Laser additive manufacturing woodworking spiral planer and preparation method thereof

Abstract

The present invention belongs to the field of advanced manufacturing technology and provides a laser additive manufacturing woodworking spiral planer and its preparation method. The preparation method is as follows: first, quenched and tempered steel is used as the spiral cutter body material, and an optimized laser additive manufacturing composite powder is used as the deposition material. Driven by the slice data of the CAD three-dimensional solid model of the spiral planer blade, the laser additive manufacturing composite powder is melted and deposited layer by layer by a finely focused laser beam. Combined with the effective regulation of process parameters and processes, a three-dimensional solid blade with excellent comprehensive performance and complex spiral surfaces is directly manufactured on the spiral cutter body. The present invention can solve the bottleneck problems of spiral planer manufacturing difficulty, insufficient comprehensive performance and poor economic efficiency. The hardness, tensile strength and elongation of the woodworking spiral planer produced can reach HRC68~76, 2010~2520MPa and 5.8~10.1% respectively, greatly improving the quality and precision of the processed surface.

Description

Technical Field

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

[0002] At present, woodworking spiral planers are gradually replacing straight-edged planers and occupying an important position in wood cutting due to their unique spiral design of the cutting edge, which has many advantages such as smooth cutting, high surface precision, low cutting noise, small chips, low power consumption and long life. However, due to the complex surface design and the widespread use of hard tool materials driven by the demand for wood composite material processing, the manufacturing of woodworking spiral planers is very difficult. There are two main traditional preparation methods:

[0003] One method is to use powder metallurgy to directly sinter carbide into shape, and then grind the blade to form the desired edge shape. Due to the complex geometric shape of the spiral planer cutter, special mold 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 cutter. The high hardness of cemented carbide makes edge grinding very difficult, which greatly increases the complexity of the process. In addition, the entire tool is made of cemented carbide, and the manufacturing cost is very expensive. In addition, the inherent hardness and brittleness of cemented carbide result in its insufficient strength and toughness. It is very easy to chip the edge during high-speed cutting under alternating impact loads, which directly deteriorates the quality of the wood processing surface.

[0004] The second method is to use a composite process of stamping / electro-spark forming and grinding to process the high-speed steel into a spiral planer as a whole, and then use coating technology to deposit a hard film on its surface to enhance the hardness and wear resistance of the cutting edge. In order to improve the disadvantage of edge passivation caused by coating, the substrate blade needs to be refined before coating to improve its size 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 thermal coupling, and the problem of insufficient strength and toughness of hard materials has not been fundamentally solved. Therefore, the improvement of the durability of the spiral planer is very limited.

[0005] In summary, the current difficulty in manufacturing spiral planer cutters, insufficient comprehensive performance and poor economy have become bottleneck problems restricting their development. Therefore, to overcome the above problems, it is necessary to develop new tool materials and advanced forming methods.

[0006] Laser additive manufacturing technology utilizes the basic principles of rapid prototyping, using metal powder as the raw material. Driven by slice data from a 3D solid model of the metal part using a CAD machine, a high-energy laser beam is used to melt and deposit the metal raw material layer by layer, directly producing high-performance, complex structural parts with non-equilibrium solidification microstructure characteristics. Due to the extraordinary metallurgical conditions and the non-equilibrium rapid solidification process, it is possible to introduce multi-element alloying, strong differential alloying, and various strengthening mechanisms that cannot be achieved by conventional methods, thereby opening up vast space for the design of new tool materials. At the same time, this technology breaks through the principle limitations of traditional manufacturing technology on structural size and complexity, providing a revolutionary technical approach for the manufacture of high-performance, complex spiral planer cutters.

[0007] To address the challenge of balancing hardness, wear resistance, strength, and toughness in hard tool materials, new composite materials need to be developed. These materials, while maintaining the advantages of each component material, achieve comprehensive performance unattainable by a single material through complementary and interdependent performance. To this end, high-speed steel (HSS), with excellent strength and toughness, was selected as the matrix material, and titanium carbide (TC), with its high hardness and thermal stability, as the hard reinforcement. Through a strategic compositional approach, a hard particle-reinforced iron-based composite tool material with excellent overall performance was achieved. However, it should be noted that conventional HSS, due to its high carbon and alloying element content, is highly susceptible to metallurgical defects and prone to cracking during laser additive manufacturing (LAM), hindering the full potential of high-performance planer cutters manufactured using LAM. To this end, based on an analysis of the relationship between HSS weldability and composition, an advanced "cluster-connecting atom" structural model was employed to construct a general cluster formula for weldable HSS alloys. Based on this formula, a novel weldable HSS composition was designed using Ta and Ce as microalloying elements. Shape and property control are another key aspect of LAM spiral planer cutters. Because the blade of a spiral planer is thin, it is very easy to deform during the layer-by-layer deposition process of laser additive manufacturing, which directly affects the size and shape accuracy of the planer. At the same time, during the layer-by-layer deposition process, each deposited layer will undergo multiple cycles, variable cycles, and strong constraints. The thermal cycling effect varies with the number of deposited layers, causing the solidification structure to change along the deposition direction, resulting in uneven performance. To this end, 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 structure distribution, thereby producing spiral planers with high precision. Summary of the Invention

