RU2491151C1 - Method of producing articles from composite powders - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to materials intended for production of articles from powder materials in layer-by-layer laser fritting. It may be used for making complex-shape composite parts. Powder is fed by proportioning container composed of a set of cells with outlets in diameter selected to rule out the powder granules fall by static friction in the range of (3-10) x d where d is powder granule diameter. Powder is displaced vertically by vibration onto every cell of said proportioning container at specified frequency. Powder compacter composed of a roller is displaced over location surface to compact the powder. Laser is displaced to preset position defined by appropriate computer model to fuse the powder so that preset-depth functional layer is formed.

EFFECT: expanded range used powders and process performances.

5 dwg, 1 tbl, 1 ex

Description

The invention relates to a method for producing material objects from powders by laser melting and can be used to obtain composite products of complex configuration from various powder materials, for example, bimetallic products, products with channels from another material, etc.

The prior art method of manufacturing products from powder materials, which consists in pressing the powder material in the molds (Kiparisov S. S. and Libenson G. A. "Powder metallurgy." - M .: Metallurgy, 1991, p. 289 )

The disadvantage of this method is the fact that for each size of the product it is necessary to produce an individual mold of complex design from expensive tool steels and hard alloys, which increases the cost of products. The design features of the mold do not allow to obtain products of complex configuration having internal cavities of variable section, closed cavities, etc. All this together limits the technological capabilities of the known method.

A device for producing bulk products is also known, in which a method is described that consists in forming a product by feeding powder by a device into the workspace above the technological platform with its further laser sintering (RF Patent No. 2299787, B22F 3/105, 2004).

The disadvantages of this method are the inability to manufacture composite products from various types of powder materials.

The closest solution in technical essence and the achieved result is a method of manufacturing gradient materials from powders, which consists in sequentially applying layers of various materials on the technological platform and selectively sintering a given area of each layer (RF Patent No. 2401180, B22F 3/105, 2008) .

A disadvantage of the known technical solution is the inability to obtain products containing parts from various materials in the applied layer in one pass, which reduces the range of products.

The technical result of the claimed method is to provide the possibility of supplying a given melting region of powder materials, various assortment and fractions, which ultimately allows to expand its technological capabilities compared to the known method.

The technical result achieved is achieved by the fact that in the method of manufacturing products from composite powder materials, which consists in melting by the action of laser radiation on a powder material, layer-by-layer supplied from a software-organized and orthogonally set relative to the plane of formation of the functional layers of the product dispenser-container to predetermined sections work surface of an adjustable technological platform that are identical to sections across according to the invention, the dispenser-container is made cellular, in each cell of which an outlet is formed, and the supply of powdered material is carried out by vibrating in the vertical direction to each of the cells of the dispensing container with a technologically regulated frequency providing in the area of the outlet a vibro-boiling layer of powdered material, while the diameter p "D" of the outlet is performed in the range of (3-10) × d, where d is the diameter of the granules of the powdered material.

A method of manufacturing products from composite powder materials is illustrated by drawings, where:

- figure 1 schematically shows a device for implementing the method for the manufacture of products from powder materials;

- figure 2 is a top view of the device of figure 1;

- figure 3 shows a dispenser container;

- figure 4 shows a General diagram of a device in three-dimensional format for implementing the inventive method;

- figure 5 shows the dispenser container in a three-dimensional format.

The claimed method of manufacturing products from composite powder materials is as follows.

At the beginning of the manufacturing process of the product using the specified program creates a three-dimensional computer model of the product (hereinafter - 3D model), divided into many cross sections. Each of these cross sections corresponds (identically) to the functional layer of the product in its specific section, i.e. the boundaries of the sites on the technological platform 1 are set, on which the powder material 2 will be applied.

This is achieved by the process of the following interconnected actions.

Technological platform 1, which is performed with the possibility of vertical reciprocating movement, is shifted down relative to the base surface 3 of the base 4 by a distance equal to the thickness of the applied layer of powder material 2 within a few tens of microns. Then, the powder material 2 is applied in a thin layer to the corresponding above-mentioned sections of the working surface 5 of the technological platform 1. The distribution of the powder material 2 is carried out by a dispenser-container 6, which is made in the form of a set of cells 7 with outlet openings 8, the diameter of which is selected from the condition that excludes the precipitation of granules of powder material 2 from cells 7 due to the forces of static (dry) friction. It was established experimentally that the diameter "D" of the outlet 8 in the cells 7 of the dispenser-container 6 must be performed on the basis of the following dependence D = (3-10) × d, where d is the diameter of the granules of the powder material 2, which is confirmed by the examples presented in table.

The dosage of the powdered material 2 is carried out by vibrating in the vertical direction on each of the cells 7 of the dispenser-container 6 with a regulated frequency, due to the vibrating effect on the powdered material 2, for example piezocrystals 9, while creating a vibratory boiling layer of the powdered material 2 in the area of the outlet 8 The vibrational effect in the piezocrystals 9 is carried out at the moment when the corresponding cell 7 of the dispenser-container 6 is located above the corresponding section of the working surface 5 of the technological platform 1. I.e. there is a process of metered supply of powdered material 2. Next, the dispenser-container 6 is moved to its original position, and the means for compaction of the powdered material 2 in the form of a roller 10 is moved along the base surface 3, while pressing the powdered material 2 (with little effort to increase the uniformity of the layer powdered material 2 and reduce its porosity).

