Equal-channel extrusion ultrasonic vibration auxiliary forming device

Abstract

The utility model belongs to the field of metal processing, and particularly relates to an equal-channel extrusion ultrasonic vibration auxiliary forming device which comprises an equal-channel extrusion die, a pressure head capable of extending into the equal-channel extrusion die and an extrusion mechanism driving the pressure head to move up and down, and the equal-channel extrusion die comprises a lower die, a first clamping block and a second clamping block. The lower die, the clamping block I and the clamping block II can be assembled to form a columnar structure with a bending and extruding channel; an amplitude-change pole is fixed to the lower portion of the lower die and connected with a transducer. According to the ultrasonic vibration equal-channel extrusion die, the ultrasonic vibration technology and the severe plastic deformation technology are combined, in the metal machining process, the transmission efficiency of ultrasonic energy is improved, forming force is effectively reduced, grain refinement is facilitated, and the ultrasonic vibration equal-channel extrusion die can be used for machining magnesium-zinc-Y alloy and other metal difficult to deform.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal processing, and in particular relates to an equal channel extrusion ultrasonic vibration auxiliary forming device. Background Art

[0002] Large plastic deformation can make metal obtain very large plastic strain during processing, thus obtaining ultrafine-grained metal materials. It is a processing technology with broad prospects. Common ones include equal channel extrusion, cumulative rolling, reciprocating extrusion, etc. Compared with ordinary deformation, large plastic deformation has greater deformation energy storage and promotes the occurrence of recrystallization.

[0003] Mg-Zn-Y alloy is a high-strength rare earth magnesium alloy with great development potential. However, due to its close-packed hexagonal structure, poor deformation ability and difficulty in processing, hot processing is often required, which inevitably brings some hot processing defects, such as complex forming process, high energy consumption, low material utilization rate, coarse grains after deformation, etc., which seriously restricts the large-scale application of this alloy in the industrial field.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Utility Model Content

[0005] The purpose of the utility model is to overcome the shortcomings of the prior art and provide an equal channel extrusion ultrasonic vibration assisted forming device, which combines large plastic deformation with ultrasonic vibration, fully utilizes the advantages of both in processing, and thereby realizes effective processing of difficult-to-deform metals such as Mg-Zn-Y alloy.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] An equal channel extrusion ultrasonic vibration assisted forming device comprises an equal channel extrusion die, a pressing head which can be inserted into the equal channel extrusion die, and an extrusion mechanism which drives the pressing head to move up and down; the equal channel extrusion die comprises a lower die, a clamping block 1 and a clamping block 2, the lower die, the clamping block 1 and the clamping block 2 can be assembled into a columnar structure with a bent extrusion channel; a variable amplitude rod is fixed to the lower part of the lower die, and the variable amplitude rod is connected to a transducer.

[0008] Furthermore, the amplitude changing rod is arranged below or on the side of the lower mold.

[0009] Furthermore, the amplitude varying rod is integrally formed with the lower mold.

[0010] Furthermore, a sleeve seat is provided below the mold, the transducer is arranged in the sleeve seat, and the amplitude changing rod is vertically fixed on the bottom surface of the lower mold.

[0011] Furthermore, a plurality of ears are provided in the middle of the amplitude changing rod, a clamping plate 1 is fixed to the sleeve seat by bolts, a clamping plate 2 is provided between the clamping plate 1 and the upper surface of the sleeve seat, a groove matching the ear is provided on the upper surface of the clamping plate 2, and the ear is accommodated in the groove.

[0012] Furthermore, the equal channel extrusion ultrasonic vibration assisted forming device also includes a gasket made of non-metallic material, and the gasket is clamped and fixed between the first clamp and the second clamp / ear.

[0013] Furthermore, the equal channel extrusion die also includes a small sleeve, and the outer diameters of the clamp block 1, the clamp block 2 and the upper part of the lower die are smaller than the outer diameter of the lower part of the lower die; the clamp block 1, the clamp block 2 and the upper part of the lower die are assembled into a cylindrical shape and embedded in the small sleeve.

[0014] Furthermore, the wall thickness of the small sleeve is not less than 7 mm, and at least one pair of opposite through holes is provided on the lower wall of the small sleeve.

