阅读说明：本技术 准晶涂层及其制备方法、锅具和烹饪器具应用 (Quasi-crystal coating, preparation method thereof, cookware and application of cookware ) 是由 万鹏 陈永君 曹达华 陈炜杰 解志文 董闯 于 2018-11-02 设计创作，主要内容包括：本发明提供了准晶涂层及其制备方法、锅具和烹饪器具。所述方法包括：通过热喷涂将准晶粉喷涂于基体表面,以便得到初级涂层；对所述初级涂层进行退火处理,以便得到所述准晶涂层。由此,通过对初级涂层进行退火处理,在退火过程中,不仅初级涂层中的非晶相在高温下会重新转化为准晶,而且初级涂层中的准晶晶种也在退火中长大成为准晶晶粒,所以,退火处理可以大大提高准晶涂层中的准晶含量,进而极大地改善准晶涂层的不粘性,有效克服了在热喷涂过程中,由于火焰温度极高,准晶粉会经历熔化和凝固的过程,在该过程中大部分准晶转变为非晶相,导致初级涂层中的准晶含量大大降低的问题。(The invention provides a quasicrystal coating, a preparation method thereof, a cooker and a cooking utensil. The method comprises the following steps: spraying quasicrystal powder on the surface of a substrate by thermal spraying so as to obtain a primary coating; annealing the primary coating to obtain the quasicrystalline coating. Therefore, by annealing the primary coating, in the annealing process, the amorphous phase in the primary coating can be converted into the quasicrystal again at high temperature, and the quasicrystal crystal seed in the primary coating also grows into the quasicrystal crystal grain in the annealing process, so that the quasicrystal content in the quasicrystal coating can be greatly improved by the annealing process, the non-adhesiveness of the quasicrystal coating is greatly improved, and the problem that in the thermal spraying process, due to the fact that the flame temperature is extremely high, the quasicrystal powder can undergo the melting and solidification processes, and most of the quasicrystal is converted into the amorphous phase in the process, and the quasicrystal content in the primary coating is greatly reduced is effectively solved.)

1. A method of preparing a quasicrystalline coating, comprising:

spraying the quasicrystal powder on the surface of a substrate by thermal spraying so as to obtain a primary coating;

annealing the primary coating to obtain the quasicrystalline coating.

2. The method according to claim 1, wherein the temperature of the annealing treatment is 600 ℃ to 800 ℃.

3. The method of claim 1, wherein the annealing is performed under vacuum or a protective atmosphere.

4. A method according to claim 1, wherein the oxygen content in the quasicrystalline coating layer does not exceed 10 at%, preferably the oxygen content in the quasicrystalline coating layer is between 4 at% and 7 at%.

5. Method according to any of claims 1-4, characterized in that the conditions of the annealing treatment are: the temperature is reduced to 200-300 ℃ at the temperature rising rate of 5-100 ℃/min, the heat preservation time is 0.5-10 hours, and the temperature is cooled to room temperature along with the furnace after the temperature is reduced to 200-300 ℃ at the temperature reducing rate of 5-100 ℃/min.

6. The method according to claim 1, wherein the quasicrystalline powder is prepared by the following steps:

mixing aluminum, copper, iron and chromium according to a predetermined atomic number ratio, and smelting to form an alloy ingot;

and carrying out atomization powder preparation treatment on the alloy ingot in vacuum or protective atmosphere so as to obtain the quasicrystal powder.

7. The method of claim 6, wherein the atomic number ratio of aluminum, copper, iron, and chromium is (60-70): (15-25): (5-15): (5-15).

8. The method of claim 1, 5 or 6, further comprising, prior to the thermal spraying: and spheroidizing the quasicrystal powder to obtain quasicrystal particles.

9. The method of claim 8, wherein the quasicrystalline particles have a particle size of less than 150 microns.

10. The method of claim 1, wherein the primary coating is formed by:

spraying a first quasicrystalline powder body on the surface of the substrate by first thermal spraying to form a first primary coating;

spraying second quasicrystal powder on the surface of the first primary coating far away from the substrate through second thermal spraying to form a second primary coating;

the grain size of the first quasicrystal powder is larger than that of the second quasicrystal powder.

11. The method as claimed in claim 10, wherein at least 90% of the quasicrystalline powder in the first quasicrystalline powder has a particle size greater than 80 microns and less than 150 microns, and at least 90% of the quasicrystalline powder in the second quasicrystalline powder has a particle size not greater than 80 microns.

