JP6853066B2 - Reflector member - Google Patents

Description

The present disclosure relates to ceramic structures and reflector members.

A xenon lamp (discharge lamp) including a reflector member can generate strong light by the reflector member. As the substrate constituting the reflector member, a metal such as aluminum or ceramics is used. Further, a coating layer is located on the substrate.

As a reflector member having such a configuration, Patent Document 1 proposes a reflector member in which the inner surface of a substrate made of ceramics is glazed in order to prevent light from leaking to the rear of the reflector member.

Japanese Unexamined Patent Publication No. 11-288610

Nowadays, a reflecting mirror member is required to have a coating layer that is hard to be peeled off from a substrate due to repeated reflection of light by the reflecting mirror member so that it can withstand use for a long period of time.

The present disclosure has been devised to satisfy such a requirement, and provides a ceramic structure and a reflector member having excellent adhesion between a substrate and a coating layer.

Reflector member of the present disclosure, Ri Do from an aluminum oxide ceramic or aluminum nitride ceramics, and the substrate that have a concave surface, a coating layer located on the concave surface is located on the said coating layer It has a reflective layer. The coating layer contains silicon oxide containing 60% by mass or more of 100% by mass of all the components constituting the coating layer, and barium and potassium. Further, when the portion of the coating layer closer to the substrate is the first region and the portion farther from the substrate than the first region is the second region, the first region is the barium rather than the second region. And has a portion containing a large amount of potassium.

The reflector member of the present disclosure has a high adhesion between the substrate and the coating layer. As a result, the reflector member of the present disclosure can be used for a long period of time even if the reflection of light is repeated.

An example of a reflector including a reflector member made of the ceramic structure of the present disclosure is shown, (a) is a schematic cross-sectional view, and (b) is an enlarged view of part A of (a). (A) is a photograph of a cross section of the ceramic structure shown in FIG. 1 taken with a scanning electron microscope, and (b) is a measurement result of B in (a) by an energy dispersive X-ray analyzer (EDS). It is a chart which shows, (c) is a chart which shows the measurement result by EDS of C in (a).

Hereinafter, a reflector member as an embodiment of the ceramic structure of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of a reflector provided with a reflector member, and FIG. 1B is an enlarged view of a portion A of FIG. 1A.

In the reflector 1 shown in FIG. 1, a substrate 3 having a concave curved surface is located on a pedestal 10 made of metal. Further, a tubular body 13 for supplying xenon gas is located in a part of the pedestal 10. Further, the anode 11 is located on the other part of the pedestal 10. The anode 11 is located so as to be exposed to the internal space 17 through the through hole of the substrate 3. The anode 11 is made of tungsten and is brazed to the pedestal 10. Further, the substrate 3 and the pedestal 10 are brazed by the lower ring 12. A cathode 14 made of tungsten is located above the anode 11 at a distance of arc discharge. The tip of the anode 11 is flat, and the tip of the cathode 14 is acute-angled. The cathode 14 is supported by a support plate 16 made of molybdenum via a support ring 15 made of molybdenum. Further, a translucent member 7 made of a disk-shaped sapphire is located above the support plate 16. The support plate 16 and the translucent member 7 are brazed to the mounting bracket 8. The mounting bracket 8 and the base 3 are fixed by being brazed by an upper ring 9 made of metal. The internal space 17 is a space in which a high-pressure gas such as xenon gas, mercury vapor, or metal halide is sealed.

The ceramic structure 2 of the present disclosure has a substrate 3 made of aluminum oxide ceramics or aluminum nitride ceramics, and a coating layer 4 located at least a part of the surface of the substrate 3. The coating layer 4 contains silicon oxide containing 60% by mass or more of 100% by mass of all the components constituting the coating layer 4, barium and potassium. Further, when the portion of the coating layer 4 closer to the substrate 3 is the first region 4a and the portion farther from the substrate 3 than the first region 4a is the second region 4b, the first region 4a is larger than the second region 4b. It has a part rich in barium and potassium.

