CN116460309A - Runner powder removing method for 3D printing part - Google Patents

Abstract

The invention provides a runner powder removing method of a 3D printing part, which comprises the steps of synchronously printing a plug at the inlet and outlet positions of a runner in the process of 3D printing the part, and sealing discrete metal powder in the runner; and when entering a runner powder cleaning procedure, removing plugs at two ends, and cleaning powder in the runner. The invention can solve the problem of powder cleaning in the runner and improve the product quality. And the runner powder cleaning process can be arranged in any link of the part processing technology, so that the degree of freedom of the 3D part printing process is increased.

Description

Runner powder removing method for 3D printing part

Technical Field

The invention belongs to the technical field of additive manufacturing, and particularly relates to a runner powder cleaning technology of a 3D printing part.

Background

The 3D printing technology is commonly called additive manufacturing technology (Additive Manufacturing), and is an advanced manufacturing technology developed by integrating information technology, new material technology and manufacturing technology in multiple subjects. Additive manufacturing is to manufacture solid parts according to a method of accumulating materials layer by CAD data. The manufacturing principle is that materials are accumulated point by point to form a surface and are accumulated surface by surface to form a body, so that a three-dimensional entity with a complex shape is manufactured.

Additive manufacturing techniques are diverse, as are printable materials ranging from metals, plastics, to concrete, biological cells, etc. Where metal printing parts currently have the largest duty cycle, SLM is the most widely used metal printing technology.

SLM, selective Laser Melting, laser selective melting, which is a technique of scanning a layer of pre-laid metal powder in a specific path according to a three-dimensional slicing drawing by using a high-energy laser beam in an inert gas chamber, completely melting the metal powder, cooling and solidifying the metal powder to form metallurgical bonding with the previous layer, stacking the metal powder layer by layer to form a desired entity, thereby obtaining a part with excellent mechanical properties ^[1] 。

When printing products with internal flow channels or channel structures, for example, when printing water-cooled motor shells, the SLM metal additive manufacturing technology is limited by the limitation of the path of the SLM metal printing technology, after the shell printing is finished, the interior of the flow channel structures is filled with dry discrete metal powder, in the process of subsequent process treatment, the moisture and oxidizing gas in the air and the water, oil, high temperature and other factors in the subsequent process are very liable to influence the discrete powder in the flow channels, so that the discrete powder cannot be kept in the dry discrete state, the condition of powder cleaning work of the internal channels of the products becomes very harsh and unstable, the powder cleaning work is very difficult, and even parts are probably directly scrapped.

The post-treatment process flow for printing and processing the products is as follows:

step 1 SLM device prints the housing parts;

after Step 2 printing is completed, the part is moved out of the equipment along with the forming cylinder;

step 3, manually cleaning powder in the forming cylinder and powder on the surface of the part;

step 4, cleaning metal powder in a part runner;

carrying out heat treatment on the Step 5 parts along with the substrate;

step 6, wire cutting to separate the part from the substrate;

step 7 machining into finished parts

The disadvantages of the above process flow are as follows:

1) The operation flow is fixed, the degree of freedom is low, the runner powder must be cleaned before the online cutting and heat treatment process, and the runner powder must be cleaned up, so that the process requirement of the next step can be met without residual powder.

2) The runner clearance is difficult, and when runner one end is located the terminal surface under the product, extends when fixing on the base plate, part internal pipeline can not form the return circuit, causes the powder clearance difficulty in the runner.

3) In the on-line cutting and separating process, even if a small amount of liquid flows into the flow channel, once powder remains in the flow channel, the flow channel is extremely easy to block and extremely difficult to clean.

4) The residual powder of the runner is stuck with liquid, and the heat treatment process is adopted to form hardening, so that the part cannot be cleaned, the part is scrapped directly, and the loss cannot be recovered.

5) When the parts are obliquely placed, the top of the inlet and outlet areas of the runner are required to be additionally supported, and the forming quality is affected.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a method for removing the powder in the runner of a 3D printing product, which solves the problem of powder removal in the runner and improves the product quality.

The technical scheme of the invention is as follows:

the invention provides a runner powder removing method of a 3D printing part, which comprises the steps of synchronously printing a plug at the inlet and outlet positions of a runner in the process of 3D printing the part, and sealing discrete metal powder in the runner; and when entering a runner powder cleaning procedure, removing plugs at two ends, and cleaning powder in the runner.

In particular, the runner powder cleaning process may be arranged at any stage of the part processing process.

Preferably, the runner powder cleaning process is not the last process of part processing.