12. The method of claim 1, wherein the thermal spray is selected from plasma spray, flame spray, or arc spray.

13. The method of claim 12, wherein the plasma spraying is accomplished under at least one of:

the power is 15-50 kw, the main air flow is 40-60L/min, the auxiliary air flow is 10-30L/min, and the powder feeding amount is 10-20 g/min.

14. The method of claim 1, further comprising: and before the thermal spraying, sanding the substrate.

15. The method of claim 1, further comprising, after the annealing process: and polishing the quasicrystalline coating.

16. The method of claim 15, wherein the surface roughness of the quasicrystalline coating is less than 2 microns.

17. A quasicrystalline coating prepared by the process of any one of claims 1 to 16.

18. The quasicrystalline coating according to claim 17, characterized in that it satisfies at least one of the following conditions:

the content of the quasicrystal material is 20-90 wt%;

a porosity of 0.1% or more and 20% or less;

the thermal conductivity is 0.1-3W/mK;

the thickness is 10 to 500 μm.

19. A cookware, comprising:

a body;

the quasicrystalline coating according to claim 17 or 18, said quasicrystalline coating being provided on at least a portion of an inner surface of said body.

20. The cookware according to claim 19, wherein the material forming said body is selected from at least one of aluminium, stainless steel, iron, carbon steel and ceramic.

21. A cooking appliance comprising the pot of claim 19 or 20.

Technical Field

The invention relates to the technical field of quasi-crystal materials, in particular to a quasi-crystal coating, a preparation method thereof, a pot and a cooking utensil.

Background

The quasicrystal has the advantages of high hardness, high corrosion resistance, wear resistance, low surface energy and the like, is widely concerned by researchers, and the quasicrystal coating also becomes a hot candidate material for replacing the existing Teflon non-stick coating. However, in the preparation process, the method has many defects, which seriously affect the quasicrystal content in the non-stick coating, further affect the non-stick property of the coating and limit the industrialization process of the application of the quasicrystal coating on the pan body.

Therefore, research on quasicrystalline coatings is awaited.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. Therefore, the invention aims to provide a quasicrystal coating which has high quasicrystal content, good non-adhesiveness or simple preparation process.

The present invention is obtained based on the following knowledge and findings:

because the intrinsic brittleness and low adhesion of quasicrystal determine that a low-temperature spraying process (such as cold spraying) cannot prepare a quasicrystal coating with better performance, the preparation process of the quasicrystal coating commonly used at present is thermal spraying (such as plasma spraying). However, the inventor finds that due to the extremely high temperature of the spraying flame in the spraying mode, after the quasicrystal powder is subjected to melting and solidification to become the quasicrystal coating, most of quasicrystal in the quasicrystal powder is converted into amorphous, so that the quasicrystal content in the coating is greatly reduced, and the non-adhesiveness of the quasicrystal coating is greatly damaged. In order to solve the problem, after a series of researches, the inventor finds that if the coating formed by spraying is annealed after spraying, the quasicrystal content of the final quasicrystal coating can be greatly improved, and further, the non-adhesiveness of the quasicrystal coating is improved.

In one aspect of the invention, the invention provides a method of making a quasicrystalline coating. According to an embodiment of the invention, the method comprises: spraying the quasicrystal powder on the surface of a substrate by thermal spraying so as to obtain a primary coating; annealing the primary coating to obtain the quasicrystalline coating. Therefore, by annealing the primary coating, in the annealing process, the amorphous phase in the primary coating can be converted into the quasicrystal again at high temperature, and the quasicrystal crystal seed in the primary coating also grows into the quasicrystal crystal grain in the annealing process, so that the quasicrystal content in the quasicrystal coating can be greatly improved by the annealing process, the non-adhesiveness of the quasicrystal coating is greatly improved, and the problem that in the thermal spraying process, due to the fact that the flame temperature is extremely high, the quasicrystal powder can undergo the melting and solidification processes, most of the quasicrystal is converted into the amorphous phase in the process, and the quasicrystal content in the primary coating is greatly reduced is effectively solved.

According to an embodiment of the present invention, the oxygen content in the quasicrystalline coating does not exceed 10 at%, preferably the oxygen content in the quasicrystalline coating is between 4 at% and 7 at%.

