Multi-directional forging forming method for titanium alloy irregular die forging

Abstract

The invention discloses a multidirectional forging forming method for a titanium alloy irregular die forging, which is characterized in that the titanium alloy irregular die forging is formed by adopting a multidirectional forging device, so that the forging is deformed in the vertical direction and the horizontal direction at the same time, metal materials are ensured to fully flow towards multiple directions, and the interiors of crystal grains are mutually staggered and crushed; and recovery recrystallization can be fully carried out, so that the aims of refining crystal grains and improving the structure property are achieved. The method is suitable for multidirectional forging forming of the titanium alloy irregular die forging.

Description

Technical Field

[0001] The present invention relates to a forging method, in particular to a multi-directional forging forming method for irregular titanium alloy die forgings. Background Art

[0002] Titanium alloy belongs to lightweight and difficult-to-deform structural materials. During the forging process, it has a large deformation resistance, a narrow deformation temperature window, and is sensitive to the strain rate. The formation of recrystallized grains in titanium alloy mainly comes from the grain boundaries and sub-grain boundaries formed during the deformation process. Therefore, the formation of deformation grain boundaries is an important process. During the deformation process, the strain amounts of adjacent original grains with different orientations are different, resulting in stress concentration near the grain boundaries. The release of stress mainly relies on the formation of deformation grain boundaries. The processes of slip and twinning will form deformation grain boundaries and cause grain rotation, thereby forming a specific orientation and making the grains fragmented. During the multi-directional forging process, the orientation of the deformation bands in titanium alloy changes with the change of the load axis direction, interlaces with each other inside the initial grains, and forms a dislocation cell structure with geometric grain boundaries. As the deformation amount increases, the cell structure will gradually transform into sub-grains. When the deformation amount further increases, the sub-grains will further transform into recrystallized grains with low-angle grain boundaries or high-angle grain boundaries. Compared with the traditional unidirectional deformation process, the multi-directional forging technology enables recrystallized grains to be generated not only at the grain boundaries of the original grains but also in large quantities inside the grains, greatly increasing the grain refinement effect.

[0003] Currently, for the multi-directional forging forming of irregular titanium alloy die forgings in China, it is mainly achieved by continuously adjusting the loading direction during the forging process, which is equivalent to forging the blank in different directions multiple times. The magnitude and angle of the force adjusted each time in this method are difficult to control, which will affect the tissue properties of the titanium alloy forgings. Moreover, for irregular die forgings, the forging dimensions in each direction are different, and this method is not applicable. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a multi-directional forging forming method for irregular titanium alloy die forgings. Through the design of the die structure, during the forging process, the forces on all directions of the forging are balanced, ensuring the tissue and properties of the irregular titanium alloy die forgings.

[0005] To solve the above technical problems, the technical solutions involved in the present invention include the following steps:

[0006] First step, fabricate a multi-directional forging device, which includes: a lower anvil, an upper anvil, a guiding connecting rod, a slider, an upper wedge block, a central connecting rod, a tower-shaped block, an intermediate wedge block, an upper die fixing backing plate, an upper die, a lateral die, a lower wedge block, a lower die fixing backing plate, and a lower die; the inclination angle of the contact surface between the upper wedge block and the tower-shaped block is α, and the initial contact surface area is S1; the inclination angle of the contact surface between the upper wedge block and the intermediate wedge block is β, and the initial contact surface area is S2; the inclination angle of the contact surface between the intermediate wedge block and the lower wedge block is θ;

[0007] Second step, after heating and insulating the blank, transfer it into the multi-directional forging device, in the middle of the upper die and the lower die; drive the upper anvil to move downward, and push the upper wedge block to move downward. The upper wedge block transmits the driving force to the tower-shaped block and the intermediate wedge block. The upper die and the lower die are gradually closed under the push of the tower-shaped block; the intermediate wedge block will continue to transmit the driving force to the lower wedge block and drive the lateral die to gradually close until the blank is formed in the cavity formed after the upper die, the lower die, and the lateral die are closed.

[0008] Further, the inclination angle α of the contact surface between the upper wedge block and the tower-shaped block, the initial contact surface area S1, the inclination angle β of the contact surface between the upper wedge block and the intermediate wedge block, the initial contact surface area S2, and the inclination angle θ of the contact surface between the intermediate wedge block and the lower wedge block satisfy the following relationship: S1×S2×cosα×cosβ×(1 - sinθ) = (S1×cosα) 2 ×sinθ - (S2×cosβ) 2 .

