Post-treatment method for selective laser sintering precoated sand

Abstract

The invention relates to a post-processing method for selective laser sintering precoated sand, which is characterized in that supports are added to easily-broken parts and easily-deformed parts of a laser sintering model, so that the probability of deformation, cracking, collapse and the like in the laser sintering process is reduced, and the sintering success rate is increased. And through primary sand removal and deep sand removal, it can be ensured that the forming quality of the precoated sand laser sintering sand mold after heating and curing is high. And deep sand cleaning is conducted on the surrounding area of the sand cleaning platform, the cleanliness of the working area is guaranteed, falling is prevented, and the working safety is improved. And surface baking is conducted on the easily-damaged part of the precoated sand laser sintering sand mold, and damage to the surface of the precoated sand laser sintering sand mold caused by deep sand removal can be effectively reduced. And the precoated sand laser sintering sand mold is heated and cured, and the overall strength of the precoated sand laser sintering sand mold is improved. And the heated and cured precoated sand laser sintering sand mold is subjected to surface inspection and defect repair, so that the forming quality of the precoated sand laser sintering sand mold is better, and the casting success rate and the forming quality are effectively improved.

Description

Technical Field

[0001] The invention relates to the technical field of additive manufacturing, and in particular to a post-processing method for laser selected roast chicken coated sand. Background Art

[0002] Laser selective sintering coated sand has a wide range of applications and significant advantages in the current manufacturing industry. Laser sintering coated sand is an advanced molding technology that combines selective laser sintering (SLS) technology and precision casting technology. It can produce sand cores with clear contours and complex shapes, and has excellent fluidity, surface quality and collapsibility.

[0003] Laser sintering coated sand post-processing is an indispensable part of the manufacturing process and is crucial to improving the performance and quality of sintered parts. However, traditional laser sintering coated sand post-processing still has problems such as easy deformation and damage of parts due to the residual stress generated by part structure and laser sintering, resulting in low sintering success rate and low molding quality. Summary of the invention

[0004] Based on this, it is necessary to provide a laser selective sintering coated sand post-processing method that can improve the sintering success rate and molding quality.

[0005] A post-processing method for laser selective sintering coated sand, comprising the steps of:

[0006] Adding support to the easily fractured parts and easily deformed parts of the laser sintered model according to the structure and shape of the laser sintered model;

[0007] Laser sintering printing is performed according to the laser sintering model after adding support to obtain a coated sand laser sintering sand mold;

[0008] Preliminary sand cleaning is performed on the coated sand laser sintering sand mold to remove the coated sand remaining on the surface of the coated sand laser sintering sand mold;

[0009] Surface baking is performed on the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning;

[0010] Deeply cleaning the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform after surface baking;

[0011] The coated sand laser sintering sand mold is heated to 180° C. to 200° C. by means of segmented heating, and kept warm for 4 h to 10 h;

[0012] Cooling the coated sand laser sintering sand mold after heat preservation to room temperature along with the furnace;

[0013] Performing a surface inspection on the cooled coated sand laser sintering sand mold;

[0014] If there is repairable damage on the coated sand laser sintering sand mold, the damaged part of the coated sand laser sintering sand mold is locally repaired.

[0015] In one of the embodiments, the step of performing preliminary sand cleaning on the coated sand laser sintering sand mold is: manually cleaning the coated sand on the surface of the coated sand laser sintering sand mold using a soft brush or a handheld fan.

[0016] In one of the embodiments, the step of deep sand cleaning the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform after preliminary sand cleaning is: using a vacuum cleaner to vacuum the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform.

[0017] In one of the embodiments, the step of baking the easily damaged parts of the coated sand laser sintering sand mold while deep sand cleaning is: while deep sand cleaning, use a spray gun, a blowtorch or a high-temperature hot air gun to bake the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning.

[0018] In one embodiment, before the step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping it warm for a first preset time period by means of segmented heating, the steps further include: providing a box; placing the sintering sand mold and an appropriate amount of glass beads in the box, and burying the sintering sand mold in the glass beads; placing the box containing the coated sand laser sintering sand mold and the glass beads in a heat treatment oven;

[0019] The step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping it warm for a first preset time period by means of segmented heating is as follows: using the heat treatment oven to segmentally heat the box containing the coated sand laser sintering sand mold and the glass beads until the surface temperature of the laser sintering model reaches 180°C to 200°C, and keeping it warm for 4h to 10h.

