COMPOSITE MATERIAL FOR CERAMIC ELECTRIC HEATING ELEMENT.

Abstract

A composite material for a ceramic electric heating element is described. The components for preparing the composite material include silicon nitride, molybdenum disilicate, silicon carbide, yttrium oxide, aluminum oxide, and lanthanum oxide. The described composite material can be used to reduce the impulse current of a ceramic electric heating element.

Description

COMPOSITE MATERIAL FOR ELECTRIC HEATING ELEMENT CERAMICS Technical Field The description refers to a composite material and, in particular, to a composite material for a ceramic electric heating element. Background As a conductive material, a ceramic electric heating element can be used as the heating element in an ignition mechanism. Ignition or heating is achieved through the extremely high temperature reached when the ceramic is electrified. It can be used in applications such as engine ignition, gas stove ignition, water heater ignition, infrared radiation sources, oxygen sensor heating, soldering iron tip heating, and similar uses. Ceramic electric heating elements offer advantages such as rapid start-up, high-temperature resistance, corrosion resistance, high strength, and a long service life. Chinese patent CN100484337C describes a multi-layer circular ceramic electric heating element and a process for preparing the same, and specifically describes that a resistance layer, an insulating layer, and a conductive layer of the ceramic electric heating element comprise four components: S13N, Al2O3, Y2O3, and MoSi; S13N3 is used to form a network structure, Al2O3 and Y2O3 are used to adjust the network structure, and MoSi2 is used to form a heating conductive material. A ceramic electric heating element prepared with the described components provides a high reaction speed, high temperature, short time to reach the desired temperature, long service life, high manufacturing process performance and low manufacturing cost. However, a composite material made with the preparation materials listed in the described patent still has the following problems in some use scenarios: the large temperature resistance coefficient and the large impulse current directly increase the cost of the power supply, and the rapid rate of change of current / resistance makes the algorithm for power control complicated. Synthesis One objective of the disclosure is to provide a composite material with a small impulse current and reduce the costs of applying a ceramic electric heating element made using the material. To achieve the described objective, the disclosure suggests a composite material for a ceramic electric heating element, characterized in that the components for the preparation of the composite material include silicon nitride, molybdenum disilicide, silicon carbide, yttrium oxide, aluminum oxide, and lanthanum oxide. Here, silicon nitride, molybdenum disilicide, and silicon carbide are the main functional materials, and aluminum oxide, yttrium oxide, and lanthanum oxide are auxiliary materials. To further reduce the impulse current, the preparation material is made with the components in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-900 ) : (50-900) : (500-2800) : (40-100) : (10-90) : (5-80) . Furthermore, the composite material is made with the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (300-800) : (400-900) : (800-2800) : (40-100) : (30-90) : (5-80) . The composite material made using the described materials is suitable as a heating layer for the ceramic electric heating element. Furthermore, the composite material is prepared using the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (400-900): (50-200): (500-800): (40-90): (30-80): (5-60). The composite material produced using the described materials is suitable as an insulating layer for the ceramic electric heating element. Furthermore, the composite material is made with the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-700) : (100-700) : (600-1500) : (40-80) : (10-70) : (5-50) . The composite material made using the described materials is suitable as a conduction layer for the ceramic electric heating element. Preferably, the main functional materials also include tungsten carbide. Preferably, the auxiliary materials also include ytterbium oxide. A ceramic electric heating element is prepared using the composite material described. Beneficial effect: The composite material and ceramic electric heating element of the disclosure have the following advantages: 1. Different resistance temperature coefficients (TCR) are achieved, and an arbitrary conversion from a negative temperature coefficient to a positive temperature coefficient is achieved, so that not only can TCR = -500 be achieved, but also TCR = 5000, while guaranteeing various performance advantages of the original ceramic material, such as fast start-up, high temperature resistance, corrosion resistance, and high strength. 2. Low impulse current: The impulse current is small when the resistance temperature coefficient (TCR) is high, and the impulse current is also small when the resistance temperature coefficient (TCR) is low. At negative or low TCRs, given the reduction in inrush current, the support costs of the power supply and control element can be significantly reduced. In this way, the high cost problems of the original ceramic structure material support electronic control element in real-world use and difficult control are effectively solved, and a performance index similar to international ceramic structure material elements is achieved.For example, the 100W power supply previously used can be replaced with a 60W power supply by using the disclosure material, thus reducing the power supply capacity requirement. Detailed Description of the Modalities The disclosure is described below through the modalities shown in the drawings, but the disclosure is not limited to the implementation modes described. Any improvements or replacements within the basic spirit of the modality still fall within the scope of protection of the disclosure claims. Modality: A composite material, in which the components for its preparation include silicon nitride (Si3N4), molybdenum disilicide (MOSi·:), silicon carbide (SiC), yttrium oxide (Y2O3), aluminum oxide (Al:Oj), and lanthanum oxide (La^Ch). Here, silicon nitride, molybdenum disilicide, and silicon carbide are the main functional materials and provide high-temperature performance, heating performance, electrical conductivity, and similar properties when the ceramic electric heating element is fabricated with the composite material. Aluminum oxide, yttrium oxide, and lanthanum oxide are auxiliary materials and primarily assist with the sintering of the ceramic, improve room-temperature and high-temperature strength, and enhance high-temperature oxidation resistance, among other properties, when the ceramic electric heating element is fabricated with the composite material. Here, the composite material is made using the materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-900) : (50-900) : (500-2800): (40-100): (10-90): (5-80); different proportions of parts can be chosen for preparation and are not limited to: For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 50: 500: 40: 10: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 400: 500: 40: 10: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 50: 1000: 40: ±0: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 50: 500: 80: 10: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 50: 500: 40: 50: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 50: 500: 40: 10: 50; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 500: 50: 500: 40: 10: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 400: 800: 500: 55: 70: 76; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 600: 700: 1200: 70: 30: 20; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 800: 70: 2100: 67: 60: 35; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 900: 900: 2800: 100: 90: 80. Here, the composite material of the modality can be used to make the ceramic electric heating element, and the ceramic electric heating element in the modality is a multi-layer ceramic electric heating element, which includes, among others, a heating layer, an insulating layer, and a conductive layer and the like. For the heating layer, the composite material can be used with the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (300-800): (400-900): (800-2800): (40-100): (30-90) : (5-80) . Different proportions of ingredients can be chosen for preparation, but are not limited to: For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 300: 400: 800: 40: 30: 5; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 4 00: 800: 1800: 50: 60: 20; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 600: 700: 2000: 80: 70: 70; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 700: 4:500: 1200: 60: 70: 70; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 800: 900: 2800: 100: 90: 80. For the insulating layer, the composite material can be made up of the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (400-900) : (50-200) : (500-800) : (40-90) : (30-80) : (5-60) . Different proportions of ingredients can be chosen for preparation, but are not limited to: For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 400: 50: 500: 40: 30: 5; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 500: 100: 600: 60: 70: 35; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 700: 150: 700: 50: 40: 30; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 800: 90: 650: 70: 40: 50; For example, silicon nitride : silicon carbide : molybdenum disilicide : yttrium oxide : lanthanum oxide : aluminum oxide = 900: 200: 800: 90: 80: 60. For the conduction layer, the composite material can be used with the following materials in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-700): (100-700): (600-1500): (40-80): (10-70) : (5-50) . Different proportions of ingredients can be chosen for preparation, but are not limited to: For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 200: 100: 600: 40: 10: 5; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 400: 300: 800: 60: 30: 15; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide -2600: 500: 1000: 70: 50: 30; For example, silicon nitride : silicon carbide molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 500: 600: 1300: 50: 60: 45; For example, silicon nitride : silicon carbide 10 molybdenum disilicide : yttrium oxide : lanthanum oxide aluminum oxide = 700: 700: 1500: 80: 70: 50. As another form of implementation of the modality, the main functional materials also include tungsten carbide 15 (WC). As another way of implementing the modality, the auxiliary materials also include ytterbium oxide (Yb20j). A ceramic electric heating element 20 is prepared using the composite material described. Here, the ceramic electric heating element in this mode is a multi-layered structure from the inside out and has at least two or more layers. In this case, there are two layers, with the inner layer being a resistive layer and the outer layer a conductive layer. In this case, there are three layers, with the inner layer being a resistive layer, the middle layer an insulating layer, and the outer layer a conductive layer. Here, the multi-layer ceramic electric heating element of the modality is manufactured using a grout modality and includes the following steps. Step 1: Preparation of a mixed slurry: Silicon nitride, silicon carbide, molybdenum disilicide, yttrium oxide, lanthanum oxide, and aluminum oxide powder are mixed with water according to a specific weight ratio and stirred thoroughly. The mixture is then placed in a container. In this document, different mixed slurries are prepared according to the different layers of the multi-layer ceramic electric heating element and placed in separate containers to settle. As a means of implementing the modality, the total weight of the described material compositions: weight of water = 1: (1-4) . Step 2: Grouting and Forming: A grout mold with two open ends is placed in a grouting machine, and the mixed ceramic grout is then injected into the grouting machine to begin the grouting and forming process. Depending on the number of layers of the ceramic electric heating element, the grouting is done in stages, sequentially from the outermost layer to the innermost layer. Step 3: Sintering: A dry ceramic element with water loss is removed from the grout mold and placed in a sintering mold. Finally, the sintering mold loaded with the raw ceramic is placed in a sintering furnace and sintered for 7-12 hours at a temperature of 1400°C and a pressure of 2000-5000 Kpa. Step 4: The sintered ceramic material element is removed from the sintering mold, an external trimming is performed, and a device with electrodes is made. Different TCRs are achieved by using the ceramic electric heating element manufactured using the composite material of the modality, and an arbitrary conversion of a negative temperature coefficient to a positive temperature coefficient is achieved, so that not only can a TCR = -500 be achieved as well as a TCR = 5000, while guaranteeing several performance advantages of the original ceramic material, such as fast start-up, high temperature resistance, corrosion resistance and high strength. Small impulse current: The impulse current is small when the resistance temperature coefficient (TCR) is large, and the impulse current is also small when the resistance temperature coefficient (TCR) is small. At negative or low TCRs, given the reduction in inrush current, the support costs of the power supply and control element can be significantly reduced. In this way, the high cost problems of the original ceramic structure material support electronic control element in real-world use and difficult control are effectively solved, and a performance index similar to international ceramic structure material elements is achieved.

