Processing method of 3D printing tantalum part

Abstract

The invention provides a processing method of a 3D printed tantalum part, which comprises the following steps: step 1, preparing a 3D printed product part, and carrying out multi-component gradient printing by adopting a porous tantalum blank to obtain the 3D printed product part; 2, a tool is installed, specifically, the suitable tool is installed on a tool rest / tool handle, and the tool rest / tool handle is arranged on a numerical control lathe; 3, clamping is conducted, specifically, the part is installed in a three-jaw clamp of a tool, the reference is aligned, and clamping is firm; and 4, machining is conducted, equipment is started, milling and turning are utilized, the part is machined according to the drawing, and the part meets the size requirement. The 3D printing tantalum piece is combined with a machining process to meet the requirements of the inner shape, the outer shape, the product appearance and the like of the 3D printing tantalum material. The strength of the blank is enhanced by adjusting the compactness of the 3D blank, metal substitutes such as titanium alloy and the like are replaced by the tantalum material in combination with a machining process, and the defects of other metal materials in the aspects of biocompatibility, biological activity, implant-bony combination and the like are overcome.

Description

Technical Field

[0001] The present invention relates to the field of powder metallurgy, and in particular to a processing method for 3D printed tantalum parts. Background Art

[0002] Oral dental implants use titanium implants, which have the disadvantage of releasing titanium ions, causing gingivitis and periodontitis, and inflammation may also occur around the implants.

[0003] Tantalum materials are known as "biophilic" metals. With their unique physical and chemical properties and excellent biological inertness and biocompatibility, they were first used in the field of orthopedics in 1940. They have a history of 80 years of clinical application and have become a new type of biomaterial after titanium metal. Tantalum materials can be widely used in medical fields such as oral implants, treatment of femoral head necrosis, coronary stent implants, artificial acetabular prosthesis implants, and surgical suture production. Pure tantalum has no adverse reactions as a human implant. Metallic tantalum has almost perfect biocompatibility, and its clinical application has been found to have excellent clinical effects.

[0004] Porous tantalum metal materials are very close to natural bone tissue in structure and mechanical properties. After porous tantalum metal implants are implanted into living bone tissue, rapid bone ingrowth and fixation force occur.

[0005] In the existing technology, tantalum materials are mainly used for tantalum developing rings and orthopedic implants. The general specifications of tantalum developing rings are diameter: 0.2~8mm, wall thickness: 0.015~0.5mm, purity: 99.95% and 99.99% purity, outer diameter tolerance: ±0.003mm, weight tolerance: ±0.005mm, L: ±0.05mm, standard is ASTMF560. Tantalum developing rings are used as a marking ring for X-ray imaging of the distal working area in interventional treatment and are disposable medical materials. Tantalum is a new type of creative material. Tantalum bars replace bones and muscles in the human body and grow on them, so it has the title of "biophilic metal". As a corrosion-resistant metal, it has a good affinity with human tissue and is cheaper than ordinary platinum-iridium developing rings.

[0006] As an orthopedic implant material, the elastic modulus of pure tantalum and bone tissue is quite different, which is not conducive to bone integration. As a new type of orthopedic implant material, porous tantalum metal material has interconnected and interwoven internal structures, and has physical properties such as high porosity, low elastic modulus and high surface friction coefficient. In terms of mechanical properties, the special pore structure of porous tantalum makes its elastic modulus between human cancellous bone and cortical bone, which is particularly suitable for bone replacement, joint replacement and human tissue filling. It can reduce stress shielding while providing mechanical strength, facilitate stress conduction, facilitate bone shaping, and has excellent bone inductivity. It can be widely used in the field of orthopedics in the future and has achieved ideal therapeutic effects. Compared with other porous materials, the friction coefficient of porous tantalum metal material is 0.80 and 0.74 relative to cancellous bone and cortical bone, respectively, and the friction coefficient between it and bone tissue is 40% to 80% higher than that of traditional metal materials, which helps to integrate with the host bone interface and enhance the stability of the initial implant.

[0007] In clinical applications, porous tantalum can be used to print small and medium-sized repair products. For large-sized repair products, considering the high density of pure tantalum, the printed implant prosthesis is too heavy, so multi-component gradient printing can be used, using porous tantalum in the bone ingrowth area, and other areas can use other metals such as cheap and lightweight titanium alloys. The results of many clinical trials have proved that new implants made of medical tantalum combined with metals such as titanium can make up for the deficiencies of other metal materials in terms of biocompatibility, bioactivity and implant-bone bonding.

[0008] Tantalum materials are easy to deform during processing, and the 3D printed products are porous and hollow in the middle, which makes processing very difficult and easy to break during processing. Tantalum metal is a biomedical material in the medical industry and needs to be implanted in the human body. In order to ensure the life, health and safety of patients, it needs to meet very strict standards and grades, so both the appearance and cleanliness requirements are very demanding.

