RU108726U1 - POWDER FEEDING DEVICE FOR SINTERING PARTS BY LASER-LAYERED SYNTHESIS METHOD - Google Patents

Abstract

 Powder supply device mainly for devices sintering by laser layered synthesis with a working table, containing a dosed vertical powder feed mechanism and a horizontal powder feed mechanism in the welding zone, the dosed vertical powder feed mechanism made in the form of a vertical cylinder with a piston, the open end of which is installed in the plane of the desktop, characterized in that the dosed vertical powder feed mechanism is equipped with a removable additional open tsil a core with a piston made with a diameter smaller than the inner diameter of the vertical cylinder and installed in its cavity, while the open end of the additional cylinder is placed on the surface of the desktop using a removable cover installed in the open end of the vertical cylinder.

Description

Technical field

A useful model of the device relates to the field of powder metallurgy, the production of metal and ceramic powder products with sequential and repeated processes of powder supply, leveling of their layers with subsequent sintering, namely, devices for the manufacture of complex labor-intensive parts from fine powder using laser layer technology synthesis (LPS), and can find application in various industries of machine and aircraft industry.

State of the art

There are various devices using laser technology, sintering (fusing) powder parts, and consisting mainly of a laser-optical system, a working chamber with a vertically movable table equipped with a mechanism for the vertical supply of powder from the hopper-feeder, followed by leveling with knives or rollers and sintering of each of its layers, with systems of vacuum, cleaning and protection of the gas environment, control system, etc. - Installation of models "Phenix 250" (France), EOSINTS750 (Germany), etc. as well as Concept M2 (Germany) - with a vertical feed of powder in the form of a piston with a vertical square cylinder of 250 × 250 (mm × mm) size, on which a powder stock is stored in the lower lowered state of the piston.

A characteristic feature of the installations of these models is the use of a powder supply device in the form of a vertical cylinder with a piston with a piston, the open end of which is mounted in the plane of the table and is used as a powder storage bin, and a sufficient supply of fine powder is stored on its piston in the down position. If it is necessary to feed a portion of powder into the working area, the piston rises up to a predetermined height, and the volume of the portion of powder is determined only by a predetermined gap between the plane of the working table and the plane of the piston with the powder (with a constant piston area) for subsequent leveling of the powder layer.

Closest to the proposed device in terms of technical nature and technical solution is the device of the powder supply mechanism according to US Pat. In accordance with the software, the piston with the powder rises, providing the necessary clearance between the plane of the working table and the plane of the piston with the powder, and the horizontal movement of the knife of the leveling device provides the required thickness of the powder layer for subsequent sintering. Thus, the volume of a portion of powder for one layer is determined by a variable value of the specified gap and a constant value of the area of the piston.

In the patent RU 2021881 C1, the volume of a portion of powder for one layer is determined by the constant dimensions of the measuring hopper, through the lower opening of which the powder is poured onto the target zone of the working table for subsequent leveling of its layer.

A known installation of laser layer-by-layer synthesis CONCEPT M2 with a vertical feed of powder in the form of a piston with a vertical square cylinder 250 × 250 (mm × mm) in size, on which the powder stock is stored in the lower lowered state.

The disadvantage of this device, as well as all the other mentioned devices, is the use of both a constant volume of the measuring hopper and a constant area of the piston-mechanism of the powder accumulator supplying the powder to the working area, and the volume of the required portion of powder for each layer is regulated solely by adjusting the gap between the plane level the desktop and the level of the piston plane.

During commissioning, as well as in the sintering of small-sized parts, this leads to a significant consumption of powder for the formation of each layer of the required thickness, an increase in the volume of excess powder to be disposed of.

Excess powder remaining on the working table after sintering of each layer is either disposed of at an additional cost or simply eliminated if it contains scale or conglomerates formed during sintering of the previous layers of powder. As a result, the cost of manufacturing small-sized parts by the method of laser layer-by-layer synthesis increases.

Utility Model Essence

The objective of this utility model is to create a powder supply device for manufacturing parts by laser layer-by-layer synthesis, which would provide significant savings in finely dispersed powder during both commissioning and sintering of small-sized parts, reducing the cost of disposing of excess powder (reducing the cost of manufacturing parts) for due to the possibility of using a reduced area of an additional removable piston with a cylinder, the open end of which is placed on the working plane its section by a removable cap mounted in the open end of the main vertical cylinder. This allows you to reduce the volume of a portion of powder for each layer of a given thickness of the sintered part while maintaining the possibility of sintering large-sized parts.

The problem is solved due to the fact that in the powder feeding device, mainly for devices for sintering parts by the method of layer-by-layer synthesis with a working table containing a mechanism for dosed vertical powder feeding and a mechanism for horizontal powder feeding into the sintering zone, the dosed vertical powder feeding mechanism is made in the form of a vertical a cylinder with a piston, the open end of which is installed in the plane of the working table, the dosed vertical powder feed mechanism is equipped with a removable an open cylinder with a piston made with a diameter smaller than the inner diameter of the vertical cylinder and installed in its cavity, while the open end of the additional cylinder is placed on the surface of the working table using a removable cover installed in the open end of the vertical cylinder.

