Test method for heat treatment recovery of blue coloration of sintered zirconia after irradiation

Abstract

The application discloses a kind of blue synthesis zirconia irradiation color change after heat treatment recovery test method, comprising: step one, according to the preparation of powder in mole percentage;Step two, using cold crucible floating zone method blue synthesis zirconia;Step three, to blue synthesis zirconia crystal is irradiated by X-ray, so that it produces color change;Step four, heat treatment;Step five, after irradiation, heat treatment of various synthesis zirconia is photographed contrast, and using fiber optic spectrometer to determine the chroma of these synthesis zirconia, seek the best heat treatment parameter of color recovery to original chroma before irradiation.The application seeks to be recycled by synthesis zirconia irradiation color change after heat treatment recovery test, and new material is considered economic and environmental benefits, to provide new selection for radiation leakage indicating lamp material, so that X-ray radiation leakage indicating lamp is more easily to popularize and apply to market.

Description

Technical Field

[0001] This invention relates to the field of material preparation and color change restoration technology, specifically to an experimental method for restoring the color change of blue synthetic cubic zirconia after irradiation through heat treatment. Background Technology

[0002] X-rays are widely used in military, medical, scientific, industrial, and agricultural fields. Their application is most common in the medical field, especially in medical diagnostic X-rays, which are an important source of artificial ionizing radiation for human use. In industry, X-rays are also commonly used in non-destructive testing, such as for semiconductors and foreign object detection. As the demand for X-ray equipment increases across various sectors, their application scope continues to expand. However, the potential hazards of X-ray radiation are unavoidable. In-depth analysis of radiation protection research is beneficial for the timely detection of radiation leaks, the elimination of potential dangers, and the protection of personnel safety, and is of great significance for the effective advancement of X-ray applications.

[0003] Currently, materials used as radiation leak indicator lights include Sri Lankan yellow sapphire, but these are expensive, and the color recovery test after irradiation is not obvious, and the test cannot be repeated multiple times. Synthetic cubic zirconia, a high-strength, high-fire crystal also known as "CZ diamond," is considered the preferred material for radiation leak indicator lights due to its relatively low price. Synthetic cubic zirconia has the chemical formula ZrO2, belongs to the isometric crystal system, has a Mohs hardness of 7.5–8.5, and is generally synthesized artificially using the cold crucible melting method, which employs spontaneous crystallization. This study aims to explore the optimal application of synthetic cubic zirconia as a radiation leak indicator light material through color recovery tests. Summary of the Invention

[0004] This invention aims to explore new materials that can be recycled multiple times and have both economic and environmental benefits through a reaction recovery test after irradiation of synthetic cubic zirconia. This will provide a new option for radiation leak indicator materials and make X-ray radiation leak indicator lights easier to promote and apply in the market.

[0005] Therefore, the technical solution adopted in this invention is: a test method for restoring the color change of blue synthetic cubic zirconia after irradiation through heat treatment, comprising the following steps:

[0006] Step 1: Prepare the powder according to the molar percentage: ZrO2:Y2O3:HfO2:Co2O3:CeO2:Pr6O 11 Er₂O₃ = 75-80: 23-28: 1-6: 0.5-0.8: 0.08-0.15: 0.05-0.08: 0.08-0.12, where Co₂O₃ is used as a colorant, and CeO₂ and Pr₆O₃ are used as colorants. 11Er2O3 is used to provide rare earth elements; all powders are mixed and then stirred evenly.

[0007] Step 2: Blue cubic zirconia is synthesized using the cold crucible melting shell method;

[0008] 4-6g of zirconium metal sheet is placed in the center of the powder for "ignition". The raw material is heated to melt using a high-frequency coil to generate and expand the molten pool. Then, cold water is passed through a steel tube to cool it, so that the outer layer does not melt, forming a "cold crucible shell". After the powder is completely melted, the melt is stabilized for 50-60 minutes. The molten crystal material inside is cooled by the crucible falling down, allowing it to crystallize and grow. Finally, a transparent blue synthetic cubic zirconium oxide crystal is obtained.

[0009] Step 3: The blue synthetic cubic zirconia crystal was irradiated with X-rays under different irradiation durations and dose parameters to induce a color change. The irradiation duration ranged from 10 to 40 minutes, and the irradiation dose was 3.06 × 10⁻⁶. 6 ~1.12×10 7 J / cm 2 ;

[0010] Step 4, heat treatment: The synthetic cubic zirconia crystals with different degrees of discoloration after X-ray irradiation are placed in a high-temperature atmosphere tube furnace, heated to 200-400℃ in an oxygen atmosphere and held for 24-48 hours, then removed and cooled to room temperature.

