Method for laser selective melting forming high-performance aluminum profile extrusion die

Abstract

A method for forming high-performance aluminum profile extrusion die by laser selective melting, the method is characterized by: (1) slicing the CAD model of the aluminum profile extrusion die part to be prepared, generating a series of laser selective melting forming two-dimensional scanning tracks; (2) according to the generated scanning track, point by point, line by line, layer by layer, the aluminum profile extrusion die is accumulated into a three-dimensional entity. Among them, the chemical composition of the iron-based alloy powder for preparing the aluminum profile extrusion die is: C≤0.3wt.%; Si 0.5-1.5wt.%; Ni 2.0-3.2wt.%; Mn 0.5-0.8wt.%; Cr 4.5-6.5wt.%; V 0.5-1.5wt.%; Mo 2.0-3.5wt.%; Cu 5.0-8.0wt.%; Al 0.5-3.5wt.%; SiB4 5-15wt.%; graphene nanosheet 1.5-3wt.%; the balance is Fe. The aluminum profile extrusion die prepared by the method has excellent high-temperature oxidation resistance, crack self-healing ability and self-lubrication performance when serving at a temperature of 500-700℃: the tensile strength is 1.2-1.3GPa, the tensile strength is 1.6-1.8GPa, the hardness is 58-62HRC, the elongation is 18.5-22%, and the service life is 2-5 times that of H13 steel.

Description

Technical Field

[0001] This invention relates to a method for laser selective melting to form a high-performance aluminum profile extrusion die, belonging to the field of laser additive manufacturing (3D printing) technology. Background Technology

[0002] Aluminum profiles possess advantages such as low density, high specific strength, good electrical and thermal conductivity, corrosion resistance, aesthetic appeal, and ease of processing and forming, making them widely used in aerospace, aviation, construction, transportation, machinery manufacturing, petroleum, and chemical industries. However, the working environment of aluminum profile extrusion dies is harsh. Under the triple effects of high temperature (520–550℃), high pressure (hundreds of megapascals), and abrasive wear (hard phase inclusions of Al2O3), the service life of aluminum profile extrusion dies is significantly shortened. This not only affects the stability of aluminum profile product quality but also increases production costs and reduces economic efficiency for enterprises. Therefore, improving the quality and service life of extrusion dies has always been a pressing issue for the aluminum processing industry.

[0003] Selective laser melting (SLM) is a novel additive manufacturing or 3D printing technology that utilizes the thermal effect of a laser beam to completely melt metal powder, followed by cooling and solidification to form complex three-dimensional parts. This technology features rapid heating, high processing efficiency, and rapid cooling, enabling the direct formation of near-perfectly dense metal parts with excellent mechanical properties. Furthermore, leveraging the immiscibility of the Cu-Fe liquid phases, the cooling rate using SLM can reach 10⁻⁶. 5-8 The K / s ratio can significantly shorten the Stokes settling and Marangoni migration times, resulting in aluminum profile extrusion dies for in-situ self-assembled spherical copper-rich particle dispersion-strengthened iron-based alloys. Simultaneously, utilizing the self-healing crack-forming borosilicate glass formed by the reaction of SiB4 particles with oxygen at high temperatures, and the self-lubricating properties of spherical copper-rich particles and graphene nanosheets, a high-performance aluminum profile extrusion die with crack self-healing and self-lubricating properties was prepared using laser selective melting technology. This method has not yet been reported in the literature. Summary of the Invention

[0004] The purpose of this invention is to provide a method for laser selective melting to form high-performance aluminum profile extrusion dies. This invention is achieved as follows: the method and steps are as follows:

[0005] (1) Iron-based alloy powder with a particle size of 40-60 μm was used as the forming powder for laser selective melting. Its chemical composition was: C ≤ 0.3 wt.%; Si 0.5-1.5 wt.%; Ni 2.0-3.2 wt.%; Mn 0.5-0.8 wt.%; Cr 4.5-6.5 wt.%; V 0.5-1.5 wt.%; Mo 2.0-3.5 wt.%; Cu 5.0-8.0 wt.%; Al 0.5-3.5 wt.%; SiB4 5-15 wt.%; graphene nanosheets 1.5-3 wt.%; balance Fe.

