Laser additive manufacturing woodworking spiral planer tool and preparation method thereof

Abstract

The invention belongs to the technical field of advanced manufacturing, and provides a laser additive manufacturing woodworking spiral planer tool and a preparation method thereof. The preparation method comprises the steps that firstly, quenched and tempered steel is adopted as a spiral cutter body material, optimally-designed laser additive manufacturing composite powder is adopted as a deposition material, and the laser additive manufacturing composite powder is melted and stacked layer by layer through a fine focusing laser beam under the driving of slicing data of a spiral planer blade CAD three-dimensional solid model; and the three-dimensional solid blade part with excellent comprehensive performance and a complex spiral curved surface is directly manufactured on the spiral cutter body in combination with effective regulation and control of technological parameters and the process. According to the manufacturing method, the bottleneck problems that the spiral planer tool is large in manufacturing difficulty, insufficient in comprehensive performance and poor in economical efficiency can be solved, the hardness, the tensile strength and the ductility of the manufactured woodworking spiral planer tool can reach HRC68-76, 2010-2520 MPa and 5.8-10.1% respectively, and the quality and precision of the machined surface are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the field of advanced manufacturing technologies, and provides a laser additive manufacturing woodworking spiral planer and a preparation method thereof. Background Art

[0002] At the present stage, due to the special spiral design of the cutting edge, the woodworking spiral planer has many advantages such as stable cutting, high machining surface accuracy, low cutting noise, small chips, less power consumption, and long service life. It is gradually replacing the straight-edge planer and playing an important role in wood cutting processing. However, due to the complex curved surface design and the widespread use of hard tool materials driven by the processing requirements of wood-based composites, the manufacturing of woodworking spiral planers is very difficult. The traditional preparation methods mainly include the following two:

[0003] One is to directly sinter the cemented carbide into a shape by powder metallurgy process, and then grind the cutting edge to form the required cutting edge shape. Due to the complex geometry of the spiral planer, special die design and optimized process parameters are required during the powder metallurgy process. However, due to the limitations of the process itself, it is still difficult to ensure the forming accuracy of the spiral planer. In addition, the high hardness of the cemented carbide makes it very difficult to grind the cutting edge, which greatly increases the complexity of the process. Moreover, since the whole tool is made of cemented carbide, the manufacturing cost is very expensive. In addition, due to the brittle nature of the cemented carbide, its strength and toughness are insufficient, and it is very easy to crack during the cutting process at high speed and under alternating impact loads, directly deteriorating the quality of the wood processing surface.

[0004] The other is to integrally process high-speed steel into a spiral planer by a composite process of stamping forming / electrical discharge forming and grinding, and then deposit a hard film on its surface by a coating technology to enhance the hardness and wear resistance of the cutting edge. To improve the disadvantage of edge passivation caused by coating, the edge of the substrate needs to be refined before coating to improve its dimensional and shape accuracy, which undoubtedly increases the process complexity and manufacturing cost. In addition, due to the weak physical interface bonding between the film and the substrate, the hard film is very easy to peel off under the action of cutting thermo-mechanical coupling, and the problem of insufficient strength and toughness of the hard material has not been fundamentally solved. Therefore, the improvement of the durability of the spiral planer is very limited.

[0005] In summary, the current difficulties in manufacturing spiral planers, insufficient comprehensive performance, and poor economy have become bottleneck problems restricting their development. Therefore, to overcome the above problems, new tool materials and advanced forming methods must be developed.

[0006] Laser additive manufacturing technology utilizes the basic principle of rapid prototyping. With metal powder as the raw material, driven by the sliced data of the 3D solid model of the metal part CAD, a high-energy laser beam is used to melt and stack the metal raw material layer by layer, directly manufacturing high-performance complex structure parts with the characteristics of non-equilibrium solidification structure. Due to the extraordinary metallurgical conditions and non-equilibrium rapid solidification process, it provides the possibility to introduce multi-element alloying, strong differential alloying, and various strengthening mechanisms that cannot be achieved by conventional methods, opening up a broad space for the design of new cutting tool materials. At the same time, this technology breaks through the principle limitations of traditional manufacturing technology on structural size and complexity, providing a transformative technical approach for the manufacturing of high-performance complex structure spiral planing tools.

