KR19980034109A - Green-colored zirconia ceramic and its manufacturing method - Google Patents

Abstract

The present invention relates to a colored zirconia ceramics having a green color, and a method for manufacturing the same. 20 to 80 wt% of chromium oxide (Cr ₂ O ₃ ) and 30 to 70 wt% of silicon dioxide (SiO ₂ ) Was calcined at 950-1300 ° C. in an air atmosphere to produce a green pigment, and zirconium oxide (ZrO ₂ ) stabilized with 3 mol% yttrium oxide (Y ₂ O ₃ ) or 5.5 wt% yttrium oxide in zirconium oxide. 2-10 wt% of the pigment prepared by calcining was added to the mixed raw material to prepare a molded body, and then the molded specimen was sintered at 1400-1500 ° C. in an air atmosphere to have a green color.

Description

Green Zirconia Ceramics and Manufacturing Method Thereof

The present invention relates to colored zirconia ceramics having a green color and a method of manufacturing the same.

In general, colored zirconia ceramics are characterized by the excellent hardness and toughness of zirconia.These are used in machinery such as watch cases, watch bands, clock faces, tie pins, decorative products, high-quality materials, and various structural materials. There is applicability in various ceramic products such as components and ceramic electronic components such as substrates for electronic components.

Zirconia ceramics have excellent mechanical properties such as strength and hardness, and are widely used in thread guides, various dies, nozzles, and various wear parts.

Recently, these excellent properties have been used and various colors have been applied to zirconia ceramics to be applied to various decorative parts.

Patents related to green colored zirconia ceramics proposed so far include Japanese Laid-Open Patent Publication Nos. 59-105055, 62-275060, and 3-35261.

By the way, the pigments of JP-A-59-105055 include chromium oxide (Cr ₂ O ₃ ), calcium oxide (CaO), nickel oxide (NiO) and manganese dioxide (MnO ₂ ), and the pigments of JP-A-62-275060 Colored pigments contain 0.3 to 9% by weight of oxides of tungsten (W), and Japanese Patent Application Laid-open No. 3-35261 has zirconia as a main component, yttrium oxide (Y ₂ O ₃ ), magnesium oxide (MgO), It is characterized by containing a stabilizer such as calcium oxide (CaO), cerium oxide (CeO ₂ ) and a pigment of 0.1 to 10 weight of chromium oxide (Cr ₂ O ₃ ), so that the chemical composition This is different.

In using colored zirconia ceramics as a decorative part, the excellent zirconia ceramics must maintain excellent mechanical properties, and the entire zirconia sintered body must have a uniform color. Its purpose is to manufacture.

The present invention having the above object is sintered finely containing 90-98 wt% of raw material containing 5.5 wt% of yttrium oxide and 2-10 wt% of pigment in zirconium oxide or zirconium stabilized with 3 mol% yttrium oxide. Green zirconia ceramics and a method for producing the same, and in the above method, the pigment is composed of 20 to 80% by weight of chromium oxide (Cr ₂ O ₃ ) and 30 to 70% by weight of silicon dioxide (SiO), And green pigment 2 ~ in a powder of green pigment, characterized in that it is calcined at 950-1300 ° C. in an atmospheric atmosphere and 90-98% by weight of a raw material containing yttrium oxide separately from zirconium oxide or zirconium oxide suggested in the above method. The molded article to which 210 weight% was added is manufactured by sintering from 1400 degreeC to 1500 degreeC in air | atmosphere.

The present invention first calcined a raw material of 20 to 80% by weight of reagent grade chromium oxide (Cr ₂ O ₃ ) and 30 to 70% by weight of silicon dioxide (SiO ₂ ) at 950-1300 ° C. in an air atmosphere. 2-10 of pigments prepared by calcination to a raw material obtained by mixing zirconium oxide (ZrO ₂ ) stabilized with 3 mol% yttrium oxide (Y ₂ O ₃ ) or 5.5 wt% yttrium oxide in zirconium oxide. After adding the weight% to prepare a molded article, the molded specimen was sintered at 1400 ~ 1500 ℃ in the air atmosphere to have green color.

