TW201730135A - High strength ceramic powder and method of producing green body using the same of which the composition contains at least feldspar, quartz, starch adhesive and high temperature adhesive - Google Patents

Abstract

The present invention discloses a high strength ceramic powder, the composition of which at least contains feldspar, quartz, starch adhesive and high temperature adhesive. It is characterized in that the weight percentage of the feldspar is 24~36%; the weight percentage of the quartz is 38~52%; the weight percentage of the starch adhesive is 7~15% and the weight percentage of the high temperature adhesive is 3~12%. Furthermore, the ceramic powder can be used for the making of green bodies to enhance the strength of the green bodies formed by sintering a three-dimensional printing article.

Description

High-strength ceramic powder and method for making the same using the same

The invention relates to a ceramic powder component improvement, in particular to a high-strength ceramic powder which is printed as a three-dimensional printing and molding article, and uses the ceramic powder to prepare a green body to improve the sintered object after the sintering process. The strength of the green body is formed.

With the rapid development of technology, 3D printing has become one of the most embarrassing industries. Many operators are actively investing in the development and research of 3D printing technology to meet the application level that traditional planar copying technology cannot achieve, and become a new generation of manufacturing technology. . However, a variety of three-dimensional object forming methods have been developed, such as Fused Deposition Modeling (FDM), Laminated Object Manufacturing (LOM), Digital Light Processing (DLP), and three-dimensional Powder Bonding (3D Printer, 3DP), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), and Stereolithography (SLA).

For example, in the case of three-dimensional powder bonding, the molding method is to first lay the bottom layer of powder on the printing platform, spray the glue with the nozzle of the 3D printer, and glue the required parts together, and then go up to the top. A layer of powder, spray glue again to stick the powder, and finally absorb the unadhered powder and recycle it. The part that is used by the glue is a three-dimensional object.

However, today, ceramic materials are used as a three-dimensional printing powder to form a three-dimensional object, and then the ceramic powder is sintered and polymerized to form a green body through a high-temperature sintering process, because the three-dimensional object lacks vertical force during the molding process and the powder gap is large. , which leads to the problem of too low strength. At present, most of them are improved by adding a molding adhesive or increasing the amount of glue sprayed in the ceramic powder, but the process of forming the green body by high-temperature sintering removes the molding adhesive at the same time. As the intensity is still not improved, as shown in the scanning electron microscope (SEM) image of Fig. 1, the gap of the ceramic powder after sintering is still large, making it impossible to carry out subsequent glazing and painting processes.

The reason is that how to provide a kind of strength that can form a green body after the sintering process is formed has become a problem that needs to be overcome at present.

The main object of the present invention is to provide a high-strength ceramic powder by adding a certain proportion of a high-temperature adhesive to a ceramic powder by a physical mixing method, thereby improving the strength of a three-dimensional printed article after forming a green body by a sintering process.

In order to achieve the above object, the present invention provides a high strength ceramic powder comprising at least feldspar, quartz, a starch adhesive and a high temperature adhesive, characterized in that the weight percentage of the feldspar is 24 to 36%, the quartz The weight percentage is 38 to 52%, the weight percentage of the starch adhesive is 7 to 15%, and the weight percentage of the high temperature adhesive is 3 to 12%.

The high-strength ceramic powder is described, wherein the high-temperature adhesive comprises 10 to 30% by weight of sodium oxide.

The high-strength ceramic powder described above, wherein the high-temperature adhesive The coating further contains 50 to 80% by weight of a cerium-containing compound.

The high-strength ceramic powder is further contained, wherein the high-temperature adhesive further contains 3 to 10% by weight of calcium oxide and 2 to 10% by weight of magnesium oxide.

The high-strength ceramic powder is described, wherein the high-temperature adhesive comprises 70-80% by weight of lead oxide.

The high-strength ceramic powder is further contained, wherein the high-temperature adhesive further contains 20 to 30% by weight of a cerium-containing compound.

The high-strength ceramic powder is described, wherein the high-temperature adhesive comprises 40 to 60% by weight of potassium oxide.

The high-strength ceramic powder is further contained, wherein the high-temperature adhesive further contains 40 to 60% by weight of a cerium-containing compound.

The ceramic powder having high strength is described, wherein the cerium-containing compound is cerium oxide.

The invention also discloses a method for preparing a green body by using ceramic powder with high strength, the steps of which at least include: Step 1: using a ball mill to make 24 to 36 weight percent of feldspar, 38 to 52 weight percent of quartz, 7 to 15 The weight percentage of the starch adhesive and the 3-12 weight percent high temperature adhesive are mixed and stirred for 1 hour, and the powder sieved by the 200 mesh sieve is collected, and the powder is a ceramic powder with high strength; Step 2: The high-strength ceramic powder is printed through a three-dimensional powder bonding process to produce a molded article; and in the third step: the molded article is sintered into a single embryo through a sintering process.