According to the embodiment of the invention, the temperature of the annealing treatment is 600-800 ℃.

According to an embodiment of the invention, the annealing treatment is performed under vacuum or a protective atmosphere.

According to an embodiment of the invention, the annealing treatment conditions are: the temperature is reduced to 200-300 ℃ at the temperature rising rate of 5-100 ℃/min, the heat preservation time is 0.5-10 hours, and the temperature is cooled to room temperature along with the furnace after the temperature is reduced to 200-300 ℃ at the temperature reducing rate of 5-100 ℃/min.

According to the embodiment of the invention, the quasicrystalline powder is prepared by the following steps: mixing aluminum, copper, iron and chromium according to a predetermined atomic number ratio, and smelting to form an alloy ingot; and carrying out atomization powder preparation treatment on the alloy ingot in vacuum or protective atmosphere so as to obtain the quasicrystal powder.

According to an embodiment of the invention, the atomic number ratio of aluminium, copper, iron and chromium is (60-70): (15-25): (5-15): (5-15).

According to an embodiment of the invention, before the thermal spraying, further comprising: and spheroidizing the quasicrystal powder to obtain quasicrystal particles.

According to an embodiment of the invention, the crystallite particles have a particle size of less than 150 microns.

According to an embodiment of the invention, the primary coating is formed by: spraying a first quasicrystalline powder body on the surface of the substrate by first thermal spraying to form a first primary coating; spraying second quasicrystal powder on the surface of the first primary coating far away from the substrate through second thermal spraying to form a second primary coating; the grain size of the first quasicrystal powder is larger than that of the second quasicrystal powder.

According to the embodiment of the invention, the grain diameter of at least 90% of the quasi-crystal powder in the first quasi-crystal powder is larger than 80 microns and smaller than 150 microns, and the grain diameter of at least 90% of the quasi-crystal powder in the second quasi-crystal powder is not larger than 80 microns.

According to an embodiment of the invention, the thermal spraying is selected from plasma spraying, flame spraying or electric arc spraying.

According to an embodiment of the invention, the plasma spraying is performed under at least one of the following conditions: the power is 15-50 kw, the main air flow is 40-60L/min, the auxiliary air flow is 10-30L/min, and the powder feeding amount is 10-20 g/min.

According to an embodiment of the present invention, the method of preparing a quasicrystalline coating further comprises: and before the thermal spraying, sanding the substrate.

According to an embodiment of the invention, after the annealing treatment further comprises: and polishing the quasicrystalline coating.

According to an embodiment of the invention, the surface roughness of the quasicrystalline coating is less than 2 microns.

In another aspect of the invention, the invention provides a quasicrystalline coating. According to an embodiment of the present invention, the quasicrystalline coating is prepared by the method described above. Therefore, the quasicrystal coating has high quasicrystal material content and good non-stick property. It will be appreciated by those skilled in the art that the quasicrystalline coating has all the features and advantages of the method described above and will not be described in detail here.

According to an embodiment of the invention, the quasicrystalline coating satisfies at least one of the following conditions: the content of the quasicrystal material is 20-90 wt%; a porosity of 0.1% or more and 20% or less; the thermal conductivity is 0.1-3W/mK; the thickness is 10 to 500 μm.

In another aspect of the invention, the invention provides a cookware. According to an embodiment of the invention, the cookware comprises a body and the aforementioned quasicrystalline coating, which is provided on an inner surface of at least a part of the body. Therefore, the non-adhesiveness, the corrosion resistance and the strength of the cookware can be greatly improved, and the market competitiveness of the cookware is improved. Of course, those skilled in the art will appreciate that the cookware has all the features and advantages of the quasicrystalline coating described above, and will not be described in detail herein.

According to an embodiment of the invention, the material forming the body is selected from at least one of aluminium, stainless steel, iron, carbon steel and ceramics.

In yet another aspect of the present invention, the present invention provides a cooking appliance. According to an embodiment of the invention, the cooking appliance comprises the pot as described above.

Drawings

FIG. 1 is a schematic flow chart of a method for preparing a quasicrystalline coating in one embodiment of the present invention.

FIG. 2 is a schematic flow chart of a method for preparing a quasicrystalline coating according to another embodiment of the present invention.

FIG. 3 is a schematic flow chart of a method for preparing a quasicrystalline coating in yet another embodiment of the present invention.

