Gas protection method for titanium alloy electric arc additive manufacturing

Abstract

The invention discloses a gas protection method for titanium alloy electric arc additive manufacturing. The method comprises the following steps that firstly, a metal block is machined; secondly, a pair of metal blocks are placed on the two sides of the first layer of titanium alloy wall structure area to be subjected to material increase in parallel, and a protective gas storage tank is formed; thirdly, material adding work of the first-layer titanium alloy wall body structure is conducted; fourthly, the metal blocks in the second step are tightly attached to the first layer of titanium alloy wall structure, a pair of new metal blocks are arranged on the metal blocks in the second step, and a protective gas storage tank synchronously increased along with the height of the additive is formed; fifthly, material adding work of a second-layer titanium alloy wall body structure is conducted; and sixthly, material adding work of the titanium alloy wall structure is conducted according to the methods from the fourth step to the fifth step till the height of the titanium alloy wall structure meets the material adding requirement. The method can be used for gas protection in the process of additive manufacturing of the titanium alloy component of the wall structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of arc additive manufacturing, and relates to a gas protection method for arc additive manufacturing of titanium alloys, and specifically to a gas protection method for TIG arc additive manufacturing of wall titanium alloys. Background Art

[0002] When using TIG arc additive manufacturing to manufacture titanium alloy wall components, during the layer-by-layer stacking process, the solidified lower layer of titanium alloy is heated by the heat conduction of the upper molten pool, which will cause high-temperature oxidation on the lower wall sidewall. Controlling the interlayer temperature cannot prevent the heat conduction during the additive process, and the wall sidewall will continue to oxidize as the height of the additive manufacturing component increases.

[0003] The common gas protection method for titanium alloy welding is to suspend a gas protection hood at the rear of the welding gun nozzle and install a gas supply pipeline on the hood. During welding, the inside of the hood is independently supplied with gas, which can provide effective gas protection for the titanium alloy welding process. However, for additive manufacturing that is stacked layer by layer, since the height of the wall structure will gradually increase during the additive process, and the density of the protective gas such as argon used is greater than that of air, the protective gas sprayed from the hood cannot remain on the side wall of the wall and will sink to the position of the substrate, making it impossible to effectively protect the wall structure. The use of a closed argon gas chamber can effectively protect the wall structure of additive manufacturing, but the argon gas chamber structure is troublesome to install, and it must be vacuumed and replaced with gas each time it is used, which increases the cost of additive manufacturing and is not conducive to improving the efficiency of additive manufacturing. Summary of the invention

[0004] In order to solve the problem of side wall oxidation when TIG arc additive manufacturing is used for titanium alloy wall structures with a height of more than 30 mm, the present invention provides a gas protection method for titanium alloy arc additive manufacturing.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A gas protection method for arc additive manufacturing of titanium alloys, comprising the following steps:

[0007] Step 1: Process a metal block with a thickness of 1 to 5 mm, a width of 10 to 50 mm, and a length equal to the length of the wall structure, wherein the metal block is made of a high melting point metal material such as titanium alloy or stainless steel;

[0008] Step 2: Place a pair of metal blocks in parallel on both sides of the first layer of titanium alloy wall structure area to be added, so that the horizontal distance between each metal block and the first layer of titanium alloy wall structure to be added is 1 to 5 mm, the height is 0 to 2 mm higher than the height of the first layer of titanium alloy wall structure to be added, and is 5 to 10 mm directly below the welding gun shielding gas nozzle to form a shielding gas storage tank;

[0009] Step 3: Carry out material addition work on the first layer of titanium alloy wall structure;

[0010] Step 4: Place the metal block in step 2 close to the first layer of titanium alloy wall structure, and place a pair of new metal blocks on the metal blocks in step 2, so that the horizontal spacing between the new metal blocks and the second layer of titanium alloy wall structure to be added is 1 to 5 mm, and the total height of the metal blocks is 0 to 2 mm higher than the height of the second layer of titanium alloy wall structure to be added, forming a protective gas storage tank that increases synchronously with the height of the added material;

[0011] Step 5: Add material to the second layer of titanium alloy wall structure;

[0012] Step 6: Perform additive work on the titanium alloy wall structure according to the methods of steps 4 and 5 until the height of the titanium alloy wall structure reaches the additive requirements.

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The method of the present invention can be used for gas protection in the process of additive manufacturing of titanium alloy components of wall structures. In the additive manufacturing process, metal blocks of suitable sizes are used to perform in-situ gas protection on the additively manufactured wall in the form of layer-by-layer stacking.

[0015] 2. The method of the present invention is simple to manufacture and install, and is flexible to use. It can effectively provide gas protection for the side walls of the additively manufactured wall structure, reduce oxidation of titanium alloy additively manufactured components, and ensure quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The gas protection workflow diagram of the present invention is as follows;

[0017] Figure 2 It is a schematic diagram of the gas protection work of the present invention;

[0018] Figure 3 It is a comparison chart of the side wall protection effects of the gas protection method of the present invention and the conventional shield protection method for wall-type structures. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is further described below in conjunction with the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0020] Embodiment 1:

[0021] This embodiment provides a gas protection method for arc additive manufacturing of titanium alloys, such as Figure 1 and Figure 2As shown, the method comprises the following steps:

[0022] Step 1: Process a stainless steel block with a thickness of 2mm, a width of 10mm, and a length of 100mm.