[0007] To solve the problem that it is difficult to balance the hardness, wear resistance, strength, and toughness of hard cutting tool materials, it is necessary to develop new composite materials. While maintaining the performance advantages of each component material, through the complementarity and correlation of the performance of each component, a comprehensive performance that cannot be achieved by a single-component material is obtained. Based on this, high-speed steel with good strength and toughness is selected as the matrix material, and titanium carbide with high hardness and high thermal stability is selected as the hard reinforcement phase. Through scientific composition ratio, a hard particle-reinforced iron-based composite cutting tool material with excellent comprehensive performance is obtained. However, it should be noted that traditional high-speed steel has a high sensitivity to metallurgical defects due to its high proportion of carbon and alloy elements, and is extremely prone to cracking during the laser additive manufacturing process, making it impossible to fully exert the potential advantages of laser additive manufacturing high-performance planing tools. Therefore, based on the analysis of the relationship between the weldability of high-speed steel and its composition, an advanced "cluster-connected atom" structure model is adopted to construct a general cluster composition formula for weldable high-speed steel alloys. Based on this, with Ta and Ce as micro-alloying components, a brand-new composition of weldable high-speed steel is designed. Controlling the shape and properties is another key point in laser additive manufacturing spiral planing tools. Since the edge of the spiral planing tool is relatively thin, it is extremely prone to deformation during the layer-by-layer stacking process of laser additive manufacturing, directly affecting the size and shape accuracy of the planing tool. At the same time, during the layer-by-layer stacking process, each deposited layer will undergo a multi-cycle, variable-cycle, and strongly constrained thermal cycle effect, and the thermal cycle effect changes with the change of the number of deposited layers, resulting in the change of the solidification structure along the deposition direction, thus leading to non-uniformity of properties. Therefore, a unique process strategy of layer-by-layer displacement compensation and gradual change of process parameters is adopted to effectively solve the technical problems of deformation and uneven tissue distribution, and thus prepare spiral planing tools with high precision. Summary of the Invention

[0008] Aiming at the problems existing in the prior art, the present invention provides a laser additive manufacturing woodworking spiral planing tool and its preparation method, which can solve the bottleneck problems of difficult manufacturing, insufficient comprehensive performance, and poor economy of spiral planing tools.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A preparation method for a laser additive manufacturing woodworking spiral planer tool, the preparation method being as follows: First, use quenched and tempered steel with good strength and toughness and relatively low cost as the material for the spiral tool body, and use an optimized laser additive manufacturing composite powder as the deposition material. Driven by the sliced data of the CAD three-dimensional solid model of the spiral planer tool edge, layer by layer melt and deposit the laser additive manufacturing composite powder through a fine-focus laser beam, and combine with the effective regulation of process parameters and process to directly manufacture a three-dimensional solid edge with excellent comprehensive performance and complex spiral curved surface on the spiral tool body, specifically including the following steps:

[0011] The first step is to prepare the spiral tool body by traditional methods;

[0012] Select quenched and tempered steel with good strength and toughness (such as 45, 40Cr, etc.) as the material for the spiral tool body. First, use stamping and grinding processes to make the quenched and tempered steel into a spiral tool body with the required shape and size, and then perform conventional stress relief annealing to eliminate the internal stress during the processing and make it reach a stable state. Finally, grind the deposition surface of the spiral tool body, remove the oxide scale and dirt on it, and clean it with acetone solution.

[0013] The second step is to determine the composition of the laser additive manufacturing composite powder;

[0014] The composition of the laser additive manufacturing composite powder consists of two parts: The first part is to use gas atomization to make the optimized high-speed steel into powder with a particle size of 53 - 150 µm, which is used as the matrix material of the laser additive manufacturing composite powder; The second part is to select titanium carbide powder with a particle size of 53 - 100 µm as the hardening reinforcement phase.

[0015] Further, in the second step, based on thermo-mechanical coupling and phase field simulation analysis, taking the total mass of the laser additive manufacturing composite powder as 100%, the addition range of titanium carbide is 15 - 35 wt.%. Too little addition of titanium carbide does not significantly increase the wear resistance of the deposition layer, while too much addition of titanium carbide will increase the sensitivity of the deposition layer to metallurgical defects and directly deteriorate the performance and formability of the deposition layer;

[0016] Further, in the second step, by mass percentage, the nominal chemical composition of the optimized high-speed steel is Fe 84.9 C 0.84 Cr 0.29 Mo 5.0 W 6.1 V 1.9 Ta 0.3 Ce 0.7 .

[0017] The third step is to prepare the composite powder used for laser additive manufacturing;

[0018] Weigh and proportion the matrix material and the hard reinforcing phase determined in the second step according to the chemical composition of the composite powder. Then, place the mixed powder in a planetary ball mill and grind it for 6 - 8 h at a ball-to-powder ratio of 1.5:1 to 2:1 and a rotation speed of 100 - 150 rpm to achieve the homogenization of the mixed powder composition. Finally, place the well-mixed composite powder in the cartridge of the powder feeder.