[0009] In view of the above reasons, a processing method for 3D printed tantalum parts is needed. Summary of the invention

[0010] The purpose of the present invention is to provide a processing method for 3D printed tantalum parts, which overcomes the problems of reduced production efficiency and increased labor costs caused by product breakage due to the difficulty of material processing when processing tantalum materials.

[0011] In order to achieve the above object, the present invention provides the following technical solutions:

[0012] A method for processing 3D printed tantalum parts, comprising the following steps:

[0013] Step 1, preparing 3D printed product parts, using porous tantalum blanks to perform multi-component gradient to obtain rod-shaped 3D printed product parts;

[0014] Step 2, installing the tool, installing the appropriate tool on the tool holder / tool ​​handle, and the tool holder / tool ​​handle is set on the CNC lathe;

[0015] Step 3: Clamp the parts into the three-jaw fixture of the tooling, align the reference, and clamp them firmly;

[0016] Step 4, processing, start the equipment, use milling and turning processing methods to process the parts according to the drawings so that the parts meet the size requirements.

[0017] Further, in the above-mentioned 3D printed tantalum parts processing method, in the step 1, the product parts are 3D printed by a multi-component gradient method;

[0018] The step 3 specifically includes:

[0019] Step 31, check whether the clamping part of the three-jaw fixture of the tooling has any bumps or scratches;

[0020] Step 32, clean the dirt on the surface of the three-jaw fixture of the tooling to avoid affecting the processing accuracy;

[0021] Step 33, using a three-jaw fixture of the tooling to clamp the outer cylindrical flat end faces and / or outer circular arc surface of the part;

[0022] Step 34, check and confirm that the parts have no burrs to prevent inadequate clamping;

[0023] Step 35, use a dial indicator to align the part to within 0.01mm.

[0024] Furthermore, in the above-mentioned 3D printed tantalum part processing method, in step 33, before the part is clamped by the three-jaw fixture of the tooling, the length ends of the part are processed flat using a tool, and / or the part is processed into an arc shape using a tool.

[0025] Furthermore, in the above-mentioned 3D printed tantalum part processing method, step 4 specifically includes:

[0026] Step 41, centerless grinding: rough grinding the surface of the part, and rough grinding the outer circle of the part to see the light;

[0027] Step 42, rough turning with a CNC lathe: rough turning the two end surfaces of the part plane by using a CNC lathe to make the two end surfaces of the part plane visible to light;

[0028] Step 43, rough milling with a CNC milling machine, rough milling the parts using a CNC milling machine;

[0029] Step 44, CNC lathe, using a CNC lathe to process the parts;

[0030] Step 45, electric spark: clamp the process step end of the part with a vise, and perform hexagonal electrode electric hexagonal processing on the part to the finished size according to the drawing requirements;

[0031] Step 46, a machining center processes the threaded step of the part;

[0032] Step 47, slow thread: Cut the total length based on the large end face of the external thread of the part, set the tool based on the large end face of the external thread, and cut the total length of the part according to the drawing size with a reserve of 0.2mm;

[0033] Step 48, CNC lathe: Use a CNC lathe to process the parts to the finished size.

[0034] Furthermore, in the above-mentioned 3D printed tantalum part processing method, the step 43 specifically includes:

[0035] Step 431, check whether the fixture is damaged and whether the clamping surface of the fixture is clean;

[0036] Step 432, testing the accuracy of the fixture and fixture, and checking if it is qualified according to the size requirements of the fixture drawing;

[0037] Step 433, after the fixture is installed, use a table to align the top surface and side surface of the fixture to ensure that the error is within 0.01 mm;

[0038] Step 434, vertically clamp the part on the fixture, the part is pressed against the fixture and compacted, the clamping direction of the part should be consistent with the program sheet, and there should be no loose positioning groove problem;

[0039] Step 435, use a 0.01mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and the pins are padded, flatten and align the parts to within 0.01mm to ensure the clamping accuracy, accurately check whether the tooling and the program route interfere with each other, compare with the tool list, simulate the tool path to prevent tool collision;

[0040] Step 436, embrace the outer circle; embrace the outer circle with the upper end face of the part as the reference, make the inner hexagonal step size of the part larger than the required size of the finished product in the drawing by 0.2mm, use a drill to drill the bottom hole of the thread, chamfer with a chamfering tool, and mill the thread with a thread cutter.