[0011] Step 5: Compare and photograph the synthetic cubic zirconia after various irradiations and heat treatments, and use a fiber optic spectrometer to measure the color of these synthetic cubic zirconia to find the optimal heat treatment parameters to restore the color to the original color before irradiation.

[0012] As a preferred embodiment of this scheme, in step two, a high-frequency coil is used to heat the temperature to above 1400°C.

[0013] More preferably, in step three, X-ray irradiation with a power range of 500–4000 W is selected.

[0014] A further preferred embodiment is that, in step five, the shooting parameters are: ISO 80, shutter speed 1 / 60 second, aperture 1.8, and focal length 54mm.

[0015] The beneficial effects of this invention are:

[0016] (1) Taking advantage of the radiation sensitivity of blue synthetic cubic zirconium oxide prepared by adding rare earth elements Ce, Pr and Er, X-ray irradiation can easily cause Ce, Pr and Er elements to be excited and change their valence state, generating oxygen vacancies. The transition between the two occurs, and finally the color change occurs. It has obvious visual advantages when used as a material for radiation leakage indicator light.

[0017] (2) When the blue synthetic cubic zirconia changes color, it can be restored from the excited state to the ground state through heat treatment process. This material has the characteristics of multiple recycling, taking into account both economic and environmental benefits, and implementing the concept of low cost, green and sustainable development, providing a new option for color-recoverable materials.

[0018] (3) By combining rare earth element doping, irradiation color change technology and heat treatment technology, the blue synthetic cubic zirconia can be effectively colored, thereby achieving the purpose of radiation color change; after heat treatment, the synthetic cubic zirconia can be restored to its original color and continue to be used.

[0019] (4) Comparative experiments revealed that: if 0.5–0.8 mol% Co₂O₃ is added as a colorant, CeO₂ and Pr₆O₂... 11 When the Er₂O₃ content is below the set range, the final crystals are light blue; when the CeO₂ content is above 0.15 mol%, the crystals are orange-colored; when the Pr₆O content is below the set range, the final crystals are light blue. 11 When the concentration of Er₂O₃ is above 0.08 mol%, the resulting crystals have a yellowish tint; when the concentration is above 0.12 mol%, the resulting crystals have a pinkish tint. Using appropriate proportions to prepare blue synthetic cubic zirconia results in a more vivid contrast with the color after X-ray irradiation, which is more conducive to determining the color recovery after discoloration. Attached Figure Description

[0020] Figure 1 These are color comparison photos of the blue synthetic cubic zirconia of this invention before X-ray irradiation for 10, 20, and 40 minutes.

[0021] Figure 2 This is the state of zirconium oxide after irradiation discoloration, which is restored to its original color after heat treatment, and the color remains consistent even after multiple repetitions. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0023] A test method for restoring the discoloration of blue synthetic cubic zirconia after irradiation through heat treatment includes the following steps:

[0024] Step 1: Prepare the powder according to the molar percentage: ZrO2:Y2O3:HfO2:Co2O3:CeO2:Pr6O 11 Er₂O₃ = 75-80: 23-28: 1-6: 0.5-0.8: 0.08-0.15: 0.05-0.08: 0.08-0.12, where Co₂O₃ is used as a colorant, and CeO₂ and Pr₆O₃ are used as colorants. 11Er₂O₃ is used to provide rare earth elements. All powders are mixed and stirred thoroughly. Cubic zirconia (CZ) is a single-crystal ceramic. Y₂O₃ and HfO₂ act as stabilizing additives, maintaining the cubic structure of ZrO₂ in the low-temperature region. A small amount of HfO₂ enhances thermal shock resistance.

[0025] Step 2: Blue synthetic cubic zirconia is produced using the cold crucible melting shell method.

[0026] The cold crucible fused shell method is a commonly used method in crystal growth. First, 4-6g of zirconium metal is placed in the center of the powder for "ignition." A high-frequency coil is used to heat the material until it melts, creating and expanding a molten pool. Then, cold water is circulated through a steel tube to cool the material, preventing the outer layer from melting and forming a "cold crucible fused shell." After the powder has completely melted, the melt is stabilized for 50-60 minutes. The molten crystal material inside then crystallizes and grows under supercooling as the crucible descends, ultimately yielding a transparent, blue synthetic cubic zirconia crystal. Ideally, the temperature is heated to above 1400℃ using a high-frequency coil.