EMBODIMENT OF THE INVENTION Hereinafter, the reason for numerical limitation of this invention is demonstrated.

Limiting the content of chromium oxide (Cr ₂ O ₃ ) to 20 to 80% by weight in green pigment composition is difficult to have a vivid green color when the amount of chromium oxide is lower than 20% by weight, and the content is 80% by weight. It is because it is difficult to manufacture a stable pigment when it becomes abnormal.

On the other hand, the pigment is mixed in a predetermined composition and calcined once in an air atmosphere, and then added to a raw material in which zirconium oxide stabilized with yttrium oxide or zirconium oxide is mixed with yttrium oxide, and then the specimen is molded and sintered. It is intended to be in a state to have a uniform color in zirconia ceramics.

In addition, it is because it is difficult to produce a green pigment due to the calcination temperature and atmosphere unless heat treatment at a suitable temperature in the air atmosphere.

2-10% by weight of the pigment prepared by calcining zirconium oxide or zirconium oxide stabilized with 3 mol% yttrium oxide separately from 5,5% by weight of yttrium oxide is added in an amount of 2% by weight or less. If it is difficult to make green color uniform to zirconia ceramics, if it is added more than 10% by weight, the color of the green system is reduced in sintering ability due to the lack of sintering ability, which reduces the mechanical properties of colored zirconia ceramics. Because it is.

And the sintering at 1400 ~ 1500 ℃ in the air atmosphere does not have vivid green color if the sintering atmosphere is not controlled, and if the sintering temperature is lower than 1400 ℃, the sintering does not proceed properly and it is impossible to manufacture dense colored zirconia ceramics. This is because when the sintering temperature is 1500 ° C. or higher, grains of zirconia grow so that the mechanical properties of the zirconia ceramics are deteriorated.

The green zirconia ceramics produced by the present invention are ball mills in which 2-10% by weight of the pigment prepared by a predetermined method is mixed with 5.5% by weight of zirconium oxide or zirconium oxide stabilized to 3 mol% of yttrium oxide. After drying and shaping the specimen, the green to dark green color can be obtained by sintering at an appropriate temperature in an air atmosphere.

The manufactured green zirconia ceramics can be used for decorative parts such as watch exterior parts and tie pins, and electronic and appliance parts.

Hereinafter, the present invention will be described in detail through examples.

Example 1

After calcining and pulverizing a pigment having a composition of 80% by weight of chromium oxide (Cr ₂ O ₃ ) and 20% by weight of silicon dioxide (SiO ₂ ) at 950, 1150 and 1300 ° C, respectively, 3 to 15% by weight of the prepared pigment was Specimens were formed by adding to commercially available 3 mol% yttrium stabilized zirconia powder and sintered at 1300 ° C., 1400 ° C., 1450 ° C. and 1500 ° C. for 60 to 90 minutes in air.

After sintered specimens were finally polished with 1 micron (μm) diamond slurry, the hardness was measured by 20 seconds at a load of 10 kg, and the fracture toughness was calculated by the formula proposed by Niihara et al. Shown in

As can be seen from Table 1, regardless of the amount of pigment added, the surface of the specimen sintered at 1300 ° C had a large amount of pores, so the mechanical properties were very low, and 15 wt% of the pigment calcined at 1300 ° C was added. Specimens sintered at 1400 ° C exhibited very low hardness values and were not suitable as colored zirconia.

TABLE 1

Zirconia powder stabilized with 3 mol% yttrium oxide on the market.

** The color of sintered specimen is defined as light green as the color of sintered specimen at 1300 ℃, and the color of other specimens is compared.

Example 2

3 mol% of yttrium oxide, which is commercially available (Y ₂ O ₃₎ with chromium oxide on the stabilized zirconia powder (Cr ₂ O ₃₎ 50% by weight, and silicon dioxide (SiO ₂₎ pigments and 50% by weight of the composition of Example 1 After the preparation in the same manner, 5 to 10% by weight of the prepared pigment was added to form a specimen, and sintered at 1300 ℃, 1400 ℃, 1450 ℃ and 1500 ℃ in the air atmosphere. The sintered specimen was measured in the same color and physical properties as in Example 1, the results are shown in Table 2 below.

