CN111377747A

CN111377747A - Precision casting powder material for 3D printing and preparation method thereof

Info

Publication number: CN111377747A
Application number: CN202010212496.4A
Authority: CN
Inventors: 严生辉; 彭凡; 李天才; 王敏; 张勇
Original assignee: Kocel Intelligent Foundry Industry Innovation Center Co Ltd
Current assignee: Kocel Intelligent Foundry Industry Innovation Center Co Ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2020-07-07

Abstract

The invention relates to a precision casting powder material for 3D printing and a preparation method thereof. The casting powder material comprises, by mass, 82-94 parts of a refractory material, 1-5 parts of a fluxing agent, 1-5 parts of a toughening agent, 2-4 parts of a plasticizer and 2-4 parts of a dispersion reinforcing agent. The invention provides a precision casting powder material for 3D printing and a preparation method thereof, aiming at the problems of various processes, complex material use, poor comprehensive performance, low production efficiency, low shell strength, long manufacturing period and the like in the prior art, so that the successful application of the powder material in the 3D printing precision casting direction is realized, only one composite material with excellent heat dissipation is needed from the prior materials to the present, and the intelligent casting, short period, high efficiency and large-scale production are realized. The powder can be directly printed out into a complex precision casting shell by a 3D printer.

Description

Precision casting powder material for 3D printing and preparation method thereof

Technical Field

The invention relates to the field of 3D printing, in particular to a precision casting powder material for 3D printing and a preparation method thereof.

Background

The 3D printing technology is a novel rapid forming technology, the applied technologies comprise a 3DP ink-jet printing technology, an SLS selective area laser sintering technology, an FDM fusion lamination forming technology and the like, wherein the 3DP technology for printing by using a powder material is wide in application range, the principle of the technology is roughly divided into three steps of droplet spraying, powder particle bonding and solidification forming, in the forming process, powder particles are firstly mixed and stirred with a curing agent, then a layer of powder particle material with fixed thickness is paved, a binder is selectively sprayed on the paved powder particle layer through a spray head, the operation is repeated, the powder particles are overlapped layer by layer, and solidification bonding forming is finally realized, however, the existing three-dimensional printing powder material mainly comprises ceramsite sand, silica sand, thermal method reclaimed sand, gypsum powder and the like, the existing material is single, the existing defect that high mechanical property and heat dissipation performance are difficult to achieve is high, the ceramic type casting is an important method for precision casting, the ceramic type casting is widely applied to traditional industrial production, the casting silica shell manufacturing mainly comprises ① lost casting, the defect that ethyl silicate is prepared by using the ethyl ester, the hydrolysis liquid as a comprehensive wax, the casting, the high-viscosity of the glass slurry, the slurry is used as a comprehensive drying process, the slurry is required to be prepared by a comprehensive drying process, the slurry is low-drying process is used for manufacturing the slurry, the slurry is used for manufacturing of the slurry, the slurry is used for manufacturing the slurry, the slurry is used for manufacturing the slurry, the slurry for manufacturing the casting, the slurry is not used for manufacturing of the slurry, the slurry for manufacturing of the slurry, the slurry for manufacturing the slurry, the casting, the slurry for manufacturing of the slurry for manufacturing the slurry for.

Disclosure of Invention

The invention provides a precision casting powder material for 3D printing and a preparation method thereof, aiming at the problems of various processes, complex material use, poor comprehensive performance, large production field, low production efficiency, low shell strength, long manufacturing period, low automation degree, slow product heat dissipation, large internal defects and the like in the prior art, the successful application of the powder material in the 3D printing precision casting direction is realized, only one composite material with excellent heat dissipation is needed from a plurality of previous materials to the present material, and the intelligent casting, short period, high efficiency and large-scale production are realized.

In order to solve the defects, the invention adopts the technical scheme that:

the casting powder material comprises, by mass, 82-94 parts of a refractory material, 1-5 parts of a fluxing agent, 1-5 parts of a toughening agent, 2-4 parts of a plasticizer and 2-4 parts of a dispersion reinforcing agent.

Further, the refractory material is one or more of 200-600-mesh fused quartz, white corundum, zircon powder and mullite, and the refractoriness of the refractory material is more than 1700 ℃.

Further, the fluxing agent is a metal oxide with 200-600 meshes; the metal oxide comprises one or more of sodium oxide, potassium oxide, magnesium oxide, calcium oxide, zinc oxide, manganese oxide, ferric oxide, nickel oxide, bismuth oxide, copper oxide, cuprous oxide, titanium oxide, beryllium oxide, barium oxide, aluminum oxide and chromium oxide.