[0023] Step 2: Place a pair of metal blocks in parallel on both sides of the first layer of titanium alloy wall structure area to be added, so that the horizontal distance between each metal block and the first layer of titanium alloy wall structure to be added is 2 mm, the height is 1 mm higher than the height of the first layer of titanium alloy wall structure to be added, and it is located 10 mm directly below the shielding gas nozzle of the welding gun to form a shielding gas storage tank.

[0024] Step 3: Carry out additive work on the first layer of titanium alloy wall.

[0025] Step 4. Place the metal blocks in step 2 close to the first layer of titanium alloy wall structure, and place a pair of new metal blocks on top of the metal blocks in step 2, that is, when placing the second layer of metal blocks, the first layer of metal blocks are close to the first layer of titanium alloy wall that has been added, and the horizontal distance between the new metal blocks and the second layer of titanium alloy wall structure to be added is 2 mm, and the height is 1 mm higher than the height of the second layer of titanium alloy wall structure, forming a protective gas storage tank that increases synchronously with the height of the addition.

[0026] Step 5: Carry out additive work on the second layer of titanium alloy wall structure.

[0027] Step 6: Perform additive work on the titanium alloy wall structure according to the methods of steps 4 and 5 until the height of the titanium alloy wall structure reaches 100 mm.

[0028] Figure 3 This is a schematic diagram of the protective effect of titanium alloy in the wall structure additive manufacturing by the method of the present invention and the conventional shielding method. Figure 3 It can be seen that the method of the present invention has a good effect on protecting the side walls of the wall structure. The side walls are silvery white with no signs of oxidation. The ordinary support cover method cannot provide effective gas protection for the side walls of the wall structure. The side walls are gray, with some areas being blue-purple and obvious signs of oxidation.

[0029] Embodiment 2:

[0030] This embodiment provides a gas protection method for arc additive manufacturing of titanium alloy, the method comprising the following steps:

[0031] Step 1: Process a titanium alloy metal block with a thickness of 1 mm, a width of 5 mm, and a length of 50 mm.

[0032] Step 2: Place a pair of metal blocks in parallel on both sides of the first layer of titanium alloy wall structure area to be added, so that the horizontal distance between each metal block and the first layer of titanium alloy wall structure to be added is 3mm, the height is 2mm higher than the height of the first layer of titanium alloy wall structure to be added, and it is located 5mm directly below the shielding gas nozzle of the welding gun to form a shielding gas storage tank.

[0033] Step 3: Add material to the first layer of titanium alloy wall;

[0034] Step 4. Place the metal blocks in step 2 close to the first layer of titanium alloy wall structure, and place a pair of new metal blocks on top of the metal blocks in step 2, that is, when placing the second layer of metal blocks, the first layer of metal blocks are close to the first layer of titanium alloy wall that has been added, and the horizontal distance between the new metal blocks and the second layer of titanium alloy wall structure to be added is 3mm, and the height is 2mm higher than the height of the second layer of titanium alloy wall structure, forming a protective gas storage tank that increases synchronously with the height of the addition.

[0035] Step 5: Carry out additive work on the second layer of titanium alloy wall structure.

[0036] Step 6: Perform additive work on the titanium alloy wall structure according to the methods of steps 4 and 5 until the height of the titanium alloy wall structure reaches 50 mm.

Claims

1. A gas protection method for arc additive manufacturing of titanium alloy, characterized in that The method comprises the following steps: Step 1: Process a metal block with a thickness of 1 to 5 mm, a width of 10 to 50 mm, and a length equal to the length of the wall structure; Step 2: Place a pair of metal blocks in parallel on both sides of the first layer of titanium alloy wall structure area to be added, so that the horizontal distance between each metal block and the first layer of titanium alloy wall structure to be added is 1 to 5 mm, forming a protective gas storage tank; Step 3: Carry out material addition work on the first layer of titanium alloy wall structure; Step 4: Place the metal block in step 2 close to the first layer of titanium alloy wall structure, and place a pair of new metal blocks on the metal blocks in step 2, so that the horizontal distance between the new metal blocks and the second layer of titanium alloy wall structure to be added is 1 to 5 mm, forming a protective gas storage tank that increases synchronously with the height of the added material; Step 5: Add material to the second layer of titanium alloy wall structure; Step 6: Perform additive work on the titanium alloy wall structure according to the methods of steps 4 and 5 until the height of the titanium alloy wall structure reaches the additive requirements.

2. The gas protection method for arc additive manufacturing of titanium alloy according to claim 1, characterized in that The material of the metal block is titanium alloy or stainless steel.

3. The gas protection method for arc additive manufacturing of titanium alloy according to claim 1, characterized in that In the step 2, the upper surface of the metal block is 5 to 10 mm directly below the shielding gas nozzle of the welding gun.

4. The gas protection method for arc additive manufacturing of titanium alloy according to claim 1, characterized in that In the step 2, the height of the metal block is 0 to 2 mm higher than the height of the first layer of the titanium alloy wall structure.

5. The gas protection method for arc additive manufacturing of titanium alloy according to claim 1, characterized in that In the step 4, the total height of the metal block is 0 to 2 mm higher than the height of the second layer of titanium alloy wall structure to be added.

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