CN117259787A - Control method for deformation of thin-wall pipe joint component manufactured by additive - Google Patents

Abstract

The invention discloses a control method for deformation of a thin-wall pipe joint component in additive manufacturing, which relates to the field of 3D printing of selective laser melting forming, and is applicable to additive manufacturing production of various small-batch high-quality thin-wall pipe joint components; meanwhile, the time-controlled structure has reasonable position and strength design, flexible post-treatment removal mode, small deformation of the pipe orifice of the part, high yield and small subsequent machining amount, and the profile degree can reach the level of +/-0.15 mm; solves the problems of the traditional manufacturing process, such as high production cost, low yield, long production period, complex working procedures, and the like.

Description

A method for controlling deformation of thin-walled pipe joint components in additive manufacturing

Technical field

The invention relates to the field of laser selective melting forming 3D printing, and specifically relates to a method for controlling the deformation of thin-walled pipe joint components in additive manufacturing.

Background technique

With the continuous development of engineering technology, the demand for small batches such as copying and repairing parts is also increasing, which also puts forward higher requirements for manufacturing technology - fewer manufacturing processes, short production cycles, and low costs. Traditional mass-produced parts manufacturing strategies are difficult to meet this demand. The emergence of additive manufacturing technology effectively solves this technical problem and enables rapid prototyping of small batches of parts. Laser selective melting technology is a processing technology with the most extensive application prospects in the field of 3D printing. At present, laser selective melting technology has realized the substitution of production processes for various materials and structural parts. However, additive manufacturing technology also faces problems such as pipe mouth deformation (shown in Figures 1 and 3) and large machining allowances when producing thin-walled pipe joints and other components, which further increases production costs and prolongs production. cycle. This patent uses laser selective melting forming technology to produce thin-walled pipe joint components. From the perspective of structure and process optimization, it can quickly produce low-cost and high-quality thin-walled components.

Contents of the invention

In view of the deficiencies in the background technology, the present invention provides a method for controlling the deformation of additively manufactured thin-walled pipe joint components, which solves the problems of traditional manufacturing processes such as high production costs, low yields, long production cycles, and cumbersome processes.

In order to achieve the above objects, embodiments of the present invention provide the following technical solutions:

A method for controlling the deformation of additively manufactured thin-walled pipe joint components, including the following steps:

S1. Model processing: Add thin slices of a certain thickness at certain intervals from the end of the tube inward. The thin slices have the same shape as the inner wall of the tube, that is, they follow the shape, while maintaining a certain contact distance. A small number of holes are opened in the thin slice to facilitate powder cleaning;

S2. Laser selective melting forming: The forming process parameters of the sheet are different from those of the parts, which is used to make the sheet forming efficient and the sheet easier to remove;

S3. Stress relief annealing: The parts are annealed together with the substrate to reduce the overall stress of the parts and slow down subsequent heat treatment cracking;

S3. Heat treatment: The parts and the substrate are heat treated together;

S4. Wire cutting: After the heat treatment is completed, wire cutting is used to separate the parts from the substrate;

S5. Support removal: Manually remove the support of the part, and remove the flakes by manual or mechanical processing;

S6. Surface treatment: After the parts are removed from the support, surface treatment is performed on them and the final product is obtained.

As a further preferred solution for the method of controlling the deformation of additively manufactured thin-walled pipe joint components of the present invention, sheets of a certain thickness are sequentially added at certain intervals from the end surface of the pipe mouth inwards.

As a further preferred embodiment of the method for controlling deformation of additively manufactured thin-walled pipe joint components of the present invention, the thickness of the sheet is greater than or equal to 0.2 times the pipe wall thickness and less than or equal to 5 times the pipe wall thickness.

As a further preferred solution of the method for controlling deformation of additively manufactured thin-walled pipe joint components of the present invention, the contact distance between the sheet and the part body is less than or equal to 0.1 mm.

As a further preferred solution of the method for controlling the deformation of additively manufactured thin-walled pipe joint components of the present invention, the number of the lamellae is greater than or equal to 1, and the spacing between the lamellae is greater than or equal to 0.1 mm.

As a further preferred solution for the method of controlling the deformation of additively manufactured thin-walled pipe joint components of the present invention, the energy density of the sheet sintering is 60% to 120% of the sintering energy density of the part body.

