CN-121992336-A - Method for preparing barium titanate functional coating by one-step method

CN121992336ACN 121992336 ACN121992336 ACN 121992336ACN-121992336-A

Abstract

The invention discloses a method for preparing a barium titanate functional coating by a one-step method, which comprises the steps of firstly adding barium octahydrate serving as a barium source into excessive glacial acetic acid, heating in a constant-temperature water bath, stirring until the solution is clear and transparent, cooling to room temperature to obtain solution A, wherein the pH value of the solution A is 5.0-6.8, secondly adding tetrabutyl titanate serving as a titanium source into absolute ethyl alcohol, stirring uniformly to obtain solution B, thirdly, dropwise adding the solution B into the solution A in a stirring state at room temperature, continuing stirring, mixing and ageing after the dropwise adding of the solution B is finished to obtain a barium titanate precursor solution, fourthly, taking a metal material as a substrate, preprocessing to obtain a preprocessed substrate, and fifthly, spraying the barium titanate precursor solution obtained in the third step onto the preprocessed substrate through a solution plasma spraying process to prepare the barium titanate functional coating. The method has simple process, and the obtained coating has uniform components, better hardness and certain density and dielectric property.

Inventors

BAI YU
XU NING
MA WEN
GAO YUANMING
Yin Diechuan

Assignees

内蒙古工业大学

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The method for preparing the barium titanate functional coating by the one-step method is characterized by comprising the following steps of: adding barium hydroxide octahydrate as a barium source into excessive glacial acetic acid, heating in a constant-temperature water bath, stirring until the solution is clear and transparent, and cooling to room temperature to obtain solution A, wherein the pH value of the solution A is 5.0-6.8; step two, tetrabutyl titanate serving as a titanium source is added into absolute ethyl alcohol and stirred uniformly to obtain a solution B; Step three, dropwise adding the solution B into the solution A under the stirring state at room temperature, and continuously stirring, mixing and ageing after the dropwise adding of the solution B is finished to obtain a barium titanate precursor solution; Step four, taking a metal material as a matrix, and preprocessing the matrix to obtain a preprocessed matrix; And step five, spraying the barium titanate precursor solution obtained in the step three onto the pretreated substrate obtained in the step four through a solution plasma spraying process, and thus obtaining the barium titanate functional coating.
2. The method for preparing a barium titanate functional coating according to claim 1, wherein in the first step, the ratio of the amounts of glacial acetic acid and the substance of barium hydroxide octahydrate is (2.02-2.10): 1.
3. The method for preparing barium titanate functional coating according to claim 1, wherein in the first step, the concentration of barium element in the solution a is 3.25-3.8mol/L.
4. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the first step, the constant-temperature water bath heating temperature is 50-60 ℃, and the heating and stirring time is 40-60min.
5. The method for preparing barium titanate functional coating according to claim 1, wherein in the second step, the ratio of the amount of titanium element in the titanium source to the amount of barium element in the barium source is 1:1.
6. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the second step, stirring time is 10-20min, and the concentration of titanium element in the solution B is 0.74-0.86mol/L.
7. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the third step, the solution B is rapidly stirred in the dripping process after the dripping is completed within 30-60min, the rapid stirring speed is 50-60rpm, the low stirring speed is 30-40rpm in the aging process.
8. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the third step, the viscosity of the barium titanate precursor solution is 0.5-10mpas, and the concentration of the barium element and the titanium element in the barium titanate precursor solution is 0.6-0.7mol/L.
9. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the fourth step, the substrate is pure titanium, titanium alloy, stainless steel or carbon steel, and the pretreatment method of the substrate comprises the steps of cleaning and drying the substrate, carrying out surface sand blasting treatment on the substrate by using white corundum with 24-220 meshes, carrying out ultrasonic cleaning by using absolute ethyl alcohol after sand blasting, and then drying the substrate.
10. The method for preparing the barium titanate functional coating by the one-step method according to claim 1, wherein in the fifth step, the condition of the solution plasma spraying process is that the spraying distance is 50-100mm, the spraying power is 50-100kW, the total gas flow is 100-400slpm, the liquid feeding amount is 10-40mL/min, the atomizing gas flow is 10-20L/h, the substrate preheating temperature is 120-300 ℃, and the gun moving speed of a spray gun is 400-700mm/s.

