A method for optimizing the structure of linear friction welding joint

Abstract

The present invention belongs to the field of welding technology, and in particular, is a method for optimizing the structure of linear friction welding joints, and is used to optimize the structure of linear friction welding joints of integral blade disk parts in the field of aero-engine manufacturing. The method comprises the following steps: after the design of the uniform cross-section welding joint is completed, the right-angled side of the uniform cross-section welding joint section is changed to an arc transition design, and an arc chamfer is made between the side of the welding joint and the shoulder of the clamping block to form a variable cross-section welding joint; the fillet design at the top of the variable cross-section welding joint is changed to a polygonal design, and the area of ​​the polygon must be larger than the fillet area; and the optimized design of the welding joint is completed. The present invention can improve the forming quality of linear friction welding joints of integral blade disk parts, improve the strength of the welding joints of integral blade disk parts, and further improve the product qualification rate and manufacturing reliability of linear friction welding integral blade disk parts.

Description

Technical Field

[0001] The invention belongs to the field of welding technology, in particular to a method for optimizing the structure of a linear friction welding joint, and is used to optimize the structure of a linear friction welding joint of integral blade disk parts in the field of aviation engine manufacturing. Background Art

[0002] Linear friction welding technology is a key manufacturing technology for integral blade disk parts. The linear friction welding structure has a decisive influence on the final dimensional accuracy of the product. The traditional linear friction welding structure adopts a tip fillet transition and an equal cross-section joint structure. During the welding process of the parts, the welding interface is subjected to a large impact force, and the welding interface is prone to local unwelded defects. The parts have poor welding repeatability, resulting in a low part qualification rate.

[0003] Patent CN201710454317.6 discloses a method for improving the shortening accuracy of linear friction welding, which sets a reference area through pre-testing and calculates the average speed of the workpiece in the reference area, divides the speed interval and sets the adjustment value corresponding to the speed interval, thereby improving the shortening accuracy. It only controls the welding accuracy in the shortening direction (Z direction) of the part, and does not involve the structural optimization method of the part welding joint.

[0004] Patent CN201811308931.2 discloses a device and method for controlling flash deformation during linear friction welding. The device includes a welding fixture and a limiting block. The welding fixture is used to install welding parts, which can effectively solve the problem of flash interference with adjacent welding parts, ensure the smooth welding process of welding parts and welded parts, and significantly improve welding efficiency. It only optimizes the design of welding tooling for parts, and does not involve the structural optimization method of parts welding joints.

[0005] Patent CN201811311708.3 discloses a blade linear friction welding joint quality control method and device, and proposes a blade linear friction welding joint quality control device, which overcomes the problem that traditional polygonal and rhombus cross-sections are prone to unwelded defects at the corners, effectively reduces the welding area of ​​components and ensures the quality of welded joints, and greatly reduces the waste of precious metals. The welding interface of the parts is rounded and the margin is increased for optimization design, but the structural optimization method of the parts welding joint is not involved.

[0006] In summary, for the linear friction welding technology of integral blisks, there is still a blank in the optimization design method of parts welding joints. Summary of the invention

[0007] The purpose of the present invention is to provide a method for optimizing the structure of a linear friction welding joint, which can improve the forming quality of the linear friction welding joints of integral blade disk parts, improve the strength of the welding joints of the integral blade disk parts, and further improve the product qualification rate and manufacturing reliability of linear friction welding integral blade disk parts.

[0008] The technical solution of the present invention is:

[0009] A method for optimizing a linear friction welding joint structure, the method comprising the following steps:

[0010] Step 1: After the design of the uniform cross-section weld joint is completed, the right-angle side of the uniform cross-section weld joint section is changed to an arc transition design, and a circular arc chamfer is made between the side of the weld joint and the shoulder of the clamping block to form a variable cross-section weld joint;

[0011] Step 2: Change the fillet design at the top of the variable-section weld joint to a polygonal design, and the polygon area must be larger than the fillet area;

[0012] Step 3: Complete the optimized design of welding joint.

[0013] The method for optimizing the structure of the linear friction welding joint adopts a variable cross-section welding joint between the welding interface and the clamping block, and the welding interface area is S 0 , contact area S between welding joint and clamping block 1 , let S 0 <S 1 .

[0014] In the method for optimizing the structure of a linear friction welding joint, a variable cross-section design with circular arc chamfers is adopted in the welding joint between the welding interface and the clamping block, so that the cross-section of the welding joint presents a "variable cross-section" structure.

[0015] The method for optimizing the structure of a linear friction welding joint changes the arc transition to a polygonal transition at the tip of the welding joint along the vibration direction, so that the tip of the welding joint presents a polygonal structure.

[0016] The beneficial effects brought about by the technical solution of the present invention are:

[0017] 1. By adopting a method for optimizing the structure of a linear friction welding joint of the present invention, the manufacturing accuracy of integral blade disk parts is improved, the parts manufacturing repeatability is high, the product qualification rate and production efficiency of the integral blade disk parts are improved, and the development and production needs of the products can be met.

