Selective laser melting (SLM) powder temperature control device

Abstract

The utility model discloses a selective laser melting (SLM) powder temperature control device, and belongs to the technical field of additive manufacturing. Comprising a silicon carbide temperature control box and a supporting base, a nichrome resistance wire is embedded in the silicon carbide temperature control box, the silicon carbide temperature control box is fixed to a synchronous lifting platform, high-torque synchronous belt wheel bases are arranged at the four corners and the middle of one side edge of the supporting base, and high-torque synchronous belt wheels are installed on the high-torque synchronous belt wheel bases. The high-torque synchronous belt wheels are in transmission through synchronous belts, one high-torque synchronous belt wheel on the side edge of the supporting base is connected with a stepping motor in the supporting base, the static pressure lead screws penetrate through the synchronous lifting platform and the four corners of the supporting base respectively, and the nichrome resistance wires and the stepping motor are connected with an external PLC control box. The device can improve the laser absorption rate of SLM selective laser melting technology powder, improve the melting efficiency, reduce the temperature difference before and after machining to reduce the residual stress of a formed part, and further avoid buckling deformation and cracking of parts.

Description

Technical Field

[0001] This utility model relates to a temperature control device for selective laser melting (SLM) powder, belonging to the field of additive manufacturing technology. Background Technology

[0002] Selective laser melting (SLM), an advanced additive manufacturing technology, uses high-energy lasers to melt and deposit metal powder layer by layer to create parts, overcoming the limitations of traditional processing methods, such as cumbersome procedures and significant material waste in manufacturing complex structures. Currently, this technology is used in the aerospace field to manufacture lightweight, high-performance components, in the medical field to customize personalized implants, and it also shows great application potential in industries such as automobiles, occupying an important position in modern manufacturing.

[0003] With the deepening application of selective laser melting (SLM) technology in precision manufacturing, the forming quality and performance of metal parts are receiving increasing attention. Powder pretreatment temperature is crucial to the quality of SLM-formed parts; a suitable temperature can improve powder flowability, reduce oxygen content, and increase laser absorption. However, current heating devices suffer from inaccurate temperature control, large temperature differences between regions, and difficulty in controlling the heating rate, leading to inconsistent powder properties. Simultaneously, traditional monitoring methods suffer from slow response times and measurement position deviations, making it impossible to accurately acquire temperature changes in real time and achieve closed-loop control, thus becoming a bottleneck restricting the improvement of forming quality. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a temperature control device for selective laser melting (SLM) powder. By optimizing the design of the heating and temperature measurement structure, the above-mentioned technical problems are effectively solved, providing a reliable guarantee for high-quality SLM molding.

[0005] The technical solution adopted in this utility model is as follows: a selective laser melting (SLM) powder temperature control device, including a silicon carbide temperature control box 1 and a support base 8. The silicon carbide temperature control box 1 is embedded with a nickel-chromium alloy resistance wire. The silicon carbide temperature control box 1 is fixed on a synchronous lifting platform 4. The four corners and the middle of one side of the support base 8 are provided with high-torque synchronous pulley bases 9. High-torque synchronous pulleys 5 are installed on the high-torque synchronous pulley bases 9. The high-torque synchronous pulleys 5 are driven by synchronous belts 7. One high-torque synchronous pulley 5 on the side of the support base 8 is connected to a stepper motor 10 inside the support base 8. The bottom of the static pressure screw 3 passes through the high-torque synchronous pulleys 5 at the four corners of the support base 8 and is connected to the angular contact ball bearings 11 at the bottom of the corresponding high-torque synchronous pulley base 9. The upper part passes through the connecting holes at the four corners of the synchronous lifting platform 4 and the static pressure screw nut 6 and extends out of the synchronous lifting platform 4. The nickel-chromium alloy resistance wire and the stepper motor 10 are both connected to an external PLC control box.

