阅读说明：本技术 一种高强度3d打印用覆膜砂的制备方法 (A kind of preparation method of high intensity 3D printing precoated sand ) 是由 丁正颖 于 2019-08-31 设计创作，主要内容包括：本发明涉及一种高强度3D打印用覆膜砂的制备方法,属于覆膜砂材料技术领域。本发明以锆英砂为原砂,并通过硫酸和乙烯基三乙氧基硅烷对其进行表面处理,制备一种高强度3D打印用覆膜砂,经过酸洗后锆英砂砂粒表面的沟槽、孔洞变得清晰,增强了树脂与砂粒表面的机械联结和啮合,促进了树脂与砂粒表面的结合,提高了覆膜砂的强度,硅烷偶联剂是一类在分子中同时含有两种不同化学性质基团的有机硅化合物,乙烯基三乙氧基硅烷在水解后可以与砂粒表面的无机物结合,生成硅氧基,并且能与树脂结合,可以在树脂和砂粒表面建立起类似“桥”、“键”的作用,促进了树脂与砂粒表面的结合,提高了锆英砂覆膜砂的附着断裂强度。(The present invention relates to a kind of preparation methods of high-intensitive 3D printing precoated sand, belong to precoated sand material technical field.The present invention is using zircon sand as roughing sand, and it is surface-treated by sulfuric acid and vinyltriethoxysilane, prepare a kind of high-intensitive 3D printing precoated sand, the groove of zircon sand sand grain surface after overpickling, hole is apparent from, it enhances resin and the mechanical connection of sand grain surface and engages, promote the combination of resin and sand grain surface, improve the intensity of precoated sand, silane coupling agent is a kind of in the molecule while containing there are two types of the organo-silicon compound of different chemical property groups, vinyltriethoxysilane after hydrolyzing can be in conjunction with the inorganic matter of sand grain surface, generate siloxy, and energy and resin-bonded, similar " bridge " can be set up with sand grain surface in resin, the effect of " key ", promote the combination of resin and sand grain surface, improve the attachment breaking strength of zircon sand precoated sand.)

1. a kind of preparation method of high intensity 3D printing precoated sand, which is characterized in that specific preparation step are as follows:

(1) modified Nano carbon fiber, tri hydroxy methyl phenol are added in deionized water, with 800~900r/min revolving speed under room temperature 30~40min is stirred, curing agent suspension is obtained；

(2) curing agent suspension is placed in ultrasonic dispersing machine, 40~60min of ultrasonic disperse under room temperature, obtains curing agent dispersion Liquid；

(3) zircon sand, resin, silicone oil will be modified to be added in sand mixer, 20~30min is preheated under conditions of 120~140 DEG C, It is blended 2~4min with 120~160r/min revolving speed, obtains zircon sand mixture；

(4) solidification agent dispersing liquid, stearic amide are added in zircon sand mixture, are cooled to 100~120 DEG C, with 180~ 200r/min revolving speed is blended 1~2min, obtains mixture；

(5) it discharges after mixture being cooled to 60~70 DEG C, is placed in crusher and is crushed 2~4h, room temperature cooling, screening obtains high Intensity 3D printing precoated sand.

2. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 1, which is characterized in that described Modified zircon sand, modified Nano carbon fiber, dcpd resin, tri hydroxy methyl phenol, stearic amide, silicone oil, deionization The parts by weight of water are 80~100 parts of modified zircon sands, 0.8~1.0 part of modified Nano carbon fiber, 4~5 parts of dicyclopentadiene trees Rouge, 16~20 parts of tri hydroxy methyl phenols, 8~10 parts of stearic amides, 4~5 parts of silicone oil, 32~40 parts of deionized waters.

3. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 1, which is characterized in that step (2) power of the ultrasonic disperse described in is 400~500W.

4. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 1, which is characterized in that step (1) the specific preparation step of the modified Nano carbon fiber described in are as follows:

(1) nitric acid, hydrogen peroxide, (beta-methoxy ethyoxyl) silane of vinyl three are added in deionized water, under room temperature with 180~ 200r/min revolving speed stirs 10~12min, obtains modification liquid；

(2) carbon nano-fiber is added in modification liquid, with the stirring of 600~800r/min revolving speed under 40~50 DEG C of water bath condition 4~8h obtains suspension；

(3) suspension is placed in ultrasonic dispersing machine, 30~40min of ultrasonic disperse under room temperature obtains dispersion liquid；

(4) dispersion liquid is placed in a centrifuge, 15~20min is centrifugated with 3500~4000r/min revolving speed under room temperature, is removed Layer solid, is washed with deionized 3~5 times, is placed in 80~90 DEG C of baking oven dry 1~2h, obtains modified Nano carbon fiber.

5. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 4, which is characterized in that described Carbon nano-fiber, nitric acid, hydrogen peroxide, vinyl three (beta-methoxy ethyoxyl) silane, deionized water parts by weight be 20~30 Nitric acid, 20~30 parts of hydrogen peroxide, 4~6 parts of three (beta-methoxys of vinyl of part carbon nano-fiber, 40~60 parts of mass concentrations 20% Ethyoxyl) silane, 80~120 parts of deionized waters.

6. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 4, which is characterized in that step (3) power of the ultrasonic disperse described in is 300~400W.

7. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 4, which is characterized in that step (4) 40~60nm of modified Nano carbon fiber average grain diameter described in.

8. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 1, which is characterized in that step (3) the specific preparation step of the modification zircon sand described in are as follows:

(1) by vinyltriethoxysilane be added deionized water in, under room temperature with 180~200r/min revolving speed stirring 12~ 16min obtains silane treatment liquid；

(2) zircon sand is added in sulfuric acid, 1~2h is stirred with 200~240r/min revolving speed under room temperature, filtering takes solid, obtains sour Handle zircon sand；

(3) acid processing zircon sand is added in silane treatment liquid, is turned under 40~60 DEG C of water bath condition with 300~360r/min Fast 40~60min of stir process, heat preservation stand 2~4h, and filtering takes solid, obtains surface treatment zircon sand；

(4) surface treatment zircon sand is washed with deionized 3~5 times, then is placed in 60~80 DEG C of baking oven dry 2~4h, Zircon sand must be modified.

9. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 8, which is characterized in that described Zircon sand, sulfuric acid, vinyltriethoxysilane, the parts by weight of deionized water are 30~40 parts of zircon sands, 120~160 parts of matter Measure sulfuric acid, 6~8 parts of vinyltriethoxysilane, 120~160 parts of deionized waters of concentration 20%.

10. a kind of preparation method of high-intensitive 3D printing precoated sand according to claim 8, which is characterized in that step (4) 0.1~0.2mm of average grain diameter of the modification zircon sand described in.

Technical field

The present invention relates to a kind of preparation methods of high-intensitive 3D printing precoated sand, belong to precoated sand material technical field.

Background technique

The basic principle of the appearance of overlay film sand mold (core) laser 3D printing technology is: firstly, building with 3D sculpting software The three-dimensional CAD model of vertical sand mold (core) carries out slicing treatment to CAD prototype using delamination software, to obtain each layer of section Profile and data mart modeling information, laser scanning system will carry out scanning work in an orderly manner according to the electrical signal information of its conversion；Its It is secondary, it is laid with one layer of precoated sand prepared in advance on sintering workbench, the scanning system of molding equipment is defeated according to computer Data information out controls laser beam and carries out selective laser sintering, the tree on precoated sand surface to precoated sand on specified path Adipose membrane melted by heating simultaneously generates bonding, and the precoated sand without being scanned still is presented original natural loose condition (of surface) and takes on branch Support effect；Finally, successively powdering, successively sintering, moves in circles, until completing the scanning work of all processing levels, is covered Film sand mold (core) is sintered prototype.The high-quality hot investment casting that large-scale complex thin-wall single-casting may be implemented in the technology provides Good technological approaches has, it can be achieved that prepared by the whole precision of complicated overlay film sand mold (core) not by part geometry shape Limitation, the characteristics of being not required to any moulds of industrial equipment, directly can convert physical prototypes part for CAD model in a relatively short period of time. Therefore, in recent years, large quantities of scholars have carried out many research work for this technology, and obtain great scientific achievement.