FIG. 4 is an X-ray diffraction pattern of quasicrystals in quasicrystalline coatings obtained in examples 1-2 of the present invention and comparative example 1.

Detailed Description

The following describes embodiments of the present invention in detail. The following examples are illustrative only and are not to be construed as limiting the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

In one aspect of the invention, the invention provides a method of making a quasicrystalline coating. According to an embodiment of the present invention, referring to fig. 1, the method includes:

s100: spraying the quasicrystal powder on the surface of the substrate by thermal spraying so as to obtain a primary coating.

According to the embodiment of the present invention, the specific material of the base body is not limited as long as it has sufficient strength such that the quasicrystalline powder is sprayed on the surface thereof. In some embodiments of the invention, the substrate is a metal substrate of (low) carbon steel, aluminum alloy, stainless steel, or iron, or a ceramic substrate. Therefore, the substrate has enough strength to bear the pressure during spraying, so that the quasicrystal coating can be applied to the pot body or the inner container of the cooking equipment, and is arranged on the inner surface of the pot body or the inner container to be directly contacted with food, and the non-stick performance of the pot body or the inner container is improved.

In the embodiment of the present invention, referring to fig. 2, the quasicrystalline powder is prepared by the following steps:

s110: mixing aluminum, copper, iron and chromium according to a predetermined atomic number ratio, and smelting to form an alloy ingot.

According to the embodiment of the invention, a person skilled in the art can flexibly select the aluminum-based quasicrystal powder or the titanium-based quasicrystal powder according to actual needs. In some embodiments of the present invention, the quasicrystal powder is an aluminum-based quasicrystal powder, wherein in the step of forming the aluminum-based quasicrystal powder, in order to obtain a quasicrystal coating with a high quasicrystal content, the atomic number ratio of aluminum, copper, iron, and chromium is (60-70): (15-25): (5-15): (5-15). Therefore, the quasicrystal content in the finally obtained quasicrystal coating is high and can reach 20% -90%, and the quasicrystal coating has better non-stickiness.

According to the embodiment of the invention, the quasicrystal obtained by the method has five-time rotational symmetry or ten-time rotational symmetry characteristics. Therefore, the quasicrystal has the special quasi-periodic arrangement characteristics, the crystal grains of the quasicrystal cannot be arranged in the whole space, and the coating surface formed by the quasicrystal is provided with the concave-convex structure with micron-scale or micro-nanometer-scale gaps formed by the crystal grains, so that the structure can play an excellent hydrophobic role and has a good non-sticking effect.

According to an embodiment of the present invention, the grain shape of the quasicrystal is a polyhedral structure. Therefore, the crystal grains formed by the polyhedral structure cannot be arranged in the whole space, and the surface of the quasicrystal coating layer contains a concave-convex structure so as to achieve the non-sticky effect. In some embodiments of the invention, the grain shape of the quasicrystal is an icosahedron or a rhombohedral (deca quasicrystal). Therefore, when the quasicrystal contains the crystal grains with the shapes of icosahedron or rhombohedra, the quasicrystal has a more compact structure, so that the quasicrystal has higher hardness, wear resistance, scratch resistance, corrosion resistance, longer service life and better non-stick performance, and the coating containing the quasicrystal has better service performance. In addition, the localization of the quasicrystal surface electrons restricts the movement of electrons, reduces the interaction between the quasicrystal and the surface substance, and further improves the non-adhesiveness.

S120: and carrying out atomization powder preparation treatment on the alloy ingot in vacuum or protective atmosphere so as to obtain the quasicrystal powder.

According to an embodiment of the present invention, in the atomization pulverization process, the alloy ingot is melted into a liquid at 1000 to 1200 ℃, and then the melted liquid is impacted or otherwise broken into fine droplets by a fast-moving fluid (atomizing medium), and then condensed into a solid powder, i.e., a quasicrystalline powder. Therefore, the method has mature process, is easy to operate and is easy for industrial production.

According to the embodiments of the present invention, in addition to the above-mentioned methods of the present application, a person skilled in the art may obtain the quasicrystalline powder by a conventional preparation method in the art, such as a conventional casting method, a rapid solidification method, a mechanical alloying method, a deep undercooling preparation technique, a gas atomization method, a czochralski method, a float zone method, a magnetron sputtering or vapor deposition method, and the like.