Further, the toughening agent is one or more of carbon fiber, nano-silica, nano-clay and glass fiber with 500-2000 meshes, and the particle size of the toughening agent is 1-100 nm.

Further, the plasticizer is 300-600 mesh zinc oxide powder or zinc stearate.

Further, the dispersion reinforcing agent is one or more of carbon black, silicon micropowder, nano titanium dioxide and nano silicon dioxide with 300-600 meshes.

A method for preparing the precision casting powder material for 3D printing as described above, comprising the steps of:

s1: sequentially adding a refractory material, a fluxing agent, a toughening agent, a plasticizer and a dispersing agent into a tank type mixer according to a proportion, and carrying out ball milling for 1-2 h;

s2: drying the ball-milled powder; and filtering after drying.

Further, the ball milling medium of the pot mixer in the S1 is

The zirconia solid spheres of (a); the ratio of the adding mass of the ball milling medium to the prepared powder is 1: 8-1: 20.

Further, the stirring speed of the pot mixer in the S1 is 200-500 r/min.

Further, the drying temperature in the S2 is 90-120 ℃, and the drying time is 2-5 hours.

Compared with the prior art, the method of the invention has the following beneficial effects:

the preparation method successfully prepares the precision casting powder material for 3D printing with low shrinkage and high strength. The cast powder material has a tighter size, a low shrinkage of less than 3% in size and less than 8.7% in volume shrinkage after sintering at 1400 ℃; the casting powder material has excellent heat conduction and heat dissipation, and the cooling and taking-out time of the casting is greatly reduced; the casting powder material is mixed with inorganic resin, and has tensile strength of more than 3MPa and compressive strength of more than 34MPa after being sintered at 1400 ℃, even the highest tensile strength reaches 44.5 MPa; casting powder material can directly print out complicated precision casting's shell through the 3D printer to the application realizes that 3D prints precision casting shell and can promote production efficiency greatly, improves the operational environment.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the accompanying examples. The preferred embodiments of the present invention are given in the examples. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In order to solve the defects, the invention adopts the technical scheme that:

Furthermore, the refractory material is one or more of 200-600-mesh fused quartz, white corundum, zircon powder and mullite, the refractoriness of the refractory material is larger than 1700 ℃, the refractory material has great influence on the dimensional accuracy, surface roughness and internal quality of a casting, and the refractory material except mullite has low dimensional shrinkage, high refractoriness, high thermal shock stability, thermal chemical stability and certain air permeability.

Further, the fluxing agent is a metal oxide with 200-600 meshes; the metal oxide includes sodium oxide (Na)₂O), potassium oxide (K)₂O), magnesium oxide (MgO), calcium oxide (CaO), oxygenZinc oxide (ZnO), manganese oxide (MnO) and ferric oxide (Fe)₂O₃) Nickel oxide (NiO), bismuth trioxide (Bi)₂O₃) Copper oxide (CuO), cuprous oxide (Cu)₂O), titanium oxide (Ti 0)₂) Beryllium oxide (BeO), barium oxide (BaO), aluminum oxide (Al)₂O₃) And chromium oxide (GeO)₂) One or more of them. After the fluxing agent is added, the sintering temperature of the refractory material can be reduced, so that the refractory material is sintered and strengthened at the temperature lower than the self-refractory temperature, the fluxing agent powder and the components in the refractory material are converted to form a certain stable low-temperature phase, the refractory material is endowed with good physical stability and high-temperature strength, and meanwhile, the addition of the fluxing agent has important influence on the improvement of the heat conductivity and heat dissipation performance of the whole product.

Further, the toughening agent is one or more of carbon fiber, nano-silica, nano-clay and glass fiber with 500-2000 meshes, and the particle size of the toughening agent is 1-100 nm. The nano SiO2 and the nano clay can not only initiate silver streaks, but also stop cracks. The nano particles have strong rigidity, and the crack encounters the nano particles to generate sheath direction or deflection when spreading, so that the energy is absorbed to achieve the toughening purpose. The toughening agent is used for refractory materials, and the main principle is that the toughening agent is separated from particles to fill up pores of the refractory materials, so that the toughening and reinforcing effects are achieved. The mesh number is preferably 500-2000 meshes, the mesh number is less than 500 meshes, the particles are large and cannot be filled in pores, the particles exceed 2000 meshes, the powder is light and cannot be filled, and the phenomena of agglomeration and uneven dispersion of the particles are easily caused, so that the product defects are caused.