[0006] (2) The CAD model of the aluminum profile extrusion die part with the support structure is sliced ​​into layers, and a series of laser selective melting forming two-dimensional scanning trajectories are generated according to the slice contour information; the laser selective melting forming chamber is evacuated and then filled with argon gas; the carbon steel plate with rust removal and sandblasting treatment is heated to 700-750℃; according to the generated scanning trajectory, the three-dimensional solid aluminum profile extrusion die is built up point by point, line by line, and layer by layer by laser selective melting method.

[0007] (3) Anneal the laser selective melting forming aluminum profile extrusion die. The process parameters are: heating at 890~920℃ for 5h, cooling down to 760~800℃ for 4h isothermal, furnace cooling to 600℃, and air cooling.

[0008] In step (2) of this invention, the process parameters for preparing the support structure are as follows: the fiber laser wavelength is 1060nm, the laser power is 300W, the support structure height is 4mm, the laser scanning speed is 600mm / s, the layer slice thickness is 50μm, and the overlap rate is 55%; the process parameters for preparing the aluminum profile extrusion die parts are as follows: the laser power is 250W, the laser scanning speed is 800~3000mm / s, the layer slice thickness is 30~50μm, the overlap rate is 50~70%, and the forming is carried out by using a laser scanning direction angle of 63° between two consecutive layers until the manufacturing of the aluminum profile extrusion die parts is completed.

[0009] In step (3) of this invention, the microstructure characteristics of the aluminum profile extrusion die obtained are as follows: due to liquid phase separation, at a solidification rate as high as 10 8 Under K / s conditions, a large number of 5-10 micrometer spherical ε-Cu particles are uniformly embedded in the α-Fe matrix; SiB4 and graphene nanosheets with a particle size of 10-20 micrometers are uniformly distributed in the α-Fe matrix; when the aluminum profile extrusion die is in service at a temperature of 500-700℃, the SiB4 particles will react with oxygen to form borosilicate glass with self-healing cracks.

[0010] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0011] (1) It can prepare aluminum profile extrusion dies with complex shapes and large sizes; (2) Due to liquid phase separation, the solidification rate is as high as 10 8 Under K / s conditions, the aluminum profile extrusion die is mainly composed of: spherical ε-Cu particles, SiB4 particles and graphene nanoparticles dispersed in the α-Fe matrix; (3) the aluminum profile extrusion die has self-healing cracks and self-lubricating properties (spherical copper-rich particles and graphene nanosheets) during high-temperature service, with a tensile strength of 1.2~1.3GPa, a tensile strength of 1.6~1.8GPa, a hardness of 58~62HRC, an elongation of 18.5~22%, and a service life of 2~5 times that of H13 steel. Detailed Implementation

[0012] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0013] Example 1

[0014] Using rust-removed and sandblasted carbon steel plates as the base material, complex-shaped, large-sized aluminum profile extrusion dies are prepared using laser selective melting. Due to liquid-phase separation, the solidification rate reaches as high as 10... 8 Under K / s conditions, the microstructure of the self-assembled copper-rich particle-reinforced iron-based composite material is characterized by: a large number of 5-micrometer spherical ε-Cu particles, 10-micrometer SiB4 and graphene nanosheets uniformly distributed in the α-Fe matrix, with a tensile strength of 1.2 GPa, a tensile strength of 1.6 GPa, a hardness of 58 HRC, an elongation of 18.5%, and a service life twice that of H13 steel.

[0015] The specific implementation process is as follows:

[0016] (1) Iron-based alloy powder with a particle size of 40-60 μm was used as the forming powder for selective laser melting. Its chemical composition was as follows: C 0.3 wt.%; Si 0.5 wt.%; Ni 2.0 wt.%; Mn 0.5 wt.%; Cr 4.5 wt.%; V 0.5 wt.%; Mo 2.0 wt.%; Cu 5.0 wt.%; Al 0.5 wt.%; SiB4 5 wt.%; graphene nanosheets 1.5 wt.%; balance Fe;

[0017] (2) The CAD model of the aluminum profile extrusion die part with the support structure is sliced ​​into layers, and a series of laser selective melting forming two-dimensional scanning trajectories are generated according to the slice contour information; the laser selective melting forming chamber is evacuated and then filled with argon gas; the carbon steel plate with rust removal and sandblasting treatment is heated to 700℃; according to the generated scanning trajectory, the three-dimensional solid aluminum profile extrusion die is built up point by point, line by line, and layer by layer by laser selective melting method.