[0015] Furthermore, the included angle of the extrusion channel is 120°, and the outer fillet radius is 15 mm.

[0016] Furthermore, the equal channel extrusion ultrasonic vibration assisted forming device also includes a ceramic heating ring and a temperature controller for controlling the temperature of the ceramic heating ring, and the ceramic heating ring is correspondingly arranged on the outer periphery of the equal channel extrusion die.

[0017] The working principle of the utility model is that ultrasonic vibration-assisted plastic deformation refers to applying ultrasonic vibration with adjustable direction, frequency and amplitude to the metal or mold during the deformation process of the metal, and improving the performance of the metal with the help of ultrasonic energy. Compared with traditional plastic processing technology, the performance of the material can be effectively improved after ultrasonic vibration-assisted processing. For example, vibration can reduce the friction between the workpiece and the mold and the overall forming force, which improves the plastic forming of the metal material. The utility model introduces ultrasonic vibration-assisted processing technology into the processing and preparation of difficult-to-deform metal processing alloys such as Mg-Zn-Y alloy, providing a new idea for processing metals.

[0018] The beneficial effects of the utility model are:

[0019] The utility model combines ultrasonic vibration with large plastic deformation technology and proposes an ultrasonic vibration equal channel extrusion die. During the metal processing process, the transmission efficiency of ultrasonic energy is increased, the forming force is effectively reduced, and it is helpful to refine the grains. It can be used for the processing of difficult-to-deform metals such as Mg-Zn-Y alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. Among them:

[0021] Figure 1 The cross-sectional structure diagram of the equal channel extrusion die of the utility model embodiment is shown in FIG. Figure 1 .

[0022] Figure 2 The cross-sectional structure diagram of the equal channel extrusion die of the utility model embodiment is shown in FIG. Figure 2 .

[0023] Figure 3 It is a schematic diagram of the top structure of the equal channel extrusion die according to an embodiment of the utility model.

[0024] Figure 4 It is a structural schematic diagram of the lower mold of an embodiment of the utility model.

[0025] Figure 5 It is a structural schematic diagram of a clamping block 1 according to an embodiment of the utility model.

[0026] Figure 6 It is a schematic structural diagram of a pressure head according to an embodiment of the utility model.

[0027] Figure 7 This is the metallographic structure photo of Mg-Zn-Y alloy after equal channel extrusion.

[0028] Figure 8 This is the metallographic structure photograph of Mg-Zn-Y alloy after ultrasonic vibration assisted equal channel extrusion.

[0029] In the figure: 1-transducer, 2-amplifier, 3-lower die, 4-small sleeve, 5-pressing head, 6-clamping block 1, 7-clamping block 2, 8-clamping plate 1, 9-clamping plate 2, 10-gasket, 11-sleeve seat, 12-bolt, 13-through hole. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the protection scope of the present invention.

[0031] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention. The terms "connected" and "connection" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0033] like Figures 1 to 6 As shown, an equal-channel extrusion ultrasonic vibration assisted forming device comprises an equal-channel extrusion die, a ram 5 which can be inserted into the equal-channel extrusion die, and an extrusion mechanism which drives the ram 5 to move up and down; the equal-channel extrusion die adopts the design of upper and lower dies 3, and the channel extrusion angle is 120°; the equal-channel extrusion die comprises a lower die 3, a clamping block 1 6 and a clamping block 2 7, and the lower die 3, the clamping block 1 6 and the clamping block 2 7 can be assembled into a columnar structure with a bent extrusion channel; a variable amplitude rod 2 is fixed to the lower part of the lower die 3, and the variable amplitude rod 2 is connected to a transducer 1.

