Ti-Al-Si-C coating modified by carbon nano material on surface of titanium and titanium alloy and preparation method thereof
阅读说明：本技术 钛及钛合金表面碳纳米材料改性的Ti-Al-Si-C镀层及其制备方法 (Ti-Al-Si-C coating modified by carbon nano material on surface of titanium and titanium alloy and preparation method thereof ) 是由 苏旭平 施东明 涂浩 王建华 刘亚 吴长军 于 2021-06-25 设计创作，主要内容包括：本发明属于金属表面镀层领域,具体提供了一种钛及钛合金表面碳纳米材料改性的Ti-Al-Si-C镀层及其制备方法。该方法为：先对钛及钛合金表面进行清洗干燥；再将碳纳米材料通过超声处理分散在溶剂中并添加适量增稠剂制备浆料；最后将钛及钛合金热浸镀于添加了制备浆料的原位反应铝硅熔池中,从而在钛及钛合金表面形成具有Ti-3AlC-2相层、Ti(Al,Si)-3相层和Al-Si相层的镀层。所得到的Ti-Al-Si-C镀层具有力学性能好、高温性能优良、易生产加工等特点。(The invention belongs to the field of metal surface coatings, and particularly provides a titanium and titanium alloy surface carbon nanomaterial modified Ti-Al-Si-C coating and a preparation method thereof. The method comprises the following steps: firstly, cleaning and drying the surfaces of titanium and titanium alloy; dispersing the carbon nano material in a solvent through ultrasonic treatment, and adding a proper amount of a thickening agent to prepare slurry; finally, the titanium and the titanium alloy are hot dipped in an in-situ reaction aluminum-silicon molten pool added with the preparation slurry, so that Ti is formed on the surface of the titanium and the titanium alloy 3 AlC 2 Phase layer, Ti (Al, Si) 3 A phase layer and a coating layer of an Al-Si phase layer. The obtained Ti-Al-Si-C coating has the characteristics of good mechanical property, excellent high-temperature property, easy production and processing and the like.)
1. A preparation method of a Ti-Al-Si-C coating modified by carbon nano materials on the surface of titanium and titanium alloy is characterized by comprising the following steps: the preparation method comprises the following steps:
(1) preparing an additive slurry: dispersing a carbon nano material in a solvent to prepare a suspension, performing ultrasonic dispersion for 30min, then adding a thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain an addition slurry;
(2) uniformly coating the added slurry prepared in the step (1) on the inner surface of a silica quartz vessel which is enlarged by 1.1-1.4 times according to the shape of a titanium or titanium alloy workpiece, drying in a vacuum drying oven, and standing for later use;
(3) polishing the surface of a titanium or titanium alloy workpiece to be flat, removing surface oxide skin and oil stain by acid washing and alkali washing, then drying in a vacuum drying oven, and standing for later use;
(4) under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the added slurry on the inner surface in the step (2), then immersing the titanium or titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), standing and preserving heat, and carrying out hot dip plating;
(5) and (4) rapidly drawing out the titanium or titanium alloy workpiece subjected to hot dip coating in the step (4), throwing away excessive liquid phase on the surface, and performing water quenching to obtain the Ti-Al-Si-C coating modified by the carbon nano material on the surface of the titanium or titanium alloy.
2. The method for preparing the Ti-Al-Si-C coating modified by the carbon nanomaterial on the surface of the titanium and the titanium alloy according to claim 1, wherein the carbon nanomaterial in the step (1) is any one of graphene and carbon nanotubes; the solvent is any one of N-methyl pyrrolidone, N-dimethylformamide, dioxane, ethanol, ethylene glycol, butanone and toluene.
3. The method for preparing the carbon nanomaterial-modified Ti-Al-Si-C coating on the surface of the titanium and the titanium alloy according to claim 1, wherein the suspension in the step (1) has a mass concentration of 5% and the thickening agent is polyvinylidene fluoride.
4. The method for preparing the carbon nanomaterial modified Ti-Al-Si-C coating on the surface of the titanium and the titanium alloy according to claim 1, wherein the inert gas in the step (4) is argon; the aluminum content of the pure aluminum ingot is more than 99.99 percent; standing and preserving heat within the range of 700-900 ℃, and preserving heat for 10-90 min.
5. The Ti-Al-Si-C coating modified by the carbon nanomaterial on the surface of the titanium and the titanium alloy prepared by the method of claim 1, wherein the coating is dense crack-free Ti3AlC2Phase layer, Ti (Al, Si)3Phase layers and Al-Si phase layers.
Technical Field
The invention belongs to the field of metal surface coatings, and particularly relates to a titanium and titanium alloy surface carbon nanomaterial modified Ti-Al-Si-C coating and a preparation method thereof.