[0019] Step 4, three-dimensional model establishment and data processing;

[0020] Use CAD software to construct a three-dimensional solid model of the cutting edge of the helical planer blade. Then, use slicing software to slice and layer the three-dimensional solid model, and through discretized data processing and data import, generate a scanning path in the laser additive manufacturing numerical control system.

[0021] Step 5, laser additive manufacturing;

[0022] Step 5.1, clamp the helical tool body prepared in the first step in the conformal fixture on the processing platform of the additive manufacturing system;

[0023] Step 5.2, under the protection of inert gas, start the powder feeder and the laser in sequence. Use a fine-focus laser beam (spot size ≤ 2 mm) to perform layer-by-layer conformal deposition of the composite powder prepared in the third step along the scanning path generated in the fourth step under the drive of the numerical control system.

[0024] Furthermore, during the conformal deposition in Step 5.2, starting from the second deposition layer, the powder feeding head offsets 0.1 - 0.2 mm towards the rake face side of the woodworking helical planer and raises 0.8 - 1.2 mm relative to the previous deposition layer to respectively maintain the deposition perpendicularity of the rake face of the woodworking helical planer and the consistency of the powder flow convergence distance; starting from the second deposition layer, gradually reduce the laser power and the powder feeding amount (the reduction per layer is 250 - 350 W and 1.5 - 2.5 g / min respectively) to relieve the heat accumulation effect during the deposition process, increase the uniformity of the tissue distribution, and inhibit the generation of metallurgical defects such as pores and cracks; gradually reduce the overlapping rate (the reduction per layer is between 5 - 10%) under the constraint of the geometric data of the cutting edge slice to obtain the required cutting edge size and shape. In this way, the laser additive manufacturing of a three-dimensional cutting edge with a complex curved surface is realized.

[0025] Furthermore, in Step 5.2:

[0026] The inert gas is argon with a flow rate of 9 - 20 L / min;

[0027] The laser additive manufacturing process parameters are: laser power 1800 - 2600 W, scanning speed 18 - 30 mm / s, spot size 1.5 - 2 mm, overlapping rate 30 - 50%;

[0028] The process parameters of the powder feeder are as follows: the powder feeding rate is 13.8 - 19.4 g / min;

[0029] Step 6, subsequent processing;

[0030] Use a profiling grinder to precisely grind the front and rear tool faces of the three-dimensional cutting edge entity on the spiral tool body obtained in the fifth step to the final shape and dimensional accuracy, and obtain a woodworking spiral planer tool.

[0031] A woodworking spiral planer tool manufactured by laser additive manufacturing is obtained by the above preparation method. The hardness, tensile strength, and elongation of the woodworking spiral planer tool can reach HRC68 - 76, 2010 - 2520 MPa, and 5.8 - 10.1% respectively.

[0032] The effects and benefits of the present invention are as follows:

[0033] (1) The present invention has excellent mechanical and cutting properties. Due to the synergistic effect of the dispersed hard titanium carbide particles and the solidification structure of the ultrafine high-speed steel matrix material, the cutting edge of the woodworking spiral planer tool exhibits excellent comprehensive mechanical properties. Its hardness, tensile strength, and elongation can reach HRC68 - 76, 2010 - 2520 MPa, and 5.8 - 10.1% respectively. Compared with traditional carbide woodworking spiral planer tools, when the hardness values are similar, the strength and toughness of the present invention are increased by 1.8 - 2.3 times and 11.6 - 20.2 times respectively compared with carbide. Moreover, under high-speed and impact load-bearing cutting conditions, the cutting edge can still maintain a high sharpness for a long time, greatly improving the quality and accuracy of the wood processing surface.

[0034] (2) The present invention has high forming accuracy and wide adaptability. Using a fine-focus laser beam to deposit layer by layer and channel by channel according to the cutting edge slice graphic trajectory, and supplemented by dimensional compensation, high-precision manufacturing of the cutting edge is achieved. Its highest forming accuracy can reach ±30 μm. Moreover, the unique forming process of laser additive manufacturing has a unique manufacturing advantage in processing complex geometric structures and can be widely used for the customization and diversification of various woodworking profile tools.

[0035] (3) The present invention has high durability and good economy. Due to the excellent mechanical and cutting properties of the additive manufacturing cutting edge and the good metallurgical interface bonding between the cutting edge and the tool body, its service life is increased by 1.5 - 3 times compared with traditional carbide woodworking spiral planer tools. In addition, due to the use of a split structure design, a three-dimensional solid cutting edge is directly manufactured on an inexpensive tool body, and only a little precision grinding of the cutting edge surface is required to achieve the designed dimensional and shape accuracy, resulting in a 65 - 80% reduction in processing cost compared with integral carbide spiral planer tools. Specific embodiments

[0036] The following further illustrates the technical solutions of the present invention in combination with specific embodiments.