This embodiment of the device allows to reduce the consumption of powder, in particular, in experimental production or in the production of small-sized parts in small experimental batches.

If it is necessary to sinter large parts, an additional cylinder with a piston of a smaller diameter is dismantled, providing the use of a cylinder with a piston of a larger diameter as a hopper - powder storage.

In other words, there is an additional opportunity for the formation of the volume of a portion of the powder of each layer, due to the reduction of its mass on the reduced area of the plane of the additional piston.

The list of figures in the drawings.

A useful model of the device is illustrated by drawings, in which:

Figure 1 presents a General view and composition of the installation of laser layer-by-layer synthesis.

Figure 2 presents the node And the mechanism of the vertical powder feed for sintering small parts

Figure 3 - presents a variant of the mechanism for the vertical supply of powder for sintering large parts.

Implementation of a utility model.

A device for manufacturing parts by laser layer-by-layer synthesis, in the form of an experimental setup (Fig. 1), consisting of a rigid frame 1, on which a working chamber 2 with a working table is placed, in which a vertical powder feeding mechanism 3 is mounted, made in the form of a removable additional cylinder 4 with a piston 5 made with a diameter smaller than the inner diameter of the main cylinder and installed in its cavity, and the open end of the additional cylinder is placed on the surface of the working table / using removable roofs and installed in the open end of a vertical cylinder 4. The operating table contains items sintering zone with a vertical cylinder 4 and the piston 5, in which the plane formed by the powder layer for subsequent sintering. A fiber optic ytterbium laser 9 with a mechanism for its movement, a mechanism for horizontal movement and leveling of the powder layer with a movable knife 10 and a drive, an inert gas pressurization system, a chamber cleaning system, a vacuum system, a control cabinet 11 with both manual and automatic control modes is also located at the facility LPS process, etc. The removable cover 1 (Figure 2) of the vertical cylinder is a single plane 2 with the working table.

The device also includes a horizontal powder feed mechanism, consisting of a vertical knife or roller with a displacement drive (not shown in the drawing).

Figure 2 shows the node And the mechanism of the dosed vertical powder supply for sintering small-sized parts by the method of laser layer-by-layer synthesis, mounted the vertical supply mechanism 3 of powder in the form of a removable additional cylinder 5 with a piston 4 made with a diameter smaller than the inner diameter of the main cylinder and installed in it cavity, and the open end of the additional cylinder is placed on the surface of the desktop using a removable cover 1 installed in the open end of the vertical cylinder 5. This cover Braz flush with the desk equipped with a knife 2 for vertical displacement and leveling of the powder layer in the sintering zone.

In figure 3. A variant of the mechanism for supplying powders for sintering large parts is shown, consisting of a vertical cylinder 1 with a large diameter piston 2, a removable ring 3.

If necessary, sintering of large-sized parts is carried out a readjustment of the powder supply device in the following sequence;

1. Raise the vertical cylinder 6 to its highest position.

2. Dismantling on the desktop a removable cover 1 with a cylinder of a smaller diameter.

3. Dismantling the smaller diameter piston in the plane of the vertical piston of the larger diameter cylinder.

4. Installing plugs on the mounting holes of the plane of the larger vertical piston diameter.

5. Installing the removable ring to replace the removable cover on the desktop.

The operation of the device is as follows:

In the initial position, the piston of reduced diameter 13, on which is placed a supply of X18H9T powder with a dispersion of up to 40 microns in an amount sufficient to sinter the entire part, together with the piston of increased diameter is lowered vertically down to the stop. In accordance with the software, the piston of the working table 5 rises relative to the working plane of the table by an amount equal to the calculated thickness of the powder layer. Thus, a metered reduced portion of the powder is fed into the cleaned working chamber, followed by leveling of its layer with a knife or roller of the powder layer leveling mechanism.

Next, the chamber is filled with protective gas (argon) with a pressure of P = 1.3 × 10 ⁵ Pa, and a laser with a power of N1 = 100 W is turned on.

The laser is turned on to sinter the areas of each cell and zone of the powder layer with an initial velocity of the sintering beam of 110 mm / s. After sintering of this layer, the piston of the working table is lowered by an amount equal to the calculated thickness of the sintered powder layer, followed by cleaning the chamber of unused powder for repeating the sintering cycle of the new powder layer.

After the sintering of the entire part is completed, the part is cooled, cleaned and removed from the delivery position.

Using the proposed device can reduce the cost of sintering processes of small-sized parts from fine powder by reducing the loss of powder during the formation of each layer of a given thickness of the sintered part, the number of which can reach several thousand.

Claims (1)

Powder supply device mainly for devices sintering by laser layered synthesis with a working table, containing a dosed vertical powder feed mechanism and a horizontal powder feed mechanism in the welding zone, the dosed vertical powder feed mechanism made in the form of a vertical cylinder with a piston, the open end of which is installed in the plane of the desktop, characterized in that the dosed vertical powder feed mechanism is equipped with a removable additional open tsil a core with a piston made with a diameter smaller than the inner diameter of the vertical cylinder and installed in its cavity, while the open end of the additional cylinder is placed on the surface of the desktop using a removable cover installed in the open end of the vertical cylinder.