[0006] Preferably, the support base 8 has three high-torque synchronous pulley bases 9 in the middle of one side. The stepper motor 10 is installed below the middle high-torque synchronous pulley base 9. The output shaft of the stepper motor 10 passes through the high-torque synchronous pulley base 9 and is connected to the corresponding high-torque synchronous pulley 5.

[0007] Preferably, the synchronous belt 7 is M-shaped when it passes over the three high-torque synchronous pulleys 5 in the middle of one side of the support base 8.

[0008] Preferably, a needle roller bearing 12 with an inner ring stamped and an outer ring pressed is installed at the connection between the hydrostatic screw 3 and the high-torque synchronous pulley base 9.

[0009] Preferably, the synchronous lifting platform 4 includes a square base and a protruding square temperature control box fixing platform, and the silicon carbide temperature control box 1 is square.

[0010] Preferably, the two sides of the square temperature control box mounting platform are fixedly connected to the square base through connecting brackets, and the silicon carbide temperature control box 1 is fixed to the square temperature control box mounting platform by external hexagonal bolts.

[0011] Preferably, the bottom surface of the high-torque synchronous pulley 5 is flush with the upper surface of the support base 8.

[0012] Preferably, the connecting holes at the four corners of the synchronous lifting platform 4 are through holes, and the high-torque synchronous pulley base 9 is fixed to the support base 8 by external hexagonal bolts.

[0013] Preferably, the four corners of the support base 8 are chamfered.

[0014] Preferably, the outer side of the static pressure screw nut 6 is fixed to the four corners of the synchronous lifting platform 4, and the inner side is fitted with the static pressure screw 3.

[0015] Preferably, the nickel-chromium alloy resistance wire is a Ni80Cr20 type resistance wire, and the static pressure screw 3 is a static pressure screw with a trajectory deviation of less than 0.1μm.

[0016] The beneficial effects of this invention are: it can precisely heat powder to the pretreatment temperature and has a reliable real-time monitoring function. This device not only solves the defects of existing temperature control and ensures the consistency of powder pretreatment effect, but also realizes dynamic temperature adjustment through precise monitoring, laying a solid foundation for high-quality selective laser melting (SLM) additive manufacturing technology and helping SLM technology to be deeply applied and innovatively developed in more demanding fields. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a perspective view of the present utility model;

[0019] Figure 2 This is a top view of the structure of this utility model;

[0020] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along line AA;

[0021] Figure 4 This is a schematic diagram of the structure of the support base of this utility model;

[0022] Figure 5 This is a schematic diagram of the high-torque synchronous belt pulley of this utility model;

[0023] Figure 6 This is a structural schematic diagram of the rectangular temperature control box fixing platform of this utility model;

[0024] Figure 7 This is a schematic diagram of the structure of the hydrostatic screw nut of this utility model;

[0025] Figure 8 This is a schematic diagram of the structure of the high-torque synchronous belt pulley base of this utility model;

[0026] Figure 9 This is a schematic diagram of the silicon carbide temperature control box of this utility model. Detailed Implementation

[0027] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] Example 1: As Figure 1-9As shown, a selective laser melting (SLM) powder temperature control device includes a silicon carbide temperature control box 1 and a support base 8. The silicon carbide temperature control box 1 is embedded with a nickel-chromium alloy resistance wire. The silicon carbide temperature control box 1 is fixed on a synchronous lifting platform 4. The four corners and the middle of one side of the support base 8 are provided with high-torque synchronous pulley bases 9. High-torque synchronous pulleys 5 are installed on the high-torque synchronous pulley bases 9. The high-torque synchronous pulleys 5 are driven by synchronous belts 7. One high-torque synchronous pulley 5 on the side of the support base 8 is connected to a stepper motor 10 inside the support base 8. The bottom of the static pressure screw 3 passes through the high-torque synchronous pulleys 5 at the four corners of the support base 8 and is connected to the angular contact ball bearings 11 at the bottom of the corresponding high-torque synchronous pulley base 9. The upper part passes through the connecting holes at the four corners of the synchronous lifting platform 4 and the static pressure screw nut 6 and extends out of the synchronous lifting platform 4. The nickel-chromium alloy resistance wire and the stepper motor 10 are both connected to an external PLC control box.

