CN116673577A - An Arc Additive Method Applicable to Inclined Structural Parts - Google Patents

Abstract

The invention belongs to the field of material increase, and particularly relates to an arc material increase method suitable for an inclined structural member. The method comprises the following steps: (1) Stacking a first stacked layer on a substrate by adopting arc additive; (2) Arranging a supporting auxiliary piece along one side of the inclined structural piece, which forms an acute angle beta with the base plate, so that a supporting surface of the supporting auxiliary piece is attached to a layer to be stacked of the inclined structural piece; (3) The welding gun moves to the arc extinguishing end of the stacking path of the Nth stacking layer, the initial N=1, and the height h of the stacking layer is increased _β The welding gun is shifted to the inclined side by dmm along the direction of the vertical stacking path, and the stacking of the (n+1) th layer is completed; offset d is d=h _β Determining the tan beta calculation; (4) Repeating the step (3) to finish the multi-layer stacking forming until the required forming of the component is metThe shape and the size. According to the invention, the supporting auxiliary piece is added, so that the problem of molten pool flowing caused by overlarge offset is effectively avoided, and high-quality forming can be realized for processing large and small inclined wall structural members.

Description

An Arc Additive Method Applicable to Inclined Structural Parts

technical field

The invention belongs to the field of material addition, and in particular relates to an arc material addition method suitable for inclined structural parts.

Background technique

Arc additive manufacturing technology is an additive manufacturing method that uses the principle of layer-by-layer cladding, uses electric arc as a heat source, and automatically fills and covers wires according to a preset trajectory program to efficiently form metal components. The metal components formed by this method have the advantages of small size limitation, low manufacturing cost, simple equipment, high material utilization and stacking efficiency, and become one of the manufacturing methods for high-quality rapid prototyping of large metal components. It is suitable for additive manufacturing of metal structural parts such as steel, aluminum, magnesium, copper, titanium and nickel-based alloys.

Since the arc additive is based on wire melting, there is no supporting structure during the additive process, and the following two methods are generally used for additive inclined structural parts: 1. Install the additive sample on the positioner, and pass through the positioner Change the position to realize the vertical upward growth of the additive sample; 2. Directly realize the inclined structure additive through the offset of the welding torch. Although method 1 can form more complex arc additive samples, when adding large-scale samples, a larger positioner is required, which increases equipment costs. At the same time, large stress is generated during the additive process, which is easy to damage the displacement machine. Method 2 can achieve additive manufacturing at a certain angle, but when the angle is too large, or when using materials with strong fluidity, defects such as flow and collapse are prone to occur.

Contents of the invention

The purpose of the present invention is to provide an arc additive method suitable for inclined structural parts.

The technical solution to achieve the purpose of the present invention is: an arc additive method suitable for inclined structural members, characterized in that it includes the following steps:

Step (1): Depositing the first layer of build-up layer on the substrate by arc additive;

Step (2): a supporting auxiliary member is provided along the side where the inclined structural member and the base plate form an acute angle β, so that the supporting surface of the supporting auxiliary member is attached to the layer to be deposited of the inclined structural member;

Step (3): The welding torch moves to the arc-extinguishing end of the accumulation path of the Nth layer, initially N=1, and raises a layer height h _β , and the welding torch is offset dmm to the inclined side along the direction of the vertical accumulation path, and the Nth layer is completed The accumulation of +1 layer; the offset d is determined by the calculation of d=h _β /tanβ;

Step (4): Repeat step (3) to complete multi-layer accumulation forming until the required forming size of the component is met.

Further, the interlayer cooling time is 1-5min during arc additive.

Further, the inclined structural member is a single straight wall inclined structural member or an annular straight wall inclined structural member;

The single-channel straight-wall inclined structural member and the base plate are integrated.

Further, when the circular straight wall inclined structural member is in the shape of an inverted cone, it is integrated with the base plate;

When the annular straight-wall inclined structural part is conical-like, an inverted conical-like annular straight-wall inclined structural part is formed on the substrate, and then the conical annular straight-wall inclined structural part is separated from the substrate, and the annular straight-wall inclined structure The pieces are fixed in the desired position in the desired shape.

Further, when the formed inclined structural member is an annular straight-wall inclined structural member, the supporting auxiliary member adopted is a ring member composed of a plurality of arc-shaped members.

Further, the floor height h _β is 3-5mm.

Further, the support surface of the support aid is formed by a ceramic plate and a copper plate with cooling channels.

Further, the side of the support surface in contact with the buildup layer is coated with a thermal barrier coating.

Further, the arc additive heat source is a melting pole heat source or a non-melting pole heat source.

A part with an inclined structural part, the inclined structural part is prepared by the above-mentioned method.