Further, the plasticizer is 300-600 mesh zinc oxide powder or zinc stearate.

Further, the dispersion reinforcing agent is one or more of carbon black, silicon micropowder, nano titanium dioxide and nano silicon dioxide with 300-600 meshes. Because of the micro ball effect of the carbon black, the friction among particles is reduced, the effect of improving the powder fluidity is achieved, and the powder spreading and forming process is facilitated. Both hydrophilic and hydrophobic carbon blacks can improve the flowability of the powder. The carbon black coats the particle surfaces of the powder, so that surface moisture is absorbed and insulation is formed among the powder particles, thereby preventing the powder from caking. In addition, the carbon black can form a network containing a large number of micropores in the powder, can adsorb and fix sprayed liquid drops, can ensure the penetration and adhesion of the liquid drops, and can shorten the drying time. The content of carbon black is not high enough because it affects the binding property of powder, strength of product, etc. The silicon micropowder is added into the refractory material to form a multi-layer protective layer in oxidation, so that the refractory material has good mechanical property and high-temperature-resistant oxidation resistance, and after the ultrafine silicon micropowder is added into the refractory material, the fluidity, sintering property, bonding property and air hole filling property of the refractory material are improved to different degrees. The structural density and strength are improved, the wear rate of the material is reduced, and the erosion resistance is enhanced.

s2: drying the ball-milled powder; and filtering after drying.

Further, the ball milling medium of the pot mixer in the S1 is

Further, the stirring speed of the pot mixer in the S1 is 200-500 r/min.

The method comprises the following specific implementation steps:

example 1:

(1) the formula of the low-shrinkage high-strength 3D printing precision casting material powder comprises the following components in parts by weight:

(2) the preparation method comprises the following steps:

① mixing 325 mesh zircon powder, 400 mesh CuO flux and nano SiO₂The toughening agent, the 325-mesh zinc oxide plasticizer and the 325-mesh white carbon black dispersing agent are sequentially added into a tank type mixer according to the parts by weight, and the diameters are

The zirconia solid sphere is a ball milling medium, and the adding mass of the ball milling medium and the ratio of the prepared powder are 1:8, setting the stirring speed to 240r/min, and performing ball milling for 1.5h to fully and uniformly mix various powder materials;

② placing the mixed powder in a vacuum drying oven for thermal drying at 110 deg.C for 2 hr, and filtering with 200 mesh screen to obtain the refractory material for printing precision casting.

(3) Test results before and after sintering

The tensile volume of the printed 8-shaped test block is 41.539cm³The compression-resistant test block is a cylinder with the radius of 20mm and the height of 40mm, and the volume is 50.24cm³. By verification, the addition of 8% of the inorganic resin can not only meet the problem of the ink jet amount of the printing head, but also meet the requirement of the initial strength of more than or equal to 1 MPa. All inorganic resins were added in an amount of 8% of the total powder. After being sintered at 1400 ℃, the tensile strength reaches 4.65MPa, and the compressive strength reaches 37.2 MPa. The linear shrinkage is less than 3 percent, and the volume shrinkage is less than 8.7 percent. Specific values are shown in tables 1 and 2.

TABLE 1 comparison table of compressive and tensile strengths of test blocks before and after sintering

	Tensile strength/MPa	Compressive strength/MPa
			At normal temperature	1.196	8.256
After sintering at 1400 DEG C	4.650	37.2

TABLE 2 shrinkage gauge before and after sintering of test block

	Length shrinkage rate	Width shrinkage ratio	High shrinkage rate	Volume shrinkage rate
					Size shrinkage at 1400 DEG C	2.94％	2.81％	2.97％	8.61％

Example 2:

(2) the preparation method comprises the following steps:

① adding 325 mesh white corundum, 400 mesh MgO fluxing agent, 500 mesh carbon fiber toughening agent, 325 mesh zinc oxide plasticizer and 325 mesh cassia powder dispersion reinforcing agent into a tank mixer in sequence according to the parts by weight, wherein the diameter is

The zirconia solid sphere is a ball milling medium, and the adding mass of the ball milling medium and the ratio of the prepared powder are 1: 12, setting the stirring speed to 240r/min, and performing ball milling for 2 hours to fully and uniformly mix various powder materials;

(3) Test results before and after sintering

The tensile volume of the printed 8-shaped test block is 41.539cm³The compression-resistant test block is a cylinder with the radius of 20mm and the height of 40mm, and the volume is 50.24cm³. By verification, the addition of 8% of the inorganic resin can not only meet the problem of the ink jet amount of the printing head, but also meet the requirement of the initial strength of more than or equal to 1 MPa. All inorganic resins were added in an amount of 8% of the total powder. After being sintered at 1400 ℃, the tensile strength reaches 5.21MPa, and the compressive strength reaches 35.8 MPa. The linear shrinkage is less than 2.9%, and the volume shrinkage is less than 7.6%. Specific values are shown in tables 3 and 4.