[0041] Furthermore, in the above-mentioned 3D printed tantalum part processing method, step 44 specifically includes:

[0042] Step 441, check whether there are any bumps or scratches on the clamping part of the three-jaw fixture;

[0043] Step 442, cleaning the dirt on the surface of the fixture to avoid affecting the processing accuracy;

[0044] Step 443, using a fixture to clamp one end of the outer diameter of the part, check and confirm that the part has no burrs to prevent the part from being clamped in place;

[0045] Step 444, using a dial indicator to align the part error within 0.01 mm;

[0046] Step 445, use the tool head to turn the inner cone, outer step, chamfer arc, outer circle, double-line thread and triangle superimposed rectangular conical spiral line.

[0047] Furthermore, in the above-mentioned 3D printed tantalum parts processing method, in step 45, the forward and reverse positions of the parts are checked during clamping, the vise accuracy is tested, the parts are aligned and leveled, and a 0.01 mm feeler gauge is used to check whether the parts and the tooling fitting surfaces are firmly fitted to prevent electrical damage to the parts.

[0048] Furthermore, in the above-mentioned 3D printed tantalum part processing method, step 46 specifically includes:

[0049] Step 461, check whether the fixture is damaged and whether the clamping surface is clean;

[0050] Step 462, testing the accuracy of the fixture and fixture, and checking whether it is qualified according to the size requirements of the fixture drawing;

[0051] Step 463, after the tooling is installed, align the upper surface and the side of the tooling by using a table to within 0.01 mm;

[0052] Step 464, four-axis clamping process step end, check whether the part clamping direction is consistent with the program sheet, and whether there is any problem of loose positioning groove;

[0053] Step 465, use a 0.01 mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and padded;

[0054] Step 466, using a milling cutter to mill the conical thread step.

[0055] Furthermore, in the above-mentioned 3D printed tantalum parts processing method, in step 47, the forward and reverse positions of the parts are checked during clamping, the vise accuracy is tested, the parts are aligned and leveled, and a 0.01mm feeler gauge is used to check whether the parts and the tooling fitting surfaces are firmly fitted to prevent electrical damage to the parts; the parts must be clamped vertically, the parts must be close to the tooling and compacted, and the parts must be leveled and aligned within 0.01mm after clamping to ensure accurate clamping accuracy. Check whether there is any interference between the tooling and the program route, compare with the tool list, and simulate the tool path to prevent tool collision.

[0056] Furthermore, in the above-mentioned 3D printed tantalum part processing method, step 48 specifically includes:

[0057] Step 481, check whether there are any bumps or scratches on the clamping parts of the fixture;

[0058] Step 482, cleaning the dirt on the surface of the fixture to avoid affecting the processing accuracy;

[0059] Step 483, when clamping the parts, check and confirm that the parts have no burrs to prevent the parts from being clamped in place;

[0060] Step 484, using a dial indicator to align the part error to within 0.01 mm;

[0061] Step 485, clamp the outer cone of the part with a three-jaw fixture, use a flat knife to flatten the small end face to maintain the overall length of the part, and use a tool head to turn the arc to the finished size of the part drawing.

[0062] It can be seen from the analysis that the present invention discloses a processing method for 3D printed tantalum parts. The 3D printed tantalum parts combined with the machining process effectively supplement the disadvantages of the immature medical 3D printed tantalum material technology and the inability to be used directly, and the requirements of the internal shape, external shape and product appearance of the 3D printed tantalum materials are achieved through the machining process technology. The processing method of 3D printed tantalum parts enhances the strength of the blank by adjusting the density of the 3D blank, and combines the machining process to realize the substitution of tantalum materials for metals such as titanium alloys, thereby making up for the deficiencies of other metal materials in terms of biocompatibility, bioactivity and implant-bone bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0064] Figure 1 is a flow chart of the processing method of the present invention;

[0065] Figure 2 This is a photo of a finished 3D printed part according to an embodiment of the present invention;

[0066] Figure 3 Photos of finished 3D printed parts of other embodiments of the present invention;

[0067] Figure 4 This is a three-dimensional structural diagram of a 3D printed part product according to Example 1 of the present invention;

[0068] Figure 5 Another three-dimensional structural diagram of the 3D printed parts product of Example 1 of the present invention;

[0069] Figure 6 This is a three-dimensional structural diagram of a finished 3D printed part according to Embodiment 2 of the present invention;

[0070] Figure 7 This is another three-dimensional structural diagram of the finished 3D printed part of Example 2 of the present invention. DETAILED DESCRIPTION

[0071] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention encompasses such modifications and variations within the scope of the appended claims and their equivalents.

[0072] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection; it can be a direct connection or an indirect connection through an intermediate component; it can be a wired electrical connection, a radio connection, or a wireless communication signal connection. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0073] One or more examples of the present invention are shown in the accompanying drawings. The detailed description uses numbers and letter labels to refer to features in the drawings. Like or similar labels in the drawings and description have been used to refer to like or similar parts of the present invention. As used herein, the terms "first", "second", "third", etc. are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0074] like Figures 1 to 7 As shown, according to an embodiment of the present invention, a method for processing a 3D printed tantalum part is provided.