Background
Titanium and titanium alloy have the advantages of low density, high specific strength, good heat resistance, excellent corrosion resistance and the like, are high-temperature materials with great application prospects, and are widely applied to high-temperature parts such as high-pressure blowers and turbine blades of aircraft engines. However, when the service temperature of titanium and titanium alloy is higher than 600 ℃, the high temperature performance of titanium and titanium alloy is sharply reduced, which is one of the important reasons for limiting the development of titanium and titanium alloy applications. Therefore, it is necessary to treat the surface of titanium and titanium alloys to improve the high temperature performance of titanium and titanium alloys, and it is desirable to coat the surface of titanium and titanium alloys.
The aluminum alloy coating is applied to the surfaces of titanium and titanium alloy, and can effectively improve the high-temperature performance of the titanium and the titanium alloy. In the Ti-Al system, only TiAl3Can form compact Al in the air2O3An antioxidant protective film having good oxidation resistance. In the Ti-Al-C system, Ti3AlC2Al in the phase can be rapidly diffused and selectively oxidized in the oxidation process to generate a layer of compact Al2O3A film that prevents the base material from being further oxidized. Ti3AlC2With the Al produced2O3The microstructure of the interface between the two materials enables the system material to have high-temperature self-healing capability. Meanwhile, the addition of Si can reduce the cracks of an aluminum coating, so that the TiAl added with Si3A plating is beneficial. In the case of the Ti-Al-Si plating, although the number of cracks in the plating is reduced, cracks in the plating are inevitable.
Disclosure of Invention
Based on the technical problems in the background art, the invention aims to provide a Ti-Al-Si-C coating modified by carbon nano materials on the surface of titanium and titanium alloy and a preparation method thereof, which integrate a Ti-Al-Si phase layer and Ti3AlC2The phase layer has the advantages of extremely excellent high-temperature performance. C atoms generated by the added carbon nano material and Si atoms generated by the in-situ reaction of silicon dioxide and liquid aluminum are diffused to the surfaces of titanium and titanium alloy, so that Ti is formed on the surfaces of the titanium and titanium alloy through the reaction3AlC2And (4) phase layer. And the addition of the carbon nano material slows down the diffusion speed of the self-generated silicon atoms to the surfaces of the titanium and the titanium alloy and inhibits the diffusion of the self-generated silicon atomsτ is2Forming an equal phase layer to form Ti tightly combined with the substrate on the surface of the titanium and the titanium alloy3AlC2Phase layer, Ti (Al, Si)3A phase layer and a coating layer of an Al-Si phase layer. The high-temperature-resistant steel plate has the characteristics of good thermal stability, high compactness, excellent high-temperature performance, easiness in production and processing, low cost and the like.
Meanwhile, various designs can be carried out on the phase structure of the coating according to the actual use requirement, and the overall thickness of the coating and the proportion distribution of each phase layer in the coating are controlled by controlling the hot dip coating time. Therefore, the Ti-Al-Si-C coating modified by the carbon nano material has good controllability.
The invention also aims to provide a preparation method of the Ti-Al-Si-C coating modified by the carbon nano material on the surface of the titanium and the titanium alloy, which comprises the following steps:
(1) preparing an addition slurry: dispersing the carbon nano material in a solvent to prepare a suspension, and ultrasonically dispersing the suspension for 30 min. And then adding a proper amount of thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain the added slurry.
The carbon nano material is any one of graphene and carbon nano tubes;
the solvent is any one of N-methyl pyrrolidone, N-dimethylformamide, dioxane, ethanol, ethylene glycol, butanone and toluene;
the mass concentration of the suspension is 5%;
the thickening agent is polyvinylidene fluoride.
(2) Uniformly coating the added slurry prepared in the step (1) with a certain mass on the inner surface of a silica quartz vessel which is enlarged by 1.1-1.4 times according to the shape of a titanium or titanium alloy workpiece, drying in a vacuum drying oven, and standing for later use.
(3) And (3) polishing the surface of a titanium or titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(4) Under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the additive slurry on the inner surface in the step (2), then immersing the titanium or titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), and standing and preserving heat within the range of 700-900 ℃;
the inert gas is argon; the aluminum content of the pure aluminum ingot is more than 99.99 percent; standing and preserving heat within the range of 700-900 ℃, and preserving heat for 10-90 min.
(5) And (3) after hot dipping, rapidly drawing out the titanium or titanium alloy workpiece in the step (4), throwing away excessive liquid phase on the surface, and performing water quenching to obtain the Ti-Al-Si-C coating modified by the carbon nano material on the surface of the titanium or titanium alloy in the claim 1.