TABLE 3 comparison table of compression and tensile strengths before and after sintering of test blocks

	Tensile strength/MPa	Compressive strength/MPa
			At normal temperature	1.017	7.924
After sintering at 1400 DEG C	5.21	35.8

TABLE 4 shrinkage gauge before and after sintering of test blocks

	Length shrinkage rate	Width shrinkage ratio	High shrinkage rate	Volume shrinkage rate
					Size shrinkage at 1400 DEG C	2.75％	2.85％	2.43	7.53％

Example 3:

(2) the preparation method comprises the following steps:

① melting quartz of 325 meshes and Bi of 400 meshes₂O₃Adding the fluxing agent, the nano clay toughening agent, the 325-mesh zinc oxide plasticizer and the 325-mesh white carbon black dispersing agent into a tank type mixer in sequence according to the parts by weight, wherein the diameters are

The zirconia solid sphere is a ball milling medium, and the adding mass of the ball milling medium and the ratio of the prepared powder are 1:8, setting the stirring speed to 240r/min, and performing ball milling for 2 hours to fully and uniformly mix various powder materials;

② placing the mixed powder in a vacuum drying oven for thermal drying at 100 deg.C for 2 hr, and filtering with 200 mesh screen to obtain the refractory material for printing precision casting.

(3) Test results before and after sintering

The tensile volume of the printed 8-shaped test block is 41.539cm³The compression-resistant test block is a cylinder with the radius of 20mm and the height of 40mm, and the volume is 50.24cm³. By verification, the addition of 8% of the inorganic resin can not only meet the problem of the ink jet amount of the printing head, but also meet the requirement of the initial strength of more than or equal to 1 MPa. All inorganic resins were added in an amount of 8% of the total powder. After being sintered at 1400 ℃, the tensile strength reaches 4.65MPa, and the compressive strength reaches 34.7 MPa. The linear shrinkage is less than 2 percent, and the volume shrinkage is less than 4.7 percent. Specific values are shown in tables 5 and 6.

TABLE 5 comparison table of compressive and tensile strengths before and after sintering of test blocks

	Tensile strength/MPa	Compressive strength/MPa
			At normal temperature	1.206	7.456
After sintering at 1400 DEG C	4.650	34.7

TABLE 6 shrinkage gauge before and after sintering of test block

	Length shrinkage rate	Width shrinkage ratio	High shrinkage rate	Volume shrinkage rate
					Size shrinkage at 1400 DEG C	1.79％	1.92％	1.87％	4.62％

Example 4:

(2) the preparation method comprises the following steps:

① mixing 325 mesh zircon powder, 325 mesh mullite, 400 mesh CuO fluxing agent and 400 mesh MgO fluxing agent₂The toughening agent, the 325-mesh zinc oxide plasticizer and the 325-mesh silicon micropowder dispersant reinforcing agent 3 are sequentially added into a tank type mixer according to the parts by weight, and the diameters are

The zirconia solid sphere is a ball milling medium, and the adding mass of the ball milling medium and the ratio of the prepared powder are 1:8, setting the stirring speed to 240r/min, and performing ball milling for 2.5 hours to fully and uniformly mix various powder materials;

(3) Test results before and after sintering

The tensile volume of the printed 8-shaped test block is 41.539cm³The compression-resistant test block is a cylinder with the radius of 20mm and the height of 40mm, and the volume is 50.24cm³. By verification, the addition of 8% of the inorganic resin can not only meet the problem of the ink jet amount of the printing head, but also meet the requirement of the initial strength of more than or equal to 1 MPa. All inorganic resins were added in an amount of 8% of the total powder. After being sintered at 1400 ℃, the tensile strength of the material reaches 5.650MPa, and the compressive strength of the material reaches 44.5 MPa. The linear shrinkage is less than 2.7%, and the volume shrinkage is less than 8.1%. Specific values are shown in tables 7 and 8.