Next, the laser 11 in accordance with the generated by the computer model of the trajectory of movement is moved to a predetermined position, and it melts the powder material 2 on the corresponding sections of the working surface 5, thereby forming a functional layer 12 of the product of a given thickness. In these zones, the powdery material 2 melts and hardens. After the formation of the first functional layer 12 of the product, the technological platform 1 is shifted downward by a distance corresponding to the thickness of the next functional layer 12 of the product, and the process is repeated accordingly. Thus, the product as a whole is formed from the fused functional layers 12 of the powdered material 2.

To create composite objects from various powder materials 2, dispenser containers 6 are combined into a system 13 for dispensing powder material, which contains the required amount, determined by the composition of the product, dispenser containers 6.

Examples of the method.

The claimed method was used in the manufacture of a product in the form of a parallelepiped with dimensions of 15 × 20 × → 10 mm from copper powder material 2 grade PMS-1 and polymer - sand mixture (15% polymer, the rest is quartz sand). The average granule size of copper powder material 2 and sand is about 100 microns. Copper powder material 2 was poured into the extreme cells 7 of the dispenser-container 6, and sand with a polymer binder was poured into the central section. Powdered materials 2 were applied in a loose state on the working surface 5 of the technological platform 1 in successive layers. The thickness of the applied functional layers 12 was about 200 microns. The vibration frequency in piezocrystals is 9-0.2 kHz.

The procedure for applying the functional layers 12 is as follows: five layers of only copper powder material 2, forty layers consisting of two powder materials 2 so that the sand forms a rectangle of 7 × 12 mm surrounded by copper powder material 2, then again five layers of copper powder material 2 Each layer was irradiated with a parallel beam of a continuous Nd: YAG laser 11 (wavelength 1.06 μm) vertically directed relative to the working surface 5 of the technological platform 1. The speed of the beam 5 mm / s, the diameter of the beam 5 mm, the radiation power of 100 watts.

When using the inventive method, a monolithic product was formed having a copper shell, inside of which there is a polymer-sand mixture playing the role of a filler.

Also, the claimed method was used for the manufacture of a parallelepiped-shaped product with dimensions of 5 × 20 × 10 mm from powdered nickel alloy material, powdered materials of grade ПГ10Н01, and powdered material of iron of grade ПЖ. The average particle size is 160 microns.

Powdered material 2 of nickel was poured into the outer cells 7 of the dispenser-container 6, and iron was introduced into the central section. Powdered materials 2 were applied to the technological platform 1 so that the boundary between the powdered materials 2 was a straight line and divided the melting zone in half. The vibration frequency in piezocrystals is 9-0.4 kHz. Each layer was irradiated with a parallel parallel beam of a continuous Nd: YAG laser 11 (radiation wavelength 1.06 μm) vertically directed relative to the technological platform 1. The speed of the beam 5 mm / s, the diameter of the beam 5 mm, the radiation power of 100 watts.

As a result of melting, a product was formed in the form of a bimetallic strip.

Table No. D hole diameter Powder material distribution in the presence of vibration Powder sprinkling in the absence of vibration one 2,8d Uneven distribution of the powdered material into predetermined areas is carried out. Jamming of granules in the hole 2 3d The powder material is evenly distributed over predetermined areas There is no spilling of powder material in the absence of vibration. There is no precipitation of granules of powdered material with the vibration unit turned off 3 7d four 10d 5 10,3d The powder material is evenly distributed over predetermined areas Spontaneous precipitation of granules of powdered material is carried out with the vibration unit turned off

Thus, the claimed combination of features set forth in the claims, allows to expand the technological capabilities of the proposed method compared to the known method by providing the ability to supply to the specified melting region powder materials of various assortment and fractions, which ultimately allows to produce composite products of complex configuration from various powdered materials.

The analysis of the claimed technical solution for compliance with the conditions of patentability showed that the characteristics indicated in the independent claim are interrelated with each other with the formation of a stable set of necessary attributes unknown at the priority date from the prior art sufficient to obtain the required synergistic (over-total) technical result.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed technical solution:

- the object embodying the claimed technical solution, in its implementation is intended to obtain material objects from powder materials by laser melting and can be used to obtain composite products of complex configuration from various types of powder materials, in particular a monolithic product having a copper shell inside which is polymer - sand mixture, playing the role of a filler and a product in the form of a bimetallic strip;

- for the claimed object in the form described in the independent clause of the formula below, the possibility of its implementation using the means and methods described above or known from the prior art on the priority date is confirmed;

- the object embodying the claimed technical solution, when implemented, is able to ensure the achievement of the technical result perceived by the applicant.

Therefore, the claimed subject matter meets the requirements of the patentability conditions of “novelty”, “inventive step” and “industrial applicability” under applicable law.

Claims (1)

A method of manufacturing products from composite powder materials, including melting by means of laser radiation of a powder material supplied in layers from a software-organized and orthogonally mounted dispenser container to technologically defined sections of the working surface of an adjustable technological platform that are identical to sections on transverse sections pre-formed by the third program of a three-dimensional computer model of the product, characterized in that the dispenser-container is made cellular, in each cell of which an outlet is formed, and the supply of powdered material is carried out by vibrating in the vertical direction to each of the cells of the dispensing container with a technologically regulated frequency that ensures the zone of the outlet a vibro-boiling layer of powdered material, while the diameter "D" of the outlet is performed in the range (3-10) × d, where d is the diameter p granules of powdered material.

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