[0075] The principle of this processing method is: since tantalum materials are easy to deform during processing, the porous hollowing in the middle of 3D printed products brings great difficulty to the processing of parts, and they are easy to break during processing. By adjusting the density of the 3D printed blank to enhance the strength of the blank, and combining it with machining technology to process the finished product, high-quality 3D printed tantalum material products can be obtained to replace medical titanium materials.

[0076] like Figure 1 As shown, the processing method comprises the following steps:

[0077] Step 1, prepare 3D printed product parts (i.e. 3D printed tantalum parts, hereinafter referred to as parts), use porous tantalum blanks for 3D printing to obtain rod-shaped 3D printed product parts, and 3D print the product parts by a multi-component gradient method; considering that the density of pure tantalum is high and the printed implant prosthesis is too heavy, multi-component gradient printing is adopted, and material powder is printed layer by layer, and stacked layer by layer to form a three-dimensional model with an arbitrary complex structure from bottom to top, thereby enhancing the density of the blank, and then enhancing the strength of the blank, and preventing the 3D printed product parts from breaking during the processing process.

[0078] Step 2, install the tool. Install the appropriate tool on the tool holder / tool ​​handle. Set the tool holder / tool ​​handle on the CNC lathe to ensure that the tool and the tool holder / tool ​​handle are fully tightened and matched without shaking.

[0079] Step 3: Clamp the parts into the three-jaw fixture of the tooling, and align the reference to ensure that the parts are firmly clamped in the three-jaw fixture of the tooling without shaking;

[0080] Specifically include:

[0081] Step 31, check whether there are any bumps or scratches on the clamping part of the three-jaw fixture of the tooling. The clamping part of the three-jaw fixture is in a qualified state if there are no bumps or scratches that can be scratched by fingernails;

[0082] Step 32, clean the dirt on the surface of the three-jaw fixture of the tooling until there is no dirt on the surface of the three-jaw fixture to avoid affecting the processing accuracy, and measure the appearance size of the three-jaw fixture to see that there is no change;

[0083] Step 33, use a tool to flatten the two ends of the length of the part, and / or use a tool to process the part into an arc shape, and process the end face and the arc to a state without blank material, and use a three-jaw fixture of the tooling to clamp the outer cylindrical flat end faces and / or outer arc surface of the part;

[0084] Step 34, check and confirm that the parts have no burrs, that is, the appearance and edges of the parts are smooth, and do not affect the clamping position and produce clamping marks on the appearance of the parts to prevent the parts from being clamped in place;

[0085] Step 35, use a dial indicator to align the part error within 0.01mm to ensure that the perpendicularity between the end face of the part and the outer cylinder after processing can meet the subsequent processing size requirements.

[0086] Step 4, processing, start the equipment, determine the coordinates, then use the tool to touch the surface of the part to calibrate the tool, confirm the tool position, calculate the precise amount of cutting (confirm the amount of cutting by calculating the difference between the drawing size and the size of the 3D printed product part), use milling, turning and other processing methods, process the parts according to the drawing, so that the parts meet the size requirements.

[0087] Specifically include:

[0088] Step 41, centerless grinding: rough grinding is performed on the surface of the part, and the outer circle of the rough-ground part is exposed to light, that is, the surface of the part shows a metallic luster and there is no blank material state.

[0089] Step 42, rough turning by CNC lathe: Use CNC lathe to rough turn the two end faces of the part plane so that the two end faces of the part plane can be exposed to light, that is, the two end faces of the part length show metallic luster, and there is no blank material state.

[0090] Step 43, rough milling by a CNC milling machine, using a CNC milling machine to rough mill the outer contour of the part.

[0091] CNC lathe fine grinding specifically includes:

[0092] Step 431, check whether the fixture is damaged, whether the fixture clamping surface has no defects such as protrusions and depressions, whether the fixture clamping surface is clean, and whether the fixture clamping surface is clean and free of impurities, that is, the clamping verticality is not affected during clamping and no clamping marks are produced on the appearance of the part after clamping;

[0093] Step 432, the accuracy of the fixture is tested, and the fixture passes the test according to the size requirements of the fixture drawing. The fixture passes the test and can meet the requirements of accurate part positioning;

[0094] Step 433, after the fixture is installed, the error of the upper surface and the side surface of the fixture is checked by a table to be within 0.01 mm, which meets the theoretical size requirements of the program operation;

[0095] Step 434, vertically clamp the part on the fixture, the part is pressed against the fixture and compacted, the clamping direction of the part should be consistent with the program sheet, there should be no loose positioning groove, the part should be consistent with the running trajectory of the program sheet, and the positioning should be accurate;

