CN112143865A - A Workpiece Surface Strengthening Process Based on Electro-evaporation of Metal Foil - Google Patents

Abstract

The invention provides a workpiece surface strengthening process based on metal foil electrification evaporation, which is characterized in that a capacitor (4) discharges to generate current, the current passes through a metal foil (5) and heats the metal foil, and after the temperature of the metal foil reaches an evaporation point and is evaporated, generated gas and plasma expand outwards to provide instantaneous pressure. The generated gas and plasma directly impact on the insulating plate (6), and the generated shock wave is then propagated in the insulating plate and the workpiece (7), so that the workpiece is subjected to plastic deformation, and a compressive stress strengthening layer is formed on the surface. The shock wave generated by the gas and plasma rapidly impacting the insulating plate propagates in the workpiece, causing the workpiece to be plastically deformed, forming a stronger residual compressive stress and a deeper surface strengthening layer than the shot peening. According to different forms of workpieces, the process can improve the mechanical strength, the wear resistance, the fatigue resistance and the corrosion resistance of the workpieces, and can also remove oxide scales, rust, molding sand and old paint films on the surfaces of the workpieces.

Description

A Workpiece Surface Strengthening Process Based on Electro-evaporation of Metal Foil

technical field

The invention belongs to the field of materials science, and in particular relates to a workpiece surface strengthening process based on the electro-evaporation of metal foil materials.

Background technique

In the process of metal processing, shot peening is one of the effective methods to reduce the fatigue of parts and improve the service life. Shot peening is to inject high-speed projectile flow onto the surface of the part to plastically deform the surface of the part and form a strengthening layer of a certain thickness. , a high residual stress is formed in the strengthening layer. Due to the existence of compressive stress on the surface of the part, when the part is under load, part of the stress can be offset, thereby improving the fatigue strength of the part. Because shot peening can improve the mechanical strength of parts, as well as wear resistance, fatigue resistance and corrosion resistance, it is widely used in metal parts that have been used in high stress conditions for a long time, such as aircraft engine compressor blades, fuselage structural parts, Automobile transmission parts, etc. However, the working environment of shot peening is poor, the unit output is low, and the work efficiency is relatively low. Improving the surface strengthening effect and work efficiency is the research focus and development direction of the surface strengthening process of metal workpieces.

SUMMARY OF THE INVENTION

In order to solve the above technical problems, the present invention provides a workpiece surface strengthening process realized by energizing and evaporating metal foil materials. The surface strengthening process can form a stronger residual compressive stress on the surface of the workpiece than the shot peening process, and the thickness of the strengthening layer is larger, thereby further improving the mechanical properties of the metal workpiece.

The technical scheme adopted by the present invention to solve its technical problems is:

A workpiece surface strengthening process, characterized in that the surface of the workpiece is impacted by gas and plasma pressure generated by evaporating foil, comprising the following steps:

A current is generated by the discharge of the capacitor, and the current flows through the metal foil in the circuit;

The resulting current increases the temperature of the metal foil until it reaches its evaporation point, which eventually causes the metal foil to evaporate;

The gas and plasma generated by the evaporation of the metal foil expand outward, providing instantaneous pressure to impact the metal workpiece, wherein an insulating plate is arranged between the metal foil and the workpiece, so that the gas and plasma generated after the metal foil evaporates Separated from the workpiece, the metal foil is at the bottom, the insulating plate is on the metal foil, the workpiece is on the insulating plate, the gas and plasma generated by the evaporation of the metal foil directly impact the insulating plate, and the generated shock wave is then It propagates in the insulating plate and the workpiece, causing plastic deformation of the workpiece and forming a compressive stress strengthening layer on the surface.

Preferably, the material of the metal foil can be any one of aluminum, copper, magnesium, silver, steel, iron, lithium, and gold.

Preferably, the insulating plate material is polyurethane, the hardness range is: 50Shore A-90Shore A, and the lower substrate material is ceramic.

Preferably, the charging energy range of the capacitor (4) is 100J-200kJ, and the range of the generated current amplitude is: 1kA-500kA.

The beneficial effects of the invention are: the gas and plasma generated by the electro-evaporation of the metal foil material rapidly impact the shock wave generated by the insulating plate, which can form a stronger residual compressive stress and a deeper strengthening layer on the surface of the workpiece than the shot peening treatment, thereby causing the workpiece Better mechanical properties, including fatigue strength, mechanical strength and wear resistance. In addition, the workpiece surface strengthening process can also be used as a cleaning method before surface coating to remove oxide scale, rust, molding sand and old paint film on the workpiece surface.