According to the embodiment of the present invention, in order to increase the powder yield during the thermal spraying, before the thermal spraying, referring to fig. 3, the method further includes S130: and spheroidizing the quasicrystal powder to obtain the quasicrystal particles. Therefore, the quasicrystal powder is more smooth, and the powder yield of the quasicrystal powder is more favorably improved during spraying in the subsequent step. According to the embodiment of the present invention, in order to further improve the powder yield of the raw material during spraying, the particle size of the quasicrystal particles is less than 150 micrometers, and specifically, after the spheroidizing treatment, the quasicrystal particles may be obtained by screening (for example, screening with a 50-200 mesh screen) to obtain quasicrystal particles with a particle size of less than 150 micrometers. From this, the play powder rate of quasi-crystal powder is best during the spraying, if the particle diameter of quasi-crystal powder is too big, not only be unfavorable for going out the powder, can not fused quasi-crystal powder's volume is great when the spraying moreover, if this can not fused quasi-crystal powder spraying is on primary coating's surface, then can make primary coating's surface unevenness, and then leads to quasi-crystal coating's surface unevenness, and roughness is great, influences quasi-crystal coating's inadhesion nature.

According to the embodiments of the invention, in order to obtain a relatively dense quasi-crystal coating with low surface roughness, quasi-crystal powder with a small particle size is selected for spraying in some embodiments of the invention, for example, the particle size is less than 80 microns; in some embodiments of the present invention, in order to improve the utilization rate of the quasicrystalline powder, the primary coating may be formed by: spraying a first quasicrystalline powder body on the surface of the substrate by first thermal spraying to form a first primary coating; spraying second quasicrystal powder on the surface of the first primary coating far away from the substrate through second thermal spraying to form a second primary coating; wherein the grain diameter of the first quasicrystal powder is larger than that of the second quasicrystal powder. Therefore, the first primary coating formed by the large-particle-size first quasicrystal powder is arranged on the surface of the substrate, the utilization rate of the quasicrystal powder can be further improved, the first primary coating has certain porosity, the thermal conductivity of the coating can be further reduced by the certain porosity, the surface temperature of the whole quasicrystal coating is more uniform, the non-adhesiveness of the coating can be further improved, the preparation cost of the large-particle-size quasicrystal powder is lower, and the consumption cost of the whole process is reduced; however, the porosity has a great influence on the corrosion resistance, so that a denser second primary coating is sprayed on the surface of the first primary coating, which is far away from the substrate, so that the corrosion resistance and the compactness of the finally obtained quasicrystal coating are improved, and the nonstick property of the quasicrystal coating formed by the quasicrystal powder with small particle size is better.

According to the embodiment of the invention, in order to reduce the production cost of the quasicrystal coating on the premise of ensuring better performances such as compactness, corrosion resistance and non-adhesiveness of the quasicrystal coating, the grain diameter of at least 90% of the quasicrystal powder in the first quasicrystal powder is larger than 80 microns and smaller than 150 microns, and the grain diameter of at least 90% of the quasicrystal powder in the second quasicrystal powder is not larger than 80 microns. Therefore, the quasicrystal coating with better performance such as compactness, corrosion resistance, non-adhesiveness and the like can be obtained, and the production cost of the quasicrystal coating can be reduced.

According to the embodiment of the invention, in order to improve the adhesion of the quasicrystal powder on the substrate, the step of cleaning the surface of the substrate can be further included before the thermal spraying, and the specific method for cleaning is not limited as long as the stain, oil stain or rust on the surface of the substrate can be cleaned to meet the requirement of the spraying. In the embodiment of the invention, the surface of the substrate can be cleaned and dried by adopting the modes of alcohol, trichloroethylene or pure water and ultrasonic waves, and the like, and the surface of the substrate cannot have rust stains and the like before spraying, so that the adhesion of the quasicrystal powder on the substrate can be greatly improved after the spraying after the cleaning.

In some embodiments of the present invention, in order to further improve the adhesion of the quasicrystalline powder on the substrate and prolong the service life of the quasicrystalline coating, the substrate is subjected to a sanding treatment after the cleaning step and before the thermal spraying. Therefore, the surface of the substrate is coarsened, the adhesive force of the quasicrystal powder on the substrate can be improved, the quasicrystal powder can be pre-positioned during spraying, and the uniform growth of crystals is promoted.