But due to the distinctive forming mode of laser 3D printing technology and technology characteristics, the technology is to precoated sand Material property also has special requirement, so that preparation process, the forming process and post-processing of overlay film sand mold of entire precoated sand Process there is also some problems.Such as: the selection of additive and its content problem in precoated sand preparation process, in forming process at The strength problem of type part, the influence etc. of holding temperature and heat preservation duration to overlay film sand mold in last handling process.These problems To seriously restrict overall surface quality, dimensional accuracy and its mechanical property etc. of precoated sand sand mold (core), while Constrain the promotion and application of this technology.

Summary of the invention

The technical problems to be solved by the invention: for the low problem of existing laser sintered part initial strength, one is provided The preparation method of the high-intensitive 3D printing precoated sand of kind.

In order to solve the above technical problems, the technical solution adopted by the present invention is that:

(1) modified Nano carbon fiber, tri hydroxy methyl phenol are added in deionized water, with 800~900r/min revolving speed under room temperature 30~40min is stirred, curing agent suspension is obtained；

(2) curing agent suspension is placed in ultrasonic dispersing machine, 40~60min of ultrasonic disperse under room temperature, obtains curing agent dispersion Liquid；

(3) zircon sand, resin, silicone oil will be modified to be added in sand mixer, 20~30min is preheated under conditions of 120~140 DEG C, It is blended 2~4min with 120~160r/min revolving speed, obtains zircon sand mixture；

(4) solidification agent dispersing liquid, stearic amide are added in zircon sand mixture, are cooled to 100~120 DEG C, with 180~ 200r/min revolving speed is blended 1~2min, obtains mixture；

(5) it discharges after mixture being cooled to 60~70 DEG C, is placed in crusher and is crushed 2~4h, room temperature cooling, screening obtains high Intensity 3D printing precoated sand.

The modification zircon sand, modified Nano carbon fiber, dcpd resin, tri hydroxy methyl phenol, stearic acid acyl Amine, silicone oil, deionized water parts by weight be 80~100 parts of modified zircon sands, 0.8~1.0 part of modified Nano carbon fiber, 4~5 parts Dcpd resin, 16~20 parts of tri hydroxy methyl phenols, 8~10 parts of stearic amides, 4~5 parts of silicone oil, 32~40 parts go from Sub- water.

The power of ultrasonic disperse described in step (2) is 400~500W.

The specific preparation step of modified Nano carbon fiber described in step (1) are as follows:

(1) nitric acid, hydrogen peroxide, (beta-methoxy ethyoxyl) silane of vinyl three are added in deionized water, under room temperature with 180~ 200r/min revolving speed stirs 10~12min, obtains modification liquid；

(2) carbon nano-fiber is added in modification liquid, with the stirring of 600~800r/min revolving speed under 40~50 DEG C of water bath condition 4~8h obtains suspension；

(3) suspension is placed in ultrasonic dispersing machine, 30~40min of ultrasonic disperse under room temperature obtains dispersion liquid；

(4) dispersion liquid is placed in a centrifuge, 15~20min is centrifugated with 3500~4000r/min revolving speed under room temperature, is removed Layer solid, is washed with deionized 3~5 times, is placed in 80~90 DEG C of baking oven dry 1~2h, obtains modified Nano carbon fiber.

The carbon nano-fiber, nitric acid, hydrogen peroxide, vinyl three (beta-methoxy ethyoxyl) silane, deionized water Parts by weight are nitric acid, 20~30 parts of hydrogen peroxide, 4~6 parts of 20~30 parts of carbon nano-fibers, 40~60 parts of mass concentrations 20% Vinyl three (beta-methoxy ethyoxyl) silane, 80~120 parts of deionized waters.