[0008] In response to the problems existing in the prior art, the present invention provides a laser additive manufacturing woodworking spiral planer and a preparation method thereof, which can solve the bottleneck problems of the spiral planer being difficult to manufacture, having insufficient comprehensive performance and poor economy.

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

[0010] A method for preparing a laser additively manufactured woodworking spiral planer blade comprises the following steps: first, using a relatively inexpensive quenched and tempered steel having excellent strength and toughness as the spiral blade body material, and using an optimized laser additively manufactured composite powder as the deposition material; driven by slice data of a 3D solid model of the spiral planer blade using a finely focused laser beam, the laser additively manufactured composite powder is melted and deposited layer by layer; and combined with effective control of process parameters and processes, a 3D solid blade with excellent comprehensive performance and a complex spiral surface is directly manufactured on the spiral blade body. The method specifically comprises the following steps:

[0011] In the first step, the spiral cutter body is prepared using the traditional method;

[0012] Quenched and tempered steel (such as 45, 40Cr, etc.) with good strength and toughness is selected as the material for the spiral cutter body. First, the quenched and tempered steel is made into a spiral cutter body of the required shape and size using stamping and grinding processes. Then, conventional stress relief annealing is performed to eliminate the internal stress during the processing and make it reach a stable state. Finally, the surface to be deposited of the spiral cutter body is ground to remove the oxide scale and dirt on it, and then cleaned with acetone solution.

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

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

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

[0016] Furthermore, in the second step, 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] The matrix material and hard reinforcement phase determined in the second step are weighed and proportioned according to the chemical composition of the composite powder. The mixed powder is then placed in a planetary ball mill and ground for 6 to 8 hours at a ball-to-material ratio of 1.5:1 to 2:1 and a speed of 100 to 150 rpm to achieve homogenization of the mixed powder components. Finally, the mixed composite powder is placed in the barrel of the powder feeder.

[0019] The fourth step is 3D model establishment and data processing;

[0020] CAD software is used to construct a three-dimensional solid model of the spiral planer blade, and then slicing software is used to slice and layer the three-dimensional solid model. Through discrete data processing and data import, the scanning path is generated in the laser additive manufacturing CNC system.

[0021] Step 5: Laser additive manufacturing;

[0022] Step 5.1, clamping the spiral cutter body prepared in the first step into the conformal fixture on the processing platform of the additive manufacturing system;

[0023] In step 5.2, under the protection of inert gas, the powder feeder and the laser are started in sequence, and a finely focused laser beam (spot size ≤ 2 mm) is used under the drive of the numerical control system to perform layer-by-layer conformal deposition of the composite powder prepared in the third step according to the scanning path generated in the fourth step.

[0024] Furthermore, during conformal deposition in step 5.2, starting from the second deposition layer, the powder feed head is offset by 0.1-0.2 mm toward the rake face of the woodworking spiral planer and raised by 0.8-1.2 mm relative to the previous deposition layer to maintain the deposition verticality and powder flow convergence distance of the woodworking spiral planer. Starting from the second deposition layer, the laser power and powder feed rate are gradually reduced (by 250-350 W and 1.5-2.5 g / min per layer, respectively) to mitigate heat accumulation during deposition, increase microstructure uniformity, and suppress metallurgical defects such as pores and cracks. Under the constraints of the blade slice geometry, the overlap ratio is gradually reduced (by 5-10% per layer) to achieve the desired blade size and shape. This enables laser additive manufacturing of three-dimensional blades with complex surfaces.

[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, overlap rate 30-50%;

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

[0029] Step 6: Subsequent processing;

[0030] The front and rear blade surfaces of the three-dimensional blade entity on the spiral cutter body obtained in the fifth step are finely ground by a profile grinder to the final shape and dimensional accuracy to obtain a woodworking spiral planer cutter.