According to the embodiments of the present invention, because quasicrystal intrinsic brittleness and low adhesion force cannot be prepared to obtain good quasicrystal coating by low temperature spraying (such as cold spraying), the present application adopts thermal spraying, i.e. quasicrystal powder is heated to a molten or semi-molten state and sprayed to the surface of a substrate at high speed to form a firmly attached coating, and in some embodiments of the present invention, the thermal spraying is selected from plasma spraying, flame spraying (such as oxy-ethylene flame powder spraying, oxy-acetylene flame wire spraying, oxy-acetylene flame spray welding, supersonic flame spraying) or electric arc spraying. Therefore, the method has mature process, is easy to operate and is easy for industrial production.

According to the embodiment of the invention, when the plasma spraying is adopted, the plasma spraying is completed under at least one of the following conditions: the power is 15-50 KW, such as 15KW, 20KW, 25KW, 30KW, 35KW, 40KW or 50KW, the main air flow is 40-60L/min, such as 40L/min, 45L/min, 50L/min, 55L/min or 60L/min, the auxiliary air flow is 10-30L/min, such as 10L/min, 15L/min, 20L/min, 25L/min or 30L/min, and the powder feeding amount is 10-20 g/min, such as 10g/min, 15g/min or 20 g/min. Thus, a primary coating layer having excellent properties can be formed. It should be noted that the Al content in the raw material is higher than that in the final quasicrystalline coating layer, since aluminum (Al) is partially ablated during the plasma spraying.

S200: annealing the primary coating to obtain a quasicrystalline coating.

According to the embodiment of the invention, in order to obtain the quasicrystal coating with high quasicrystal content on the basis of ensuring the quality of the quasicrystal coating, the annealing treatment temperature is 600 ℃ to 800 ℃, such as 600 ℃, 650 ℃, 700 ℃, 750 ℃ or 800 ℃, and it is noted that the annealing temperature refers to the heat preservation temperature in the annealing process. Therefore, annealing within the temperature range can not only convert the amorphous phase in the primary coating, which is converted by spraying, into quasicrystal at high temperature, but also enable the quasicrystal crystal seeds in the primary coating to grow into quasicrystal crystal grains, and furthermore, the quality of the quasicrystal coating cannot be influenced; if the temperature is lower than 600 ℃, the speed of converting the amorphous phase into the quasicrystal is slower, and a longer time is needed to convert the amorphous phase into the quasicrystal completely, so that the quasicrystal content in the quasicrystal coating is still improved compared with the primary coating before annealing treatment; if the temperature is higher than 800 ℃, although the content of the quasicrystal in the quasicrystal coating can be greatly increased, in the annealing process, the too high temperature can cause the coating to have too high thermal stress, and the too high thermal stress can cause the quasicrystal coating to crack, thereby seriously affecting the quality and the service performance of the quasicrystal coating and also affecting the non-adhesiveness of the quasicrystal coating.

According to an embodiment of the present invention, since the primary coating layer contains a metal element that is easily oxidized (such as aluminum), the annealing treatment is performed under vacuum or a protective atmosphere (such as nitrogen or argon). Therefore, metal elements which are easy to oxidize, such as aluminum, can be protected from being oxidized in the annealing process, and the content of quasicrystal in the quasicrystal coating is further improved. According to an embodiment of the invention, oxygen is inevitably incorporated into the quasicrystalline coating during the manufacturing process or during the use process, the content of oxygen in the quasicrystalline coating is not more than 10 at% based on the total amount of elements in the quasicrystalline coating, and preferably the content of oxygen in the coating is 4 at% to 7 at%. At the moment, because the oxygen content in the coating is lower, the content of metal elements in the quasi-crystal coating is increased, and the quasi-crystal coating and the metal substrate are metallurgically bonded, so that the bonding force between the quasi-crystal coating and the metal substrate can be increased; in addition, if the oxygen content is too high, the bonding of oxygen with other metal elements is increased, the crystal phase type in the coating is changed, and further, a crystal grain structure with n > 8-face bodies cannot be generated in the quasicrystalline coating, so that the non-stick performance, the corrosion resistance and the hardness of the coating are greatly reduced.