[0027] Step 3: The blue synthetic cubic zirconia crystal was irradiated with X-rays under different irradiation durations and dose parameters to induce a color change. The irradiation duration ranged from 10 to 40 minutes, and the irradiation dose was 3.06 × 10⁻⁶. 6 ~1.12×10 7 J / cm 2 Ideally, X-ray irradiation with a power range of 500–4000 W should be used.

[0028] Step 4, heat treatment: The synthetic cubic zirconia crystals with different degrees of discoloration after X-ray irradiation are placed in a high-temperature atmosphere tube furnace, heated to 200-400℃ in an oxygen atmosphere and held for 24-48 hours, and then cooled to room temperature.

[0029] Step 5: Compare and photograph the synthetic cubic zirconia after various irradiations and heat treatments. Ideally, the shooting parameters should be ISO 80, shutter speed 1 / 60 second, aperture f / 1.8, and focal length 54mm. Then, use a fiber optic spectrometer to measure the color of these synthetic cubic zirconias to find the optimal heat treatment parameters for restoring the color to its original state before irradiation.

[0030] Example:

[0031] Multiple 1 cm diameter blocky blue synthetic cubic zirconia prepared by doping with Co and rare earth elements Ce, Pr and Er were irradiated with different doses of X-rays. The color changed from blue to brownish-yellow, as shown in Table 1.

[0032] Table 1. X-ray irradiation data for Examples 1-3

[0033] Group X-ray irradiation time (min) X-ray irradiation dose (J / cm 2 ) Example 1 10 <![CDATA[3.06x10 6 ]]> Example 2 20 <![CDATA[6.12x10 6 ]]> Example 3 40 <![CDATA[1.12x10 7 ]]>

[0034] The samples were then subjected to heat treatment. The heat treatment was carried out in a high-temperature atmosphere tube furnace, with the temperature increased to 200-300℃ at 5℃ / min and then held for 36 hours.

[0035] Various irradiated and heat-treated synthetic cubic zirconia were photographed and compared, and the chromaticity of these synthetic cubic zirconia was measured using a fiber optic spectrometer to seek the optimal heat treatment parameters for restoring the color to the original chromaticity before irradiation. Table 2 shows the chromaticity data of Examples 1 to 3.

[0036] Table 2 Colorimetric data for Examples 1-3

[0037] Group L a* b* Before X-ray irradiation 62.01 -15.32 46.19 Example 1 61.86 -15.83 43.58 Example 2 60.39 -14.37 49.64 Example 3 61.76 -12.66 50.27

[0038] in:

[0039] 1) Examples 1, 2, and 3 show the synthetic cubic zirconia obtained after irradiation for 10, 20, and 40 minutes, respectively. These are compared with photographs of the synthetic cubic zirconia before irradiation. Figure 1 It can be seen that the color of the blue synthetic cubic zirconia changed from blue to brownish-yellow after irradiation for 10 minutes, and the brownish-yellow hue increased significantly after further irradiation. It can be seen that the color change of the synthetic cubic zirconia after irradiation is obvious.

[0040] 2) By Figure 2 It can be seen that after irradiation, the brownish-yellow zirconium oxide, after heat treatment at 200-300℃ for 36 hours, eventually reverted to its original blue color. The color recovery remained consistent after more than five repeated tests.

[0041] 3) The chromaticity values ​​in Table 2 were obtained by using a USB2+H07263 fiber optic spectrometer to collect the colors of Examples 1 to 3 under a D65 light source. The CIE-Lab color coordinate system was used to measure the color of each synthetic cubic zirconia.

[0042] This invention involves incorporating rare earth elements during preparation, then using X-ray irradiation to alter the internal valence state of blue synthetic cubic zirconia, causing a color change. The color is then restored through heat treatment, resulting in a material with recoverable color change. This invention can both change the color of blue synthetic cubic zirconia prepared with rare earth elements through irradiation and restore it through heat treatment, ultimately allowing for multiple cycles of restoration and reuse, meeting the requirements for applications in materials with recoverable color change.