[0020] In one embodiment, the particle size of the glass beads is 0.4 mm to 0.6 mm.

[0021] In one embodiment, the step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping the temperature for a first preset time period by means of segmented heating includes:

[0022] The coated sand laser sintering sand mold after deep sand cleaning is heated to 98°C to 105°C for the first time at a heating rate of 48°C / h to 52°C / h, and kept warm for 28min to 33min;

[0023] The coated sand laser sintering sand mold after the first heating is heated for a second time to 180° C. to 200° C. at a heating rate of 48° C. / h to 52° C. / h, and kept warm for 4 h to 10 h.

[0024] In one embodiment, the step of cooling the coated sand laser sintering sand mold to room temperature after heat preservation includes:

[0025] The heated coated sand laser sintering sand mold is first cooled to 95° C. to 105° C. with the furnace, and kept warm for 28 min to 35 min;

[0026] The coated sand laser sintering sand mold after the first furnace cooling is then cooled to 46°C to 55°C for the second time and kept at this temperature for 28min to 35min;

[0027] The coated sand laser sintering sand mold after the second furnace cooling is furnace cooled to room temperature for the third time.

[0028] In one of the embodiments, after the step of locally repairing the damaged part of the coated sand laser sintering sand mold, the method further includes: returning to perform the surface inspection step;

[0029] After the step of locally repairing the damaged parts of the coated sand laser sintering sand mold, the method further includes: if the coated sand laser sintering sand mold has no surface defects after cooling, the coated sand laser sintering sand mold is stored in a dry environment away from light.

[0030] In one embodiment, before the step of storing the coated sand laser sintering sand mold in a dark place, the method further comprises:

[0031] Using a double-layer packaging bag to seal and package the coated sand laser sintering sand mold;

[0032] Marking the sand mold information and storage information of the coated sand laser sintering sand mold on the double-layer packaging bag; and / or

[0033] After the step of storing the coated sand laser sintering sand mold in a dry environment away from light, the method further includes:

[0034] When the storage time is greater than or equal to the preset storage time, performing a surface inspection on the coated sand laser sintering sand mold;

[0035] If there is a problem on the surface of the coated sand laser sintering sand mold, determine whether the defect of the coated sand laser sintering sand mold can be repaired;

[0036] If yes, locally repair the defects of the coated sand laser sintering sand mold;

[0037] If not, the coated sand laser sintering sand mold is cleaned out for destruction or recycling;

[0038] Record the defects of the coated sand laser sintering sand mold and the results of handling the defects.

[0039] The above-mentioned post-processing method for laser selective sintering coated sand, by adding support to the easily broken and easily deformed parts of the laser sintering model, helps to reduce the probability of deformation, cracking, collapse, etc. during the laser sintering process, so as to improve the sintering success rate. Preliminary sand cleaning and deep sand cleaning are performed to ensure the cleanliness of the coated sand laser sintering sand mold before heating and curing, and to ensure that the molding quality of the coated sand laser sintering sand mold after heating and curing is high. By performing deep sand cleaning on the surrounding area of ​​the sand cleaning platform, the cleanliness of the working area is ensured, the staff is prevented from falling, and the work safety is improved. Before deep sand cleaning, the easily damaged parts of the coated sand laser sintering sand mold are surface baked to improve the surface strength of the coated sand laser sintering sand mold, which can effectively reduce the damage to the surface of the coated sand laser sintering sand mold caused by sand cleaning, so as to further improve the molding quality of the coated sand laser sintering sand mold. By heating, keeping warm, and cooling the coated sand laser sintering sand mold in sections, the coated sand laser sintering sand mold can be heated and solidified, and the overall strength of the coated sand laser sintering sand mold can be improved, so as to further improve the molding quality of the coated sand laser sintering sand mold. The coated sand laser sintering sand mold after heating and solidification is inspected on the surface and defects are repaired to further improve the molding quality of the coated sand laser sintering sand mold. Therefore, the use of the above-mentioned laser selective sintering coated sand post-processing method effectively improves the casting success rate and molding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0041] Figure 1 It is a schematic flow chart of a post-processing method of laser selective sintering coated sand in a preferred embodiment of the present invention;