[0034] like Figures 1 to 6 As shown, the lower mold 3 includes a base portion and an arched column portion and a lower block portion integrally formed on the base portion, the base portion is used to connect with the amplitude transformer 2; the arched column portion is arched when viewed from above and rectangular when viewed from the side, and has an arc surface and a vertical surface; the lower block portion is approximately a right-angled trapezoid when viewed from the side and a rectangle when viewed from above, with a width less than the chord length of the arched column portion, and is centrally arranged at the lower part of the vertical surface of the arched column portion; the clamping block 1 6 and the clamping block 2 7 are symmetrical in structure, and the clamping block 1 6 includes a half arched column portion and a right-angled trapezoidal block portion fixed on the upper part of the half arched column portion away from the arched column portion of the lower mold 3; when assembled The semi-arched column of the clamp block 1 6 and the clamp block 2 7 is pressed against the vertical surface of the arched column of the lower die 3, and the right-angled trapezoidal block of the clamp block 1 6 and the clamp block 2 7 is located above the lower block, thereby forming a continuous extrusion channel at the lower die 3 and the joint of the clamp block 1 6 and the clamp block 2 7; the equal channel extrusion die of this embodiment is designed with the convenience of disassembly and sampling in mind, and the die material is selected from 9CrSi, such as SKD11 die steel, so that the die has a certain rigidity, is not easily deformed during repeated tests, and can adapt to the larger extrusion pressure of repeated large plastic deformation; the material of other components can be 45 steel.

[0035] Further, the horn 2 is arranged below or on the side of the lower die 3; the horn 2 and the lower die 3 are integrally formed, such as by using an integral milling method to make the horn 2 and the lower die 3, so that the vibration can be better transmitted to the mold and the energy loss during the transmission process can be reduced; or the horn 2 and the lower die 3 are connected by threads, such as Figure 1 to Figure 2 As shown, the amplitude transformer 2 is connected and fixed to the lower die 3 by stud bolts.

[0036] Further, such as Figure 1 to Figure 2 As shown, a sleeve seat 11 is arranged below the mold, and the sleeve seat 11 is used to support the equal channel extrusion mold and place the transducer 1 for generating ultrasonic waves; the transducer 1 is arranged in the sleeve seat 11, and the amplitude rod 2 is vertically fixed on the bottom surface of the lower mold 3.

[0037] Further, such as Figure 1 to Figure 2 As shown, a plurality of ears are provided in the middle of the amplitude changing rod 2, a clamp plate 18 is fixed to the sleeve seat 11 by bolts 12, a clamp plate 2 9 is provided between the clamp plate 18 and the upper surface of the sleeve seat 11, a groove matching the ear is provided on the upper surface of the clamp plate 2 9, and the ear is accommodated in the groove; the groove depth is 6±0.1mm; the clamp plate 1 8 and the clamp plate 2 9 are used to cover the top of the sleeve seat 11 and position and install the amplitude changing rod 2.

[0038] Further, such as Figure 2 As shown, the equal channel extrusion ultrasonic vibration assisted forming device also includes a gasket 10 made of non-metallic material, and the gasket 10 is clamped and fixed between the clamp plate 1 8 and the clamp plate 2 9 / card, and the gasket 10 is made of rubber, silicone, plastic, polyurethane and other materials.

[0039] like Figures 1 to 3 As shown, the equal channel extrusion die also includes a small sleeve 4, and the outer diameters of the clamp block 1 6, the clamp block 2 7 and the upper part of the lower die 3 are smaller than the outer diameter of the lower part of the lower die 3; the clamp block 1 6, the clamp block 2 7 and the upper part of the lower die 3 are assembled into a cylindrical shape and embedded in the small sleeve 4; specifically, the wall thickness of the small sleeve 4 is not less than 7 mm, and at least one pair of opposite through holes 13 is provided on the lower wall of the small sleeve 4. When the mold needs to be installed or removed, a disassembly tool is inserted into the through hole 13 to facilitate the installation or removal of the small sleeve 4.

[0040] Furthermore, the outer fillet radius at the corner of the extrusion channel is 15 mm.

[0041] Furthermore, the equal channel extrusion ultrasonic vibration assisted forming device also includes a ceramic heating ring and a temperature controller for controlling the temperature of the ceramic heating ring, and the ceramic heating ring is correspondingly arranged on the outer periphery of the equal channel extrusion die.

[0042] Experimental example:

[0043] The entire extrusion experiment was carried out at high temperature, and the experimental temperature was set at 300℃. The ultrasonic vibration device used in the experiment had a vibration frequency of 20kHz and an amplitude of 5μm. The extrusion power was a hydraulic press. Before the extrusion began, MoS2 grease was applied to the extrusion channel and the alloy surface to reduce the friction coefficient between the die and the sample. The ultrasonic vibration-assisted equal channel extrusion experiment used the Bc path (after each pass, the sample rotated 90° clockwise) for extrusion, and the extrusion speed was 0.04mm / s. The sample needs to be preheated in the die for about 20 minutes to improve the deformation ability of the alloy and prevent cracks in the sample during the extrusion process.

