JP3216737B2 - Spray heating element for composite particles and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal spraying heating element for generating electric current, and more particularly to a thermal spraying heating element formed by spraying composite particles obtained by coating a conductive material, an insulator or a semiconductor material on each particle.

[0002]

2. Description of the Related Art A conventional heating element is formed by applying, sintering, sheathing, vapor-depositing, or spraying a metal, carbon, conductive ceramic, or a mixture of the above-mentioned conductive substance and insulating substance according to its characteristics. Had been manufactured. However, for example, when a heating element is formed by thermal spraying of metal, the resistivity is usually on the order of 10 ^-4, and therefore, in order to obtain a predetermined resistance value, the length of the heating element is increased (using a jig or the like). In addition, it was necessary to reduce the cross-sectional area, but there was a problem that the power density was particularly small because the thickness was limited. Further, a metal spray material is expensive at about 10,000 yen / kg. On the other hand, conductive ceramics such as TiO ₂ have problems in electric characteristics and durability.

As documents that disclose such techniques, there are JP-A-59-94394 and JP-B-2-56425. On the other hand, JP-A-64-8260 discloses a method for forming a metal-ceramic composite film. This is mainly a method of manufacturing a composite film, and since it mainly uses electroless plating, it is only a limited metal and cannot be made of conductive ceramics. There is a concern about the impact. Further, the evaluation of the characteristics of the heating element by applying electric power is also a disadvantage.

[0004]

[SUMMARY OF THE INVENTION] is to establish a technique for the technical essence apparent resistivity of the can be controlled to 10 ^-3 to 10 ^0. If this technique is achieved, a predetermined resistance value can be easily obtained because the three elements of resistivity, length, and cross-sectional area can be arbitrarily changed. In addition, it is important that the conductive material is continuous in order to be electrically stable, and it is necessary for uniform heating that the ratio be substantially the same in macroscopic view. Therefore, an object of the present invention is to provide a high value-added thermal spray heating element that can satisfy the above-mentioned various requirements and a method of manufacturing the same.

[0005]

In order to solve the above problems SUMMARY OF THE INVENTION In the present invention, an insulator substrate, a conductive cell to the substrate surface
A thermal spray heating element consisting of a thermal spray coating formed by spraying composite particles consisting of insulating or semiconductor particles coated with Lamix or conductive oxide , or an insulator substrate,
A thermal spray heating element comprising a thermal spray coating formed by thermal spraying composite particles comprising conductive particles coated with an insulating or semiconductor substance on the surface of the substrate.

Further, according to the present invention, the surface of the insulating base material is
Composite particles comprising an electrically conductive ceramic or conductive oxides from Kotengu the insulating or semiconductor particles, or by spraying the composite particles composed of conductive particles Kotengu the insulating or semiconductor material, forming a thermal spray coating to electric heating A method for producing a composite particle thermal spray heating element characterized in that: As described above, in the present invention, the thermal spray coating formed by ceramics of the conductive particle surfaces of the ceramic or oxide Kotengu composite material (particles) and thermal spraying, a heating element by power application .

In the above, the coating film can be manufactured by plating, mechanical alloying, sputtering, or the like, and the film thickness can be changed to about 0.1 μm to 20 μm. As conductive materials, metals, alloys and B ₄ C, TiC, W
C, ZrC, TiB ₂ , Mo ₂ B ₅ , TiN, AlN,
Conductive ceramics such as MoSi ₂ , SnO, Pb
Conductive oxides such as O ₂ , ReO ₂ and V ₂ O ₃ can be used. The particle size of the insulating or semiconductor particles is about 10 to 75 μm, and the insulating material (particles) is Al ₂ O ₃ , TiO _2
2 , ZrO ₂ , CaO, Y ₂ O ₃ , Cr ₂ O ₃ , Mg
O, MnO, etc. and their respective mixtures, and the semiconductor material is Sn, Se, Te, SiC, GaN, ZnS, P
bS and the like.

[0008]

[Effect] For example, 30 μm coated with 1 μm metal
If the film thickness is reduced to 100 μm by thermal spraying using composite particles of m, it is assumed that 30 μm particles are shrunk by 積 層 and stacked to form one 15 μm lamella, and six of them are arranged in the radial direction. For example, if only the coating layer is used, the overall film thickness is similarly 6 μm. This is about 1 compared to the case of metal only.
A seven-fold resistance value is obtained. In addition, since the coating layer is continuous in three dimensions, it is electrically stable,
Macroscopically, the ratio of the conductive material is substantially the same, and the material is uniformly heated. Also, by changing the coating film thickness, the apparent resistivity also changes.