[0096] Step 435, use a 0.01mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and the pad pins are in place, and the parts are leveled and aligned within 0.01mm to ensure the clamping accuracy, accurately check whether the tooling and the program route are interfering, compare the tool list, simulate the tool path to prevent tool collision, and if there are pad pins, they need to be removed. Without pad pins, the part clamping position can be guaranteed to be accurate;

[0097] Step 436, hold the outer circle; the short end of the outer circle of the part faces upward, and the outer circle is held with the upper end face of the part as the reference, so that the inner hexagonal step size of the part is 0.2mm larger than the required size of the finished product in the drawing, and a drill is used to drill the bottom hole of the thread, the chamfering tool is used to chamfer, and the thread cutter is used to mill the thread to produce the finished thread product.

[0098] Step 44, CNC lathe, using a CNC lathe to process the parts.

[0099] Step 441, check whether there are any bumps or scratches on the clamping part of the three-jaw fixture, and check whether there are any defects such as protrusions or depressions on the clamping surface of the fixture, and no clamping marks are left on the appearance of the part;

[0100] Step 442, cleaning the surface dirt of the fixture to make it free of impurities, that is, the verticality of the fixture is not affected during clamping and no clamping marks are left on the appearance of the part after clamping, so as to avoid affecting the processing accuracy;

[0101] Step 443, using a fixture to clamp one end of the outer circle of the part, check and confirm that the part has no burrs, that is, the appearance and edges of the part are smooth, and there is no clamping mark on the appearance of the part that affects the clamping position, so as to prevent the clamping from being in place;

[0102] Step 444, use a dial indicator to calibrate the part error to within 0.01 mm to ensure that the part can meet the subsequent processing size requirements.

[0103] Step 445, using the inner hexagonal end face of the part as a reference, use a tool head to turn an inner cone, an outer step, a chamfered arc, an outer circle, a double-line thread, and a triangular superimposed rectangular conical surface spiral.

[0104] Step 45, electric spark: clamp the process step end of the part with a vise, and perform hexagonal electrode electric hexagonal on the part to the finished size according to the drawing requirements.

[0105] When clamping, check the forward and reverse positions of the parts (make reverse marks on the surface of the tooling), check the accuracy of the vise, align and level it, and use a 0.01mm feeler gauge to check whether the parts and the fitting surfaces are firmly fitted to prevent electrical damage to the parts.

[0106] Step 46, machining center, processing the thread steps of the part.

[0107] The machining center specifically includes:

[0108] Step 461, check whether the fixture is damaged, whether the clamping surface is clean, whether the clamping surface of the fixture has no defects such as protrusions and depressions, and whether there are no clamping marks on the appearance of the parts;

[0109] Step 462, the accuracy of the jig is tested, and the jig passes the test according to the size requirements of the jig drawing. The jig passes the test and can meet the requirements of accurate part positioning;

[0110] Step 463, after the tooling is installed, the upper surface and the side surface of the tooling are aligned within 0.01 mm by using a table to meet the theoretical size requirements of the program operation;

[0111] Step 464, the four-axis clamping process step end is compared to see whether the part clamping direction is consistent with the program sheet, whether there is any loose positioning groove, etc., to ensure that the part clamping direction is consistent with the program running direction, to ensure that the part is not loose during the processing, and thus to ensure that the processed part is consistent with the theoretical size of the program;

[0112] Step 465, use a 0.01mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and whether the pad pins are in place, to ensure that the clamping position of the parts meets the program running trajectory. If there are pad pins, they need to be removed. Without pad pins, the clamping position of the parts can be guaranteed to be accurate.

[0113] Step 466, using the large end face of the external thread of the part as a reference, find the hexagonal shape and use a milling cutter to mill the conical thread step.

[0114] Step 47, slow thread: Cut the total length based on the large end face of the external thread of the part. Use the large end face of the external thread as the reference for the cutter, and cut the total length of the part according to the drawing size with a allowance of 0.2mm.

[0115] When clamping, check the positive and negative positions of the parts (make reverse marks on the surface of the tooling) to prevent defective products, check the accuracy of the vise, align and level, and use a 0.01mm feeler gauge to check whether the parts and the tooling are firmly fitted to prevent electrical damage to the parts;

[0116] The parts must be clamped vertically, the parts must be close to the tooling and compacted, and the parts must be leveled and aligned within 0.01mm after clamping to ensure accurate clamping accuracy. Check whether there is any interference between the tooling and the program route, ensure processing according to the program route, meet the program theoretical dimensions, compare with the tool list, and simulate the tool path to prevent tool collision.

[0117] Step 48, CNC lathe: Use a CNC lathe to process the parts to the finished size.