The invention provides a carbon nano material modified composite coating, which effectively adds a carbon nano material into the composite coating through a liquid process. Ti-Al-Si-C plating which is tightly combined with a matrix and has excellent high-temperature performance is prepared on the surfaces of titanium and titanium alloy. The invention has the advantages of simple process, easy production and processing and low cost, and has very important significance for promoting the application of titanium and titanium alloy in aerospace.
Description of the drawings:
FIG. 1 is a microstructure and morphology diagram of a Ti-Al-Si-C coating modified by a carbon nanomaterial prepared in example 1;
FIG. 2 is a microstructure and morphology diagram of a Ti-Al-Si-C coating modified by a carbon nanomaterial prepared in example 2;
FIG. 3 is a microstructure and morphology diagram of a Ti-Al-Si-C coating modified by a carbon nanomaterial prepared in example 3;
FIG. 4 is a microstructure and morphology diagram of a Ti-Al-Si-C coating modified by a carbon nanomaterial prepared in example 4;
FIG. 5 is an XRD pattern of a Ti-Al-Si-C plating layer modified by a carbon nanomaterial prepared in example 2;
FIG. 6 is a graph of the high temperature oxidation resistance of titanium and titanium alloy obtained in comparative example 1, comparative example 2 and example 2;
FIG. 7 is a microstructure morphology of the plating layers obtained in comparative example 2 and example 2 after oxidation for 120h at 800 ℃, (a) comparative example 2, and (b) example 2.
Detailed Description
In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention is further described in detail with reference to the following examples. The described embodiments are only a part of the embodiments of the present application and are only intended to illustrate the present invention and not to limit the scope of the present invention.
Comparative example 1
11 TC4 titanium alloy samples without plating layers are prepared to carry out a continuous air oxidation experiment at 800 ℃. A sample is taken every 5, 10, 15, 20, 30, 40, 50, 60, 80, 100 and 120 hours to measure the oxidation weight gain, and the obtained oxidation weight gain curve is shown in FIG. 6.
Comparative example 2
(1) And (3) polishing the surface of the TC4 titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(2) Melting and pouring a pure aluminum ingot into a silica quartz vessel, then immersing the TC4 titanium alloy workpiece obtained in the step (1) into the silica quartz vessel which is enlarged by 1.2 times according to the shape of the TC4 titanium alloy workpiece, standing and preserving heat for 40min at 800 ℃, and carrying out hot dip coating;
(3) and (3) rapidly extracting the TC4 titanium alloy workpiece in the step (2), throwing away excessive liquid phase on the surface, and performing water quenching to obtain the Ti-Al-Si coating on the surface of the TC4 titanium alloy disclosed in claim 1.
(4) 11 obtained TC4 titanium alloy samples are selected to be subjected to a continuous air oxidation experiment at 800 ℃, one sample is taken out every 5, 10, 15, 20, 30, 40, 50, 60, 80, 100 and 120 hours to measure the oxidation weight gain, and the obtained oxidation weight gain curve is shown in figure 6. The microstructure topography of the plating layer after 120h oxidation is shown in fig. 7(a), and the plating layer has defects such as cracks and holes under high temperature oxidation.
Example 1
(1) Preparing an addition slurry: 5 parts of graphene powder is dispersed in 95 parts of N-methylpyrrolidone to prepare a suspension, and the suspension is subjected to ultrasonic dispersion for 30 min. And then adding polyvinylidene fluoride accounting for 0.5 percent of the mass of the suspension as a thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain the addition slurry.
(2) Uniformly coating the added slurry prepared in the step (1) on the inner surface of a silica quartz vessel which is enlarged by 1.2 times according to the shape of a TC4 titanium alloy workpiece, wherein the thickness of the slurry layer is 100 mu m, and then drying in a vacuum drying oven and placing for later use.
(3) And (3) polishing the surface of the TC4 titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(4) Under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the added slurry on the inner surface in the step (2), then immersing the TC4 titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), standing at 800 ℃ and preserving heat for 20min, and carrying out hot dip plating;
(5) and (4) quickly drawing out the TC4 titanium alloy workpiece subjected to hot dip coating in the step (4), throwing away redundant liquid phase on the surface, and performing water quenching to obtain the TC4 titanium alloy surface carbon nano material modified Ti-Al-Si-C coating.
(6) The obtained TC4 titanium alloy sample is subjected to a continuous air oxidation experiment at 800 ℃, and the result shows that the oxidation weight gain is less than 3mg/cm within 120h3. It can be seen that the samples having the plating layer exhibited extremely excellent high temperature oxidation resistance.
Example 2
(1) Preparing an addition slurry: 5 parts of graphene powder is dispersed in 95 parts of N-methylpyrrolidone to prepare a suspension, and the suspension is subjected to ultrasonic dispersion for 30 min. And then adding polyvinylidene fluoride accounting for 0.5 percent of the mass of the suspension as a thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain the addition slurry.