On the other hand, a metal spray material is expensive at about 10,000 yen / kg, but since an inexpensive ceramic is used as a core,
The ratio of metal is small and inexpensive. Therefore, a heater having an arbitrary shape that can be used with a home power supply can be easily obtained by performing the thermal spraying of the composite particles without performing a complicated thermal spraying.

[0010]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 Ni ₂ particles having an average particle diameter of 1.3 μm were used as a conductive substance at a ratio of 10: 3 wt% to particles composed of Al ₂ O ₃ +2.3 TiO ₂ having an average particle diameter of 27.5 μm by a mechanical alloying method. I did the coating. Composite particles having a Ni film thickness of about 2 μm were obtained. 25A SUS3 which has already been subjected to insulation treatment with Al ₂ O ₃ by plasma spraying of these composite particles.
04, a sprayed heating element having a thickness of 80 μm was formed on the outer surface having a length of 10 cm.

FIG. 1 shows a heating apparatus for resistivity measurement using a composite particle-sprayed heating element. In FIG. 1, a thermal spray heating element 1 is formed on a main body (SUS304) 2,
Electrodes 3 are attached to both ends of the thermal spray heating element 1 and an ammeter 5
Is connected to the SLIDAC (100V, 10A) 4 via the. A thermocouple 6 is installed at the center of the thermal spray heating element 1 to measure the temperature.

When a voltage of 50 V was applied to the electrode 3 attached to the thermal spray heating element 1 by means of a sliderac 4, a current value of 10 A flowed.
Met. From this, the resistivity is calculated to be 0.04Ω
Cm, and the apparent resistivity increased about 100 times compared to the Ni powder alone.

Next, 5 W of the above-mentioned thermal spraying heating element is
(5.0V, 1.0A) 20W (10.0V, 2.0A
The heating-heating experiment of A) was performed. The result is shown in FIG. 45 ° C. at a power density of 0.05 W / cm ² in 30 minutes,
75 ° C. at 0.2 W / cm ² . Room temperature 28.1
° C. The temperature was measured with a thermocouple 6 attached to the surface of the thermal spray heating element.

[0014]

According to the present invention, the following effects can be obtained. (1) In the present invention, the apparent resistivity of this film could be arbitrarily controlled by spray-coating composite particles coated with a conductive substance. Therefore, a heater can be easily obtained with a home power supply, and the range of use has been expanded. (2) Since this film is three-dimensionally continuous with a conductive material, it is electrically stable and is uniformly heated macroscopically. (3) The composite particles became inexpensive by using inexpensive insulating particles as nuclei. (4) The resistance increased due to an increase in apparent resistivity. Therefore, the heater can be made compact.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a heating experimental apparatus using a thermal spraying heating element of the present invention.

FIG. 2 is a graph showing the surface temperature of a thermal spray heating element.

[Explanation of symbols]

1: Thermal spray heating element, 2: Main body (SUS304), 3: Electrode, 4: Slidac, 5: Ammeter, 6: Thermocouple

──────────────────────────────────────────────────続 き Continuation of the front page (72) Yoshikazu Murata Inventor 11-1 Haneda Asahimachi, Ota-ku, Tokyo Ebara Corporation (56) References JP-A-64-8260 (JP, A) (58 ) Surveyed field (Int.Cl. ⁷ , DB name) C23C 4/04 H05B 3 / 12,3 / 16,3 / 20

Claims (3)

(57) [Claims] 1. A an insulator substrate, a conductive canceller to the substrate surface
A thermal spray heating element comprising a thermal spray coating formed by thermal spraying composite particles comprising insulating or semiconductor particles coated with a mixed or conductive oxide . 2. A thermal spray heating element comprising: an insulating substrate; and a thermal spray coating formed by thermal spraying composite particles comprising conductive particles coated with an insulating or semiconductor material on the surface of the insulating substrate. 3. A conductive ceramic is provided on a surface of an insulating base material.
Composite particles comprising a scan or conductive oxides from Kotengu the insulating or semiconductor particles, or, characterized in that by thermal spraying the composite particles composed of conductive particles Kotengu the insulating or semiconductor material to form a thermal spray coating to electric heating A method for producing a composite particle thermal spray heating element.