[0018] 2. The welding joint structure optimization method of the present invention is used for the manufacture of integral blade disks of aircraft engines. The welding joint structure optimization method avoids the problems of defects and poor welding quality consistency in conventional linear friction welding joints, can improve the linear friction welding geometric dimension accuracy of the integral blade disk parts of the engine, improve the manufacturing accuracy of the integral blade disk parts, further improve the production efficiency and product qualification rate of integral blade disk parts, and improve the manufacturing reliability of linear friction welding integral blade disk parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of variable cross-section design of welded joints, including (a) original right-angle design and (b) variable cross-section design.

[0020] Figure 2 Schematic diagram of the polygonal design at the tip of the weld joint.

[0021] Figure 3 Schematic diagram of the structure of a new variable-section welding joint.

[0022] The numbers in the figure are: 1 clamping block, 2 uniform cross-section welding joint, 3 variable cross-section welding joint, 4 welding interface. DETAILED DESCRIPTION

[0023] like Figure 1 As shown in (a), on the clamping block 1 of the conventional linear friction welding joint, an equal-section welding joint 2 with an equal-section butt joint structure is adopted, and a rounded transition is adopted in the welding vibration direction. Figure 2 (Left). During the welding process, this conventional structure often causes the welding interface to be subjected to greater friction and impact forces. Such a welding structure will result in insufficient frictional heat generation of the material at the initial stage of welding, and the friction resistance of the metal at the welding interface will be greater, which can easily cause minor defects at the welding interface. In the middle stage of welding, the plastic metal extruded from the welding interface is likely to accumulate around the joint, resulting in uneven heat dissipation at the welding joint, and overheating defects are likely to occur at the welding joint, resulting in minor deviations in the welding dimensions of the parts. These dimensional errors directly affect the final welding quality.

[0024] like Figure 1 (b) Figure 2 (right) and Figure 3 As shown, the design principle of the present invention is as follows:

[0025] 1) Variable cross-section design of welded joints

[0026] A variable cross-section welding joint 3 is used between the welding interface 4 and the clamping block 1, and the welding interface area is S 0 , contact area S between welding joint and clamping block 1 , let S 0 <S1 The welding joint between the welding interface 4 and the clamping block 1 adopts a variable cross-section design with an arc chamfer, so that the cross-section of the welding joint presents a "variable cross-section" structure. The advantages of this structure are: first, the variable cross-section increases the rigidity and stability of the root of the welding joint, and the welding joint is not easy to become unstable. Second, the variable cross-section increases the space for extruding metal in the welding cross-section, which is conducive to the discharge of plastic metal, avoids the overheating problem at the tip of the welding joint, and improves the forming quality of the welding joint.

[0027] 2) Polygonal design of the welding joint tip

[0028] At the tip of the weld joint along the vibration direction, the arc transition is changed to a polygonal transition, and the tip of the weld joint presents a polygonal structure. The advantages of this structure are: First, the polygonal structure directly increases the area of ​​the tip of the weld joint by adding redundant materials, which can compensate for the welding surface loss caused by metal extrusion during the welding process, avoid damage to the part body caused by insufficient weld joint margin, and improve the welding quality of the part. Second, the polygonal structure increases the space for extruded metal in the welding section, which is beneficial to the discharge of plastic metal, avoids the overheating problem at the tip of the weld joint, and improves the forming quality of the weld joint. Third, the polygonal design of the tip of the welding surface reduces the processing difficulty of the weld joint and improves the processing efficiency.

[0029] Below, the present invention is further described in detail with reference to embodiments:

[0030] Example

[0031] like Figure 1-Figure 3 As shown, the present embodiment provides a method for optimizing the structure of a linear friction welding joint, comprising the following steps:

[0032] Step 1: After the design of the right-angle weld joint (equal-section weld joint 2) is completed, the right-angle side of the cross-section of the equal-section weld joint 2 is changed to an arc transition design, and a circular arc chamfer is made between the side of the weld joint and the shoulder of the clamping block 1 to form a variable-section weld joint 3.

[0033] Step 2: Change the fillet design at the top of the variable-section weld joint 3 to a polygonal design, and the polygon area must be larger than the fillet area.

[0034] Step 3: Complete the optimized design of welding joint.

[0035] The implementation results show that linear friction welding technology is a key technology for the manufacturing of integral blade disk parts of aircraft engines. The linear friction welding parameter control method can greatly improve the manufacturing accuracy of integral blade disk parts, improve the production efficiency and manufacturing qualification rate of integral blade disk parts, and has broad application prospects.

Claims

1. A method for optimizing the structure of a linear friction welding joint, It is characterized in that The method comprises the following steps: Step 1: After the design of the uniform cross-section weld joint is completed, the right-angle side of the uniform cross-section weld joint section is changed to an arc transition design, and a circular arc chamfer is made between the side of the weld joint and the shoulder of the clamping block to form a variable cross-section weld joint; Step 2: Change the fillet design at the top of the variable-section weld joint to a polygonal design, and the polygon area must be larger than the fillet area; Step 3: Complete the optimization design of the welding joint; A variable cross-section weld joint is used between the welding interface and the clamping block, and the welding interface area is S 0 , contact area S between welding joint and clamping block 1 , let S 0 <S 1 ; The welding joint between the welding interface and the clamping block adopts a variable cross-section design with arc chamfers, so that the cross-section of the welding joint presents a "variable cross-section" structure; At the tip of the weld joint along the vibration direction, the arc transition is changed to a polygonal transition, and the tip of the weld joint presents a polygonal structure.

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