(2) Uniformly coating the added slurry prepared in the step (1) on the inner surface of a silica quartz vessel which is enlarged by 1.2 times according to the shape of a TC4 titanium alloy workpiece, wherein the thickness of the slurry layer is 100 mu m, and then drying in a vacuum drying oven and placing for later use.
(3) And (3) polishing the surface of the TC4 titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(4) Under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the added slurry on the inner surface in the step (2), then immersing the TC4 titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), standing at 800 ℃ and preserving heat for 40min, and carrying out hot dip plating;
(5) and (4) quickly drawing out the TC4 titanium alloy workpiece subjected to hot dip coating in the step (4), throwing away redundant liquid phase on the surface, and performing water quenching to obtain the TC4 titanium alloy surface carbon nano material modified Ti-Al-Si-C coating.
(6) 11 of the obtained TC4 titanium alloy samples with the coatings are selected to be subjected to a continuous air oxidation experiment at 800 ℃, one sample is taken out every 5, 10, 15, 20, 30, 40, 50, 60, 80, 100 and 120 hours to measure the oxidation weight gain, and the obtained oxidation weight gain curve is shown in figure 6. The microstructure morphology of the coating after 120h oxidation is shown in fig. 7(b), and the coating after high-temperature oxidation is still compact and has no defects such as cracks, holes and the like. It can be seen that the samples having the plating layer exhibited extremely excellent high temperature oxidation resistance.
Example 3
(1) Preparing an addition slurry: 5 parts of graphene powder is dispersed in 95 parts of N-methylpyrrolidone to prepare a suspension, and the suspension is subjected to ultrasonic dispersion for 30 min. And then adding polyvinylidene fluoride accounting for 0.5 percent of the mass of the suspension as a thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain the addition slurry.
(2) Uniformly coating the added slurry prepared in the step (1) on the inner surface of a silica quartz vessel which is enlarged by 1.2 times according to the shape of a TC4 titanium alloy workpiece, wherein the thickness of the slurry layer is 100 mu m, and then drying in a vacuum drying oven and placing for later use.
(3) And (3) polishing the surface of the TC4 titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(4) Under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the added slurry on the inner surface in the step (2), then immersing the TC4 titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), standing at 800 ℃ and preserving heat for 60min, and carrying out hot dip plating;
(5) and (4) quickly drawing out the TC4 titanium alloy workpiece subjected to hot dip coating in the step (4), throwing away redundant liquid phase on the surface, and performing water quenching to obtain the TC4 titanium alloy surface carbon nano material modified Ti-Al-Si-C coating.
(6) The obtained TC4 titanium alloy sample is subjected to a continuous air oxidation experiment at 800 ℃, and the result shows that the oxidation weight gain is less than 3mg/cm within 120h3. It can be seen that the samples having the plating layer exhibited extremely excellent high temperature oxidation resistance.
Example 4
(1) Preparing an addition slurry: 5 parts of carbon nanotube powder was dispersed in 95 parts of N-methylpyrrolidone to prepare a suspension, and the suspension was ultrasonically dispersed for 30 min. And then adding polyvinylidene fluoride accounting for 0.5 percent of the mass of the suspension as a thickening agent, uniformly stirring, and then putting into an oven to keep the temperature at 80 ℃ for 30min to obtain the addition slurry.
(2) Uniformly coating the added slurry prepared in the step (1) on the inner surface of a silica quartz vessel which is enlarged by 1.2 times according to the shape of a TC4 titanium alloy workpiece, wherein the thickness of the slurry layer is 100 mu m, and then drying in a vacuum drying oven and placing for later use.
(3) And (3) polishing the surface of the TC4 titanium alloy workpiece to be flat, carrying out acid washing and alkali washing to remove surface oxide skin and oil stain, then drying in a vacuum drying oven, and standing for later use.
(4) Under the condition of introducing inert gas, melting and pouring a pure aluminum ingot into the silica quartz vessel coated with the added slurry on the inner surface in the step (2), then immersing the TC4 titanium alloy workpiece in the step (3) into the silica quartz vessel in the step (2), standing at 800 ℃ and preserving heat for 40min, and carrying out hot dip plating;
(5) and (4) quickly drawing out the TC4 titanium alloy workpiece subjected to hot dip coating in the step (4), throwing away redundant liquid phase on the surface, and performing water quenching to obtain the TC4 titanium alloy surface carbon nano material modified Ti-Al-Si-C coating.
(6) The obtained TC4 titanium alloy sample is subjected to a continuous air oxidation experiment at 800 ℃, and the result shows that the oxidation weight gain is less than 3mg/cm within 120h3. It can be seen that the samples having the plating layer exhibited extremely excellent high temperature oxidation resistance.