[0018] (3) Anneal the laser selective melting forming aluminum profile extrusion die. The process parameters are: heating at 890℃ for 5 hours, cooling down to 760℃ for 4 hours, furnace cooling to 600℃, and air cooling.

[0019] The process parameters for fabricating the support structure are as follows: fiber laser wavelength of 1060nm, laser power of 300W, support structure height of 4mm, laser scanning speed of 600mm / s, layer slice thickness of 50μm, and overlap rate of 55%. The process parameters for fabricating the aluminum profile extrusion die parts are as follows: laser power of 250W, laser scanning speed of 800mm / s, layer slice thickness of 30μm, and overlap rate of 50%. The forming process is carried out by using a laser scanning direction angle of 63° between two consecutive layers until the aluminum profile extrusion die parts are manufactured.

[0020] Example (II)

[0021] Using rust-removed and sandblasted carbon steel plates as the base material, complex-shaped, large-sized aluminum profile extrusion dies are prepared using laser selective melting. Due to liquid-phase separation, the solidification rate reaches as high as 10... 8 Under K / s conditions, the microstructure of the self-assembled copper-rich particle-reinforced iron-based composite material is characterized by: a large number of 8-micrometer spherical ε-Cu particles, 15-micrometer SiB4 and graphene nanosheets uniformly distributed in the α-Fe matrix, a tensile strength of 1.25 GPa, a tensile strength of 1.7 GPa, a hardness of 60 HRC, an elongation of 20%, and a service life 3.5 times that of H13 steel.

[0022] The specific implementation process is as follows:

[0023] (1) Iron-based alloy powder with a particle size of 40-60 μm was used as the forming powder for selective laser melting. Its chemical composition was as follows: C 0.25 wt.%; Si 1.0 wt.%; Ni 2.8 wt.%; Mn 0.65 wt.%; Cr 5.5 wt.%; V 1.0 wt.%; Mo 3.0 wt.%; Cu 6.5 wt.%; Al 2.5 wt.%; SiB4 10 wt.%; graphene nanosheets 2.5 wt.%; balance Fe;

[0024] (2) The CAD model of the aluminum profile extrusion die part with the support structure is sliced ​​into layers, and a series of laser selective melting forming two-dimensional scanning trajectories are generated according to the slice contour information; the laser selective melting forming chamber is evacuated and then filled with argon gas; the carbon steel plate with rust removal and sandblasting treatment is heated to 725℃; according to the generated scanning trajectory, the three-dimensional solid aluminum profile extrusion die is built up point by point, line by line, and layer by layer by laser selective melting method.

[0025] (3) Anneal the laser selective melting forming aluminum profile extrusion die. The process parameters are: heating at 900℃ for 5 hours, cooling down to 780℃ for 4 hours, furnace cooling to 600℃, and air cooling.

[0026] The process parameters for fabricating the support structure are as follows: fiber laser wavelength of 1060nm, laser power of 300W, support structure height of 4mm, laser scanning speed of 600mm / s, layer slice thickness of 50μm, and overlap rate of 55%. The process parameters for fabricating the aluminum profile extrusion die parts are as follows: laser power of 250W, laser scanning speed of 2000mm / s, layer slice thickness of 40μm, and overlap rate of 60%. The forming process is carried out by using a laser scanning direction angle of 63° between two consecutive layers until the aluminum profile extrusion die parts are manufactured.

[0027] Example (3)

[0028] Using rust-removed and sandblasted carbon steel plates as the base material, complex-shaped, large-sized aluminum profile extrusion dies are prepared using laser selective melting. Due to liquid-phase separation, the solidification rate reaches as high as 10... 8 Under K / s conditions, the microstructure of the self-assembled copper-rich particle-reinforced iron-based composite material is characterized by: a large number of 10-micrometer spherical ε-Cu particles, 20-micrometer SiB4 and graphene nanosheets uniformly distributed in the α-Fe matrix, a tensile strength of 1.3 GPa, a tensile strength of 1.8 GPa, a hardness of 62 HRC, an elongation of 22%, and a service life 5 times that of H13 steel.