Compared with the prior art, the present invention has significant advantages in that:

The invention creatively adds supporting auxiliary parts to support various alloy inclined wall additions, which overcomes the problems of high equipment cost, complex system, and low forming precision of stacked parts in the traditional addition of inclined wall structural parts, and can replace the adjustment and control of the substrate by a positioner The way to complete the addition of inclined thin-walled structural parts.

The invention introduces support auxiliary parts with cooling channels to support auxiliary material addition, and the molten wire completes the additive forming of structural parts under the action of the support parts, limits the solidification space of the deposition layer, and effectively overcomes the second layer and The problem of melt pool flow caused by excessive lateral offset during the subsequent layer accumulation; in addition, the cooling channel on the support auxiliary part is conducive to the heat dissipation of the deposited layer, which can further accelerate the solidification rate of the additive deposited layer. The cooling time between layers can be reduced to a certain extent, thereby improving the efficiency of material addition.

The invention can realize high-quality forming of various alloy inclined thin-walled structural parts, and has wide applications.

Description of drawings

Fig. 1 is a schematic diagram of the principle of the arc additive process of the multi-layer single-channel straight-wall inclined structural member in embodiment 1;

Fig. 2 is a schematic diagram of the principle of the arc additive process of the multi-layer annular straight wall inclined structure in embodiment 2;

Fig. 3 is a schematic diagram of the disassembly of the supporting auxiliary parts used in the multi-layer annular straight wall inclined structure in embodiment 2;

Fig. 4 is a comparison diagram of the forming of the multi-layer single-channel straight-wall inclined structural part with or without supporting auxiliary parts in the experimental arc-added material in Example 1.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

An arc additive method suitable for inclined structural parts, used to manufacture thin-walled alloy structural parts inclined at a certain angle with a substrate, the structural part is a multi-layer single-channel thin-walled structure, comprising the following steps:

Step 1: Use arc additive manufacturing to accumulate the first layer of accumulation layer on the substrate, and the cooling time between layers is 1-5min;

Step 2: Fix the supporting auxiliary part forming an angle β with the base plate along one side of the inclined direction of the inclined structural member, so that the accumulation layer and the supporting auxiliary part are closely attached;

Because in the present invention, it is necessary to add supporting auxiliary parts for support, it can be fixed after the first layer of accumulation is completed, which can facilitate positioning and fit perfectly with the accumulation layer. The supporting auxiliary parts used in the experiment do not react with the accumulation layer accumulated by the added alloy filler wire, and the coating layer on the surface will not adhere to the accumulation layer. The added supporting aids only play a supporting role.

Considering the large heat input in the arc additive manufacturing process, the heat dissipation conditions of the accumulated layers gradually deteriorate from the second layer onwards. In order to prevent problems such as molten pool flow or collapse in the subsequent accumulation process, it is necessary to strictly control the interlayer temperature. If the interlayer cooling time is too small, the heat accumulation will be greater than the heat loss, and the final surface of the manufactured part will easily have obvious excessive melting; if the interlayer cooling time is too long, the molding efficiency will be reduced. Therefore, it is necessary to set an appropriate interlayer cooling time, and the set interlayer cooling time is 1-5min;

Step 3: The welding torch moves to the arc-extinguishing end of the accumulation path of the Nth layer (initial N=1), raises a layer height h _β , and then the welding torch shifts dmm in the horizontal direction to complete the accumulation of the N+1th layer , the interlayer cooling time is 1-5min; during the accumulation process of the N+1th layer and subsequent layers, the layer height h _β raised by the welding torch is determined by calculating the offset d = h _β /tanβ, where β is The angle between the inclined wall and the substrate, h _β range is generally 3-5mm, which is determined according to the parameters of the additive process;

Step 4: Repeat step 3 to complete multi-layer stacking and forming until the required component forming size is met.

As a preferred mode, the welding torch is offset by d=h _β /tanβ along the direction perpendicular to the stacking direction. When the offset between layers is d=0mm, the formed structural member is perpendicular to the substrate and has no inclined features. When the offset d is too large, the added supporting auxiliary parts can sufficiently withstand the heat input and various forces during the arc additive process, and have good thermal conductivity, effectively avoiding the Melt pool flow problem caused by excessive offset.

As a preferred manner, the stacking directions of adjacent layers are opposite. Mainly considering the use of arc additives,

The arc-starting end of the accumulation layer has a large height and the arc-extinguishing end has a small height. If the adjacent layers accumulate in the same direction, the accumulation layer height at the arc-starting end will become higher and higher, and the height of the arc-extinguishing end will become lower and lower, resulting in The forming process does not work properly. However, the stacking method with the opposite stacking direction of adjacent layers can make up for the size difference between the arc starting end and the arc extinguishing end to a certain extent, so that the material addition process can proceed smoothly.