The method for producing a green body by using a ceramic powder having high strength, wherein the sintering temperature of the sintering process is 500 to 1200 degrees Celsius, if When the sintering temperature is 800 to 1200 degrees Celsius, a high temperature adhesive containing sodium oxide is used; if the sintering temperature is 650 to 850 degrees Celsius, a high temperature adhesive containing lead oxide is used; if the sintering temperature is 500 degrees Celsius At ~700 degrees, a high temperature adhesive containing potassium oxide is used.

In summary, the invention will be described in detail below with specific embodiments. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art will readily appreciate various non-critical parameters that can be changed or adjusted to produce substantially the same results.

S10‧‧‧Step one

S20‧‧‧Step 2

S30‧‧‧Step three

Fig. 1 is a scanning electron micrograph of a conventional ceramic powder after sintering.

Fig. 2 is a scanning electron micrograph of the ceramic powder of the present invention after sintering.

Fig. 3a is a scanning electron micrograph of the high temperature adhesive of the ceramic powder of the present invention containing sodium oxide sintered.

Fig. 3b is a scanning electron micrograph of the high temperature adhesive of the ceramic powder of the present invention containing sintered lead oxide.

Fig. 3c is a scanning electron micrograph of the high temperature adhesive of the ceramic powder of the present invention containing potassium oxide sintered.

Fig. 4a is a view showing the finished product of the high temperature adhesive of the ceramic powder of the present invention containing sodium oxide sintered to form a green body.

Fig. 4b is a view showing the finished product of the high temperature adhesive of the ceramic powder of the present invention containing the lead oxide sintered to form a green body.

Fig. 4c is a view showing the finished product of the high temperature adhesive of the ceramic powder of the present invention containing the potassium oxide sintered to form a green body.

Fig. 5 is a flow chart showing the production of a green body using the high strength ceramic powder of the present invention.

The high-strength ceramic powder of the present invention comprises at least feldspar, quartz, a starch adhesive and a high-temperature adhesive, wherein the weight percentage of the feldspar is 24 to 36%, and the weight percentage of the quartz is 38 to 52. %, the weight percentage of the starch adhesive is 7 to 15%, and the weight percentage of the high temperature adhesive is 3 to 12%, and the sintering temperature at the time of forming the green body is lowered by adding a high temperature adhesive. Among them, one embodiment of the present invention contains about 30% by weight of feldspar, about 50% of quartz, about 15% of starch adhesive, and about 5% of high temperature adhesive, as shown in Fig. 2, ceramic powder. After sintering, it will polymerize to form a number of massive structures and reduce the porosity to effectively increase the strength of the ceramic green body.

Since the ceramic material has a viscosity in a molten state, and the viscosity is lowered as the sintering temperature is higher, it is necessary to use different sintering temperatures for sintering, and the sintering temperature of the sintering process and the high temperature adhesive are mutually The high temperature adhesive further contains one of sodium oxide (Na ₂ O), lead oxide (PbO) or potassium oxide (K ₂ O), and the high temperature adhesives of the three different components have different melting temperature ranges. Therefore, different compositions can be selected depending on the sintering temperature used.

For example, when a molded article containing a high-temperature adhesive containing these three different components is sintered at a sintering temperature of 1,100 ° C, respectively, a scanning electron microscope (SEM) image after sintering at 3a to 3c is compared. High-strength ceramic powder printing containing sodium oxide as a high-temperature adhesive The molded object has the most prominent area after sintering, the smallest pores, and the smallest degree of cracking of the green body (as shown in Figure 4a); the high-strength ceramic powder containing lead oxide as a high-temperature adhesive is printed and formed. The molded object has many areas of adhesion after sintering, and the pores are the second largest, so the degree of fragmentation of the green body is second (as shown in Figure 4b); the ceramic powder column with high strength containing potassium oxide as a high temperature adhesive The molded article is the least adhered to the molded part, and the pores are the largest, and there are still particles, so the green body has the largest degree of fragmentation (as shown in Fig. 4c). From this, it is understood that when the molded article is sintered at a sintering temperature of 1200 ° C, it is preferred to use a ceramic powder containing sodium oxide as a high-temperature adhesive.

Further, when the high-temperature adhesive contains 10 to 30% by weight of sodium oxide, the high-temperature adhesive contains 50 to 80% by weight of a cerium-containing compound, and also contains 3 to 10% by weight of calcium oxide (CaO) and 2 ~10% by weight of magnesium oxide (MgO) as a component of the high-temperature adhesive; when the high-temperature adhesive contains 70-80% by weight of lead oxide, the high-temperature adhesive contains 20 to 30% by weight of a cerium-containing compound; When the high-temperature adhesive contains 40 to 60% by weight of potassium oxide, the high-temperature adhesive contains 40 to 60% by weight of a cerium-containing compound, and the aforementioned cerium-containing compound is cerium oxide (SiO ₂ ).

