Plasma non-stick pan and manufacturing method thereof

Abstract

The present invention discloses a plasma non-stick pan and manufacturing method thereof. The plasma non-stick pan comprises a pan body and a non-stick layer applied to the pan body; a plasma layer is provided between the non-stick layer and the pan body, and the plasma layer comprises a MCrALY layer sprayed to the surface of the pan body and a mixture layer sprayed outside of the MCrALY layer, and the mixture layer is composed of MCrALY particles and metal oxide particles. The MCrALY layer has good toughness and strong adhesion, and it is easy to bind with the substrate with high fastness after binding, playing a buffering role and laying a foundation for the subsequent spraying of mixture layer.

Claims

1. A plasma non-stick pan comprising a pan body and a non-stick layer applied to the pan body, wherein a plasma layer is provided between the non-stick layer and the pan body, the plasma layer comprises a MCrAlY layer, where M stands for a transition metal, sprayed to the surface of the pan body and a mixture layer sprayed on top of the MCrAlY layer such that the mixture layer is located between the MCrAlY layer and the non-stick layer, and the mixture layer is composed of a mixture of 40-50% MCrAlY particles and 50-60% of metal oxide particles.

2. The plasma non-stick pan according to claim 1, wherein a cushion layer is provided between the MCrAlY layer and the mixture layer, the cushion layer is composed of a mixture of 70-80% MCrAlY particles and 20-30% metal oxide particles.

3. A method for manufacturing a plasma non-stick pan, comprising the following steps: (1) molding a pan body; (2) oil removing: removing surface oil dirt and scale on the pan body, and drying; (3) forging the pan body using a forging press; (4) cleaning the pan body, and drying; (5) blasting: blasting to the pan body surface with 20# and 46# mixed corundum, to make the surface roughness of pan body Ra=7.0-10.0 m; (6) pre-heating: heating the pan body to 220-280 C.; (7) spraying a plasma layer: MCrAlY powder particles where M stands for a transition metal, are heated to molten or semi-molten state using a DC motor-driven plasma arc as a heat source, and sprayed to the pan body surface at a rate of 150 m/s, to form a firm MCrAlY layer attached to the pan body surface; and then a mixture of MCrAlY powder particles and metal oxide particles are heated to molten or semi-molten state, sprayed on top of the MCrAlY layer at a rate of 150 m/s, to form a plasma layer comprising the mixture layer attached on top of the MCrAlY layer; (8) spraying a primer layer: after spraying the plasma layer, spraying a composition on the plasma layer, wherein the composition comprises polyetheretherketone (PEEK) and polyether sulfone (PES), and baking the coated pan body for 5-10 min at the temperature of 120-280 C., to form a primer layer with thickness of 3-5 m; (9) inner spraying: spraying polytetrafluoroethylene (PTFE) coating on the primer layer, and baking 10 min at 380-440 C., to form a PTFE coating layer with a thickness of 30-45 m.

4. The method according to claim 3, wherein the metal oxide is at least one selected from the group consisting of alumina, zirconia, titania and chromium oxide, and the particle size of the MCrAlY and metal oxide particles is 60-80 m.

5. The method according to claim 3, wherein the spraying thickness of the plasma layer in step (7) is 30-60 m, the range of roughness of the plasma layer is Ra=10-15 m, Rz=50-70 m.

6. The method according to claim 3, wherein the plasma layer is sprayed at a current of 400-800 A, a voltage of 25-45V, a powder feeding amount of 50-80 g/min, a spraying distance of 10-20 mm, and a spraying time of 90-120 s.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a structural diagram of this invention.

(2) FIG. 2 is an enlarged view of A in FIG. 1.

DETAILED DESCRIPTION

(3) The technical solutions in the invention are described explicitly and completely in combination with embodiments and drawings to allow technicians skilled in the art to understand them.