Green zirconia with 5-10% by weight of a pigment having a composition of 50% by weight of chromium oxide (Cr ₂ O ₃ ) and 50% by weight of silicon dioxide (SiO ₂ ) had a low mechanical property at a low sintering temperature of 1300 ° C. Specimens sintered at 1400 ~ 1500 ℃ showed relatively good color and physical properties.

TABLE 2

* Zirconia powder stabilized with 3 mol% yttrium oxide on the market.

** The color of sintered specimen is defined as light green as the color of sintered specimen at 1300 ℃, and the color of other specimens is compared.

Example 3

After preparing a pigment having a composition of 30% by weight of chromium oxide (Cr ₂ O ₃ ) and 70% by weight of silicon dioxide (SiO ₂ ) in the same manner as in Example 1, commercially available 3 mol% yttrium oxide (Y ₂ O ₃ ) 2-7 wt% of the pigment prepared in the stabilized zirconia powder was added to shape the specimen and sintered at 1300 ° C., 1400 ° C., 1450 ° C. and 1500 ° C. in an air atmosphere.

The sintered specimen was measured in the same color and physical properties as in Example 1, the results are shown in Table 3 below.

The pigment of this composition had a lower saturation, that is, a dark green color because the amount of chromium oxide (Cr ₂ O ₃ ) causing color development was lower than that of Examples 1 and 2, but in the specimens in which the amount of pigment increased to 7% by weight, It has a relatively vivid green color.

As in the case of Examples 1 and 2, a large amount of pores existed in the specimen having a low sintering temperature, thereby deteriorating physical properties.

Green zirconia ceramics prepared by the method of the present invention as described above is a mixture of 5.5% by weight of yttrium oxide in zirconium oxide or zirconium stabilized to 3 mol% of the pigment 2-10% by weight prepared by a predetermined method. After ball milling and drying in a raw material, the specimen is molded, and then sintered at an appropriate temperature in an air atmosphere to obtain a green to dark green color.

TABLE 3

Zirconia powder stabilized with 3 mol% yttrium oxide on the market.

** The color of sintered specimen is defined as light green as the color of sintered specimen at 1300 ℃, and the color of other specimens is compared.

Example 4

The specimen was molded by adding 89.5% by weight of unstabilized zirconium oxide (ZrO ₂ ), 5.5% by weight of yttrium oxide (Y ₂ O ₃ ) and 5% by weight of a pigment prepared by calcining the pigment of the composition of Example 3 at 950 ° C. And sintered at 1300 ° C., 1400 ° C. and 1500 ° C. for 90 minutes in an air atmosphere.

The sintered specimens were shown in Table 4 in the same manner as in Example 1, color and properties.

The physical properties of the specimen sintered by mixing yttrium oxide and 5% by weight of pigment were respectively lower than those of the specimen sintered by mixing the pigment with zirconia powder stabilized with 3 mol% yttrium oxide and sintering at 1300 ° C. One specimen was not suitable as colored zirconia.

TABLE 4

* Pigment calcined the pigment of the composition of Example 3 at 950 ℃.

** The color of the sintered specimen is defined as light green as the color of the specimen sintered at 1300 ℃, and the color of other specimens is compared.

Claims (3)

Zirconium oxide stabilized with 3 mol% yttrium oxide or green based on dense sintering containing 90 to 98 wt% of a raw material containing 5.5 wt% of yttrium oxide according to zirconium oxide and 2 to 10 wt% of a pigment Method for producing zirconia ceramics. The method of claim 1, The pigment presented above is composed of 20 to 80% by weight of chromium oxide (Cr ₂ O ₃ ) and 30 to 70% by weight of silicon dioxide (SiO ₂ ), and is calcined at 950 to 1300 ° C. in an air atmosphere. Green zirconia ceramics characterized by the above. The method of claim 1, Sintering a molded article in which 2-10% by weight of green pigment is added to 90-98% by weight of the raw material containing acid white comb according to the zirconium oxide or zirconium oxide described above is sintered from 1400 ° C to 1500 ° C in an air atmosphere. A method for producing green zirconia ceramics, characterized in that.