The reflecting mirror member includes the reflecting layer 6 on the covering layer 4 in the ceramic structure 2. The reflective layer 6 is made of silver, a silver alloy, or the like that reflects visible light, or magnesium fluoride (MgF ₂ ), titanium oxide (TiO ₂ ), or the like that reflects visible light and emits infrared rays. is there. The thickness of the reflective layer 6 is, for example, about 1 μm.

FIG. 2 (a) is a photograph of a cross section of the ceramic structure shown in FIG. 1 taken with a scanning electron microscope, and FIG. 2 (b) is measurement by the energy dispersive X-ray analyzer (EDS) of B in (a). It is a chart which shows the result, (c) is the chart which shows the measurement result by EDS of C in (a). The cross section is a polished surface, and the vertical axis in the chart shows the intensity of characteristic X-rays peculiar to an element generated when an electron beam is irradiated.

As shown in FIG. 2, the first region 4a of the coating layer 4 in the ceramic structure 2 of the present disclosure contains a larger amount of barium and potassium than the second region 4b (hereinafter, simply referred to as a portion 5). have. In the ceramic structure 2 of the present disclosure satisfying such a configuration, the substrate 3 and the coating layer 4 have a high adhesion force. The reason why the substrate 3 has such a high adhesion is that the aluminum contained in the substrate 3 diffuses to the first region 4a side in order to form a covalent bond with barium and potassium when the coating layer 4 is formed. Conceivable.

The first region 4a and the second region 4b in the present embodiment divide the thickness of the coating layer 4 into two in the cross section as shown in FIG. The thickness of the coating layer 4 is, for example, 20 μm or more and 100 μm or less.

The coating layer 4 may contain calcium, aluminum, sodium and the like in addition to silicon oxide, barium and potassium.

Further, the first region 4a may have a layered portion 5a of the portion 5 along the interface between the substrate 3 and the first region 4a. When such a configuration is satisfied, the substrate 3 and the coating layer 4 are less likely to be peeled off, and the substrate 3 and the coating layer 4 have a higher adhesion force.

Further, the first region 4a may have a columnar portion 5b of the portion 5 extending from the interface between the substrate 3 and the coating layer 4 toward the second region 4b. When satisfying such a configuration, the substrate 3 and the coating layer 4 further have a high adhesion force. Here, the columnar portion 5b means that the aspect ratio (major axis / minor axis) is 2 or more. Further, when the columnar portion 5b is crystallized, the growth of cracks generated in the coating layer 4 can be suppressed, so that the decrease in adhesion is small.

Further, a plurality of columnar portions 5b may be present, and an aspect ratio of 3 or more may occupy 50% or more. When satisfying such a configuration, the substrate 3 and the coating layer 4 further have a high adhesion force.

A plurality of columnar portions 5b may be present, and the occupancy rate of the angle formed by the interface between the substrate 3 and the first region 4a and the columnar portion 5b in the range of 70 ° to 110 ° may be 50% or more. When such a configuration is satisfied, the pressure due to the high pressure gas is applied from the second region 4b side, and the stress reflected and scattered by the substrate 3 is dispersed in the columnar portion 5b and easily relaxed, so that it remains in the coating layer 4. Stress can be suppressed. Therefore, the substrate 3 and the coating layer 4 are less likely to be peeled off.

Next, the measurement method and the like will be described.

The material of the substrate 3 is first measured using an X-ray diffractometer (XRD), and identified from the obtained 2θ (2θ is a diffraction angle) value using a JCPDS card. Next, a quantitative analysis of the contained components is performed using an ICP (Inductively Coupled Plasma) emission spectroscopic analyzer (ICP) or a fluorescent X-ray analyzer (XRF). If the presence of aluminum oxide is confirmed by the above identification and the content converted from the Al content measured by ICP or XRF to aluminum oxide (Al ₂ O ₃ ) is 80% by mass or more, it is an aluminum oxide ceramic. .. Further, if the presence of aluminum nitride is confirmed by the above identification and the content converted from the Al content measured by ICP or XRF into aluminum nitride (AlN) is 80% by mass or more, it is an aluminum nitride ceramic.