TABLE 7 comparison table of compressive and tensile strengths of test blocks before and after sintering

	Tensile strength/MPa	Compressive strength/MPa
			At normal temperature	1.324	9.286
After sintering at 1400 DEG C	5.650	44.5

TABLE 8 shrinkage gauge before and after sintering of test block

	Length shrinkage rate	Width shrinkage ratio	High shrinkage rate	Volume shrinkage rate
					Size shrinkage at 1400 DEG C	2.52％	2.68％	2.56％	8.1％

Example 5:

(2) the preparation method comprises the following steps:

① mixing 325 mesh white corundum, 325 mesh mullite, 400 mesh CuO flux and 400 mesh Na₂Adding the O fluxing agent, the nano clay toughening agent, the 325-mesh zinc oxide plasticizer and the 325-mesh white carbon black dispersing agent into a tank type mixer in sequence according to the parts by weight, wherein the diameters are

The zirconia solid sphere is a ball milling medium, and the adding mass of the ball milling medium and the ratio of the prepared powder are 1: 10, setting the stirring speed to 240r/min, and performing ball milling for 2.5 hours to fully and uniformly mix various powder materials;

(3) Test results before and after sintering

The tensile volume of the printed 8-shaped test block is 41.539cm³The compression-resistant test block is a cylinder with the radius of 20mm and the height of 40mm, and the volume is 50.24cm³. By verification, the addition amount of the inorganic resin is 8The% can not only meet the problem of ink jet quantity of the printing head, but also meet the requirement of initial strength of more than or equal to 1 MPa. All inorganic resins were added in an amount of 8% of the total powder. After being sintered at 1400 ℃, the tensile strength of the material reaches 5.050MPa, and the compressive strength of the material reaches 39.8 MPa. The linear shrinkage is less than 2.7%, and the volume shrinkage is less than 8%. Specific values are shown in tables 9 and 10.

TABLE 9 comparison table of compressive and tensile strengths of test blocks before and after sintering

	Tensile strength/MPa	Compressive strength/MPa
			At normal temperature	1.127	7.856
After sintering at 1400 DEG C	5.050	39.8

TABLE 10 shrinkage gauge before and after sintering of test pieces

	Length shrinkage rate	Width shrinkage ratio	High shrinkage rate	Volume shrinkage rate
					Size shrinkage at 1400 DEG C	2.58％	2.69％	2.68％	7.97％

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The precision casting powder material for 3D printing is characterized by comprising, by mass, 82-94 parts of a refractory material, 1-5 parts of a fluxing agent, 1-5 parts of a toughening agent, 2-4 parts of a plasticizer and 2-4 parts of a dispersion reinforcing agent.

2. The precision casting powder material for 3D printing according to claim 1, wherein the refractory material is one or more of 200-600 mesh fused silica, white corundum, zircon powder and mullite, and the refractoriness of the refractory material is more than 1700 ℃.

3. The precision casting powder material for 3D printing according to claim 1, wherein the flux is a metal oxide of 200-600 mesh; the metal oxide comprises one or more of sodium oxide, potassium oxide, magnesium oxide, calcium oxide, zinc oxide, manganese oxide, ferric oxide, nickel oxide, bismuth oxide, copper oxide, cuprous oxide, titanium oxide, beryllium oxide, barium oxide, aluminum oxide and chromium oxide.

4. The precision casting powder material for 3D printing according to claim 1, wherein the toughening agent is one or more of carbon fiber, nano-silica, nano-clay and glass fiber with 500-2000 meshes.

5. The precision casting powder material for 3D printing according to claim 1, wherein the plasticizer is 300-600 mesh zinc oxide powder or zinc stearate.

6. The precision casting powder material for 3D printing according to claim 1, wherein the dispersion enhancer is one or more of carbon black, silica powder, nano titanium dioxide and nano silica with 300-600 meshes.

7. A method for preparing the precision-cast powder material for 3D printing according to any one of claims 1 to 6, comprising the steps of:

s2: drying the ball-milled powder; and filtering after drying.

8. The method of claim 7The method for preparing the precision casting powder material for 3D printing is characterized in that the ball milling medium of the pot mixer in S1 is

9. The method for preparing a precision casting powder material for 3D printing according to claim 7, wherein the stirring rotation speed of the pot mixer in S1 is 200-500 r/min.

10. The method for preparing the precision casting powder material for 3D printing according to claim 7, wherein the drying temperature in S2 is 90-120 ℃ and the drying time is 2-5 h.