Description of drawings

Fig. 1 is the circuit schematic diagram of the present invention;

Fig. 2 is the mould structure diagram of the present invention;

Fig. 3 is the complete structural drawing of the present invention;

Among them, 1. Inductor, 2. Switch, 3. Resistor, 4. Capacitor, 5. Metal foil, 6. Insulating plate, 7. Workpiece, 8. Die, 9. Lower substrate, 10. Upper substrate, 11. Bolts, 12. Bolts.

Detailed ways

Now in conjunction with the accompanying drawings, the content of the present invention and the specific embodiments thereof will be further described

As shown in Figure 1, both ends of the metal foil (5) are connected to the circuit to form a complete loop. When the capacitor (4) is discharged, the resulting current passes through the metal foil (5), thereby heating it. The temperature of the metal foil (5) is gradually increased, and when its temperature reaches the evaporation point, the metal foil (5) is completely evaporated. As shown in Figure 2, after the metal foil (5) evaporates, the gas generated expands outward and directly impacts the insulating plate (6). The function of the insulating plate (6) is to isolate the generated gas from the workpiece (7). to prevent the surface of the workpiece (7) from being burned by the generated gas. At the same time, the shock wave generated by the gas rapidly impacting the insulating plate (6) propagates in the workpiece (7), causing plastic deformation of the workpiece (7), and finally forming a residual compressive stress and a surface strengthening layer on the surface of the workpiece (7). The upper base plate (10) and the lower base plate (9) are connected by bolts to fix the module in the middle.

A specific embodiment of the present invention is to improve the fatigue strength of the workpiece, connect the aluminum foil to the circuit, and after the capacitor (4) is discharged, the generated current heats the aluminum foil, the aluminum foil evaporates, and the generated gas impacts the insulating plate (4). 6), the shock wave propagates in the workpiece (7), causing the workpiece (7) to undergo compressive plastic deformation, thereby forming residual compressive stress and a strengthening layer on the surface, and improving the mechanical properties of the workpiece (7). The process can improve the mechanical strength of the workpiece, wear resistance, fatigue resistance and corrosion resistance, etc., and prolong the safe working life of the workpiece.

Another specific embodiment of the present invention is to remove oxide scale, rust, molding sand and old paint films on metal products and castings and forgings. The aluminum foil is connected to the circuit, and when the capacitor (4) is discharged, the generated current heats the aluminum foil, the aluminum foil evaporates, and the generated gas impinges on the insulating plate (6), and the shock wave propagates in the workpiece (7), and the workpiece (7) The surface is subjected to the action of pulse pressure, thereby removing the oxide scale, rust, molding sand and old paint film on the surface. This process can be used as a cleaning method before surface coating and is widely used in large shipyards, heavy machinery factories and automobile factories.

Finally, it should be noted that the above is only the specific implementation of this case or the description of the specific implementation, and the protection scope of this case is not limited to this. Any thought of changes or substitutions should be covered within the scope of protection of this case. The scope of protection in this case shall be subject to the scope of protection of the claims.

Claims (4)

1. a workpiece surface strengthening process based on the electro-evaporation of metal foil material, it is characterized in that, utilize the gas that evaporated foil material produces and plasma pressure to impact metal workpiece, comprise the following steps: The discharge of the capacitor (4) generates a current, and the current flows through the metal foil (5) in the circuit; The generated electric current increases the temperature of the metal foil (5) until it reaches its evaporation point, and finally causes the metal foil (5) to evaporate; The gas and plasma generated by the evaporation of the metal foil (5) expand outward to provide instantaneous pressure to impact the metal workpiece, wherein an insulating plate (6) is arranged between the metal foil (5) and the workpiece (7), The gas and plasma generated by the evaporation of the metal foil (5) and the workpiece (7) are separated from each other, the metal foil (5) is at the bottom, the insulating plate (6) is on the metal foil (5), and the workpiece ( 7) On the insulating plate (6), the gas and plasma generated by the evaporation of the metal foil (5) directly impact on the insulating plate (6), and the generated shock wave is then passed between the insulating plate (6) and the workpiece (7) Propagation occurs in the workpiece (7), resulting in plastic deformation of the workpiece (7), and a compressive stress strengthening layer is formed on the surface. 2. The workpiece surface strengthening process according to claim 1, wherein the material of the metal foil (5) is any of several materials of aluminum, copper, magnesium, silver, steel, iron, lithium, and gold. A sort of. 3 . The workpiece surface strengthening process according to claim 1 , wherein the insulating plate material is polyurethane, the hardness range is: 50 Shore A-90 Shore A, and the lower substrate material is ceramic. 4 . 4. The workpiece surface strengthening process according to claim 1, wherein the charging energy range of the capacitor (4) is 100J-200kJ, and the range of the generated current amplitude is: 1kA-500kA.

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