The embodiments of the present invention have the following advantages:

Adding shape-controlling sheets that follow the shape of the inner wall can resist the elliptical deformation caused by uneven radial stress near the circular tube mouth during the printing process (as shown in Figure 1);

The axial stress model of the pipe wall can be simplified to a simply supported beam model. When the number of slices used is greater than 1, a reasonably designed slice spacing can also control the deformation of the pipe wall at the gap between the slices, thereby ensuring the deformation of the entire pipe joint component. Small quantity;

The appropriate method of removing the flakes can be selected based on the accuracy of the assembly of the pipe joint. When removed manually, a certain distance between the flakes and the pipe wall can be maintained, and at the same time, the flakes use a smaller sintering energy density; when removed by mechanical processing, it can be reduced The distance between the sheet and the tube wall can even be a negative value. The sheet uses a slightly larger sintering energy density, even the same as the body; different processes can be flexibly used to achieve low-cost, high-quality and rapid production;

Through this control method, the present invention is suitable for additive manufacturing of various small batches of high-quality thin-walled pipe joint components; the method has less shape control structures, high printing efficiency, and saves raw materials; at the same time, the position and strength of the shape control structure are designed reasonably and post-processing The removal method is flexible; the part nozzle deformation is small, the contour can reach ±0.15mm level (as shown in Figure 4), the yield rate is high, and the subsequent machining volume is small; it solves the problem of traditional manufacturing technology, high production cost, low yield rate and Problems include long production cycle and cumbersome processes.

Description of the drawings

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the drawings that need to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only exemplary. For those of ordinary skill in the art, other implementation drawings can be obtained based on the extension of the provided drawings without exerting creative efforts.

The structures, proportions, sizes, etc. shown in this specification are only used to coordinate with the contents disclosed in the specification for the understanding and reading of people familiar with this technology. They are not used to limit the conditions under which the invention can be implemented, and therefore do not have any technical Any structural modification, change in proportion or size adjustment shall still fall within the scope of the technical content disclosed in the present invention without affecting the effectiveness and purpose achieved by the present invention. within the scope that can be covered.

Figure 1 is a schematic diagram of the oval deformation of a thin-walled circular tube manufactured by additive manufacturing according to the present invention;

Figure 2 is a schematic structural diagram of the shape-controlling sheet of the present invention;

Among them, Figure a) A cross-sectional view of a pipe joint without a shape-controlling sheet; Picture b) A cross-sectional view of a pipe joint with a shape-controlling sheet added; Picture c) A two-dimensional view of a pipe joint with a shape-controlling sheet added; Picture d) A cross-sectional view of a pipe joint with a shape-controlling sheet added Pipe joint diagram;

Figure 3 is a schematic diagram of the deformation of a pipe joint without adding shape-controlling sheets according to the present invention;

Figure 4 is a diagram of the shape control effect of adding a shape control sheet pipe joint according to the present invention.

Detailed ways

The following specific embodiments are used to illustrate the implementation of the present invention. Persons familiar with this technology can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only part of the embodiments of the present invention. , not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

As shown in Figures 1 to 4, a method for controlling the deformation of additively manufactured thin-walled pipe joint components includes the following steps:

S1. Model processing: Add thin slices of a certain thickness at certain intervals from the end of the tube inward. The thin slices have the same shape as the inner wall of the tube, that is, they follow the shape, while maintaining a certain contact distance. A small number of holes are opened in the thin slice to facilitate powder cleaning;

S2. Laser selective melting forming: The forming process parameters of the sheet are different from those of the parts, which is used to make the sheet forming efficient and the sheet easier to remove;

S3. Stress relief annealing: The parts are annealed together with the substrate to reduce the overall stress of the parts and slow down subsequent heat treatment cracking;

S3. Heat treatment: The parts and the substrate are heat treated together;

S4. Wire cutting: After the heat treatment is completed, wire cutting is used to separate the parts from the substrate;

S5. Support removal: Manually remove the support of the part, and remove the flakes by manual or mechanical processing;

S6. Surface treatment: After the parts are removed from the support, surface treatment is performed on them and the final product is obtained.

Add slices of a certain thickness at certain intervals from the end of the tube opening inward.

The thickness of the sheet is greater than or equal to 0.2 times the pipe wall thickness and less than or equal to 5 times the pipe wall thickness.

The contact distance between the sheet and the part body is less than or equal to 0.1 mm.

