KR101233546B1 - Composition of earthenware ceramic comprising bone ash and zirconia stabilized by stabilizer and method of manufacturing earthenware ceramic sintered body using composition of earthenware ceramic comprising bone ash and zirconia stabilized by stabilizer - Google Patents

Abstract

The present invention relates to a ceramic ceramic sintered body using pottery ceramic powder containing zirconia stabilized with lime and a stabilizer and ceramic ceramic powder containing zirconia stabilized with bone and stabilizer. Mixing zirconia stabilized with bone and stabilizer to obtain a mixture, calcining the mixture, molding the calcined mixture, plasticizing it, processing the plasticized sintered body to form a shape and sintering the processed molded body The ceramic sintered compact is manufactured. The ceramic ceramic powder may be used in a method of manufacturing a ceramic ceramic sintered body having sufficient strength and improved wettability while reducing bone ash content, and thus may be applied to ceramics, jewelry, and the like.

Description

Ceramic ceramic powder containing zirconia stabilized with lime and stabilizer and ceramic ceramic sintered body using zirconia stabilized with lime and stabilizer SINTERED BODY USING COMPOSITION OF EARTHENWARE CERAMIC COMPRISING BONE ASH AND ZIRCONIA STABILIZED BY STABILIZER}

The present invention relates to a ceramic ceramic powder containing zirconia stabilized with a lime and a stabilizer and a ceramic ceramic sintered body using zirconia stabilized with a bone and a stabilizer.

Bone ash is bone powder made from burned powder, and generally highly refined bovine bone powder is used in ceramics. Pottery containing bone flakes has the advantage of being able to reduce the thickness of the product because it is light and warm. However, ceramics containing bone may be disadvantageous in terms of strength, wettability, and the like. In addition, bone ash is expensive, and when the content of bone ash is high, the price of ceramic ceramic powder for ceramics is increased, and in the case of natural bone ash, sintering requires a high temperature of 1250 to 1300 ° C. or higher, and the strength is weakened so that it is calcined at a higher temperature than general ceramics. There is a problem. There is a demand for the development of ceramic powder for ceramics having sufficient strength and sufficient strength and improved wettability.

It is an object of the present invention to provide a ceramic powder for ceramics having sufficient strength, including zirconia stabilized with bone and stabilizer.

Another object of the present invention is to provide a method for producing a ceramic sinter for ceramics using zirconia stabilized with bone and stabilizer.

In order to achieve the above object, the present invention provides a ceramic ceramic powder comprising zirconia stabilized with bone and stabilizer.

The bone ash is bone powder made by burning powder, and refers to animal bone powder. However, human bone powder is excluded. For example, the bone circuit may use highly refined bovine bone flour.

The zirconia is chemically very stable as a material used in engineering ceramics and electronic ceramics, and has high fire resistance (melting point of 2700 ° C.), low thermal conductivity, and high electrical conductivity when combined with other oxides, but changes phase from tetragonal to cubic When (phase transformation) has a cracking phenomenon due to volume expansion of about 3 to 5%, it can be stabilized with a stabilizer that can stabilize the solid crystal cubic crystal to room temperature. That is, the stabilizer includes an oxide and the like that can form a solid solution together with zirconia to stabilize the cubic structure in the tetragonal crystal. When the zirconia is stabilized by the stabilizer, sufficient sintering may be performed even at a relatively low temperature of 1500 ° C. or less, thereby having sufficient strength.

The concept of ceramic powder for pottery in the present invention is not only porcelain but also a concept including a product formed by firing ceramic powder and may include jewelry and the like.

According to one embodiment of the invention, the stabilizer is from a group consisting of rare earth metal oxides, calcium oxide, magnesium oxide and precursor compounds that decompose at a temperature below the sintering temperature of the ceramic powder for pottery to form the oxides It may include one or more compounds selected.

The rare earth metal includes scandium (Sc), yttrium (Y), and a metal element corresponding to an atomic number between 57 and 71. Examples of rare earth metal oxides include yttrium oxide (Y ₂ O ₃ ), cesium oxide (CeO ₂ ), and the like.