[0029] The specific implementation process is as follows:

[0030] (1) Iron-based alloy powder with a particle size of 40-60 μm was used as the forming powder for selective laser melting. Its chemical composition was as follows: C 0.2 wt.%; Si 1.5 wt.%; Ni 3.2 wt.%; Mn 0.8 wt.%; Cr 6.5 wt.%; V 1.5 wt.%; Mo 3.5 wt.%; Cu 8.0 wt.%; Al 3.5 wt.%; SiB4 15 wt.%; graphene nanosheets 3 wt.%; balance Fe;

[0031] (2) The CAD model of the aluminum profile extrusion die part with the support structure is sliced ​​into layers, and a series of laser selective melting forming two-dimensional scanning trajectories are generated according to the slice contour information; the laser selective melting forming chamber is evacuated and then filled with argon gas; the carbon steel plate with rust removal and sandblasting treatment is heated to 750°C; according to the generated scanning trajectory, the three-dimensional solid aluminum profile extrusion die is built up point by point, line by line, and layer by layer by laser selective melting method.

[0032] (3) Anneal the laser selective melting forming aluminum profile extrusion die. The process parameters are: heating at 920℃ for 5 hours, cooling down to 800℃ for 4 hours, furnace cooling to 600℃, and air cooling.

[0033] The process parameters for fabricating the support structure are as follows: fiber laser wavelength of 1060nm, laser power of 300W, support structure height of 4mm, laser scanning speed of 600mm / s, layer slice thickness of 50μm, and overlap rate of 55%. The process parameters for fabricating the aluminum profile extrusion die parts are as follows: laser power of 250W, laser scanning speed of 3000mm / s, layer slice thickness of 50μm, and overlap rate of 70%. The forming process is carried out by using a laser scanning direction angle of 63° between two consecutive layers until the aluminum profile extrusion die parts are manufactured.

[0034] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method of laser selective melting to form a high-performance aluminum profile extrusion die, characterized in that, It comprises the following steps: (1) iron-based alloy powder with particle size of 40-60 μm is used as the forming powder for laser selective melting, and its chemical composition is: C ≤ 0.3 wt.%; Si 0.5-1.5 wt.%; Ni 2.0-3.2 wt.%; Mn 0.5-0.8 wt.%; Cr 4.5-6.5 wt.%; V 0.5-1.5 wt.%; Mo 2.0-3.5 wt.%; Cu 5.0-8.0 wt.%; Al 0.5-3.5 wt.%; SiB4 5-15 wt.%; graphene nanosheet 1.5-3 wt.%; and the balance is Fe; (2) the CAD model of the aluminum profile extrusion die part with a support structure is sliced, a series of two-dimensional scanning tracks for laser selective melting are generated according to the slicing profile information; the laser selective melting forming chamber is evacuated and then filled with argon; the carbon steel plate with rust removal and sand blasting treatment is heated to 700-750℃; according to the generated scanning track, the aluminum profile extrusion die is accumulated into a three-dimensional entity by laser selective melting point by line by layer; (3) the laser selective melting forming aluminum profile extrusion die is annealed, and the process parameters are: heating at 890-920℃ for 5h, cooling to 760-800℃ for 4h, furnace cooling to 600℃, and air cooling; At a solidification rate of up to 10 8 Spherical ε-Cu particles, SiB4 particles and graphene nanosheets are dispersed in the α-Fe matrix under K / s conditions; When the step (2) is performed, the process parameters for preparing the support structure are: the wavelength of the fiber laser is 1060nm, the laser power is 300W, the support structure height is 4mm, the laser scanning speed is 600mm / s, the slicing thickness is 50μm, and the overlap rate is 55%; the process parameters for preparing the aluminum profile extrusion die part are: the laser power is 250W, the laser scanning speed is 800-3000mm / s, the slicing thickness is 30-50μm, the overlap rate is 50-70%, the continuous two layers are formed by laser scanning direction angle of 63°, and the aluminum profile extrusion die part manufacturing is completed.

2. The method of claim 1, wherein the method is used to form an extrusion die for high-performance aluminum profiles. The microstructure of the aluminum profile extrusion die obtained in the step (3) has the following characteristics: the solidification speed is up to 10 8 Under the K / s condition, 5-10 micron spherical ε-Cu particles are uniformly embedded in the α-Fe matrix; the particle size is 10-20 micron SiB4 and graphene nanosheet are uniformly distributed in the α-Fe matrix; when the aluminum profile extrusion die is used at a temperature of 500-700 ℃, the SiB4 particles will react with oxygen to form borosilicate glass with self-healing cracks; the obtained aluminum profile extrusion die has self-lubricating performance, the hardness is 58-62 HRC, the elongation is 18.5-22%, and the service life is 2-5 times that of H13 steel.