阅读说明：本技术 一种耐磨损高导磁功能涂层的原料制备和施工方法 (Raw material preparation and construction method of wear-resistant high-permeability functional coating ) 是由 郭纯 胡瑞章 李云 陈丰 魏宝丽 张华� 于 2019-10-18 设计创作，主要内容包括：一种耐磨损高导磁功能涂层的原料制备方法,包括以下步骤：依次取Si、B、Cr、C、W、Y、Fe的单质粉末混合置于中频感应炉中进行冶炼熔化,然后进行水雾化处理,得到的水粉水混合料,然后过滤脱水、干燥处理,筛选后即得耐磨损高导磁功能涂层的原料粉末；施工方法为：将原料粉末采用冷喷涂工艺施工,工艺参数如下：工作气体和载粉气体均为氮气,工作气体压力2～3.5MPa、温度600～750℃、距离40mm,枪速300～600mm/s,送粉器的转盘转速为3～5r/min。该制备方法步骤简单,原料易得,喷涂后的涂层可以显著提高基材在高磁场下的耐磨性能。施工方法简单易操作,可以达到原料粉末更好的喷涂效果。(A raw material preparation method of a wear-resistant high-permeability functional coating comprises the following steps: sequentially mixing simple substance powder of Si, B, Cr, C, W, Y and Fe, placing the mixture in a medium-frequency induction furnace for smelting and melting, then carrying out water atomization treatment to obtain a water-powder-water mixture, then carrying out filtration dehydration and drying treatment, and screening to obtain raw material powder of the wear-resistant high-permeability functional coating; the construction method comprises the following steps: the raw material powder is constructed by adopting a cold spraying process, and the process parameters are as follows: the working gas and the powder carrying gas are both nitrogen, the pressure of the working gas is 2-3.5 MPa, the temperature is 600-750 ℃, the distance is 40mm, the gun speed is 300-600 mm/s, and the rotating speed of a rotary plate of the powder feeder is 3-5 r/min. The preparation method has simple steps and easily obtained raw materials, and the sprayed coating can obviously improve the wear resistance of the base material under a high magnetic field. The construction method is simple and easy to operate, and can achieve better spraying effect of the raw material powder.)

1. A raw material preparation method of a wear-resistant high-permeability functional coating is characterized by comprising the following steps:

(1) sequentially mixing simple substance powder of Si, B, Cr, C, W, Y and Fe, placing the mixture in a medium-frequency induction furnace for smelting and melting, wherein the content of each component is recorded by weight percentage, the content of Si is 8-15%, the content of B is 5-10%, the content of Cr is 3-5%, the content of C is 1-1.5%, the content of W is 2-3%, the content of Y is 0.2-0.5%, and the balance is Fe, and the temperature of a melt is 1500 ℃ to obtain a liquid mixture in a molten state;

(2) carrying out water atomization treatment on the liquid mixture in the molten state obtained in the step (1), crushing the liquid mixture into metal droplets by high-pressure atomized water, then rapidly cooling and solidifying the metal droplets into powder to obtain a water-powder mixture, wherein the water atomization parameters are as follows: the atomization apex angle is 40 degrees, the high-pressure water pressure is 40MPa, the inner diameter of a liquid guide pipe is 3mm, and the atomization water flow is 70L/min;

(3) and (3) filtering and dehydrating the gouache water mixture obtained in the step (2), drying in a vacuum drier, and screening out particles with the particle size of 50-125 microns, namely the raw material powder of the wear-resistant high-permeability functional coating.

2. The raw material preparation method of the wear-resistant high-permeability functional coating according to claim 1, characterized by comprising the following steps: and nitrogen is introduced in the smelting process to be used as protective gas.

3. A construction method of a wear-resistant high-permeability functional coating is characterized by comprising the following steps: the raw material powder prepared by the method for preparing the raw material of the wear-resistant high-permeability functional coating according to claim 1 or 2 is applied by a cold spraying process, and the process parameters are as follows: the working gas and the powder carrying gas are both nitrogen, the pressure of the working gas is 2-3.5 MPa, the temperature is 600-750 ℃, the spraying distance is 40mm, the gun speed is 300-600 mm/s, and the rotating speed of a rotary plate of the powder feeder is 3-5 r/min when the coating is prepared.

Technical Field

The invention relates to a raw material preparation and construction method of a wear-resistant high-permeability functional coating.