Also included are precursors that decompose at temperatures below the sintering temperature and become one or more of the oxides. That is, the precursor may be decomposed at a temperature between room temperature and sintering temperature to include the oxide.

According to an embodiment of the present invention, the stabilizer may include one or more compounds selected from the group consisting of yttrium oxide and precursors decomposed at a temperature below the sintering temperature of the ceramic ceramic powder to form yttrium oxide. have.

According to one embodiment of the invention, the stabilizer may be 3 mol% yttrium oxide.

The content of the bone ash and the content of the zirconia stabilized with the stabilizer may be selected in consideration of the contact angle and strength enhancement side of the ceramic ceramic sintered body manufactured using the ceramic ceramic powder containing the bone and the zirconia stabilized with the stabilizer. have.

In the ceramic ceramic sintered body manufactured using the ceramic ceramic powder containing zirconia stabilized with the bone and stabilizer, shrinkage due to sintering may decrease as the bone ash content increases. In the ceramic powder for ceramics, the contact angle increases as the bone ash content increases, and a significant increase in the contact angle is observed in the content of the bone ash at 20% to 30% by weight. In addition, in the ceramic sinter for ceramics manufactured using the ceramic ceramic powder containing zirconia stabilized with the bone and stabilizer, when zirconia stabilized with the stabilizer is contained, the zirconia stabilized with bone and stabilizer containing bone It has been observed that the strength of the ceramic sinter for ceramics produced using the ceramic powder containing ceramics increases. However, the zirconia stabilized with the stabilizer is not linearly increased in strength with the content, and when the content of bone ash is 5% by weight, the greatest bending strength is observed, and when the content of bone content is 20% by weight, the smallest The bending strength was observed, and when the content of bone ash contained 30% by weight, an improved bending strength was observed than when the content of bone ash was included 20% by weight.

According to an embodiment of the present invention, the ceramic ceramic powder may include 5 to 30% by weight of the bone ash and 70 to 95% by weight of zirconia stabilized with the stabilizer.

According to an embodiment of the present invention, the ceramic ceramic powder may further include alumina (Al ₂ O ₃ ) or silica (SiO ₂ ). Alumina or silica as the main component of the porcelain raw material, when alumina or silica is included, has the effect of enhancing the strength after firing, and because of the low cost it can have an effect of lowering the production cost of the ceramic ceramic powder. However, alumina or silica can increase the production cost by increasing the firing temperature if the component content is too large.

In order to achieve the above another object, the present invention comprises the steps of mixing the zirconia stabilized with bone and stabilizer to obtain a mixture; Calcining the mixture; Molding the calcined mixture; Pre-sintering the molded body at a temperature of 900 to 1300 ° C; Processing the pre-sintered molded body to form a shape; And it provides a method for producing a ceramic sinter for ceramics comprising the step of sintering the processed molded body.

The bone ash is very sensitive to moisture, and when reacted with moisture, it is preferable to use a dried one because it changes to another material and its molecular weight changes easily. In addition, the mixture has a property to aggregate when exposed to air, it is preferable to store in a dryer.

According to one embodiment of the present invention, in the manufacturing method of the ceramic sintered ceramics, the step of obtaining a mixture by mixing zirconia stabilized with a bone ash and stabilizer is wet grinding the zirconia stabilized with the bone ash and stabilizer in a ball mill (Ballmill) It may further comprise the step. The wet milling of the zirconia stabilized with the bone ash and stabilizer with the ball mill may be performed for the purpose of grinding the mixture and homogeneous mixing. For example, wet ball milling using ethanol as a solvent may be performed at 60 to 100 rpm for 1 to 3 hours.

In the calcining of the mixture, the volatile components of the bone may be decomposed and removed, and the mixture powder may be prevented from being entangled.

After molding the calcined mixture, it may be plasticized at a temperature of about 70 to 90% (eg 900 to 1300 ℃) of the sintering temperature to facilitate processing to have a shape in a desired shape.

In the step of sintering the processed molded body, it is possible to select a suitable sintering temperature to maintain a sufficient temperature and time to densify the ceramic ceramic sintered body, increase the density, and improve the mechanical strength.