Description

Method for preparing barium titanate functional coating by one-step method Technical Field The invention relates to the technical field of coating preparation, in particular to a method for preparing a barium titanate functional coating by a one-step method. Background The rapid development of electronic information technology has led to the continuous expansion and deepening of research on functional dielectric materials. Barium titanate, one of the functional electrolyte materials, has been attracting attention because of its high dielectric and ferroelectric properties and environmental friendliness without containing lead, and has been widely used in the fields of aerospace, communication technology, multilayer ceramic capacitors, and the like. The preparation method of the barium titanate coating mainly comprises a sol-gel method, a magnetron sputtering method, chemical vapor deposition, micro-arc oxidation, plasma spraying and the like. With the continuous development of thermal spraying technology, the deposition, development and research of BaTiO 3 coatings by plasma spraying have become an inevitable trend of the development of the era in recent years. The plasma spraying method is a technology for forming a high-temperature plasma arc by ionizing inert gases such as argon, nitrogen, hydrogen and the like, melting and accelerating the spraying raw materials to impact on a substrate to obtain a compact coating. Plasma spray techniques include Atmospheric Plasma Spraying (APS), supersonic plasma spraying (HVOF), and Solution Precursor Plasma Spraying (SPPS), among others. Solution Precursor Plasma Spraying (SPPS) requires less powder particle size than Atmospheric Plasma Spraying (APS) and supersonic plasma spraying (HVOF), and the apparatus is relatively simple. However, in the prior art, a Solution Precursor Plasma Spraying (SPPS) technology is less used for preparing the barium titanate functional coating, mainly because the traditional precursor solution for preparing the barium titanate does not accurately regulate the hydrolysis rate of the titanium source and the dissociation rate of the barium source, the titanium source and the barium source lack a stable coordination structure, and the condition that the titanium source is hydrolyzed firstly to generate precipitate and then coordinated later to cause component segregation of a system can occur due to the use of an unfit titanium source, barium source and solvent, so that the dielectric property and mechanical property of the material are further weakened. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to provide a method for preparing the barium titanate functional coating by a one-step method, and the prepared barium titanate functional coating has the advantages of uniform components, good bonding strength, better hardness and certain compactness and dielectric property. In order to solve the technical problems, the invention provides the following technical scheme: The method for preparing the barium titanate functional coating by the one-step method comprises the following steps: adding barium hydroxide octahydrate as a barium source into excessive glacial acetic acid, heating in a constant-temperature water bath, stirring until the solution is clear and transparent, and cooling to room temperature to obtain solution A, wherein the pH value of the solution A is 5.0-6.8; step two, tetrabutyl titanate serving as a titanium source is added into absolute ethyl alcohol and stirred uniformly to obtain a solution B; Step three, dropwise adding the solution B into the solution A under the stirring state at room temperature, and continuously stirring, mixing and ageing after the dropwise adding of the solution B is finished to obtain a barium titanate precursor solution; Step four, taking a metal material as a matrix, and preprocessing the matrix to obtain a preprocessed matrix; And step five, spraying the barium titanate precursor solution obtained in the step three onto the pretreated substrate obtained in the step four through a solution plasma spraying process, and thus obtaining the barium titanate functional coating. According to the method, barium hydroxide octahydrate is used as a barium source, glacial acetic acid is used as a reactant and a solvent, the reaction is carried out under the condition of heating in a water bath to obtain a solution A with the pH value of 5.0-6.8, excessive water in the solution A is avoided, an ethanol solution of tetrabutyl titanate is dripped into the solution A, meanwhile, the dosage of each raw material is accurately regulated and controlled to obtain a barium titanate precursor solution with specific concentration and viscosity. The solution plasma spraying is carried out by controlling the decomposition kinetics of the precursor solution and combining a proper spraying process, the phase composition of the coating is controlled, the growth of crystal grains i