[0037] Example 1:

[0038] In the first step, 45 steel is selected as the tool body material, and it is made into a spiral tool body with dimensions of 300 mm × 30 mm × 5 mm by stamping and grinding processes. Then it is placed in a box furnace and kept at 850 °C for 6 h to eliminate the internal stress during the processing. Finally, the deposition surface of the tool body is polished to remove the oxide scale and dirt on it. After careful cleaning with acetone solution, it is placed in the conforming fixture on the processing platform of a 6KW fiber laser additive manufacturing system;

[0039] In the second step, Fe with a particle size of 53 - 150 μm 84.9 C 0.84 Cr 0.29 Mo 5.0 W 6.1 V 1.9 Ta 0.3 Ce 0.7 and TiC with a particle size of 35 - 75 μm are weighed and proportioned according to a mass percentage of 75:25. Then they are placed in a planetary ball mill and ground for 6 h at a ball-to-powder ratio of 2:1 and a rotation speed of 100 rpm. Finally, the mixed composite powder is poured into the barrel of a coaxial powder feeder;

[0040] In the third step, based on the construction and slicing layering of the three-dimensional model of the spiral planer blade edge, the scanning path is generated in the numerical control system. Then, the coaxial powder feeder and the laser switch are started in sequence, and the conforming deposition is carried out layer by layer along the planned scanning path driven by the numerical control system to directly manufacture the spiral planer blade edge with the required shape and size on the tool body. The specific process parameters are as follows:

[0041] For the first deposition layer, the laser power is 2.5 KW, the scanning speed is 25 mm / s, the spot size is 2 mm, the overlap rate is 50%, the powder feeding rate is 19.4 g / min, and the argon protection flow rate is 20 L / min;

[0042] For the second deposition layer, the lateral compensation and upward displacement of the powder feeding head at the starting position are 0.1 mm and 1.0 mm respectively, the laser power is 2.2 KW, the scanning speed is 25 mm / s, the spot size is 2 mm, the overlap rate is 40%, the powder feeding rate is 17.4 g / min, and the argon protection flow rate is 20 L / min;

[0043] For the third deposition layer, the lateral compensation and upward displacement of the powder feeding head at the starting position are 0.1 mm and 0.8 mm respectively, the laser power is 2.0 KW, the scanning speed is 25 mm / s, the spot size is 2 mm, the overlap rate is 35%, the powder feeding rate is 15.7 g / min, and the argon protection flow rate is 20 L / min;

[0044] For the fourth deposition layer, the lateral compensation and upward displacement of the powder feeding head at the starting position are 0.1 mm and 0.6 mm respectively, the laser power is 1.8 KW, the scanning speed is 25 mm / s, the spot size is 2 mm, the overlapping rate is 30%, the powder feeding rate is 13.8 g / min, and the argon protection flow rate is 20 L / min;

[0045] Step 4: Use a profiling grinding machine to precisely grind the front and rear cutting surfaces of the blade of the woodworking helical planer to the final shape and dimensional accuracy, obtaining the woodworking helical planer.

[0046] The comparative example is: a traditional cemented carbide woodworking helical planer.

[0047] The performance data of the woodworking helical planers prepared in this embodiment and the comparative example:

[0048] Mechanical properties Laser additive manufacturing woodworking spiral planer tool (this invention) Cemented carbide woodworking spiral planer tool (comparative example) Rockwell hardness (HRC) 74 76 Tensile strength (MPa) 2520 1100 Elongation rate (%) 9.8 0.5

[0049] It can be analyzed from Table 1 that under the condition of similar hardness values, the strength (tensile strength) and toughness (elongation) of this embodiment are increased by 2.3 times and 19.6 times respectively compared with the comparative example.