Background

The magneto-rheological device adopts magneto-rheological fluid (MRF) as a working medium, after a magnetic field is applied, the magneto-rheological fluid can be rapidly converted into a quasi-solid state from a Newtonian fluid state, the change can be finished within millisecond-level time, and is continuous and adjustable, controllable yield strength is presented, semi-active real-time continuous control of damping force can be realized, and the change is reversible. Due to its excellent rheological properties, its research on properties and the development of technical products are receiving more and more attention. However, during the use of magnetorheological devices, in particular high-power magnetorheological devices, it has been found that: under the working condition of large slip (large recoil), the recoil time is extremely short for a few milliseconds, and the moving line speed of the magnetorheological fluid under the action of the recoil force can reach more than 10 m/s. The magnetorheological fluid is a suspension containing micron or nanometer soft magnetic particles (such as carbonyl iron powder, iron-cobalt alloy powder, iron oxide powder and the like), and is equivalent to a solid-liquid two-phase fluid. Meanwhile, under the action of a strong magnetic field (up to 2T), the magnetorheological liquid is converted into a semi-solid state, and particles in the magnetorheological liquid can rub with the cylinder body and the piston violently, so that the piston head and the cylinder body of the magnetorheological device are seriously abraded. Finally, the gap between the piston and the cylinder body is increased, and the sealing of the magnetorheological device fails, which seriously affects the transmission control performance and the service life of the magnetorheological device, so that the lubricating and sealing problems are key problems to be solved urgently in the research and application of high-end equipment high-power magnetorheological devices. It is known that the wear, corrosion and fracture of mechanical equipment parts generally occur or start from the surface of the part material, and the surface modification of high-end equipment system parts by using surface engineering technology is one of the effective measures for prolonging the service life of the high-end equipment and improving the performance stability of the high-end equipment. Therefore, the wear-resistant high-permeability functional coating is prepared on the surface of the key part of high-end technical equipment such as a magnetorheological device, and the service life of the part under the working condition of a magnetic field and wear composite service can be prolonged.

Cold spraying is a spray technique based on aerodynamics. The compressed gas enters a scalable Laval nozzle for acceleration after being preheated by the heating device, and high-speed gas flow (300-. The particles (5-50 μm) are accelerated by the airflow field and then impact the substrate at high speed, and the particles and the substrate are subjected to high plastic deformation, so that a coating is deposited on the surface of the substrate. Cold spraying is so called because the temperature of the particles during spraying is below their melting point. The cold spraying equipment mainly comprises a powder feeder, a heater, a spray gun, a Laval nozzle and the like. The technological parameters of cold spraying are mainly as follows: the powder feeding device comprises a working gas, a powder carrying gas, the type of the working gas, the pressure and the temperature of the working gas, a spraying distance, a gun speed, and the powder feeding rate of the powder feeder during coating preparation, wherein the gun speed is the swinging speed of a spray gun, a turntable is arranged in the powder feeder, and the faster the rotating speed of the turntable is, the more powder is fed out, so the powder feeding rate is generally expressed by the rotating speed of the turntable, and the unit is r/min.

Disclosure of Invention

The first technical problem to be solved by the invention is to provide a raw material preparation method of a wear-resistant high-permeability functional coating, the preparation method has simple steps and easily-obtained raw materials, and the wear resistance of a base material under a high magnetic field can be obviously improved by the coating formed by spraying the prepared raw materials.

The second technical problem to be solved by the invention is to provide a construction method of the wear-resistant high-permeability functional coating, which is simple and easy to operate and can achieve better spraying effect of the raw material powder.

In order to solve the first technical problem, the invention provides a raw material preparation method of a wear-resistant high-permeability functional coating, which comprises the following steps:

(1) sequentially mixing simple substance powder of Si, B, Cr, C, W, Y and Fe, placing the mixture in a medium-frequency induction furnace for smelting and melting, wherein the content of each component is recorded by weight percentage, the content of Si is 8-15%, the content of B is 5-10%, the content of Cr is 3-5%, the content of C is 1-1.5%, the content of W is 2-3%, the content of Y is 0.2-0.5%, the balance is Fe, and the temperature of the molten mixture is 1500 ℃ to obtain a liquid mixture in a molten state;

(2) carrying out water atomization treatment on the liquid mixture in the molten state obtained in the step (1), crushing the liquid mixture into metal droplets by high-pressure atomized water, then rapidly cooling and solidifying the metal droplets into powder to obtain a water-powder mixture, wherein the water atomization parameters are as follows: the atomization apex angle is 40 degrees, the high-pressure water pressure is 40MPa, the inner diameter of a liquid guide pipe is 3mm, and the atomization water flow is 70L/min;

(3) and (3) filtering and dehydrating the gouache water mixture obtained in the step (2), drying in a vacuum drier, and screening out particles with the particle size of 50-125 microns, namely the raw material powder of the wear-resistant high-permeability functional coating.