[0118] Step 481, check whether there are any bumps or scratches on the clamping parts of the fixture, and check whether there are any defects such as protrusions or depressions on the clamping surfaces of the fixture, and whether there are no clamping marks on the appearance of the parts;

[0119] Step 482, cleaning the dirt on the surface of the fixture, cleaning until there is no impurity, that is, the verticality of the fixture is not affected during clamping and no clamping marks are left on the appearance of the part after clamping, so as not to affect the processing accuracy;

[0120] Step 483, when clamping the parts, check and confirm that the parts have no burrs, that is, the appearance and edges of the parts are smooth, and there are no clamping marks on the appearance of the parts that affect the clamping position, so as to prevent the clamping from being in place;

[0121] Step 484, using a dial indicator to align the part error within 0.01 mm, meeting the theoretical size requirements of the program operation;

[0122] Step 485, the three-jaw fixture clamps the outer cone of the part, uses a flat knife to flatten the small end face to ensure the overall length of the part, and uses a tool head to turn the arc to the finished size of the part drawing to complete the processing of the part. The finished photos of the 3D printed tantalum parts processed by some embodiments of the present invention are as follows Figure 2 and Figure 3 shown.

[0123] Embodiment 1: In this embodiment, the outer dimensions of the 3D printed tantalum part are φ4*12.5 mm, and the processing method of the 3D printed tantalum part comprises the following steps:

[0124] Step 1: prepare 3D printed product parts, use porous tantalum blanks to perform multi-component gradient printing to obtain rod-shaped 3D printed product parts.

[0125] Step 2: Install the tool.

[0126] Step 3: Clamp the part into the three-jaw fixture of the tooling, align the reference, and clamp it firmly.

[0127] Step 4, processing, start the equipment, determine the coordinates, and process the parts according to the drawings to make the parts reach the required size.

[0128] Specifically include:

[0129] Step 41, centerless grinding: Roughly grind the outer circle of the part until it is polished.

[0130] Step 42, CNC lathe rough turning: the short side of the part's outer circle faces outward: flat surface, keep the dimension from the end face to the middle porous step to be 3.828 (+0.05, -0.05) mm. Surface removal: the long end of the flat outer circle can be exposed to light.

[0131] Step 43, rough milling by CNC milling machine: hold the outer circle (the short end of the outer circle of the part faces upward, pay attention to the length process allowance, and take the upper end face of the part as the reference): rough mill the inner hexagonal step into Φ2.2 (+0.05, -0.05)*3.1 (+0.1 / 0) depth, drill M2 thread bottom hole Φ1.65 (0 / -0.05)*7.1 (+0.1 / 0) depth (starting from the large end face of the part), chamfer with chamfering tool, and mill threads with thread cutter.

[0132] Step 44, CNC lathe: clamp the end of the outer circle of the part (the total length has a process allowance, based on the inner hexagonal end face of the part): turn a 23.1° (+0.25°, -0.25°) * Φ3.32 (+0.05, -0.05) inner cone, turn an outer step of size Φ3.7 (+0.01, -0.01) * 0.3 (+0.05, -0.05), chamfer, turn an outer circle of φ4 (+0.01, -0.01), a triangular spiral (double-line thread) and a triangular superimposed rectangular conical spiral [pay attention to the angle of the cone, refer to the three-dimensional drawing for processing, the spirals at both ends of the porous step in the middle of the blank are picked up to the boundary of the step (the end is inside the porous step), and a 45° chamfer transition is made at the step].

[0133] Step 45, electric spark: clamp the process table end of the part with a vise (there is a allowance for the total length process, based on the end face of the part): electric hexagon.

[0134] Step 46, machining center: four-axis clamping process table end (the total length process has a allowance, take the large end face of the external thread of the part as the reference, find the regular hexagon): mill the conical thread at three places with a size of 0.2 (+0.05, -0.05) (soft material, small knife processing).

[0135] Step 47, slow thread: Take the large end face of the external thread of the part as the reference: cut the total length 12.5 (+0.5 / +0.4).

[0136] Step 48, CNC lathe: Hold the outer cone flat small end surface to maintain the total length, and turn the R2.1754 (+0.05, -0.05) arc.

[0137] like Figure 4 and Figure 5 As shown, the finished size of the 3D printed tantalum part produced in this embodiment is completely consistent with the drawing, meeting the requirements of the drawing.

[0138] Embodiment 2: In this embodiment, the outer dimensions of the 3D printed tantalum part are φ3.5*12 mm, and the processing method of the 3D printed tantalum part comprises the following steps:

[0139] Step 1: prepare 3D printed product parts, use porous tantalum blanks to perform multi-component gradient printing to obtain rod-shaped 3D printed product parts.

[0140] Step 2: Install the tool.

[0141] Step 3: Clamp the part into the three-jaw fixture of the tooling, align the reference, and clamp it firmly.