According to an embodiment of the present invention, in the method of manufacturing a ceramic sintered ceramic, the mixture may include 70 to 95% by weight of zirconia stabilized with 5 to 30% by weight of the bone ash and 3 mol% yttrium oxide as the stabilizer. have.

The method for producing a ceramic sinter for ceramics according to the present invention has a sufficient strength while reducing the bone ash content, has improved wettability, and has an advantageous effect on coloring.

Pottery ceramic powders comprising zirconia stabilized with lime and stabilizer according to the present invention can be used in a method for producing a ceramic ceramic sintered body having a sufficient strength, reduced wettability, improved wettability, and a favorable effect on coloring, etc. Can be applied to ceramics, ornaments and the like.

1 shows X-ray diffraction analysis of a mixture of zirconia stabilized with pure 3 mol% yttrium oxide, pure bone ash, and a mixture of zirconia and bone lime stabilized with 3 mol% yttrium oxide at each concentration before calcination.
Figure 2 shows the X-ray diffraction analysis of zirconia and bone mixture stabilized with 3 mol% yttrium oxide at each concentration after calcination.
3 is a photograph after sintering of a test piece of a mixture containing 10% by weight of bone ash.
4 is a photograph after sintering of a test piece of a mixture containing 20% by weight of bone ash.
5 is a photograph after sintering of a test piece of a mixture containing 20% by weight of bone ash.
6 is a photograph after sintering of a zirconia test piece stabilized with pure 3 mol% yttrium oxide.
7 is a comparison of the shrinkage rate according to the bone ash content in the case of the bone ash content 0 shows a zirconia test piece stabilized with pure 3mol% yttrium oxide.
8 is a comparison of the contact angle according to the bone ash content, it shows a zirconia test piece stabilized with pure 3mol% yttrium oxide in the case of 3YZ.
9 shows the load and extension length applied to each specimen at the instant of cutting.

Hereinafter, the present invention will be described in detail by way of examples, but the following examples are merely illustrative of the present invention, and the content of the present invention is not limited thereto.

<Examples>

1. Mix zirconia stabilized with bone mineral and stabilizer

Bone ash (Hanmangi Co., Ltd.) and zirconia (ZrO ₂ ) stabilized with ₃ mol% yttria (yttria, Y ₂ O ₃ ) were prepared. To the zirconia stabilized with 3 mol% yttrium oxide, the bone ash was mixed at a ratio of 5% by weight, 8% by weight, 10% by weight, 20% by weight and 30% by weight, respectively. At this time, the bone ash is very sensitive to moisture, and when reacted with water, it changes to another substance and the molecular weight is easily changed, so that it is stored in a dryer, and mixed in a weight ratio (wt%) by induction before mixing. The mixture was also stored in a dryer because it has a property to aggregate when exposed to air. The mixture was subjected to wet ball milling at 80 rpm for 2 hours for the purpose of grinding and homogeneous mixing. 0.4 "Zirconia Ball and ethanol were used as solvent. The ball milled mixture was dried in a drying oven at 80 ° C for 24 hours.

2. Calcination

X-ray diffraction analysis of the dried mixture and the sample before mixing was performed to calcinate the mixture of bone excluding zirconia stabilized with pure 3 mol% yttria and zirconia stabilized with 3 mol% yttrium oxide. The temperature increase rate of calcination was maintained at 900 ° C for 2 hours at 5 ° C / min. Zirconia stabilized with pure 3 mol% yttrium oxide before mixing is excluded because it is originally calcined. X-ray diffraction analysis of the mixture after calcination was performed.

3. Molding and Compression Molding

Zirconia powder stabilized with pure 3 mol% yttrium oxide and zirconia powder stabilized with 3 mol% yttrium oxide were mixed with 5% by weight, 8% by weight, 10% by weight, 20% by weight and 30% by weight, respectively. The cutting mold roll was uniaxially formed. 30 × 10.05 × 5 mm was used and molded by applying pressure twice at 1.5 t. The molded specimens were measured for width, length, and height with vernier calipers to calculate shrinkage.