The number of the lamellae is greater than or equal to 1, and the spacing between the lamellae is greater than or equal to 0.1mm.

Adding shape-controlling sheets that follow the shape of the inner wall can resist the elliptical deformation caused by uneven radial stress near the circular tube mouth during the printing process (as shown in Figure 1);

Figure 2 is a schematic structural diagram of the shape-controlling sheet of the present invention; Figure a) a cross-sectional view of a pipe joint without a shape-controlling sheet; Figure b) a cross-sectional view of a pipe joint with a shape-controlling sheet added; Figure c) a second view of a pipe joint with a shape-controlling sheet added Dimensional diagram; Figure d) A schematic diagram of a pipe joint with a shape-controlling sheet added; Figure 3 is a schematic diagram of the deformation of a pipe joint without a shape-controlling sheet added according to the present invention;

2) The axial force model of the pipe wall can be simplified to a simply supported beam model. When the number of slices used is greater than 1, a reasonable design of the slice spacing can also control the pipe wall deformation at the gap between the slices, thereby ensuring that the entire pipe joint component The deformation is small;

3) The appropriate method of removing the flakes can be selected according to the assembly accuracy of the pipe joint. When removing by hand, a certain distance between the flakes and the pipe wall can be maintained, and the flakes can be sintered with a smaller energy density; when removed by mechanical processing, the flakes can be removed by mechanical processing. Reduce the distance between the sheet and the tube wall, or even to a negative value. The sheet uses a slightly larger sintering energy density, even the same as the body; flexibly adopt different processes to achieve low-cost, high-quality and rapid production;

4) Through this control method, the present invention is suitable for the additive manufacturing of various small batches of high-quality thin-walled pipe joint components; the method has less shape control structures, high printing efficiency, and saves raw materials; at the same time, the position and strength of the shape control structure are designed reasonably, The post-processing removal method is flexible; the part nozzle deformation is small, the contour can reach ±0.15mm level (as shown in Figure 4), the yield is high, and the subsequent machining volume is small; it solves the problem of high production costs and yield rate of traditional manufacturing processes Low cost, long production cycle, and cumbersome processes.

Although the present invention has been described in detail with general descriptions and specific examples above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims (6)

1. The method for controlling the deformation of the thin-wall pipe joint component in the additive manufacturing process is characterized by comprising the following steps of:

s1, model processing: sequentially adding thin slices with certain thickness from the end face of the pipe orifice inwards at certain intervals, wherein the thin slices have the same shape as the inner wall of the pipe, namely, the shape is along with the shape, and meanwhile, a certain contact distance is kept, and a small number of holes are formed in the thin slices so as to facilitate powder cleaning;

s2, laser selective melting and forming: the forming process parameters of the sheet are different from those of the part, so that the sheet forming efficiency is high, and the sheet is easy to remove;

s3, stress relief annealing: the part and the substrate are annealed together, so that the integral stress of the part is reduced, and the subsequent heat treatment cracking is slowed down;

s3, heat treatment: carrying out heat treatment on the parts and the base plate together;

s4, wire cutting: separating the parts from the substrate by wire cutting after the heat treatment is completed;

s5, support removal: removing the sheet by manual removing the support of the part, manual or mechanical processing and other methods;

s6, surface treatment: and after the support removal of the part is completed, carrying out surface treatment on the part, and obtaining a final product.

2. The method for controlling deformation of an additively manufactured thin-walled pipe joint member of claim 1, wherein: and sequentially adding thin slices with certain thickness from the end face of the pipe orifice inwards at certain intervals.

3. The method for controlling deformation of an additively manufactured thin-walled pipe joint member of claim 2, wherein: the thickness of the thin sheet is more than or equal to 0.2 times of the wall thickness of the pipe wall and less than or equal to 5 times of the wall thickness of the pipe wall.

4. The method for controlling deformation of an additively manufactured thin-walled pipe joint member of claim 1, wherein: the contact distance between the sheet and the part body is less than or equal to 0.1mm.

5. The method for controlling deformation of an additively manufactured thin-walled pipe joint member of claim 1, wherein: the number of the thin sheets is more than or equal to 1, and the spacing between the thin sheets is more than or equal to 0.1mm.

6. The method for controlling deformation of an additively manufactured thin-walled pipe joint member of claim 1, wherein: the energy density of the sintering of the thin sheet is 60% -120% of the energy density of the sintering of the part body.