The power of ultrasonic disperse described in step (3) is 300~400W.

40~60nm of modified Nano carbon fiber average grain diameter described in step (4).

The specific preparation step of modification zircon sand described in step (3) are as follows:

(1) by vinyltriethoxysilane be added deionized water in, under room temperature with 180~200r/min revolving speed stirring 12~ 16min obtains silane treatment liquid；

(2) zircon sand is added in sulfuric acid, 1~2h is stirred with 200~240r/min revolving speed under room temperature, filtering takes solid, obtains sour Handle zircon sand；

(3) acid processing zircon sand is added in silane treatment liquid, is turned under 40~60 DEG C of water bath condition with 300~360r/min Fast 40~60min of stir process, heat preservation stand 2~4h, and filtering takes solid, obtains surface treatment zircon sand；

(4) surface treatment zircon sand is washed with deionized 3~5 times, then is placed in 60~80 DEG C of baking oven dry 2~4h, Zircon sand must be modified.

The zircon sand, sulfuric acid, vinyltriethoxysilane, the parts by weight of deionized water are 30~40 parts of zirconium English Sand, the sulfuric acid of 120~160 parts of mass concentrations 20%, 6~8 parts of vinyltriethoxysilane, 120~160 parts of deionized waters.

0.1~0.2mm of average grain diameter of modification zircon sand described in step (4).

The present invention is compared with other methods, and advantageous effects are:

(1) present invention is using zircon sand as roughing sand, and is surface-treated by sulfuric acid and vinyltriethoxysilane to it, makes A kind of standby high-intensitive 3D printing precoated sand, it is the mineral mainly formed, pickling processes that zircon sand, which is a kind of silicate with zirconium, The pollutant of mud part and sand grain surface contained in zircon sand, especially alkaline pollutant can be cleared up, sand grain surface is become It is cleaner, improve the wetting ability with resin, is conducive to the combination of zircon sand and resin, the zircon sand sand grain surface after overpickling Groove, hole be apparent from, this increases the contact area of resin and sand grain surface, and resin easily penetrates into sand grain surface Groove, in hole, enhance resin and the mechanical connection of sand grain surface and engage, promote the knot of resin and sand grain surface It closes, improves the intensity of precoated sand, also, zircon sand sand grain surface is thoroughly protonated or activated in acid cleaning process, sand grains Surface Creation is conducive to the reactive group bonded between resin and sand grains, promotes the combination of resin and sand grain surface, mentions The high intensity of precoated sand, silane coupling agent be it is a kind of contain simultaneously in the molecule there are two types of different chemical property groups organosilicon Compound, vinyltriethoxysilane can generate siloxy, and energy in conjunction with the inorganic matter of sand grain surface after hydrolyzing With resin-bonded, the effect of similar " bridge ", " key " can be set up with sand grain surface in resin, promotes resin and sand grain surface Combination, improve the attachment breaking strength of zircon sand precoated sand；

(2) present invention prepares a kind of high-intensitive 3D printing precoated sand by addition modified Nano carbon fiber, and carbon nano-fiber is High-performance fiber shape nanometer prepared by being carbonized at a high temperature of 1000 DEG C or more as organic fiber or low molecular hydrocarbons gas raw material Carbon materials, after there are the excellent performances such as light weight, high temperature resistant, high-modulus, high intensity, carbon nano-fiber to pass through nitric acid treatment, Surface adhesion a certain amount of basis material, nitric acid oxidation effect under, surface produces a large amount of grooves, increases nano-sized carbon The specific surface area and surface roughness of fiber form more carboxyl, hydroxyl and acidic groups isoreactivity group on surface, have Conducive to and precoated sand combination, so as to effectively improve the initial strength of precoated sand, vinyl three (beta-methoxy ethyoxyl) silicon Alkane is a kind of containing there are two types of the coupling agent of heterogeneity functional group, with (beta-methoxy ethyoxyl) silane of vinyl three to carbon fiber into Row surface coated treatment, a part of functional group can be in conjunction with the groups such as the carboxyl of carbon fiber surface, hydroxyl, another part function Group can provide biggish contact area with the resin-bonded in precoated sand again, more conducively and the combination of precoated sand, can be effective Improve the intensity of precoated sand.