However, in order to effectively increase the strength of the ceramic green body, the high-strength ceramic powder of the present invention can be used to make the green body. As shown in FIG. 5, the manufacturing steps include at least: Step 1 S10: using a ball mill to remove 24~ 36% by weight of feldspar, 38 to 52% by weight of quartz, 7 to 15% by weight of starch adhesive and 3 to 12% by weight of high temperature adhesive were mixed and stirred for 1 hour, and the powder was sieved through a 200 mesh sieve. And the powder is a ceramic powder having high strength; Step 2: S20: printing a high-strength ceramic powder through a three-dimensional powder bonding process to print a molded article; and Step 3: S30: sintering the molded article into a one through a sintering process Prime embryo.

The sintering temperature of the sintering process is 500 to 1200 degrees Celsius. Further, if the sintering temperature is 800 to 1200 degrees Celsius, a high temperature adhesive containing sodium oxide is used; if the sintering temperature is 650 to 850 degrees Celsius, a high temperature adhesive containing lead oxide is used; When the temperature is 500 to 700 degrees Celsius, a high temperature adhesive containing potassium oxide is used.

In detail, the powder after sieving in a 200mesh sieve in the first step can obtain a ceramic powder having a small particle diameter and having a particle diameter of less than 75 μm. Next, the ceramic powder collected with a powder particle size of less than 75 micrometers is placed in a molding tank, and a thin powder is applied to the bottom bed platform through a three-dimensional powder bonding or glue curing printing process, and then the printing is performed. The nozzle of the machine sprays the glue to glue the required parts together, and then puts a new layer of thin powder, and then sprays the glue again to bond the powder together. Repeating these steps, the objects can be stacked one by one, and the objects are listed. Printing and forming, after the object is printed and formed, the green body is formed through the sintering process, and then the glazing and color drawing process can be performed.

In summary, the present invention does provide a high-strength ceramic powder and a method for preparing the same by using the method, and adding a certain proportion of a high-temperature adhesive to the ceramic powder by physical mixing method, thereby improving the three-dimensional printing object. The strength of the green body is formed after the sintering process.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications of the scope of the invention and the description of the invention are It is still within the scope of the invention patent.

Claims (14)

A high-strength ceramic powder comprising at least feldspar, quartz, a starch adhesive and a high-temperature adhesive, wherein the weight percentage of the feldspar is 24 to 36%, and the weight percentage of the quartz is 38 to 52%. The weight percentage of the starch adhesive is 7 to 15% and the weight percentage of the high temperature adhesive is 3 to 12%. The high-strength ceramic powder according to claim 1, wherein the high-temperature adhesive comprises 10 to 30% by weight of sodium oxide. The high-strength ceramic powder according to claim 2, wherein the high-temperature adhesive further contains 50 to 80% by weight of a cerium-containing compound. The high-strength ceramic powder according to claim 3, wherein the high-temperature adhesive further contains 3 to 10% by weight of calcium oxide and 2 to 10% by weight of magnesium oxide. The high-strength ceramic powder according to claim 1, wherein the high-temperature adhesive comprises 70 to 80% by weight of lead oxide. The high-strength ceramic powder according to claim 5, wherein the high-temperature adhesive further contains 20 to 30% by weight of a cerium-containing compound. The high-strength ceramic powder according to claim 1, wherein the high-temperature adhesive comprises 40 to 60% by weight of potassium oxide. The high-strength ceramic powder according to claim 7, wherein the high-temperature adhesive further contains 40 to 60% by weight of a cerium-containing compound. A ceramic powder having high strength as described in claim 3, 6 or 8, wherein the cerium-containing compound is cerium oxide. A method for preparing a green body by using the high-strength ceramic powder according to claim 1, the method comprising the following steps: Step 1: using a ball mill to make 24 to 36 weight percent of feldspar, 38 to 52 The weight percentage of quartz, 7 to 15 weight percent of the starch adhesive, and 3 to 12 weight percent of the high temperature adhesive are mixed and stirred for 1 hour, and the powder sieved by the 200 mesh sieve is collected, and the powder is high in strength. Ceramic powder; Step 2: printing a high-strength ceramic powder through a three-dimensional powder bonding process to produce a molded article; and Step 3: sintering the molded article into a single embryo through a sintering process. A method for producing a green body of a high-strength ceramic powder according to claim 10, wherein the sintering process has a sintering temperature of 500 to 1200 degrees Celsius. A method for producing a green body of a high-strength ceramic powder according to the invention of claim 11, wherein when the sintering temperature is 800 to 1200 degrees Celsius, a high-temperature adhesive containing sodium oxide is used. A method for producing a green body of a high-strength ceramic powder according to the invention of claim 11, wherein when the sintering temperature is 650 to 850 degrees Celsius, a high-temperature adhesive containing lead oxide is used. A method for producing a green body of a high-strength ceramic powder according to claim 11, wherein when the sintering temperature is 500 to 700 degrees Celsius, a high-temperature adhesive containing potassium oxide is used.