assembly adaptability to substrates of complex shape, etc.

In addition to the above method, the 2012 foreign scholars Sullivan first prepared nano Al/CuO coating by Electrophoretic deposition (EPD), and since EPD has the advantages of simple equipment, convenient method, low cost, and capability of adapting to substrates with complex and various shapes, it is used for preparing Al-MO-containing coating_xVarious strategies for energetic coatings have received attention from researchers. Of these, most exciting is that second-order (seconds or tens of seconds) preparation of the coating is expected to be achieved when the electrophoretic suspension nanoparticle concentration is significantly increased. Zhang successfully realizes Al/Fe₂O₃、Al/Co₃O₄EPD preparation of various energy-containing coatings such as Al/NiO, B/Ti and the like, and verification is carried out for the first timeEPD provides advantages and feasibility for rapid device-based assembly of energetic coatings on MEMS system micro-ignition bridges. Guo and Yin et al, achieve the preparation of energetic materials on substrates of different micro-morphologies, and disclose that the feasibility of EPD preparation of energetic coatings is not affected by the micro-morphology of the substrate.

However, due to the nano thermite (Al-MO)_x) The contradiction between the thermite reaction triggering temperature and the sintering temperature of the coating (fig. 5) does not allow the use of post-sintering treatment to convert the nano thermite (Al-MO) into a nano thermite_x) The microscopic morphology of the coating is transformed from a simple accumulation of nanoparticles to a continuous, solidified state. Therefore, the extremely poor adhesion between the energy-containing coating prepared by EPD and the device substrate leads to easy large-area cracking and shedding, and the key bottleneck which cannot be solved so far is still formed.

Disclosure of Invention

The invention aims to provide a method for preparing a high-adhesion nano thermite coating by electrophoretic deposition and a coating prepared by the method, which can effectively overcome some or all of the defects.

A method for preparing a high-adhesion nano thermite coating by electrophoretic deposition adopts an oil phase synthesis method to prepare metal oxide MO_xNanoparticles, MO_xMixing the nano particles with nano aluminum powder, dispersing the mixture in an organic solution, adding a dispersing agent to form a suspension, and obtaining the nano thermite coating by using an electrophoretic deposition method.

The method specifically comprises the following steps:

(1) heating octadecylamine to be molten, heating to 120-250 ℃, and adding MO_xNitrate corresponding to nano particles is stirred at high temperature to prepare MO_xCentrifugally collecting the nano particles for later use;

(2) polishing and washing the cathode and anode electrode plates, and then placing the cathode and anode electrode plates in a vacuum drying oven for drying for later use;

(3) mixing nano aluminum powder and MO obtained in step (1)_xSequentially adding the nano particles into the dispersion liquid according to the weight ratio of 10: 1-1: 10, adding a proper amount of dispersing agent into the dispersion liquid, wherein the total concentration range of the solid powder is 1.0-20.0 g/L, and performing ultrasonic dispersion to form stable suspension;

(4) fixing the cathode and anode plates, inserting them verticallyElectrophoretic deposition is carried out in evenly dispersed suspension liquid, and the external electric field is 50-200Vcm^-1After 5-30 minutes, obtaining a deposition film on the cathode plate;

(5) and drying the deposition film obtained by electrophoretic deposition.

The MO_xM is one of Fe, Co, Ni, Cu and Zn.

In the step (1), the mass ratio of the octadecylamine to the nitrate is 40: 1-10: 1, the synthesis reaction temperature is 120-250 ℃, and the synthesis reaction time is 10-180 minutes.

In the step (3), the dispersion liquid is selected from isopropanol and ethanol, or a mixture of ethanol and acetylacetone according to a volume ratio of 1: 1; the dispersant is polyethyleneimine, nitric acid or hydrochloric acid.

The prepared nano thermite Al-MO_xThe adhesion of the coating (above 4B) is significantly better than with commercially available MO_xNano thermite Al-MO prepared from nano particles_xThe coating (2B) has uniform film surface distribution, good heat release performance and thermal stability.

The preparation method adopts an oil phase synthesis method, namely' octadecylamine (C1)₈H₃₇NH₂ODA) -nitrate "synthesis, referred to herein as the ODA method, for the preparation of nano-MOs_xMO prepared_xThe coating and the substrate have extremely strong adhesion effect, and the reasons are that: octadecylamine is used as a solvent and a surfactant, and a long-chain oleophylic group of octadecylamine can be adsorbed on nano MO prepared from a nitrate metal precursor_xSurface, long chain lipophilic group is expected to endow MO_xStrong adhesion performance. In contrast, commercially available nanoparticles for EPD production of energetic coatings have been reported to have "clean" surfaces and no adhesion-forming elements. Therefore, the method utilizes the ODA oil phase synthesis method to prepare MO_xNanoparticle replacement for commercially purchased MO_xUsed as EPD powder raw material to prepare novel nano thermite Al-MO_xCoating of MO_xThe Al nano-particles and the MO are effectively improved by taking the Al nano-particles as a reactant in the energy-containing coating and simultaneously playing the role of a binder_xIn order to construct a material with good adhesionThe energy-containing device provides a brand-new and effective technical scheme.

The invention constructs the nano thermite Al-MO with good adhesive force_xThe coating (M ═ Fe, Co, Ni and Cu) solves the problem of Al-MO prepared by the current EPD method_xThe problems of poor adhesion between the energetic coating and the substrate, easy large-area shedding and environmental failure are solved, and a universal strategy is provided for developing and rapidly preparing a practical initiating explosive device which is suitable for a complex storage and transportation environment and has high energy output. The method has simple nano synthesis process conditions and high coating assembling speed, is suitable for industrial production, can be widely applied to various fields such as national defense and military industry, micromotor systems and the like, and has good market application prospect.

Drawings

FIG. 1(a) is a schematic diagram showing comparative example 1 using commercially available Co₃O₄Al/Co by electrophoretic deposition₃O₄A nano-coating;

FIG. 1(b) shows the preparation of Co by ODA method in example 1 of the present invention₃O₄Al/Co by electrophoretic deposition₃O₄A nano-coating;

FIG. 2 shows Al/Co ratios of example 1 of the present invention₃O₄Characteristic XRD diffractogram of the nanocoating;

FIG. 3 shows Al/Co of example 1 of the present invention₃O₄The exotherm for the nanocoating;

FIG. 4 shows Al/Co photographed by the high-speed camera in embodiment 1 of the present invention₃O₄A burning picture of the nano-coating;

FIG. 5 is Al-MO prepared by prior art EPD_xThe inherent contradiction between improving adhesion by coating sintering and triggering thermite reaction.

Detailed Description

The specific technical scheme of the invention is described by combining the embodiment.