[0029] Furthermore, three high-torque synchronous pulley bases 9 are provided on the middle of one side of the support base 8. The stepper motor 10 is installed below the middle high-torque synchronous pulley base 9. The output shaft of the stepper motor 10 passes through the high-torque synchronous pulley base 9 and is connected to the corresponding high-torque synchronous pulley 5.

[0030] Furthermore, such as Figure 1 As shown, the synchronous belt 7 is M-shaped when it passes over the three high-torque synchronous pulleys 5 in the middle of one side of the support base 8 (that is, it passes over the inner, outer and inner sides of the three middle high-torque synchronous pulleys 5 in sequence). This shape arrangement can make the operation of all high-torque synchronous pulleys 5 more precise and stable, thereby ensuring the smooth operation of the synchronous lifting platform 4.

[0031] Furthermore, a needle roller bearing 12 with an inner ring stamped outer ring is installed at the connection between the hydrostatic screw 3 and the high-torque synchronous pulley base 9, so that the connection between the hydrostatic screw 3 and the high-torque synchronous pulley base 9 is a soft friction.

[0032] Furthermore, the synchronous lifting platform 4 includes a square base and a protruding square temperature control box fixing platform. The silicon carbide temperature control box 1 is square, which facilitates installation and fixing.

[0033] Furthermore, the two sides of the square temperature control box mounting platform are fixedly connected to the square base through connecting brackets, and the silicon carbide temperature control box 1 is fixed to the square temperature control box mounting platform by external hexagonal bolts. The structure is simple and the installation is convenient.

[0034] Furthermore, the bottom surface of the high-torque synchronous pulley 5 is flush with the upper surface of the support base 8.

[0035] Furthermore, the connection holes at the four corners of the synchronous lifting platform 4 are through holes, and the high-torque synchronous pulley base 9 is fixed to the support base 8 by external hexagonal bolts, which facilitates disassembly and installation.

[0036] Furthermore, the four corners of the support base 8 have been chamfered, which enhances the contour features and makes it easier and more accurate to fix the support base 8 to the selective laser melting equipment.

[0037] Furthermore, the outer side of the static pressure screw nut 6 is fixed to the four corners of the synchronous lifting platform 4, and the inner side is fitted with the static pressure screw 3, so as to stably connect the synchronous lifting platform 4 and the static pressure screw 3 together.

[0038] Furthermore, the nickel-chromium alloy resistance wire is a Ni80Cr20 type resistance wire. This resistance wire, controlled by an external PLC control box, simultaneously heats the powder and precisely controls the temperature inside the silicon carbide temperature control chamber 1. Combined with the bottom power system, it achieves precise temperature control and heating of the powder. The static pressure screw 3 uses a static pressure screw with a trajectory deviation of less than 0.1μm, achieving nanometer-level positioning resolution over a long stroke, enabling precise control of the lifting position of the synchronous lifting platform 4.

[0039] This invention adds the weight of the high-torque synchronous pulley base 9, the high-torque synchronous pulley 5, and the stepper motor 10 to the weight of the support base 8, making the weight at the bottom much greater than the weight of the synchronous lifting platform 4 at the top of the device. This top-light and bottom-heavy structural design lowers the center of gravity of the entire device with minimal counterweight, which ensures that the synchronous lifting platform 4 will not tip over due to instability during the lifting process driven by the static pressure screw 3.