[0044] like Figure 7 , Figure 8 The metallographic microstructures of Mg-Zn-Y alloys subjected to equal channel extrusion and ultrasonic vibration assisted equal channel extrusion are shown. Compared with conventional equal channel extrusion, the grain boundaries in ultrasonic vibration assisted equal channel extrusion are more obvious, the proportion of dynamic recrystallization is larger, and the dynamic recrystallization process tends to be complete. The part where dynamic recrystallization does not occur in conventional channel extrusion is gradually replaced by small recrystallized grains after applying ultrasonic vibration. After the addition of ultrasonic vibration, the grain size distribution of the alloy is more uniform, and the twins in the grains basically disappear compared with the conventional channel extrusion alloy. It can be concluded that the application of ultrasonic vibration during the equal channel extrusion of Mg-Zn-Y alloy can accelerate the process of dynamic recrystallization inside the alloy, improve the grain refinement and overall uniformity of the alloy, and after statistical analysis, the proportion of ultrafine grains after ultrasonic vibration assisted equal channel extrusion is 10.12%, while the proportion of ultrafine grains after conventional equal channel extrusion is only 3.04%, indicating that the use of ultrasonic vibration assisted equal channel extrusion can improve the comprehensive performance of the alloy.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. An equal channel extrusion ultrasonic vibration assisted forming device, comprising an equal channel extrusion die, a pressing head (5) that can be inserted into the equal channel extrusion die, and an extrusion mechanism that drives the pressing head (5) to move up and down, characterized in that: The equal channel extrusion die comprises a lower die (3), a clamping block 1 (6) and a clamping block 2 (7), wherein the lower die (3), the clamping block 1 (6) and the clamping block 2 (7) can be assembled into a columnar structure having a bent extrusion channel; a variable amplitude rod (2) is fixed at the lower part of the lower die (3), and the variable amplitude rod (2) is connected to a transducer (1).

2. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 1, characterized in that: The amplitude changing rod (2) is arranged below or on the side of the lower mold (3).

3. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 2, characterized in that: The amplitude changing rod (2) and the lower mold (3) are integrally formed.

4. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 1, characterized in that: A sleeve seat (11) is arranged below the mold, the transducer (1) is arranged in the sleeve seat (11), and the amplitude changing rod (2) is vertically fixed on the bottom surface of the lower mold (3).

5. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 4, characterized in that: A plurality of ears are arranged in the middle of the amplitude change rod (2); a clamping plate (8) is fixed to the sleeve seat (11) by bolts (12); a clamping plate (9) is arranged between the clamping plate (8) and the upper surface of the sleeve seat (11); a clamping groove matching the ears is arranged on the upper surface of the clamping plate (9); and the ears are accommodated in the clamping grooves.

6. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 5, characterized in that: It also includes a gasket (10) made of non-metallic material, and the gasket (10) is clamped and fixed between the first clamping plate (8) and the second clamping plate (9) / the clamping ear.

7. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 1, characterized in that: The equal channel extrusion die also includes a small sleeve (4); the outer diameters of the clamp block 1 (6), the clamp block 2 (7) and the upper part of the lower die (3) are smaller than the outer diameter of the lower part of the lower die (3); the clamp block 1 (6), the clamp block 2 (7) and the upper part of the lower die (3) are assembled into a cylindrical shape and embedded in the small sleeve (4).

8. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 7, characterized in that: The wall thickness of the small sleeve (4) is not less than 7 mm, and at least one pair of opposite through holes (13) is provided on the lower wall of the small sleeve (4).

9. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 1, characterized in that: The included angle of the extrusion channel is 120°, and the outer fillet radius is 15 mm.

10. The equal channel extrusion ultrasonic vibration assisted forming device according to claim 1, characterized in that: It also includes a ceramic heating ring and a temperature controller for controlling the temperature of the ceramic heating ring, and the ceramic heating ring is correspondingly arranged on the outer periphery of the equal channel extrusion die.

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