When the substrate 3 is an aluminum oxide ceramic, it may contain an oxide of silicon, an oxide of calcium, and an oxide of magnesium. Further, when the substrate 3 is an aluminum nitride ceramic, it may contain oxides of rare earth elements (yttrium, ytterbium, erbium, etc.). These are used as sintering aids, and the content in the substrate 3 can be determined by measuring using ICP or XRF and converting them into oxides.

Next, the components and contents contained in the coating layer 4 can be confirmed using EDS. Further, in comparing barium and potassium in the first region 4a and the second region 4b, the thickness of the coating layer 4 is divided into two, the one closer to the substrate 3 is the first region 4a, and the one farther from the substrate 3 is the second. Region 4b may be used, and the barium content and potassium content in the first region 4a may be compared with the barium content and potassium content in the second region 4b. In addition, in the chart as shown in FIGS. 2 (b) and 2 (c), the intensity value may be compared.

Regarding the presence or absence of the layered portion 5a, for example, a plurality of measurements by EDS were performed on the portion of the first region 4a near the interface between the substrate 3 and the coating layer 4, and barium and potassium were more than those of the second region 4b. It can be confirmed whether or not the part containing a large amount of is continued. Specifically, it may be measured every 30 μm, and if 5 points are continued, it may be considered that the layered portion 5a is present. If there is a portion containing more barium and potassium than the second region 4b, it may be confirmed by the color difference as shown in FIG. 2 (a).

Next, the presence or absence of the columnar portion 5b can be confirmed by a photograph of the cross section of the ceramic structure shown in FIG. 2A taken with a scanning electron microscope. Regarding whether or not the aspect ratio of 3 or more occupies 50% or more, the columnar portions 5b having an aspect ratio of 2 or more are counted using the above photograph, and then the columnar portions 5b having an aspect ratio of 3 or more are counted. And calculate the ratio.

Further, whether or not the occupancy of the angle formed by the interface between the substrate 3 and the first region 4a and the columnar portion 5b in the range of 70 ° to 110 ° is 50% or more is determined by using the above photographs. The angle of the columnar portion 5b may be obtained, and the occupancy rate in the range of 70 ° to 110 ° may be obtained.

Further, when the arithmetic mean roughness Ra of the surface of the coating layer 4 or the reflective layer 6 is 0.2 μm or more and 0.6 μm or less, diffused reflection of light can be reduced.

Here, in order to obtain the arithmetic mean roughness Ra of the surface of the coating layer 4 or the reflective layer 6, it may be measured under the following conditions using a CNC surface roughness / contour shape measuring machine (manufactured by Mitutoyo Co., Ltd.). ..

・ Device name: Surftest Extreme ・ Model number: SV-3000CNC
・ Standard OLDMIX
・ Evaluation curve type R
・ Standard length 0.8mm
・ Number of sections 5
・ Cutoff (λc) 0.8mm
-Filter type Gaussian
・ Evaluation length 4.0 mm,
・ Run-up 0.4mm
・ Back run 0.4mm
・ Smooth connection OFF
・ Average correction OFF when calculating parameters
Next, an example of a method for manufacturing the ceramic structure and the reflector member of the present embodiment will be described.

Prepare barium carbonate, kaolin, lime, fused silica and feldspar powders. The ratio of each powder in the total 100% by mass of the above powders was 5% by mass or more and 9% by mass or less for barium carbonate, 10% by mass or more and 16% by mass or less for kaolin, 10% by mass or more and 16% by mass or less for lime, and molten silica. Is 27% by mass or more and 35% by mass or less, and the balance is feldspar. The barium source is barium carbonate, and the potassium sources are kaolin and feldspar.