[0040] The specific operating steps of the selective laser melting (SLM) powder temperature control device of this utility model are as follows:

[0041] Step 1: Place the support base 8 parts according to the laser pre-sintering area of ​​the external selective laser melting SLM equipment, and use the chamfered structure on the support base 8 for more precise positioning;

[0042] Step 2: After cleaning the support base 8 and mounting holes, align the four high-torque synchronous pulley bases 9 at the four corners with the base holes. Pre-tighten the hex bolts with a wrench, then tighten them to the standard torque value with a torque wrench. Apply lubricating oil to the threaded section of the hydrostatic screw 3, and vertically insert it into the center hole of the corresponding high-torque synchronous pulley base 9 (ensuring the perpendicularity error does not exceed ±0.5°). Initially fix it with an hex wrench to complete the installation of the four hydrostatic screws 3. Finally, tighten them a second time with a torque wrench, visually check the installation status, manually test the smoothness of rotation of the hydrostatic screw 3, and use a level or dial indicator to check the perpendicularity and parallelism of the hydrostatic screw 3, making minor adjustments as needed.

[0043] Step 3: Smoothly insert the synchronous lifting platform 4 onto the upper end of the static pressure screw 3, taking care to avoid tilting or scraping the surface of the static pressure screw 3. After inserting, gently shake the platform to ensure it slides freely on the static pressure screw 3 without jamming. Then, place a level at the center of the top of the silicon carbide temperature control box 1 and observe the direction of the bubble offset. Make fine adjustments to achieve a horizontal accuracy of ±0.5° for the silicon carbide temperature control box 1. Next, align the assembled device of the synchronous lifting platform 4 and silicon carbide temperature control box 1 with the four mounting holes on the base, ensuring that the holes are completely aligned. Tighten the bolts in a crisscross manner, first pre-tightening diagonally to 10 N·m, then gradually increasing the torque to 25 N·m clockwise, ensuring that the gap between the device and the base plane is <0.1 mm. Finally, manually operate the lifting platform 4 to check its smoothness of lifting within a stroke of 0-500mm and ensure that the synchronization error is ≤0.3mm. Start the silicon carbide temperature control box 1, set the 500℃ heating program, and monitor the temperature control curve fluctuation range within ±2℃ to confirm that the installation is complete.

[0044] Step 4: After completing the installation of the device and the base of the selective laser melting (SLM) equipment, open the silicon carbide temperature control box 1. Connect the Ni80Cr20 nickel-chromium alloy resistance wire inside the box to the designated port of the external PLC control box. At the same time, accurately connect the control cable of the stepper motor 10 to the corresponding interface of the external PLC control box. In the operation interface of the PLC control box, carefully set the layer-by-layer sintering height and powder spreading height parameters of the selective laser melting (SLM) equipment. After setting, the system starts running. First, the powder spreading operation is performed. The external PLC control box controls the rotation angle of the stepper motor 10, which in turn drives the high-torque synchronous pulley 5 to rotate. The high-torque synchronous pulley 5 then drives the static pressure screw 3 to rotate. Through the static pressure screw nut 6, the synchronous lifting platform 4 is precisely raised and lowered to the powder layer that needs to be heated, achieving precise temperature control and measurement of the powder. The lifting platform 4 precisely lowers the silicon carbide temperature control box 1 to the powder-laying position, then activates the Ni80Cr20 nickel-chromium alloy resistance wire. This not only heats the powder layer but also enables real-time temperature monitoring. When the temperature reaches the preset pre-sintering temperature, the selective laser melting (SLM) equipment immediately starts working. After the SLM equipment finishes its operation, the external PLC control box sends a command to the stepper motor 10, driving the synchronous lifting platform 4 to descend, cooperating with the SLM equipment to complete a new round of powder-laying. After powder-laying is completed, the external PLC control box again controls the stepper motor 10 to rise the synchronous lifting platform 4 to the powder layer, activating the Ni80Cr20 resistance wire to heat the newly laid powder. This cycle repeats continuously, advancing the entire processing flow.