[0050] The above embodiments only represent the implementation manners of the present invention, but should not be construed as limiting the scope of the present invention patent. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. A preparation method of a laser additive manufacturing woodworking spiral planer tool, characterized in that, The preparation method comprises the following steps: In the first step, a spiral cutter body is prepared by a traditional method; In the second step, the composition of the laser additive manufacturing composite powder is determined; The composition of the laser additive manufacturing composite powder includes high-speed steel and titanium carbide, where the high-speed steel is the matrix material and the titanium carbide is the hard reinforcing phase; In the third step, the composite powder used for laser additive manufacturing is prepared; The matrix material and the hard reinforcing phase determined in the second step are weighed and proportioned according to the chemical composition of the composite powder and then ball-milled. The ball-milled composite powder is placed in the cartridge of the powder feeder; In the fourth step, three-dimensional model establishment and data processing are carried out; First, a three-dimensional solid model of the cutting edge of the spiral planer blade is constructed, then the three-dimensional solid model is sliced and layered, and finally a scanning path is generated in the laser additive manufacturing numerical control system; In the fifth step, laser additive manufacturing is carried out; Step 5.1, the spiral cutter body prepared in the first step is clamped in the conformal fixture on the processing platform of the additive manufacturing system; Step 5.2, under the protection of inert gas, the powder feeder and the laser are started in sequence. A fine-focus laser beam is used to perform layer-by-layer conformal deposition of the composite powder prepared in the third step along the scanning path generated in the fourth step under the drive of the numerical control system; In the sixth step, subsequent processing is carried out; The front and back tool faces of the three-dimensional cutting edge entity on the spiral cutter body obtained in the fifth step are precision ground by a profiling grinder to the final shape and dimensional accuracy to obtain a woodworking spiral planer blade.

2. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, characterized in that, The first step is as follows: Select quenched and tempered steel as the material of the spiral cutter body. First, the quenched and tempered steel is made into a spiral cutter body with the required shape and size by stamping and grinding processes, then conventional stress relief annealing is carried out, and finally the deposition surface of the spiral cutter body is ground and cleaned.

3. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, characterized in that, In the second step: The matrix material is powder made of optimized high-speed steel with a particle size of 53 - 150 µm by gas atomization method; the hard reinforcing phase is titanium carbide with a particle size of 53 - 100 µm.

4. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, wherein In the second step described above: based on 100% of the total mass of the laser additive manufacturing composite powder, the addition range of titanium carbide is 15 - 35 wt.%; by mass percentage, the nominal chemical composition of the optimized high-speed steel is Fe 84.9 C 0.84 Cr 0.29 Mo 5.0 W 6.1 V 1.9 Ta 0.3 Ce 0.7 .

5. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, characterized in that, In the third step: The ball milling is realized in a planetary ball mill, the ball-to-material ratio is 1.5:1 - 2:1, the rotation speed is 100 - 150 rpm, and the time is 6 - 8 h.

6. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, characterized in that, In step 5.2, the spot size of the fine-focus laser beam ≤ 2 mm.

7. The preparation method of a laser additive manufacturing woodworking spiral planer cutter according to claim 1, characterized in that, During the conformal deposition process in step 5.2, starting from the second deposition layer, the powder feeding head is offset a certain distance towards the front tool face side of the spiral cutter body and raised a certain distance relative to the previous deposition layer to respectively maintain the deposition perpendicularity of the front tool face of the spiral cutter body and the consistency of the powder flow convergence distance; starting from the second deposition layer, the laser power and the powder feeding amount are gradually reduced layer by layer; under the constraint of the geometric data of the cutting edge slice, the overlapping rate is gradually reduced layer by layer to obtain the required cutting edge size and shape; thus realizing the laser additive manufacturing of a three-dimensional cutting edge with a complex curved surface.

8. The preparation method of a laser additive manufacturing woodworking spiral planer cutter according to claim 7, characterized in that, During the conformal deposition process in step 5.2: Starting from the second deposition layer, the offset distance of the powder feeding head towards the front tool face side of the spiral cutter body is 0.1 - 0.2 mm, and the raised distance relative to the previous deposition layer is 0.8 - 1.2 mm; Starting from the second deposition layer, the reduction of the laser power and the powder feeding amount per layer are 250 - 350 W and 1.5 - 2.5 g / min respectively.

9. The preparation method of a laser additive manufacturing woodworking spiral planer tool according to claim 1, characterized in that, In step 5.2: The inert gas is argon, and the flow rate is 9 - 20 L / min; The process parameters of laser additive manufacturing are as follows: laser power is 1800 - 2600 W, scanning speed is 18 - 30 mm / s, spot size is 1.5 - 2 mm, and overlapping rate is 30 - 50%; The process parameters of the powder feeder are as follows: powder feeding rate is 13.8 - 19.4 g / min.

10. A laser additive manufacturing woodworking spiral planer tool, characterized in that, The woodworking spiral planer knife is obtained by using the preparation method described in any one of claims 1 - 9, and the hardness, tensile strength, and elongation of the woodworking spiral planer knife can reach HRC68 - 76, 2010 - 2520 MPa, and 5.8 - 10.1% respectively.