[0031] A laser additively manufactured woodworking spiral planer is manufactured using the above-mentioned preparation method. The hardness, tensile strength and elongation of the woodworking spiral planer 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 solidified structure of the ultra-fine high-speed steel matrix material, the blade of the woodworking spiral planer 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 planers, under the condition of similar hardness values, the strength and toughness of the present invention are respectively improved by 1.8-2.3 times and 11.6-20.2 times compared with carbide. Moreover, the blade can still maintain high sharpness for a long time under high-speed cutting conditions and impact loads, greatly improving the quality and precision of the wood processing surface.

[0034] (2) The present invention has high forming accuracy and wide adaptability. It uses a finely focused laser beam to perform layer-by-layer deposition along the blade slice pattern trajectory, supplemented by dimensional compensation, to achieve high-precision manufacturing of the blade. Its highest forming accuracy can reach ±30μm. The unique forming process of laser additive manufacturing has unique manufacturing advantages in processing complex geometric structures. It can be widely used in the customized and diversified manufacturing of various woodworking knives.

[0035] (3) The present invention has high durability and good economy. Due to the excellent mechanical and cutting properties of the additively manufactured blade and the good metallurgical interface bonding between the blade and the cutter body, its service life is increased by 1.5 to 3 times compared with the traditional carbide woodworking spiral planer. In addition, it adopts a split structure design, and a three-dimensional solid blade is directly manufactured on the cheap cutter body. Only a slight fine grinding of the blade surface is required to achieve the designed size and shape accuracy, resulting in a processing cost of 65 to 80% lower than that of the integral carbide spiral planer. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0037] Example 1:

[0038] In the first step, 45 steel was selected as the blade body material and formed into a spiral blade body with dimensions of 300mm × 30mm × 5mm through stamping and grinding. It was then placed in a box furnace and kept at 850°C for 6 hours to eliminate internal stress during processing. Finally, the surface of the blade to be deposited was polished to remove the oxide scale and dirt. After being carefully cleaned with acetone solution, it was placed in a conformal fixture on the processing platform of a 6KW fiber laser additive manufacturing system.

[0039] In the second step, Fe 84.9 C 0.84 Cr 0.29 Mo 5.0 W 6.1 V 1.9 Ta 0.3 Ce 0.7 The mixture was weighed and mixed with TiC with a particle size of 35 to 75 μm in a mass ratio of 75:25. The mixture was then placed in a planetary ball mill and ground at a ball-to-material ratio of 2:1 and a speed of 100 rpm for 6 h. The mixed composite powder was finally poured into the barrel of a coaxial powder feeder.

[0040] In the third step, based on the 3D model construction and slicing layer processing of the spiral planer blade, a scanning path is generated in the CNC system. Then, the coaxial powder feeder and laser switch are started in sequence. Driven by the CNC system, conformal deposition is performed layer by layer according to the planned scanning path, and the spiral planer blade of the required shape and size is directly manufactured on the cutter body. The specific process parameters used are as follows:

[0041] The first deposition layer had a laser power of 2.5 KW, a scanning speed of 25 mm / s, a spot size of 2 mm, an overlap rate of 50%, a powder feed rate of 19.4 g / min, and an argon shielding flow rate of 20 L / min.

[0042] At the starting position of the second deposition layer, the lateral compensation and upward displacement of the powder feeder were 0.1 mm and 1.0 mm, respectively. The laser power was 2.2 kW, the scanning speed was 25 mm / s, the spot size was 2 mm, the overlap rate was 40%, the powder feed rate was 17.4 g / min, and the argon shielding flow rate was 20 L / min.

[0043] At the starting position of the third deposition layer, the lateral compensation and upward displacement of the powder feeder were 0.1 mm and 0.8 mm, respectively. The laser power was 2.0 kW, the scanning speed was 25 mm / s, the spot size was 2 mm, the overlap rate was 35%, the powder feed rate was 15.7 g / min, and the argon shielding flow rate was 20 L / min.

[0044] At the starting position of the fourth deposition layer, the lateral compensation and upward displacement of the powder feeder were 0.1 mm and 0.6 mm, respectively. The laser power was 1.8 kW, the scanning speed was 25 mm / s, the spot size was 2 mm, the overlap rate was 30%, the powder feed rate was 13.8 g / min, and the argon shielding flow rate was 20 L / min.

[0045] The fourth step is to use a profile grinder to grind the front and rear blades of the woodworking spiral planer blade to the final shape and size accuracy to obtain the woodworking spiral planer blade.