According to the embodiment of the invention, in order to obtain the quasicrystal coating with the best service performance and higher quasicrystal content, the annealing treatment conditions are as follows: the heating rate is 5-100 ℃/min, such as 5 ℃/min, 10 ℃/min, 20 ℃/min, 30 ℃/min, 40 ℃/min, 50 ℃/min, 60 ℃/min, 70 ℃/min, 80 ℃/min, 90 ℃/min or 100 ℃/min, the heat preservation time is 0.5-10 hours, such as 0.5 hour, 1 hour, 3 hours, 5 hours, 7 hours, 9 hours or 10 hours, the temperature reduction rate is 5-100 ℃/min, such as 5 ℃/min, 10 ℃/min, 20 ℃/min, 30 ℃/min, 40 ℃/min, 50 ℃/min, 60 ℃/min, 70 ℃/min, 80 ℃/min, 90 ℃/min or 100 ℃/min, the temperature is reduced to 200-300 ℃, such as 200 ℃, 230 ℃, 250 ℃, 270 ℃ or 300 ℃, and then the temperature is cooled to room temperature along with the furnace. Therefore, the content of the quasicrystal in the quasicrystal coating can be improved to the greatest extent, the non-adhesiveness of the quasicrystal coating is further improved to the greatest extent, and in addition, if the temperature rising rate or the temperature reduction rate is too low, the process duration can be prolonged; if the temperature rising rate or the temperature reduction rate is too high, the quality of the quasicrystal coating is influenced, such as cracking of the coating; if the holding time is too short, the amorphous phase can not be completely and fully converted into the quasi-crystal or the crystal seeds can not be completely grown into crystal grains, and the quasi-crystal content of the quasi-crystal coating is still improved compared with that of the primary coating; if the holding time is too long, the process cost is excessively increased.

According to the embodiment of the invention, in order to obtain the quasicrystalline coating with more suitable surface roughness, the method further comprises the following steps after the annealing treatment: and polishing the alignment crystal coating. Therefore, the surface roughness of the quasi-crystal coating can be reduced, the quasi-crystal coating with more suitable surface roughness can be obtained, and the non-adhesiveness of the quasi-crystal coating is improved. According to an embodiment of the invention, the surface roughness of the quasicrystalline coating is less than 2 microns. Therefore, the nonstick property of the quasicrystal coating is further improved, if the roughness is too large, the capillary action of the surface is triggered, water drops spread along the surface under the capillary action, and the hydrophobicity of the quasicrystal is relatively reduced; further, if the roughness is too high, the conditioning materials and the like are easy to deposit in the gaps, and the non-stick performance of the quasicrystal coating is reduced in the long-time use process, so that the use effect is influenced.

The inventor finds that by annealing the primary coating, in the annealing process, the amorphous phase converted by spraying in the primary coating is converted into quasicrystal again at high temperature, and the quasicrystal crystal seeds in the primary coating grow into quasicrystal crystal grains in the annealing process, so that the quasi-crystal content in the quasicrystal coating can be greatly increased by the annealing process, the non-adhesiveness of the quasicrystal coating is greatly improved, and the problem that in the thermal spraying process, due to the fact that the flame temperature is extremely high, the quasicrystal powder can undergo the melting and solidification processes, most of quasicrystal is converted into the amorphous phase in the melting and solidification processes, and the quasicrystal content in the primary coating is greatly reduced is effectively solved.

The nonstick property of the quasicrystal coating refers to the performance that when the quasicrystal coating is used in cooking equipment and arranged on the inner surface of a pot body or an inner container body, the quasicrystal coating is directly contacted with food and the food is not stuck to the pot in the cooking process.

In another aspect of the invention, the invention provides a quasicrystalline coating. According to an embodiment of the present invention, the quasicrystalline coating is prepared by the method described above. Therefore, the quasicrystal coating has high quasicrystal content and good non-stick property. It will be appreciated by those skilled in the art that the quasicrystalline coating has all the features and advantages of the method described above and will not be described in detail here.