(4) Referring to FIG. 1 and FIG. 2, the thickness of various coatings in figure is not the actual proportion, which is enlarged for understanding. A plasma non-stick pan, comprising a pan body 1 and a non-stick layer 11 applied to the pan body, wherein a plasma layer 2 is provided between the non-stick layer 11 and the pan body, the plasma layer comprises a MCrALY layer 21 sprayed to the surface of the pan body 1 and a mixture layer 22 sprayed outside of the MCrALY layer 21, and the mixture layer is composed of MCrALY particles and metal oxide particles. By setting a special plasma layer between the non-stick layer and the pan body, the surface hardness of the pan body is significantly enhanced; the plasma layer is a dual layer structure; the MCrALY layer composed of MCrALY particles is bonded with the pan body substrate, with strong toughness and high adhesion to the substrate. The mixture layer is composed of MCrALY particles and metal oxide particles, with greater hardness; and through the transition and convergence of MCrALY layer, the mixture layer can be firmly attached to the substrate.

(5) In order to improve a coating adhesion strength and abrasion resistance, a cushion layer 23 is provided between the MCrALY layer 21 and the mixture layer 22, the cushion layer is composed of a mixture of 70-80% MCrALY and 20-30% metal oxide particles, playing a transition role, to ensure that the entire plasma layer has the best hardness and adhesion under the optimum thickness.

(6) Specifically, the mixture layer 22 is composed of a mixture of 40-50% MCrALY particles and 50-60% of metal oxide particles.

(7) A method for manufacturing the plasma non-stick pan, comprising the following steps:

(8) (1) molding. The pan body is die-casting molded by 4,800-ton pressure. It has dense texture. It can be heated more evenly then ordinary pan, with faster heat transfer, to achieve no fumes really.

(9) (2) oil removing: Clean the pan body with 5% SCD nonfat powder to remove pan body surface oil dirt and scales at the pH of 13 and temperature at 40-50 C.; and then put the pan body into 3-5% SCD polishing agent to implement neutralizing and cleaning at room temperature and Ph 2-3; and then wash the pan body with water, then blow-dry the pan body surface.

(10) (3) thermal coating; implement the thermal coating using the forging press at the pressure of 2,500 tons, to make the body more dense and homogeneous. The superconducting thermal coating technology can enhance the thermal efficiency by more than 20% compared with the ordinary cold coating (with holes) technology, saving energy and time.

(11) (4) cleaning. Clean the pan body with 2-3% NaOH at a temperature of 30-40 and PH value 12-14; clean the pan body with water, then neutralize and cleaning the pan body using 1-2% dilute nitric acid at room temperature and PH 1-3; and then clean the pan body with water, dry the pan body surface;

(12) (5) blasting: blasting to the pan body surface with 20 # and 46 # mixed corundum, to make the surface roughness of pan body Ra=7.0-10.0 m;

(13) (6) Pre-heating, heat the pan body to 220-280 C.; under the temperature, the surface hardness of the aluminum pan begins to drop, the surface tension drops to a lower state, to effectively combine with the subsequently coated plasma layer.

(14) (7) Spraying plasma layer: The powder MCrALY particles are heated to molten or semi-molten state using a DC motor-driven plasma arc as a heat source, and sprayed to the pan body surface at a rate of 150 m/s, to form a firm MCrAlY layer attached to the pan body surface; and then the mixture of 70-80% MCrALY powder particles and 20-30% metal oxide particles are heated to molten or semi-molten state, sprayed to the pan body surface at a rate of 150 m/s, to form a mixture layer attached outside of the MCrALY layer; finally the mixture of 40-50% MCrALY powder particles and 50-60% metal oxide powder particles are heated to molten or semi-molten state, sprayed to the pan body surface at a rate of 150 m/s, to form a mixture layer attached outside of the cushion layer. A large number of experiments have demonstrated that, the mixture layer of 40-50% MCrALY powder particles and 50-60% metal oxide powder particles has the best surface hardness and best adhesion; 50-60% metal oxide is in the surface layer, playing a role of hardness supporting, with the hardness up to 1800-2000 HV; if the content is less than 50%, the coverage is not enough, hardness is not enough; if the content is higher than 60%, the local accumulation occurs, leading to brittleness. A large number of experiments have verified that, the mixture of metal oxide and MCrALY under this scope has the best distribution.