Claims

1. A composite material for a ceramic electric heating element, wherein the components for making the composite material include silicon nitride, molybdenum disilicide, silicon carbide, yttrium oxide, aluminum oxide, and lanthanum oxide.

2. The composite material of claim 1, wherein the composite material is made from the components in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-900) : (50-900) : (500-2800) : (40-100) : (10-90) : (5-80).

3. The composite material according to claim 2, wherein the following materials are prepared in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (300-800) : (400-900) : (800-2800) : (40-100): (30-90): (5-80).

4. Ξ1 composite material according to claim 2, wherein the following materials are prepared in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (400-900 (30-80): (5-60). (50-200): (500-800): (40-90):

5. The composite material according to claim 2, wherein the following materials are prepared in the following proportions: silicon nitride: silicon carbide: molybdenum disilicide: yttrium oxide: lanthanum oxide: aluminum oxide = (200-700) : (100-700) : (600-1500) : (40-80) : (10-70) : (5-50) .

6. The composite material according to claim 1, 2, 3, 4 or 5, wherein the main functional materials further include tungsten carbide.

7. The composite material according to claim 1, 2, 3, 4 or 5, wherein the auxiliary materials further include ytterbium oxide.

8. The composite material according to claim 6, wherein the auxiliary materials further include ytterbium oxide.

9. The ceramic electric heating element, wherein 5 is manufactured using a composite material according to any of the preceding claims.