[0043] Comparative Experiment 1: The final product obtained in this experiment was a transparent blue synthetic cubic zirconia crystal. This was achieved by adding 0.5–0.8 mol% Co₂O₃ as a colorant, along with CeO₂ and Pr₆O₃. 11When the Er₂O₃ content is below the set range, the final crystals are light blue; when the CeO₂ content is above 0.15 mol%, the crystals are orange-colored; when the Pr₆O content is below the set range, the final crystals are light blue. 11 When the concentration of Er₂O₃ is above 0.08 mol%, the resulting crystals have a yellowish tint; when the concentration of Er₂O₃ is above 0.12 mol%, the resulting crystals have a pinkish tint.

[0044] Comparative Experiment 2: A comparative experiment was conducted with blue synthetic cubic zirconia containing only Co and no rare earth elements. The results showed that the blue synthetic cubic zirconia doped with rare earth elements changed color from blue to blue-green after X-ray irradiation. Further irradiation significantly increased the brownish-yellow hue, and after 40 minutes, the brownish-yellow hue no longer increased with increasing irradiation dose. The blue synthetic cubic zirconia without rare earth elements, lacking Ce, Pr, and Er doping, could not complete the oxidation state change of Ce, Pr, and Er elements to generate oxygen vacancies, leading to the transition between these vacancies and the resulting color change.

[0045] Comparative Experiment 3: Rare-earth-doped blue synthetic cubic zirconia, after being irradiated with X-rays to turn brownish-yellow, underwent heat treatment at 200–400℃ for 36 hours. The final color of the zirconia recovered from brownish-yellow to its original blue. However, if the heat treatment temperature was below 200℃, the color changed from brownish-yellow to bluish-green and could not fully recover to blue. Conversely, if the heat treatment temperature was above 400℃, the color would remain blue after recovering from brownish-yellow, resulting in a waste of energy and time.

Claims

1. A test method for restoring the color of blue synthetic cubic zirconia after irradiation and heat treatment, characterized in that, Includes the following steps: Step 1: Prepare the powder according to the molar percentage: ZrO2:Y2O3:HfO2:Co2O3:CeO2:Pr6O 11 Er₂O₃ = 75~80: 23~28: 1~6: 0.5~0.8: 0.08~0.15: 0.05~0.08: 0.08~0.12, where Co₂O₃ is used as a colorant, and CeO₂ and Pr₆O₃ are used as colorants. 11 Er₂O₃ is used to provide rare earth elements; all powders are mixed and stirred evenly, and the sum of the molar percentages of all the above components is 100%. Step 2: Blue cubic zirconia is synthesized using the cold crucible melting shell method; 4-6g of metallic zirconium sheet is placed in the center of the powder for "ignition". The raw material is heated to melt using a high-frequency coil to generate and expand the molten pool. Then, cold water is passed through a steel tube to cool it, so that the outer layer does not melt, forming a "cold crucible shell". After the powder is completely melted, the melt is stabilized for 50-60 minutes. The molten crystal material inside is cooled by the crucible descending, allowing it to crystallize and grow. Finally, a transparent blue synthetic cubic zirconium oxide crystal is obtained. Step 3: The blue synthetic cubic zirconia crystal was irradiated with X-rays under different irradiation durations and dose parameters to induce a color change. The irradiation duration ranged from 10 to 40 minutes, and the irradiation dose was 3.06 × 10⁻⁶. 6 ~1.12×10 7 J / cm 2 ; Step 4, heat treatment: Place the synthetic cubic zirconia crystals with different degrees of discoloration after X-ray irradiation in a high-temperature atmosphere tube furnace, heat them to 200~400℃ in an oxygen atmosphere and hold them at that temperature for 24~48h, then remove them and cool them to room temperature. Step 5: Compare and photograph the synthetic cubic zirconia after various irradiations and heat treatments, and use a fiber optic spectrometer to measure the color of these synthetic cubic zirconia to find the optimal heat treatment parameters to restore the color to the original color before irradiation.

2. The test method for restoring the discoloration of blue synthetic cubic zirconia after irradiation and heat treatment according to claim 1, characterized in that: In step two, a high-frequency coil is used to heat the temperature to above 1400°C.

3. The test method for restoring the discoloration of blue synthetic cubic zirconia after irradiation and heat treatment according to claim 1, characterized in that: In step three, X-ray irradiation with a power range of 500~4000w is selected.

4. The test method for restoring the discoloration of blue synthetic cubic zirconia after irradiation and heat treatment according to claim 1, characterized in that: In step five, the shooting parameters are ISO 80, shutter speed 1 / 60 second, aperture 1.8, and focal length 54mm.

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