As a preferred mode, the support plate of the supporting auxiliary member does not react with the magnesium alloy substrate, and the surface is coated with a coating material such as a thermal barrier coating, a ceramic coating, etc. that is resistant to high temperatures and will not adhere to the accumulation layer. The support aid material is preferably ceramic and copper plates with cooling channels. The shape of the support aid can be selected according to the shape of the additive sample, and it can be composed of one support aid or a combination of multiple support aids.

Example 1

As shown in Figure 1, the AZ91 magnesium alloy straight-wall structure is a multi-layer single-channel structure. The height of the structure is 70mm, the width is 14mm, and the length is 130mm. The angle between the straight-wall structure and the substrate is 60°. The structural part is composed of EWMPC300 additive power supply (built-in water cooling system), MOTOMAN YRC1000 six-axis Yaskawa robot as the motion mechanism, the push-pull wire melting electrode welding torch is fixed at the end of the sixth axis of the robot, and the substrate preheating equipment is DB-3AB stainless steel electric heating plate, the highest It can be preheated to 400°C. The size of the supporting auxiliary parts is 150×30×1mm. The combination of 3 supporting auxiliary parts forms a supporting plate with a total size of 150×90×1mm. Arc additive manufacturing parameters: stacking current 170A, wire feeding speed 8m/min, stacking speed 24cm/min, swing amplitude 5mm, swing frequency 1.4Hz, stacking layer height h _β when the angle between the structural part and the substrate is 90° is about 3mm, the protective gas used in the stacking process is pure Ar gas, the filler wire is AZ91 magnesium alloy with a diameter of 1.2mm, the substrate is AZ91 magnesium alloy with a diameter of 450×250×8mm, and the heat source for arc additive manufacturing is the melting electrode gas shielded arc. Specific steps are as follows:

Step 1: Place and fix the substrate on the DB-3AB stainless steel electric heating plate, preheat to 400°C and keep the temperature constant to participate in the additive process. By controlling the MOTOMAN YRC1000 six-axis Yaskawa robot, adjust the height of the welding torch to ensure that the distance from the nozzle of the welding torch to the substrate is 13mm, the dry elongation of the welding wire is 12mm, and the distance from the end of the welding wire to the substrate is 1mm. Determine the arc starting point on the substrate, use arc additive manufacturing heat source to accumulate the first layer on the substrate, and the cooling time between layers is 2 minutes;

Step 2: Fix the supporting auxiliary part at an angle of β to the base plate along one side of the inclined direction of the inclined structural member, so that the accumulation layer and the supporting auxiliary part are closely attached; when the height of the supporting auxiliary part is not enough to accumulate the next accumulation layer, combine Install subsequent support aids to complete the additive process;

Step 3: Move the welding torch to the arc-extinguishing end of the accumulation path of the Nth (initial N=1) layer, raise a layer height h _β , and then offset the welding torch by dmm in the horizontal direction to complete the accumulation of the N+1 layer , the cooling time between layers is 2 minutes; during the accumulation process of the N+1 layer and subsequent layers, the welding torch raises the layer height h _β , and the offset d is 3mm, where β is the angle between the inclined wall of the additive and the substrate;

Step 4: Repeat step 3 to complete multi-layer stacking and forming until the required component forming size is met.

During the stacking process of the above inclined thin-walled structural members, the stacking directions of adjacent layers are opposite.

Figure 4 is a comparison diagram of the multi-layer single-channel straight-wall inclined structure with or without supporting auxiliary parts in Example 1. It can be seen from the figure that when the material is directly added without supporting auxiliary parts, the added With the increase in the number of layers of the inclined wall of the material, the problem of molten pool flow becomes more and more serious. After the introduction of supporting auxiliary parts, the problem of molten pool flow is solved, and high-quality forming of inclined structural parts is realized.

Example 2

As shown in Figure 2, the AZ91 magnesium alloy ring structure is a multi-layer single-channel structure with a height of 75 mm and a width of 14 mm. The bottom radius of the ring structure is 50 mm, and the cross section of the ring structure is 65° from the substrate. The structural part is composed of EWMPC300 additive power supply (built-in water cooling system), MOTOMAN YRC1000 six-axis Yaskawa robot as the motion mechanism, the push-pull wire melting electrode welding torch is fixed at the end of the sixth axis of the robot, and the substrate preheating equipment is DB-3AB stainless steel electric heating plate, the highest It can be preheated to 400°C. The bottom support auxiliary part has a bottom radius of 50mm, an angle between the inclination range and the base plate of 65°, a height of 20mm, and a thickness of 1mm. As shown in Figure 3, the supporting ring plate used in Example 2 It is composed of 4 identical 1/4 rings seamlessly spliced together; 4 pieces of supporting auxiliary parts are combined into a supporting ring plate with a total height of 80mm. Arc additive manufacturing parameters: stacking current 170A, wire feeding speed 8m/min, stacking speed 24cm/min, swing amplitude 5mm, swing frequency 1.4Hz, stacking layer height h _β when the angle between the structural part and the substrate is 90° is about 3mm, the protective gas used in the stacking process is pure Ar gas, the filler wire is AZ91 magnesium alloy with a diameter of 1.2mm, the substrate is AZ91 magnesium alloy with a diameter of 450×250×8mm, and the heat source for arc additive manufacturing is the melting electrode gas shielded arc. Specific steps are as follows:

Step 1: Place and fix the substrate on the DB-3AB stainless steel electric heating plate, preheat to 400°C and keep the temperature constant to participate in the additive process. By controlling the MOTOMAN YRC1000 six-axis Yaskawa robot, adjust the height of the welding torch to ensure that the distance from the nozzle of the welding torch to the substrate is 13mm, the dry elongation of the welding wire is 12mm, and the distance from the end of the welding wire to the substrate is 1mm. The arc starting point is determined on the substrate, the welding torch moves along the outside of the ring, and the first layer is deposited on the substrate by using the arc additive manufacturing heat source, and the cooling time between layers is 2 minutes;

Step 2: Fix the support ring plate with an angle of β to the base plate along one side of the inclined direction of the inclined structural member, so that the accumulation layer and the support auxiliary parts are closely attached; when the height of the support ring plate is not enough to accumulate the next accumulation layer, combine Install subsequent support aids to complete the additive process;

Step 3: The welding torch moves to the arc-extinguishing end of the accumulation path of the Nth (initial N=1) layer, raises a layer height h _β , then the welding torch is offset dmm in the horizontal direction, and the welding torch moves along the inner side of the supporting auxiliary ring , the accumulation of the N+1th layer is completed, and the interlayer cooling time is 2min; during the accumulation process of the N+1th layer and subsequent layers, the welding torch raises the layer height h _β , and the offset d is 3mm, where β is the additive The angle between the inclined wall and the base plate;

Step 4: Repeat step 3 to complete multi-layer stacking and forming until the required component forming size is met.

During the stacking process of the above-mentioned multi-layer single-track circular ring inclined thin-walled structural parts, the stacking directions of adjacent layers are opposite.

By adding support aids as supports, problems with molten pool flow caused by excessive offsets can be effectively avoided. The invention is applicable to the addition of inclined structural parts of various metal materials, and overcomes the problems of high equipment cost, complex system, and poor forming shape in the addition of various alloy inclined walls, and does not need to use a positioner to adjust the angle of the substrate. The forming of the inclined wall is realized by supporting and fixing the support auxiliary material. High-quality forming can be achieved for large and small inclined wall structural parts.

Claims (10)

1. An arc additive method for a tilting structure comprising the steps of:

step (1): stacking a first stacked layer on a substrate by adopting arc additive;

step (2): arranging a supporting auxiliary piece along one side of the inclined structural piece, which forms an acute angle beta with the base plate, so that a supporting surface of the supporting auxiliary piece is attached to a layer to be stacked of the inclined structural piece;

step (3): the welding gun moves to the arc extinguishing end of the stacking path of the Nth stacking layer, the initial N=1, and the height h of the stacking layer is increased _β The welding gun is shifted to the inclined side by dmm along the direction of the vertical stacking path, and the stacking of the (n+1) th layer is completed; offset d is d=h _β Determining the tan beta calculation;

step (4): and (3) repeating the step (3) to finish the multi-layer stacking forming until the required forming size of the component is met.

2. The arc additive process of claim 1 wherein the interlayer cooling time is 1-5 minutes during arc additive.

3. The arc additive method of claim 2 wherein the inclined structure is a single pass straight wall inclined structure or a circular straight wall inclined structure;

the single pass straight wall inclined structure and the base plate are integrated.

4. The arc additive process of claim 3 wherein the annular straight wall inclined structure is in an inverted conical like shape and is integral with the base plate;

when the annular straight wall inclined structural member is in a conical shape, an inverted conical annular straight wall inclined structural member is formed on the base plate, and then the annular straight wall inclined structural member is fixed at a required position according to a required shape after the conical annular straight wall inclined structural member is separated from the base plate.

5. The arc additive method of claim 4 wherein the shaped inclined structure is a circular straight wall inclined structure and the support aid is a circular member comprised of a plurality of arcuate members.

6. The arc additive process of claim 5 wherein the layer height h _β 3-5mm.

7. The arc additive method of claim 6 wherein the support surface of the support aid is formed from a ceramic plate and a copper plate with cooling channels.

8. The arc additive process of claim 7 wherein the side of the support surface in contact with the build-up layer is coated with a thermal barrier coating.

9. The arc additive process of claim 8 wherein the arc additive heat source is a consumable electrode heat source or a non-consumable electrode heat source.

10. A part having a sloping structure, characterized in that the sloping structure is produced by the method according to any one of claims 1-9.