4. Sintering

The temperature increase during sintering was maintained for 2 hours to 1400 ℃ at 5 ℃ / min. The exception was that the zirconia powder stabilized with pure 3 mol% yttrium oxide did not calcinate, so the rate of ascent was set at 2 ° C / min. The sintered test pieces were also measured for width, length, and height with vernier calipers.

5. Characterization

The degree of shrinkage of the zirconia powder stabilized with 3 mol% yttrium oxide, bone ash and the mixture was measured before and after sintering. Differential characteristics were analyzed by differential thermal analysis (DTA) and thermogravimetric analysis (TG), with the rate of temperature rise in air at 10 ° C./min. The crystal phase was observed using an X-ray diffraction analyzer (X-RD). The contact angle was measured to measure the adhesion and surface tension of the ultra pure water (DI water) and the test piece, and the three-point bending strength specified in KSL 1591 was measured using a universal testing machine (UTM5544, INStron).

6. Test result

(1) X-ray diffraction analysis result

1 shows X-ray diffraction analysis of a mixture of zirconia stabilized with pure 3 mol% yttrium oxide, pure bone ash, and a mixture of zirconia and bone lime stabilized with 3 mol% yttrium oxide at each concentration before calcination. As a result, the peak of bone ash was the same as calcium phosphide (CaP ₃ , calcium phosphide), it could be confirmed that the crystal phase. In the case of the zirconia stabilized with 3 mol% yttrium oxide and the bone mixture, the peak of the bone ash was hardly observed and the peak of zirconia stabilized with 3 mol% yttrium oxide was superior. The result was that zirconia stabilized with 3 mol% yttrium oxide and bone ash are not present as a solid solution, but due to the phenomenon of simple mixture and separation after mixing with zirconia stabilized with 3 mol% yttrium oxide due to the aggregation of bone. . In addition, no significant changes in peak or intensity could be observed even if the contents of the bone increased or decreased.

Figure 2 shows the X-ray diffraction analysis of zirconia and bone mixture stabilized with 3 mol% yttrium oxide at each concentration after calcination. Referring to FIG. 2, when the peaks of the mixtures after calcination were observed, it was confirmed that 2θ before calcination had no low intensity peak appearing around 25 ° to 35 °. The peak of 2θ of 30-35 ° which can be seen in the X-ray diffraction analysis of bone was found in the mixture before calcination, but it was confirmed that the gas component of bone was removed through calcination.

(2) Test piece after sintering

3 is a photograph after sintering of a test piece of a mixture containing 10% by weight of bone ash. Referring to FIG. 3, the test piece was bent due to the difference in shrinkage rate, and the lengths of both ends of the test piece were different. This is considered to be a result of uneven mixing of the specimen during sintering due to the inability to mix evenly the zirconia stabilized with 3 mol% yttrium oxide. In addition, the pressure was not evenly transmitted during the molding process, and it was considered that the specimen was bent due to gravity because one dummy per one specimen was not used during the sintering process.

4 is a photograph after sintering of a test piece of a mixture containing 20% by weight of bone ash. Referring to Figure 4, compared to the mixture containing 10% by weight of bone, the degree was weak, but it was confirmed that slightly spoiled. This is believed to be the same reason for the mixture containing 10% by weight of the bone ash. The zirconia stabilized with 3 mol% yttrium oxide was not evenly mixed, resulting in uneven mixing of the specimen during sintering, uneven pressure transfer during the molding process, and the absence of one pile per test specimen during sintering. The test piece is considered to be bent. After sintering, specimens containing 20% by weight of bone ash were attempted to be pulverized in the mortar for X-ray diffraction analysis (XRD) measurement but the edges were slightly broken without being crushed.

5 is a photograph after sintering of a test piece of a mixture containing 20% by weight of bone ash. Referring to FIG. 5, the thicknesses of the three test pieces were different, and the thicknesses of both ends of the test pieces were also different. After sintering, as a result of pulverizing a test piece containing 30% by weight of bone ash, it was more easily broken than a test piece containing 20% by weight of bone ash, but the grinding in the mortar was not easy.