[0142] Step 4, processing, start the equipment, determine the coordinates, and process the parts according to the drawings to make the parts reach the required size.

[0143] Specifically include:

[0144] Step 41, centerless grinding: Roughly grind the outer circle of the part until it is polished.

[0145] Step 42, CNC lathe rough turning: the short side of the part's outer circle faces outward: flat surface, keep the dimension from the end face to the middle porous step to be 3.2575 (+0.05, -0.05) mm. Surface removal: the long end of the flat outer circle can be exposed to light.

[0146] Step 43, rough milling by CNC milling machine: hold the outer circle (the short end of the outer circle of the part faces upward, pay attention to the length process allowance, and take the upper end face of the part as the reference): rough mill the inner hexagonal step into Φ2 (+0.05, -0.05)*3.2 (+0.1 / 0) depth, drill M2 thread bottom hole Φ1.65 (0 / -0.05)*7.2 (+0.1 / 0) depth (starting from the large end face of the part), chamfer with chamfering tool, and mill threads with thread cutter.

[0147] Step 44, CNC lathe: clamp one end of the outer circle (the total length has a process allowance, based on the inner hexagonal end face of the part): turn a 21.97° (+0.25°, -0.25°) * Φ2.7 (+0.05, -0.05) inner cone, turn an outer step of size Φ3.2 (+0.01, -0.01) * 0.3 (+0.05, -0.05), chamfer, turn an outer circle of φ3.5 (+0.01, -0.01), a triangular spiral (double-line thread) and a triangular superimposed rectangular conical spiral [pay attention to the cone angle, refer to the three-dimensional drawing for processing, the spirals at both ends of the porous step in the middle of the blank are picked up to the step boundary (the end is inside the porous step), and a 45° chamfer transition is made at the step].

[0148] Step 45, electric spark: clamp the process table end (the total length process has a allowance, based on the end face of the part): electric hexagon.

[0149] Step 46, machining center: four-axis clamping process table end (the total length process has a allowance, take the large end face of the external thread of the part as the reference, find the regular hexagon): mill the conical thread at three places with a size of 0.1532 (+0.05, -0.05) (soft material, processed with a small knife).

[0150] Step 47, slow thread: Take the large end face of the external thread of the part as the reference: cut the total length 12 (+0.5 / +0.4).

[0151] Step 48, CNC lathe: Hold the outer cone flat small end surface to maintain the total length, and turn the R1.5243 (+0.05, -0.05) arc.

[0152] like Figure 6 and Figure 7 As shown, the finished size of the 3D printed tantalum part produced in this embodiment is completely consistent with the drawing, meeting the requirements of the drawing.

[0153] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0154] 1. 3D printed tantalum parts combined with machining technology effectively supplement the shortcomings of medical 3D printed tantalum materials that are immature and cannot be used directly. The requirements of the internal shape, external shape and product appearance of 3D printed tantalum materials can be achieved through machining technology.

[0155] 2. The processing method of 3D printed tantalum parts enhances the strength of the blank by adjusting the density of the 3D blank, and combines the machining process to realize the replacement of tantalum materials for metals such as titanium alloys, thereby making up for the deficiencies of other metal materials in terms of biocompatibility, bioactivity and implant-bone bonding.

[0156] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for processing tantalum parts by 3D printing, characterized in that: The steps include: Step 1, preparing 3D printed product parts, using porous tantalum blanks to perform multi-component gradient to obtain rod-shaped 3D printed product parts; Step 2, installing the tool, installing the appropriate tool on the tool holder / tool ​​handle, and the tool holder / tool ​​handle is set on the CNC lathe; Step 3: Clamp the parts into the three-jaw fixture of the tooling, align the reference, and clamp them firmly; Step 4, processing, start the equipment, use milling and turning processing methods to process the parts according to the drawings so that the parts meet the size requirements.

2. The method for processing 3D printed tantalum parts according to claim 1, characterized in that: In the step 1, 3D printing of product parts is performed by means of multi-component gradient; The step 3 specifically includes: Step 31, check whether the clamping part of the three-jaw fixture of the tooling has any bumps or scratches; Step 32, clean the dirt on the surface of the three-jaw fixture of the tooling to avoid affecting the processing accuracy; Step 33, using a three-jaw fixture of the tooling to clamp the outer cylindrical flat end faces and / or outer circular arc surface of the part; Step 34, check and confirm that the parts have no burrs to prevent inadequate clamping; Step 35, use a dial indicator to align the part to within 0.01mm.

3. The method for processing 3D printed tantalum parts according to claim 2, characterized in that: In step 33, before the part is clamped by the three-jaw fixture of the tooling, the two ends of the length of the part are processed flat by a tool, and / or the part is processed into an arc shape by a tool.