Preferably, the plugs are printed with a sheet at the inlet and outlet positions of the flow channels synchronously.

According to the technical scheme, in the process of printing the part in the 3D mode, the plugs are synchronously printed at the positions of the water inlet and the water outlet of the runner, discrete metal powder in the runner is sealed, and meanwhile, a certain supporting effect is achieved, so that the following advantages are brought:

1. the defect that a loop is not easy to form in runner cleaning is overcome.

2. Solves the difficult problems of residual powder cleaning and easy blockage.

3. The possibility of scrapping products caused by hardening of runner powder due to various factors in the subsequent working procedures is completely eradicated.

4. The degree of freedom of the placing mode during printing of the product is enhanced, and the printing risk is reduced.

5. The problem of the low degree of freedom of present 3D printing part process is solved, runner powder clearance process can arrange in the arbitrary link of part processing technology, and as shown in figure 3, very big increase the degree of freedom that each process was arranged, runner powder clearance process can even stay the last process completion of part processing.

Drawings

FIG. 1 is a schematic illustration of the appearance of a 3D printed part with internal flow channels, according to one embodiment;

FIG. 1A is a schematic view of the internal flow path of the part of FIG. 1;

FIG. 2 is an outline view of the flow channel inlet/outlet portion of the 3D printed part shown in FIG. 1;

FIG. 2A is a cross-sectional view of the flow channel inlet/outlet portion of the 3D printed part shown in FIG. 2;

FIG. 3 is a process schematic of a 3D printed part according to one embodiment.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

referring to fig. 1, 1A, 2 and 2A, a water-cooled motor housing structure to be 3D printed is provided, and a flow passage structure 2 is provided inside the water-cooled motor housing 1. 3D printing processing is carried out on the part, and the shape and the position of the plug are designed at the inlet and the outlet of the runner according to the printing and placing mode of the part. For example, in this embodiment, the plug is designed as a sheet positioned 3.5mm from the inlet and outlet of the flow channel. Then, according to the designed position and shape, the plug 3 and the part structure are synchronously and integrally printed, so that the discrete state filling metal powder 4 in the flow channel is completely isolated from the external environment when the printing processing is finished. Thus, the gas/liquid in the external air and the water, oil, high temperature and the like in the subsequent various operations can not react to the external air, and the discrete state of the external air is ensured to be kept all the time. When the cleaning is needed, only the plugs at the two ends are needed to be removed, the metal powder in a discrete state in the flow channel flows out, and then the high-pressure gas is assisted, so that the powder in the flow channel can be completely cleaned.

Referring to fig. 3, in the above manner, the process of 3D printing the parts can be very freely set, for example, the following process arrangement can be adopted:

step 1, printing a water-cooled motor shell part by SLM equipment;

after Step 2 printing is completed, the part is moved out of the equipment along with the forming cylinder;

step 3, manually cleaning powder in the forming cylinder and powder on the surface of the part;

carrying out heat treatment on the Step 4 part along with the substrate;

step 5, wire cutting to separate the part from the substrate;

step 6, machining to obtain a finished part;

step 7, removing plugs at two ends of the runner, and cleaning metal powder in the runner of the part.

The runner powder cleaning is arranged in the last procedure. Of course, the printing device can be arranged at any link after printing according to the need, and the gas/liquid in the outside air and water, oil, high temperature and the like in various operations can not influence the metal powder in the flow before cleaning the powder due to the existence of the plug, so that the freedom degree of the process arrangement of parts is greatly improved.

In addition, the difficulty that the channel cannot be formed by the clear powder of the channel is completely solved by the mode, so that the channel is easy to clean and clean. The possibility of scrapping products caused by hardening of the runner powder in the subsequent steps of Du Juehou can be thoroughly realized, and the qualification rate of the products can be greatly improved.

Claims (4)

1. A method for removing runner powder of a 3D printing part is characterized by comprising the following steps of

In the process of printing the part, a plug is synchronously printed at the inlet and outlet positions of the runner to seal the discrete metal powder in the runner; and when entering a runner powder cleaning procedure, removing plugs at two ends, and cleaning powder in the runner.

2. The method of claim 1, wherein the step of cleaning the flow path powder is performed at any stage of the part manufacturing process.

3. The method of claim 2, wherein the step of cleaning the flow path powder is a final step of part processing.

4. A method of removing powder from a flow path of a 3D printed part according to any one of claims 1 to 3, wherein the plugs are printed with a sheet at both the inlet and outlet positions of the flow path.