6 is a photograph after sintering of a zirconia test piece stabilized with pure 3 mol% yttrium oxide. Referring to Figure 6, when compared with Figures 3 to 5, it can be seen that the test piece is molded and sintered well to the most smooth and constant size. There was no warpage and molding and sintering were very good with little difference in thickness. The zirconia test piece stabilized with pure 3 mol% yttrium oxide did not break in the mortar, and only a small amount of powder was broken from the surface.

(3) shrinkage

1) Experiment Method

Shrinkage was calculated from the ratio (%) of (volume of test piece before sintering) and (volume of test piece before sintering-volume of test piece after sintering). Shrinkage of zirconia stabilized with 3 mol% yttrium oxide and bone mixture was compared with that of pure 3 mol% yttrium stabilized zirconia. The specimens were sintered 30 mm long, 10.05 mm long, and 5 mm high, each having a volume of 1507.5 mm, zirconia stabilized with pure 3 mol% yttrium oxide, and zirconia stabilized with 3 mol% yttrium oxide at each concentration. Three specimens each were prepared from the mixture, and the average size thereof was calculated and measured.

2) Experimental results

i) The average size of the specimens containing 10% by weight of bone ash was 23.59 mm, 8.47 mm and 4 mm in height, and the volume was 799.23 mm, respectively. ii) The average size of specimens containing 20% by weight of bone ash was 24.15 mm. Mm, 8.52mm long and 4mm high with 823.03㎣ of volume. Iii) The average size of the specimen including 30% by weight of bone ash was 24.48mm in width, 8.52mm in length and 4.1mm in height, respectively. Iv) The average size of the zirconia specimens stabilized with pure 3 mol% yttrium oxide was 22.78 mm wide, 8 mm long and 3.6 mm high, with a volume of 653.76 mm 3.

7 is a comparison of the shrinkage rate according to the bone ash content in the case of the bone ash content 0 shows a zirconia test piece stabilized with pure 3mol% yttrium oxide. Zirconia stabilized with pure 3 mol% yttrium oxide had the largest shrinkage of 56.63%, and the shrinkage of the specimens containing 30%, 20%, and 10% by weight of bone ash was 43.27%, 45.40%, and 46.98% roll bone ash, respectively. As the mixing ratio decreased, the shrinkage increased. It was confirmed that the shrinkage of zirconia stabilized with pure 3 mol% yttrium oxide was greater than that of bone ash, and the higher the content of bone ash, the smaller the shrinkage rate.

(3) Contact Angle

1) Experiment Method

The contact-to-contact is a measure of the wettability of the liquid surface at an angle at which the free surface of the liquid makes contact with the solid plane when the liquid and the solid are in contact. The contact angle determined by the cohesion of the liquid molecules and the adhesion between the liquid solid walls was measured. The liquid was measured on a specimen using ultra pure water (DI water) and zirconia specimens stabilized with pure 3 mol% yttrium oxide and 10% by weight, 20% by weight and 30% by weight, respectively. The contact angle was measured five times for one drop of ultrapure water and a total of ten times per test piece was measured. The measured data values are expressed as the mean and standard deviation of Table 1.

Specimen Average (°) Standard deviation (°) Zirconia stabilized with 3 mol% yttrium oxide 56.78 6.49 Contains 10% by weight of bone marrow 65.71 3.77 Contains 20% by weight of bone 66.32 6.06 Contains 30% by weight of bone ash 105.79 10.21

8 is a comparison of the contact angle according to the bone ash content, it shows a zirconia test piece stabilized with pure 3mol% yttrium oxide in the case of 3YZ. As a result, as the content of bone ash increases, the contact angle increases, so that it is close to hydrophobicity and has a high surface energy. In particular, the contact angle difference between the test piece containing 20% by weight of the bone and the test piece containing 30% by weight of the contact angle between the test piece containing zirconia stabilized with 3 mol% yttrium to 39.47 ° and the test piece containing 10% by weight of bone A difference of 8.93 ° (4.42 times greater contact angle difference between a test piece containing 20% by weight of bone and a test piece containing 30% by weight of bone) and a test piece containing 10% by weight of bone and a test piece containing 20% by weight of bone. When the contact angle difference was 0.61 ° (a difference of 64.70 times larger than the contact angle difference between the test piece containing 20% by weight of the bone and the 30% by weight of the bone) was confirmed that the sharp rise.