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0010] For the multi-directional forging forming method of the titanium alloy irregular die forgings of the present invention, a multi-directional forging device is used to deform the forging simultaneously in the vertical and horizontal directions, ensuring that the metal material flows fully in multiple directions, making the grains inside intersect with each other. After being broken, it can fully undergo recovery and recrystallization, thereby achieving the purpose of refining grains and improving the tissue performance. On the other hand, the inclination angle α of the contact surface between the upper wedge block and the tower-shaped block, the initial contact surface area S1, the inclination angle β of the contact surface between the upper wedge block and the intermediate wedge block, the initial contact surface area S2, and the inclination angle θ of the contact surface between the intermediate wedge block and the lower wedge block satisfy S1×S2×cosα×cosβ×(1 - sinθ) = (S1×cosα) 2 ×sinθ - (S2×cosβ) 2 The relationship can ensure the balanced force of the forging in the vertical and horizontal directions during the forging process. Description of the Drawings

[0011] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0012] Figure 1 It is a schematic structural diagram of the multi-directional forging device described in the present invention. Specific implementation mode

[0013] To implement the multi-directional forging and forming method of the titanium alloy irregular die forging described in the present invention, equipment such as a forging heating furnace, a press, and a manipulator need to be provided. The specific implementation mode of this method:

[0014] Manufacture a multi-directional forging device: This device includes: a lower anvil 1, an upper anvil 2, a guiding connecting rod 3, a slider 4, an upper wedge block 5, a central connecting rod 6, a tower-shaped block 7, an intermediate wedge block 8, an upper die fixing backing plate 9, an upper die 10, a lateral die 11, a lower wedge block 12, a lower die fixing backing plate 14, and a lower die 15; the inclination angle of the contact surface between the upper wedge block 5 and the tower-shaped block 7 is α, and the initial contact surface area is S1; the inclination angle of the contact surface between the upper wedge block 5 and the intermediate wedge block 8 is β, and the initial contact surface area is S2; the inclination angle of the contact surface between the intermediate wedge block 8 and the lower wedge block 12 is θ;

[0015] The inclination angle α of the contact surface between the upper wedge block 5 and the tower-shaped block 7, the initial contact surface area S1, the inclination angle β of the contact surface between the upper wedge block 5 and the intermediate wedge block 8, the initial contact surface area S2, and the inclination angle θ of the contact surface between the intermediate wedge block 8 and the lower wedge block 12 satisfy the following relationship: S1×S2×cosα×cosβ×(1 - sinθ) = (S1×cosα) 2 ×sinθ - (S2×cosβ) 2 .

[0016] Multi-directional forging and forming: After heating and insulating the blank 13, transfer it to the middle of the upper die 10 and the lower die 15 in the multi-directional forging device; drive the upper anvil 2 to move downward, and push the upper wedge block 5 to move downward. The upper wedge block 5 transmits the driving force to the tower-shaped block 7 and the intermediate wedge block 8. The upper die 10 and the lower die 15 are gradually closed under the push of the tower-shaped block 7; the intermediate wedge block 8 will continue to transmit the driving force to the lower wedge block 12 and drive the lateral die 11 to gradually close until the blank is formed in the cavity formed after the upper and lower dies (10, 15) and the lateral die 11 are closed.

Claims

1. A multi-directional forging forming method for titanium alloy irregular die forgings, characterized in that It includes the following steps: The first step is to fabricate a multi-directional forging device, which includes: a lower anvil, an upper anvil, a guiding connecting rod, a slider, an upper wedge block, a central connecting rod, a tower-shaped block, an intermediate wedge block, an upper die fixing backing plate, an upper die, a lateral die, a lower wedge block, a lower die fixing backing plate, and a lower die; the inclination angle of the contact surface between the upper wedge block and the tower-shaped block is α, and the initial contact surface area is S1; the inclination angle of the contact surface between the upper wedge block and the intermediate wedge block is β, and the initial contact surface area is S2; the inclination angle of the contact surface between the intermediate wedge block and the lower wedge block is θ. In the second step, after heating and holding the blank, transfer it into the multi-directional forging device, in the middle of the upper die and the lower die; drive the upper anvil to move downward and push the upper wedge block to move downward. The upper wedge block transmits the driving force to the tower-shaped block and the intermediate wedge block, and the upper die and the lower die gradually close under the push of the tower-shaped block; the intermediate wedge block will continue to transmit the driving force to the lower wedge block and drive the lateral die to gradually close until the blank is formed in the cavity formed after the upper die, the lower die, and the lateral die are closed.

2. The multi-directional forging forming method of the titanium alloy irregular die forging according to claim 1, characterized in that, The inclination angle α of the contact surface between the upper wedge block and the tower-shaped block, the area S1 of the initial contact surface, the inclination angle β of the contact surface between the upper wedge block and the middle wedge block, the area S2 of the initial contact surface, and the inclination angle θ of the contact surface between the middle wedge block and the lower wedge block satisfy the following relationship: S1×S2×cosα×cosβ×(1 - sinθ) = (S1×cosα) 2 ×sinθ - (S2×cosβ) 2 .

Images