Specific embodiment

According to parts by weight, 30~40 parts of zircon sands, the sulfuric acid of 120~160 parts of mass concentrations 20%, 6~8 are weighed respectively Part vinyltriethoxysilane, 120~160 parts of deionized waters, vinyltriethoxysilane are added in deionized water, often Under temperature with 180~200r/min revolving speed stir 12~16min, obtain silane treatment liquid, by zircon sand be added sulfuric acid in, under room temperature with 200~240r/min revolving speed stirs 1~2h, and filtering takes solid, obtains sour processing zircon sand, silane is added in acid processing zircon sand In treatment fluid, with 300~360r/min revolving speed 40~60min of stir process under 40~60 DEG C of water bath condition, heat preservation stands 2 ~4h, filtering, takes solid, obtains surface treatment zircon sand, and surface treatment zircon sand is washed with deionized 3~5 times, then is placed in Dry 2~4h, obtains the modification zircon sand of 0.1~0.2mm of average grain diameter in 60~80 DEG C of baking oven；Again according to parts by weight, divide Also known as measure nitric acid, 20~30 parts of hydrogen peroxide, 4~6 parts of second of 20~30 parts of carbon nano-fibers, 40~60 parts of mass concentrations 20% Alkenyl three (beta-methoxy ethyoxyl) silane, 80~120 parts of deionized waters, by nitric acid, hydrogen peroxide, (the beta-methoxy second of vinyl three Oxygroup) silane be added deionized water in, under room temperature with 180~200r/min revolving speed stir 10~12min, obtain modification liquid, will receive Rice carbon fiber is added in modification liquid, stirs 4~8h under 40~50 DEG C of water bath condition with 600~800r/min revolving speed, obtains outstanding Suspension is placed in ultrasonic dispersing machine by supernatant liquid, with power 30~40min of ultrasonic disperse of 300~400W, score under room temperature Dispersion liquid is placed in a centrifuge by dispersion liquid, is centrifugated 15~20min under room temperature with 3500~4000r/min revolving speed, is taken lower layer Solid is washed with deionized 3~5 times, is placed in 80~90 DEG C of baking oven dry 1~2h, obtains 40~60nm's of average grain diameter Modified Nano carbon fiber；Again according to parts by weight, 80~100 parts of modified zircon sands, 0.8~1.0 part of modified Nano are weighed respectively Carbon fiber, 4~5 parts of dcpd resins, 16~20 parts of tri hydroxy methyl phenols, 8~10 parts of stearic amides, 4~5 parts of silicon Modified Nano carbon fiber, tri hydroxy methyl phenol are added in deionized water for oil, 32~40 parts of deionized waters, under room temperature with 800~ 900r/min revolving speed stirs 30~40min, obtains curing agent suspension, curing agent suspension is placed in ultrasonic dispersing machine, often With power 40~60min of ultrasonic disperse of 400~500W under temperature, solidification agent dispersing liquid is obtained, by modified zircon sand, resin, silicone oil It is added in sand mixer, 20~30min is preheated under conditions of 120~140 DEG C, 2 are blended with 120~160r/min revolving speed~ 4min obtains zircon sand mixture, and solidification agent dispersing liquid, stearic amide are added in zircon sand mixture, it is cooled to 100~ 120 DEG C, 1~2min is blended with 180~200r/min revolving speed, obtains mixture, discharges, sets after mixture is cooled to 60~70 DEG C 2~4h, room temperature cooling are crushed in crusher, screening obtains high-intensitive 3D printing precoated sand.