[0042] Figure 2 for Figure 1 The schematic flow chart of step S60-1 and step S60-2 added before step S60 in the post-processing method of laser selective sintering coated sand is shown;

[0043] Figure 3 for Figure 1 The schematic flow chart of step S60 in the post-processing method of laser selective sintering coated sand is shown;

[0044] Figure 4 for Figure 1 The schematic flow chart of step S70 in the post-processing method of laser selective sintering coated sand is shown;

[0045] Figure 5 for Figure 1 The schematic flow chart of step S101 and step S102 added before the step of storing the coated sand laser sintered sand mold in a dark place in the post-processing method of the coated sand by laser selective sintering is shown;

[0046] Figure 6 for Figure 1 The flowchart shown is a schematic diagram of steps S103 to S107 added after the step of storing the coated sand laser sintered sand mold in a dark place in the post-processing method of laser selective sintering coated sand. DETAILED DESCRIPTION

[0047] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0049] When describing positional relationships, unless otherwise specified, when an element is referred to as being "on" another element, it can be directly on the other element or there can be an intermediate element. It is also understood that when an element is referred to as being "between" two elements, it can be the only one between the two elements, or there can be one or more intermediate elements.

[0050] In the case of using “including”, “having”, and “comprising” described herein, another component may be added unless a clear limiting term such as “only”, “consisting of”, etc. is used. Unless mentioned otherwise, a term in the singular form may include a plural form and should not be understood as being one in number.

[0051] See also Figure 1 The post-processing method of laser selective sintering coated sand in a preferred embodiment of the present invention includes steps S10 to S90.

[0052] Step S10, adding support to the easily fractured parts and easily deformed parts of the laser sintered model according to the structure and shape of the laser sintered model.

[0053] Step S20, performing laser sintering printing according to the laser sintering model after adding supports to obtain a coated sand laser sintering sand mold.

[0054] The above-mentioned coated sand laser sintering sand mold is obtained by using coated sand material as printing material and performing laser sintering printing according to the laser sintering model after adding support.

[0055] Step S30, preliminary sand cleaning is performed on the coated sand laser sintering sand mold to remove the coated sand remaining on the surface of the coated sand laser sintering sand mold. It should be noted that when performing step S30, it is necessary to operate carefully to avoid damaging the coated sand laser sintering sand mold.

[0056] Specifically, the coated sand on the surface of the coated sand laser sintering sand mold is manually cleaned by using a soft brush. Because the soft brush is relatively soft, it is not easy to damage the coated sand laser sintering sand mold when brushing the coated sand on the surface of the coated sand laser sintering sand mold.

[0057] Step S40, surface baking is performed on the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning.

[0058] Specifically, a spray gun, a blowtorch or a high-temperature hot air gun is used to bake the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning. A spray gun, a blowtorch or a high-temperature hot air gun can locally bake the surface of the easily damaged parts on the Jigang sintering sand mold, which is easy to operate.

[0059] Step S50, deep sand cleaning is performed on the concave parts of the coated sand laser sintering sand mold after surface baking and the surrounding area of ​​the sand cleaning platform. The concave parts of the coated sand laser sintering sand mold refer to the inaccessible gaps, grooves and other parts on the coated sand laser sintering sand mold that are not easy to clean with the coated sand.

[0060] Specifically, a vacuum cleaner is used to vacuum the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform, so as to achieve the purpose of deep sand cleaning of the inaccessible parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform.

[0061] Of course, in other embodiments, compressed air guns, sand cleaning platform equipment, etc. can also be used to perform sand cleaning on the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform.

[0062] Step S60, heating the coated sand laser sintering sand mold to 180°C to 200°C by segmented heating, and keeping the temperature for 4h to 10h. In practical applications, the holding time can be selected according to the size of the coated sand laser sintering sand mold. The larger the coated sand laser sintering sand mold, the longer the holding time selected.

[0063] Step S70, cooling the heat-insulated coated sand laser sintering sand mold to room temperature along with the furnace.

[0064] Step S80, performing a surface inspection on the cooled coated sand laser sintering sand mold, wherein the surface inspection items include the integrity, dimensional accuracy and surface quality of the coated sand laser sintering sand mold.

[0065] Step S90: If there is repairable damage on the coated sand laser sintering sand mold, locally repair the damaged part of the coated sand laser sintering sand mold.