According to an embodiment of the invention, the quasicrystalline coating satisfies one of the following conditions:

the content of the quasicrystalline material in the quasicrystalline coating is 20 to 90 wt%, for example, 20 wt%, 30 wt%, 40 wt%, 50 wt%, 60 wt%, 70 wt%, 80 wt% or 90 wt%. Therefore, the quasi-crystal coating can be ensured to have better non-adhesiveness;

the porosity of the quasicrystalline coating is greater than or equal to 0.1% and less than or equal to 20%, such as 0.1%, 0.5%, 1%, 1.5%, 2.0%, 2.5%, 3%, 3.5%, 4%, 5%, 5.5%, 6%, 7%, 8%, 8.5%, 9%, 9.5%, 10%, 11%, 13%, 15%, 17%, 18%, 20%. Therefore, the reasonable pores in the quasicrystal coating can reduce stress concentration and avoid the generation of coating cracks, but when the porosity in the quasicrystal coating is more than 20%, the hardness and the wear resistance of the coating are greatly reduced, so that the durability of the coating is reduced;

the thermal conductivity of the quasicrystal coating is 0.1-3W/mK, such as 0.1W/mK, 0.5W/mK, 1W/mK, 1.5W/mK, 2W/mK or 3W/mK. The thermal conductivity of the metal matrix is very high, if the thermal conductivity of low-carbon steel exceeds 50W/mK, when the metal matrix is applied to a pot, the pot body and the pot bottom generate temperature difference to cause the pot to stick and stick, the thermal conductivity of the quasi-crystal coating is low and ranges from 0.1W/mK to 3W/mK, so that the quasi-crystal coating is coated on the metal matrix and equivalently a protective layer is arranged on the surface of the pot, the heat is uniformly distributed on the surface of the pot due to the characteristic of low thermal conductivity of the quasi-crystal coating, and the problem of sticking the pot and the bottom is solved;

the thickness of the quasicrystalline coating is 10-500 microns, such as 10 microns, 50 microns, 100 microns, 150 microns, 200 microns, 250 microns, 300 microns, 400 microns or 50 microns. Because the quasi-crystal coating has the characteristics of high hardness and high wear resistance, when cleaning tools such as an iron shovel, a scouring pad and the like are used for cleaning for a long time, the quasi-crystal coating cannot be damaged and fall off, the pot body can be endowed with permanent non-adhesiveness, but the quasi-crystal coating cannot be uniformly heated when being too thin and cannot be heated when being too thick, and the quasi-crystal coating has loose structure and increased pores on the outer surface and reduced hardness, wear resistance and non-adhesiveness, so that the thickness of the quasi-crystal coating in the embodiment of the invention is 10-500 micrometers, so that the quasi-crystal coating can be ensured to have good uniform heating effect, and the problems of loose structure, increased pores on the outer surface of the quasi-crystal coating, and reduced hardness, wear resistance and non-adhesiveness of the coating can be avoided.

In another aspect of the invention, a cooking pot is provided. According to an embodiment of the invention, a cookware comprises a body and the aforementioned quasicrystalline coating, the quasicrystalline coating being provided on an inner surface of at least a portion of the body. Therefore, the non-adhesiveness, the corrosion resistance and the strength of the cookware can be greatly improved, and the market competitiveness of the cookware is improved. Of course, those skilled in the art will appreciate that the cookware has all the features and advantages of the quasicrystalline coating described above, and will not be described in detail herein.

According to the embodiment of the invention, the specific type of the cookware has no limitation requirement, and the skilled person can flexibly select the cookware according to actual requirements. In some embodiments of the invention, the pot is a frying pan, a stewpan, and an electric cooker or pressure cooker with an inner container.

According to an embodiment of the invention, the material forming the body is selected from at least one of aluminium, stainless steel, iron, carbon steel and ceramics. Therefore, the use performance of the pot can be improved.

According to the embodiment of the invention, in order to better improve the non-adhesiveness of the pot, the quasi-crystal can be doped in the body, so that the non-adhesiveness, the strength and the corrosion resistance of the pot can be improved to the greatest extent, and the service life of the pot is further prolonged.

Of course, it can be understood by those skilled in the art that the cooking device includes the necessary structures or components of the conventional cooking device, such as the wok, besides the quasicrystal coating and the body, and the handle, etc. besides the quasicrystal coating and the body; taking an electric cooker as an example, the electric cooker comprises a cooker body, a base, a steam valve, a cooker cover, an electric heating plate, an operation interface and other structures or components besides the inner container.

In yet another aspect of the present invention, the present invention provides a cooking appliance. According to an embodiment of the invention, the cooking appliance comprises the pot as described above. Therefore, the nonstickness, corrosion resistance and strength of the cooking utensil can be greatly improved, and the market competitiveness of the cooking utensil is improved. Of course, those skilled in the art will appreciate that the cooking appliance has all the features and advantages of the aforementioned cookware, and thus the description thereof is omitted.