Then, the powder is put into a pot mill together with water and a binder, and then mixed and pulverized to obtain a paste.

By applying a paste to the surface of aluminum oxide ceramics or aluminum nitride ceramics by brush coating, spray coating, etc., and heat-treating with a holding temperature of 1350 ° C or higher and 1450 ° C or lower and a holding time of 2 hours or more and 4 hours or less. The ceramic structure of the present embodiment can be obtained. In order to allow more barium and potassium to be contained on the side of the first region than in the second region, the temperature lowering rate up to 1000 ° C. may be 180 ° C./hour or more and 550 ° C./hour or less.

Further, in order to make the layered portion exist, when the above-mentioned paste is used as the first paste, the method is the same as that of the first paste except that the amounts of barium carbonate and kaolin are increased within the above-mentioned range. Two pastes may be prepared, the second paste may be applied, and then the first paste may be applied.

Further, in order to make the columnar portion exist, the temperature lowering rate up to 1000 ° C. in the heat treatment may be set to 200 ° C./hour or more and 500 ° C./hour or less. Further, in order to obtain more than half of the columnar portions having an aspect ratio of 3 or more in terms of the number ratio, the temperature lowering rate may be 250 ° C./hour or more and 500 ° C./hour or less. Further, in order to occupy 50% or more of the angle formed by the interface between the substrate and the first region and the columnar portion in the range of 70 ° to 110 °, the temperature lowering rate is 350 ° C./hour or more and 500 ° C./hour or less. And it is sufficient.

In any of the above cases, the temperature lowering rate after 1000 ° C. may be less than 180 ° C./hour.

Then, in order to obtain the reflector member of the present embodiment, a vacuum vapor deposition method may be used when a reflective film made of silver, a silver alloy or the like is formed on the coating layer as the reflective layer. Further, when forming a multiple interference film made of magnesium fluoride (MgF ₂ ), titanium oxide (TiO ₂ ) or the like as a reflective layer on the coating layer, a vacuum vapor deposition method or a chemical vapor deposition method (CVD) is used. Just do it.

The ceramic structure obtained by the above-mentioned manufacturing method has a high adhesion between the substrate and the coating layer. Further, since the reflector member of the present embodiment has a high adhesion between the substrate and the coating layer, it can be used for a long period of time even if light reflection is repeated.

1 Reflector 2 Ceramic structure (reflector member)
3 Base 4 Coating layer 4a 1st region 4b 2nd region 5 Part containing more barium and potassium than 2nd region 4b 5a Layered part 5b Columnar part 6 Reflective film 7 Translucent member 8 Mounting bracket 9 Upper ring 10 Pedestal 11 Anode 12 Lower ring 13 Tubular body 14 Cathode 15 Support ring 16 Support plate 17 Internal space

Claims (5)

Ri Do from an aluminum oxide ceramic or aluminum nitride ceramics, and includes a substrate that having a concave surface, and a covering layer located above the concave surface, a reflective layer located on top of the coating layer,
The coating layer contains silicon oxide containing 60% by mass or more of 100% by mass of all the components constituting the coating layer, and barium and potassium.
When the portion of the coating layer close to the substrate is the first region and the portion farther from the substrate than the first region is the second region,
The first region is a reflector member having a portion containing more barium and potassium than the second region. The reflector member according to claim 1, wherein the first region has a layered portion of a portion containing more barium and potassium than the second region along the interface between the substrate and the coating layer. Claim 1 or claim 1, wherein the first region has a columnar portion of a portion containing more barium and potassium than the second region, which extends from the interface between the substrate and the coating layer toward the second region. The reflector member according to claim 2. The reflector member according to claim 3, wherein a plurality of columnar portions are present, and an aspect ratio of 3 or more occupies 50% or more. The reflector member according to claim 3 or 4, wherein a plurality of the columnar portions are present, and the occupancy rate of the angle formed by the interface and the columnar body in the range of 70 ° to 110 ° is 50% or more.

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