[0045] This invention uses an external PLC control box to control the forward and reverse rotation of a stepper motor, which in turn drives the forward and reverse rotation of a high-torque synchronous pulley, enabling the synchronous lifting platform to rise or fall as required. The PLC control box controls the nickel-chromium alloy resistance wire inside the silicon carbide temperature control chamber to heat the powder, allowing it to initially reach the pretreatment temperature. Simultaneously, the PLC control box determines the current temperature by detecting the current flowing through the nickel-chromium alloy resistance wire. This device improves the absorption rate of the powder to the laser in SLM selective laser melting technology, increasing melting efficiency, while reducing the temperature difference before and after processing to lower residual stress in the formed parts, thereby preventing warping, deformation, and cracking. It should be noted that the above control methods are all achievable with existing technology and do not involve any innovation in the method.

[0046] The above description only illustrates certain exemplary embodiments of this utility model patent. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of this utility model patent. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of this utility model patent or its claims.

Claims

1. A temperature control device for selective laser melting (SLM) powder, characterized in that: The system includes a silicon carbide temperature control box (1) and a support base (8). The silicon carbide temperature control box (1) is embedded with a nickel-chromium alloy resistance wire. The silicon carbide temperature control box (1) is fixed on a synchronous lifting platform (4). The support base (8) has high-torque synchronous pulley bases (9) at its four corners and one side center. High-torque synchronous pulleys (5) are installed on the high-torque synchronous pulley bases (9). The high-torque synchronous pulleys (5) are driven by synchronous belts (7). A high-torque synchronous pulley on the side of the support base (8) is connected to the support base (8). The synchronous pulley (5) is connected to the stepper motor (10) inside the support base (8). The bottom of the static pressure screw (3) passes through the high torque synchronous pulley (5) at the four corners of the support base (8) and is connected to the angular contact ball bearing (11) at the bottom of the corresponding high torque synchronous pulley base (9). The upper part passes through the connection holes at the four corners of the synchronous lifting platform (4) and the static pressure screw nut (6) and then extends out of the synchronous lifting platform (4). The nickel-chromium alloy resistance wire and the stepper motor (10) are both connected to the external PLC control box.

2. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: The support base (8) has three high-torque synchronous pulley bases (9) in the middle of one side. The stepper motor (10) is installed below the middle high-torque synchronous pulley base (9). The output shaft of the stepper motor (10) passes through the high-torque synchronous pulley base (9) and is connected to the corresponding high-torque synchronous pulley (5).

3. The selective laser melting (SLM) powder temperature control device according to claim 2, characterized in that: The synchronous belt (7) forms an M-shape when it passes around the three high-torque synchronous pulleys (5) on one side of the support base (8).

4. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: A needle roller bearing (12) with an inner ring stamped outer ring is installed at the connection between the static pressure screw (3) and the high torque synchronous pulley base (9).

5. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: The synchronous lifting platform (4) includes a square base and a protruding square temperature control box fixing platform. The silicon carbide temperature control box (1) is square.

6. The temperature control device for SLM powder according to claim 5, wherein: The two sides of the square temperature control box fixing platform are fixedly connected to the square base through connecting brackets, and the silicon carbide temperature control box (1) is fixed on the square temperature control box fixing platform by external hexagonal bolts.

7. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: The bottom surface of the high-torque synchronous pulley (5) is flush with the upper surface of the support base (8). The connecting holes at the four corners of the synchronous lifting platform (4) are through holes. The high-torque synchronous pulley base (9) is fixed to the support base (8) by external hexagonal bolts.

8. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: The four corners of the support base (8) have been chamfered.

9. The temperature control device for selective laser melting (SLM) powder according to claim 1, wherein: The outer side of the static pressure screw nut (6) is fixed to the four corners of the synchronous lifting platform (4), and the inner side is fitted with the static pressure screw (3).

10. The temperature control device for SLM powder according to claim 1, wherein: The nickel-chromium alloy resistance wire is a Ni80Cr20 type resistance wire, and the static pressure screw (3) is a static pressure screw with a trajectory deviation of less than 0.1μm.

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