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

[0047] The performance data of the woodworking spiral planer obtained in this embodiment and the comparative example are as follows:

[0048] Category Mechanical Properties Laser additive manufacturing of woodworking spiral planer (invention) Carbide woodworking spiral planer (comparative example) Rockwell hardness (HRC) 74 76 Tensile strength (MPa) 2520 1100 Elongation (%) 9.8 0.5

[0049] From the analysis of Table 1, it can be seen that, under the condition of similar hardness values, the strength (tensile strength) and toughness (elongation) of the embodiment of the present invention are respectively increased by 2.3 times and 19.6 times compared with the comparative example.

[0050] The above-described embodiments merely express the implementation methods of the present invention, but should not be understood as limiting the scope of the patent of the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a woodworking spiral planer by laser additive manufacturing, characterized in that: The preparation method The following steps are involved: In the first step, the spiral cutter body is prepared using the traditional method; The second step is to determine the composition of the composite powder for laser additive manufacturing; The laser additive manufacturing composite powder comprises high-speed steel and titanium carbide, wherein the high-speed steel is the matrix material and the titanium carbide is the hard reinforcing phase; based on 100% of the total mass of the laser additive manufacturing composite powder, the titanium carbide addition range is 15-35 wt.%; in terms of mass percentage, the nominal chemical composition of the 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 ; The third step is to prepare the composite powder used for laser additive manufacturing; The matrix material and the hard reinforcement phase determined in the second step are weighed and proportioned according to the chemical composition of the composite powder and then ball-milled. The milled composite powder is placed in the barrel of the powder feeder; The fourth step is 3D model establishment and data processing; First, a 3D solid model of the spiral planer blade is constructed, then the 3D solid model is sliced ​​and layered, and finally a scanning path is generated in the laser additive manufacturing CNC system. Step 5: Laser additive manufacturing; Step 5.1, clamping the spiral cutter body prepared in the first step into the conformal fixture on the processing platform of the additive manufacturing system; Step 5.2: Under inert gas protection, the powder feeder and the laser are started in sequence, and the composite powder prepared in the third step is deposited layer by layer according to the scanning path generated in the fourth step using a finely focused laser beam driven by a numerical control system; During the conformal deposition process in step 5.2, starting from the second deposition layer, the powder feed head is offset a certain distance toward the rake face of the spiral cutter body and raised a certain distance relative to the previous deposition layer to maintain the deposition verticality of the rake 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 powder feed rate are gradually reduced; and under the constraints of the blade section geometry data, the overlap ratio is gradually reduced to obtain the desired blade size and shape, thereby achieving laser additive manufacturing of a three-dimensional blade with a complex curved surface; Step 6: Subsequent processing; The front and rear blade surfaces of the three-dimensional blade entity on the spiral cutter body obtained in the fifth step are finely ground by a profile grinder to the final shape and dimensional accuracy to obtain a woodworking spiral planer cutter.

2. The method for preparing a woodworking spiral planer by laser additive manufacturing according to claim 1, characterized in that: The first step is to select quenched and tempered steel as the spiral cutter body material, firstly use stamping and grinding technology to make the quenched and tempered steel into a spiral cutter body of the required shape and size, then perform conventional stress relief annealing, and finally grind and clean the surface of the spiral cutter body to be deposited.

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

4. The method for preparing a woodworking spiral planer by laser additive manufacturing according to claim 1, characterized in that: In the third step, the ball milling is carried out in a planetary ball mill with a ball-to-material ratio of 1.5:1 to 2:1, a rotation speed of 100 to 150 rpm, and a time of 6 to 8 hours.

5. The method for preparing a woodworking spiral planer cutter by laser additive manufacturing according to claim 1, characterized in that: In step 5.2, the spot size of the finely focused laser beam .

6. The method for preparing a woodworking spiral planer cutter by laser additive manufacturing 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 by 0.1-0.2 mm toward the rake face of the spiral cutter body, and is raised by 0.8-1.2 mm relative to the previous deposition layer. Starting from the second deposition layer, the laser power and powder feed rate were reduced by 250~350W and 1.5~2.5 g / min per layer, respectively.

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

8. A laser additive manufacturing woodworking spiral planer, characterized in that: The woodworking spiral planer is obtained by the preparation method according to any one of claims 1 to 7. The hardness, tensile strength and elongation of the woodworking spiral planer can reach HRC68-76, 2010-2520 MPa and 5.8-10.1% respectively.