Preferably, nitrogen is introduced as a protective gas in the smelting and melting process.

In order to solve the second technical problem, the invention provides a method for constructing a wear-resistant high-permeability functional coating, wherein the raw material powder prepared by the method for preparing the wear-resistant high-permeability functional coating according to claim 1 or 2 is constructed by a cold spraying process, and the process parameters are as follows: the working gas and the powder carrying gas are both nitrogen, the pressure of the working gas is 2-3.5 MPa, the temperature is 600-750 ℃, the spraying distance is 40mm, the gun speed is 300-600 mm/s, and the rotating speed of a rotary plate of the powder feeder is 3-5 r/min when the coating is prepared.

For the sake of simple explanation, the raw material preparation method of the wear-resistant high-permeability functional coating according to the present invention is simply referred to as the present preparation method, and the construction method of the wear-resistant high-permeability functional coating according to the present invention is simply referred to as the present construction method.

In the preparation method, the novel Fe-Si-B-Cr-C-W soft magnetic amorphous alloy component with high magnetic conductivity, high saturation magnetic induction, low loss and low coercive force is used as a basis. The alloy system for the Fe-Si-B-Cr-C-W amorphous wear-resistant high-permeability functional coating is optimally designed according to the existing amorphous alloy theory, and the content of each component is optimized.

The preparation method adds Si and B, and mainly aims to improve the enthalpy of mixing of Fe-based coating components by adding Si and B elements according to the existing amorphous system design principle, thereby improving the amorphous forming capability of the coating. The Si element can effectively improve the magnetism of the alloy (because the electrons of the 3d orbit filled with Fe are reduced, the magnetic moment is increased). And according to the reports of the prior literature, the Fe-Si-B amorphous material has good magnetic permeability, saturation magnetic induction, low loss and low coercive force. The content interval of a certain component is mainly determined according to the mixing enthalpy among elements in the composition design. The content of a certain element exceeds this range, and either too high or too low results in a sharp decrease in amorphous forming ability.

Cr, C and W are added in the preparation method, and the main purpose is that the addition of the Cr, C and W elements can react to generate chromium carbide and a carbide reinforced phase in the preparation process of the powder and the coating, the chromium carbide and the carbide reinforced phase have higher hardness, and the chromium carbide and the carbide reinforced phase are dispersed in the iron-based amorphous base material to play a role in enhancing the wear resistance, so that the wear resistance of the coating is improved. The Cr element can also enhance the corrosion resistance of the material (because a Cr-rich passivation protective film can be formed on the surface of the alloy). However, if the content of the reinforcing phase generated in the coating is too high, the plasticity of the coating is reduced, the stress is increased, and even cracks and other serious defects can be caused.

The rare earth element Y is added in the preparation method, the main purpose is that the rare earth element Y belongs to a large atom, a small amount of addition can cause the increase of the number of the components and the strong binding force among the components, and the amorphous forming capability of the alloy can be improved after the addition of Y. The addition of Y can purify the alloy melt, improve the mismatching degree between atoms in the alloy, enhance the stability of the alloy undercooling melt, inhibit the precipitation of crystal phases and further improve the amorphous forming capability of the alloy.

The coating obtained by spraying by adopting the construction method is detected to be 0.5-5 mm in thickness, the bonding strength of the coating is more than or equal to 60Mpa, the hardness of the coating is more than or equal to HRC40, the internal structure of the coating is compact, the porosity is less than or equal to 2%, and the wear rate of the coating to a friction pair is less than or equal to 1 x 10^-5mm³The initial magnetic conductivity of the coating is more than or equal to 5000, the coercive force is less than or equal to 2A/m, the saturation magnetic induction intensity is more than or equal to 1.0T, and the wear resistance is very excellent.

Detailed Description