(15) Specifically, the spraying current of plasma layer is 400-800 A, the voltage is 25-45V, the major gas pressure is from nitrogen, with the pressure of 40-60 psi; and the auxiliary gas pressure is from hydrogen, the pressure varies with the variance of voltage; the carrier gas is nitrogen, with the pressure of 40-60 psi, the powder feeding amount is 50-80 g/min, the spraying distance is 10-20 mm, and the spraying time is 90-120 s;

(16) The spraying thickness of the plasma layer is 30-60 m, the range of roughness is Ra=10-15 m, Rz=50-70 m. Through the above process, the adhesion force between the pan body and the plasma coating layer is 110 N/mm.sup.2;

(17) Specifically, the metal oxide is selected from one of alumina, zirconia, titania, chromium oxide, titanium nitride and MCrAlY or a mixture thereof, and the particle size of the MCrAlY and metal oxide particles is 60-80 m; in the embodiment, zirconia is used;

(18) (8) Spraying a primer layer: After spraying plasma layer, bake 5-10 min with a composition at the temperature of 120-280 C. to form a primer layer with thickness of 3-5 m; specifically, the composition comprises 30-50% of peek (polyetheretherketone) and 35-40% of pes (polyether sulfone), which is prepared with other components of conventional adhesive coating by mixing evenly. Technicians skilled in the art can adjust the types and ratio of components as needed, as long as the contents of peek (polyetheretherketone) and pes (polyether sulfone) are controlled. The primer can enhance the adhesion between the PTFE coating and the plasma layer;

(19) (9) Inner spraying: spraying PTEE coating on the inner surface of the pan body, and baking 10 min at 380-440 C., to form a PTFE coating layer with a thickness of 30-45 m, to get the plasma non-stick pan in the invention.

(20) In order to validate the performance of plasma non-stick pan in the invention, we conduct a series of tests on the pan body. The test process is as follows:

(21) Test 1: Hot and cold impact on the pan body. Heat the pan body to 400, maintain 1 min, then put into 0 C., after 30 consecutive times of impact, observe the coating on the pan body surface; no falling-off or cracking is found;

(22) Test 2: impact of pan body with steel balls. Fall a 250 g steel ball to the pan body surface from a height of 1.2 mm vertically, to impact more than 5 points on the surface of the pan body, to observe the surface of the pan body, no falling-off or cracking is found.

(23) Test 3: brine boiling: Put the pan body to 10% saline solution for boiling 24 h, to observe the surface of the pan body, and no corrosion is found.

(24) Test 4: Hot oil boiling: add 500 g of soybean oil to the pan body to boil 30 min at the constant temperature of 220 C., to observe the surface of the pan body, and no corrosion or falling-off is found.

(25) Test 5: acetic acid boiling. Add 5% acetic acid solution in the pan body to boil 15 min at the constant temperature of 100 C., to observe the surface of the pan body, and no corrosion or falling-off is found.

(26) After these tests, pan body can still be used normally, thus confirming the performance of the non-stick of the present invention has been greatly improved:

(27) (1) non-stickness: a very thin PTFE coating layer has a good non-sticknesss performance;

(28) (2) Heat resistance: PTFE coating layer has excellent heat resistance and low temperature resistance; and in a short time, it can resist the high temperature of 300 C.; and usually it can be used continuously at 240260 C. with a significant thermal stability, without melting at high temperature and no embrittlement in a freezing temperature;

(29) (3) moisture resistance: PTFE coating layer surface has the performance of no-stickness of water and oil dirt; and if a small amount of dirt, you can remove them by simply wiping;

(30) (4) Abrasion resistance: Have double performance of wear resistance and non-sticking;

(31) (5) Corrosion resistance: resist corrosion of drugs and other chemicals;

(32) (6) Anti-falling-off: Even if the coating is fallen off, only break and damage will occur at the peak point, which will not involve in other regions, to maintain the integrity of the coating in other regions.

(33) In addition, the pan body has the following advantages: 1) the pan body surface is in a state of uniform peaks and valleys, denser and more bonding; 2) the pan body hardness is up to 1500-2000 HV, increased by 3-4 times compared with the hard oxide film; 3) The anti-scratch and wear-resistant hardness is increased by 3-4 times compared with the existing non-stick pan, with a longer service life; 4) stronger corrosion resistance. The acid, alkali and salt water resistances of metal ceramic membrane are increased by more than twice compared with the oxidation membrane.

(34) Apparently, the above described are only partial rather than whole embodiments of the invention. It should be noted that, technicians skilled in the art can make a number of improvements and modifications without departing from the concepts and spirit of the invention, and these improvements and modifications should be considered within the scope of protection of the present invention.