(4) Bending Strength

The bending strength was measured using a universal testing machine (UTM5544, Instron) to measure the three-point bending strength. The bending strength was measured using a well polished sintered body having parallel upper and lower surfaces and having a dimension of 3 × 4 × 36 mm as a test piece, and twice for each test piece. When measuring the three-point bending strength, the span between the supports was 30 ± 0.5 mm, and the measurement method specified in KSL 1591 was used. When the compressive stress on the upper part of the specimen and the tensile stress on the lower part of the specimen are applied to the specimen from the top, the crack starts to be destroyed at the lower part of the specimen which has a smaller tensile strength than the compressive strength. The applied load, stress and extension length are shown in Table 2.

Flexural load, standard, kgf Flexural stress (standard stress, MPa) Length of cutting moment (Flexure extension, standard, mm) Bone 5% by weight 1 63.31746 336.46106 -0.62667 Bone 5% by weight 2 62.45882 331.89835 -0.69979 Bone 8% by weight 1 57.13096 303.58676 -0.53583 Bone 8% by weight 2 61.76474 328.21011 -0.60729 Bone 10% by weight 1 50.06870 226.05884 -0.53583 Bone 10% by weight 2 54.57437 290.00137 -0.60729 Oste 20% by weight 1 52.73432 280.22357 -0.57021 Bone 20% by weight 2 42.69526 226.87729 -0.55396 Bone 30% by weight 1 44.16323 234.67786 -0.37562 Bone 30% by weight 2 55.59803 295.44101 -0.42458 Maximum value 63.31746 336.46101 -0.37562 Minimum value 42.69526 226.87729 -0.69979

In addition, the load and extension length applied to each test piece are shown in FIG. 9. Specimens that withstand the largest loads can be said to have high stress and high strength. The load and bending stress that the test piece containing 5% by weight of cartilage withstand were 63.317246kgf and 336.46106MPa, respectively. The test piece containing 20% by weight of the cartilage had the lowest strength of 42.69526kgf and 226.87729MPa, respectively. Rather, the test piece containing 30% by weight of the cartilage was 55.59803kgf and 295.4401MPa, respectively, withstand load and flexural stress.

If the processing is performed before sufficient strength is developed, the processing is easy. Therefore, after sintering at a temperature of about 70 to 90% of the sintering temperature where the weak strength is expressed (for example, a temperature of 900 to 1300 ° C), It is possible to make a shaped cerammix by having a suitable shape and sintering at an appropriate temperature.

Claims (8)

Ceramic powder for ceramics containing zirconia stabilized with bone ash and yttrium, except bone ash is human bone powder. delete delete The ceramic powder for ceramics according to claim 1, wherein the yttrium oxide has a concentration of 3 mol%. The ceramic powder for ceramics according to claim 1, comprising 5 to 30% by weight of the bone ash and 70 to 95% by weight of zirconia stabilized with the yttrium oxide. The ceramic powder for ceramics according to claim 1, further comprising alumina (Al ₂ O ₃ ) or silica (SiO ₂ ). Mixing zirconia stabilized with bone ash and yttrium to obtain a mixture, except bone ash is not human bone powder;
Calcining the mixture; And
Molding the calcined mixture;
Pre-sintering the molded body at a temperature of 900 to 1300 ° C;
Processing the pre-sintered molded body to form a shape;
A method of manufacturing a ceramic sinter for ceramics comprising the step of sintering the processed molded body. The method of manufacturing a ceramic ceramic sintered body according to claim 7, wherein the mixture is a ceramic ceramic powder comprising 5 to 30% by weight of bone ash and 70 to 95% by weight of zirconia stabilized at a concentration of 3 mol% of yttrium oxide. .

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