[0066] Specifically, the damaged parts are filled, repaired, compacted and baked using the same type of coated sand material as the coated sand laser sintering sand mold to ensure that the filled part is tightly combined with the original sand mold.

[0067] In the above-mentioned laser sintering coated sand post-processing method, executing step S10 helps to reduce the probability of deformation, cracking, collapse, etc. occurring during the laser sintering process of executing step S20, so as to improve the sintering success rate.

[0068] By executing step S30 and step S50, the coated sand attached to the surface of the laser sintering model and the coated sand in the unreachable parts of the laser sintering model are removed, so as to ensure the cleanliness of the coated sand laser sintering sand mold before heating and curing, and ensure that the molding quality of the coated sand laser sintering sand mold after heating and curing is high. By executing step S50, the surrounding area of ​​the sand cleaning platform is deeply cleaned to ensure the cleanliness of the working area, prevent workers from falling, and improve work safety.

[0069] By executing step S40, the easily damaged parts on the laser sintering model are surface baked before deep sand cleaning to improve the surface strength of the coated sand laser sintering sand mold, which can effectively reduce the damage to the surface of the coated sand laser sintering sand mold caused by sand cleaning, and further improve the molding quality of the coated sand laser sintering sand mold. By executing steps S60 and S70, the coated sand laser sintering sand mold is heated and solidified, and the overall strength of the coated sand laser sintering sand mold is improved to further improve the molding quality of the coated sand laser sintering sand mold. By executing steps S80 and S90, the coated sand laser sintering sand mold after heating and solidification is inspected on the surface and defects are repaired to further improve the molding quality of the coated sand laser sintering sand mold.

[0070] Therefore, the use of the above-mentioned laser selective sintering coated sand post-processing method can effectively improve the casting success rate and molding quality.

[0071] Please also read Figure 2 In some embodiments, before step S60, steps S60-1 to S60-3 are also included.

[0072] Step S60-1, providing a box, wherein the box is made of a material that is resistant to high temperatures and has good thermal conductivity.

[0073] Step S60-2, putting the coated sand laser sintering sand mold and an appropriate amount of glass beads into the box, and filling the coated sand laser sintering sand mold in the glass beads. Specifically, the particle size of the glass beads is 0.4 mm to 0.6 mm.

[0074] Step S60-3, placing the box containing the coated sand laser sintering sand mold and the glass beads in a heat treatment oven.

[0075] Step S60 is: using a heat treatment oven to heat the box containing the coated sand laser sintering sand mold and glass beads in sections until the surface temperature of the laser sintering model reaches 180° C. to 200° C., and keep it warm for 4 h to 10 h.

[0076] In this way, by executing steps S60-1 to S60-3, glass beads of appropriate particle size are used as filling materials, and the coated sand sintering sand mold is completely buried in an appropriate amount of glass beads and filled tightly to reduce the risk of deformation of the coated sand laser sintering sand mold during the execution of step S60, improve the curing strength, and enable the coated sand laser sintering sand mold to achieve better curing effect, ultimately improving the casting success rate and molding quality.

[0077] Please also read Figure 3 In some embodiments, step S60 includes step S61 and step S62.

[0078] Step S61, heating the coated sand laser sintering sand mold after deep sand cleaning to 98°C to 105°C for the first time at a heating rate of 48°C / h to 52°C / h, and keeping the temperature for 28min to 33min.

[0079] Step S62, heating the coated sand laser sintering sand mold after the first heating to 180°C to 200°C at a heating rate of 48°C / h to 52°C / h for a second time, and keeping the temperature for 4h to 10h.

[0080] By executing step S61 and step S62, segmented heating of the coated sand laser sintering sand mold is achieved. Moreover, during the heating and curing process, if the heating is too fast, the temperature difference between the inside and outside of the coated sand laser sintering sand mold may be too large, thereby generating thermal stress, and the length of the insulation time directly affects the organizational structure and performance of the coated sand laser sintering sand mold. Therefore, the heating rates in step S61 and step S62 are both 48℃ / h~52℃ / h, so as to reduce the temperature difference between the inside and outside of the coated sand laser sintering sand mold during the heating process, reduce the probability of generating thermal stress, and first heat the coated sand laser sintering sand mold to 98℃~105℃ and keep it warm for 28min~33min, and then heat the coated sand laser sintering sand mold to 180℃~200℃ and keep it warm for 4h~10h, so as to ensure that the coated sand laser sintering model can obtain a better heating and curing effect.