4. The method for processing 3D printed tantalum parts according to claim 1, characterized in that: The step 4 specifically includes: Step 41, centerless grinding: rough grinding the surface of the part, and rough grinding the outer circle of the part to see the light; Step 42, rough turning with a CNC lathe: rough turning the two end surfaces of the part plane by using a CNC lathe to make the two end surfaces of the part plane visible to light; Step 43, rough milling with a CNC milling machine, rough milling the parts using a CNC milling machine; Step 44, CNC lathe, using a CNC lathe to process the parts; Step 45, electric spark: clamp the process step end of the part with a vise, and perform hexagonal electrode electric hexagonal processing on the part to the finished size according to the drawing requirements; Step 46, a machining center processes the threaded step of the part; Step 47, slow thread: cut the total length based on the large end face of the external thread of the part, set the tool based on the large end face of the external thread, and cut the total length of the part according to the drawing size with a reserve of 0.2mm; Step 48, CNC lathe: Use a CNC lathe to process the parts to the finished size.

5. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: The step 43 specifically includes: Step 431, check whether the fixture is damaged and whether the clamping surface of the fixture is clean; Step 432, testing the accuracy of the fixture and fixture, and checking whether it is qualified according to the size requirements of the fixture drawing; Step 433, after the fixture is installed, use a table to align the top surface and side surface of the fixture to ensure that the error is within 0.01 mm; Step 434, vertically clamp the part on the fixture, the part is pressed against the fixture and compacted, the clamping direction of the part should be consistent with the program sheet, and there should be no loose positioning groove problem; Step 435, use a 0.01mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and the pins are padded, flatten and align the parts to within 0.01mm to ensure the clamping accuracy, accurately check whether the tooling and the program route interfere with each other, compare with the tool list, simulate the tool path to prevent tool collision; Step 436, embrace the outer circle; embrace the outer circle with the upper end face of the part as the reference, make the inner hexagonal step size of the part larger than the required size of the finished product in the drawing by 0.2mm, use a drill to drill the bottom hole of the thread, chamfer with a chamfering tool, and mill the thread with a thread cutter.

6. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: The step 44 specifically includes: Step 441, check whether there are any bumps or scratches on the clamping part of the three-jaw fixture; Step 442, cleaning the dirt on the surface of the fixture to avoid affecting the processing accuracy; Step 443, using a fixture to clamp one end of the outer diameter of the part, check and confirm that the part has no burrs to prevent the part from being clamped in place; Step 444, using a dial indicator to align the part error within 0.01 mm; Step 445, use the tool head to turn the inner cone, outer step, chamfer arc, outer circle, double-line thread and triangle superimposed rectangular conical spiral line.

7. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: In step 45, during clamping, the forward and reverse positions of the parts are checked, the vise accuracy is tested, the parts are aligned and leveled, and a 0.01 mm feeler gauge is used to check whether the parts and the tooling surfaces are firmly fitted to prevent electrical damage to the parts.

8. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: The step 46 specifically includes: Step 461, check whether the fixture is damaged and whether the clamping surface is clean; Step 462, testing the accuracy of the fixture and fixture, and checking whether it is qualified according to the size requirements of the fixture drawing; Step 463, after the tooling is installed, align the upper surface and the side of the tooling by using a table to within 0.01 mm; Step 464, four-axis clamping process step end, check whether the part clamping direction is consistent with the program sheet, and whether there is any problem of loose positioning groove; Step 465, use a 0.01 mm feeler gauge, caliper or meter to measure and check whether the parts are clamped in place and padded; Step 466, using a milling cutter to mill the conical thread step.

9. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: In step 47, during clamping, check the positive and negative positions of the parts, check the accuracy of the vise, align and level them, and use a 0.01mm feeler gauge to check whether the parts and the tooling fitting surfaces are firmly fitted to prevent electrical damage to the parts; Parts must be clamped vertically, parts must be close to the tooling and compacted, and parts must be leveled and aligned within 0.01mm after clamping to ensure accurate clamping accuracy. Check whether there is any interference between the tooling and the program route, compare with the tool list, and simulate the tool path to prevent tool collision.

10. The method for processing 3D printed tantalum parts according to claim 4, characterized in that: The step 48 specifically includes: Step 481, check whether there are any bumps or scratches on the clamping parts of the fixture; Step 482, cleaning the dirt on the surface of the fixture to avoid affecting the processing accuracy; Step 483, when clamping the parts, check and confirm that the parts have no burrs to prevent the parts from being clamped in place; Step 484, using a dial indicator to align the part error to within 0.01 mm; Step 485, clamp the outer cone of the part with a three-jaw fixture, use a flat knife to flatten the small end face to maintain the overall length of the part, and use a tool head to turn the arc to the finished size of the part drawing.

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