[0081] Please also read Figure 4 In some embodiments, step S70 includes steps S71 to S73.

[0082] Step S71, cooling the heated coated sand laser sintering sand mold to 95°C to 105°C for the first time with the furnace, and keeping the temperature for 28min to 35min.

[0083] Step S72, cooling the coated sand laser sintering sand mold after the first furnace cooling to 46°C to 55°C for the second time, and keeping it warm for 28min to 35min.

[0084] Step S73, cooling the coated sand laser sintering sand mold after the second furnace cooling to room temperature for the third time.

[0085] By executing steps S71 to S73, segmented cooling of the coated sand laser sintering sand mold is achieved, thereby achieving a better heating and curing effect of the coated sand laser sintering sand mold.

[0086] In some embodiments, before step S90, the process also includes: returning to execute step S80.

[0087] After step S80, the method further includes: if the coated sand laser sintering sand mold has no surface defects, storing the coated sand laser sintering sand mold in a dry environment away from light.

[0088] That is, after executing step S90, it is necessary to return to execute step S80 to re-inspect the surface of the coated sand laser sintering sand mold after local repair. If the coated sand laser sintering sand mold has no surface problems, the coated sand laser sintering model is stored in a dry environment away from light; if the coated sand laser sintering sand mold still has surface problems, continue to execute step S90.

[0089] In practical applications, the coated sand laser sintering sand mold obtained after the above steps S10 to S90 can be stored in a dry environment away from light to reduce the probability of dimensional changes in the coated sand laser sintering sand mold during storage.

[0090] Please also read Figure 5 In some embodiments, before the step of storing the coated sand laser sintering sand mold in a dark place, step S101 and step S102 are also included.

[0091] Step S101: using a double-layer packaging bag to seal and package the coated sand laser sintering sand mold.

[0092] Step S102, marking the sand mold information and storage information of the coated sand laser sintering sand mold on the double-layer packaging bag.

[0093] In step S101, the coated sand laser sintering sand mold is sealed and packaged with a double-layer packaging bag to prevent the coated sand laser sintering sand mold from getting damp and agglomerating during light-proof storage, and further reduce the probability of the coated sand laser sintering sand mold changing in size during storage. In step S102, the sand mold information (e.g., sand mold name, sand mold specifications, etc.) and storage information (e.g., storage location, storage date, etc.) of the coated sand laser sintering sand mold are placed on the upper surface of the double-layer packaging bag to facilitate management and use.

[0094] Please also read Figure 6 Furthermore, in some embodiments, after the step of storing the coated sand laser sintering sand mold in a dry environment away from light, it also includes steps S103 to S107.

[0095] Step S103, when the storage time is greater than or equal to the preset storage time, the surface of the coated sand laser sintering sand mold is inspected.

[0096] Step S104, if there is a problem on the surface of the coated sand laser sintering sand mold, it is determined whether the defect of the coated sand laser sintering sand mold can be repaired.

[0097] Step S105: If yes, locally repair the defects of the coated sand laser sintering sand mold.

[0098] Step S106: If not, the coated sand laser sintering sand mold is cleaned out for destruction or recycling.

[0099] Step S107, recording defects of the coated sand laser sintering sand mold and the results of processing the defects.

[0100] In step S103, the surface of the coated sand laser sintering sand mold stored for a long time is checked to ensure that the coated sand laser sintering sand mold is in good condition. If one or some coated sand laser sintering sand molds have problems, step S104 is executed to determine the problem. If the problem can be repaired, step S105 is executed to perform local repair. If it is found that it cannot be repaired, step S106 is executed to destroy or recycle the unqualified coated sand laser sintering sand mold. By executing step S107, the storage process is recorded for easy management and use.

[0101] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0102] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A post-processing method for laser selective sintering coated sand, characterized in that: Includes steps: Adding support to the easily fractured parts and easily deformed parts of the laser sintered model according to the structure and shape of the laser sintered model; Laser sintering printing is performed according to the laser sintering model after adding support to obtain a coated sand laser sintering sand mold; Preliminary sand cleaning is performed on the coated sand laser sintering sand mold to remove the coated sand remaining on the surface of the coated sand laser sintering sand mold; Surface baking is performed on the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning; Deeply cleaning the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform after surface baking; The coated sand laser sintering sand mold is heated to 180° C. to 200° C. by means of segmented heating, and kept warm for 4 h to 10 h; Cooling the coated sand laser sintering sand mold after heat preservation to room temperature along with the furnace; Performing a surface inspection on the cooled coated sand laser sintering sand mold; If there is repairable damage on the coated sand laser sintering sand mold, the damaged part of the coated sand laser sintering sand mold is locally repaired.

2. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: The step of performing preliminary sand cleaning on the coated sand laser sintering sand mold is: manually cleaning the coated sand on the surface of the coated sand laser sintering sand mold using a soft brush or a handheld fan.

3. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: The step of deeply cleaning the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform after preliminary sand cleaning is: using a vacuum cleaner to vacuum the concave parts of the coated sand laser sintering sand mold and the surrounding areas of the sand cleaning platform.

4. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: The step of baking the easily damaged parts of the coated sand laser sintering sand mold while deep sand cleaning is as follows: while deep sand cleaning, baking the easily damaged parts of the coated sand laser sintering sand mold after preliminary sand cleaning using a spray gun, a blowtorch or a high-temperature hot air gun.

5. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: Before the step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping it warm for a first preset time period in a segmented heating manner, the method further includes the following steps: providing a box; placing the sintering sand mold and an appropriate amount of glass beads in the box, and burying the sintering sand mold in the glass beads; placing the box containing the coated sand laser sintering sand mold and the glass beads in a heat treatment oven; The step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping it warm for a first preset time period by means of segmented heating is as follows: using the heat treatment oven to segmentally heat the box containing the coated sand laser sintering sand mold and the glass beads until the surface temperature of the laser sintering model reaches 180°C to 200°C, and keeping it warm for 4h to 10h.

6. The post-processing method of laser selective sintering coated sand according to claim 5, characterized in that: The particle size of the glass microbeads is 0.4 mm to 0.6 mm.

7. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: The step of heating the coated sand laser sintering sand mold to a first preset temperature and keeping the temperature for a first preset time period by means of segmented heating includes: The coated sand laser sintering sand mold after deep sand cleaning is heated to 98°C to 105°C for the first time at a heating rate of 48°C / h to 52°C / h, and kept warm for 28min to 33min; The coated sand laser sintering sand mold after the first heating is heated for a second time to 180° C. to 200° C. at a heating rate of 48° C. / h to 52° C. / h, and kept warm for 4 h to 10 h.

8. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: The step of cooling the coated sand laser sintering sand mold after heat preservation to room temperature with the furnace comprises: The heated coated sand laser sintering sand mold is first cooled to 95° C. to 105° C. with the furnace, and kept warm for 28 min to 35 min; The coated sand laser sintering sand mold after the first furnace cooling is then cooled to 46°C to 55°C for the second time and kept at this temperature for 28min to 35min; The coated sand laser sintering sand mold after the second furnace cooling is furnace cooled to room temperature for the third time.

9. The post-processing method of laser selective sintering coated sand according to claim 1, characterized in that: After the step of locally repairing the damaged part of the coated sand laser sintering sand mold, the method further includes: returning to perform the surface inspection step; After the step of locally repairing the damaged parts of the coated sand laser sintering sand mold, the method further includes: if the coated sand laser sintering sand mold has no surface defects after cooling, the coated sand laser sintering sand mold is stored in a dry environment away from light.

10. The post-processing method of laser selective sintering coated sand according to claim 9, characterized in that: Before the step of storing the coated sand laser sintering sand mold in a dark place, the method further comprises: Using a double-layer packaging bag to seal and package the coated sand laser sintering sand mold; Marking the sand mold information and storage information of the coated sand laser sintering sand mold on the double-layer packaging bag; and / or After the step of storing the coated sand laser sintering sand mold in a dry environment away from light, the method further comprises: When the storage time is greater than or equal to the preset storage time, performing a surface inspection on the coated sand laser sintering sand mold; If there is a problem on the surface of the coated sand laser sintering sand mold, determine whether the defect of the coated sand laser sintering sand mold can be repaired; If yes, locally repair the defects of the coated sand laser sintering sand mold; If not, the coated sand laser sintering sand mold is cleaned out for destruction or recycling; The defects of the coated sand laser sintering sand mold and the treatment results of the defects are recorded.

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