Device and method for controlling residual stress on surface of metal microstructure

Abstract

The invention discloses a device and a method for controlling the residual stress on the surface of a metal microstructure. A laser micro shot blasting generation system and a measuring feedback system are respectively connected with a control system; a pulse laser beam is focused on an area to be subjected to shot blasting on the surface of a workpiece; incident X rays emitted by a synchronous accelerating irradiation light source enter a measurement box, are diffracted by the surface of the workpiece and then are received by a detector; electric pulse is amplified by an amplifier and enters a pulse height analyzer; signal pulse is transmitted to a counter, processed by a microcomputer and fed back to a computer control system by the microcomputer for error analysis and parameter correction; and a charge Coupled device (CCD) optical camera is used for positioning and monitoring a processing area on the surface of the workpiece. The invention effectively controls the residual stress on the surface of the metal microstructure, improves the mechanical properties of the metal micro component, prolongs the service life of the metal micro component, and enables the surface of the metalmicro component to generate the residual pressure stress with the depth up to over 20mu m and the pressure ranging from -120 to -100Mpa.

Description

technical field [0001] The invention relates to the microstructure surface treatment of microelectromechanical systems and the application field of laser technology, in particular to a method and device for controlling the residual stress level on the metal microstructure surface, and is especially suitable for the surface treatment of metal microcomponents with a thickness of 100-200 μm. Background technique [0002] At present, metal microstructures and microdevices with specific functional material properties are increasingly used in microsystems or embedded into conventional machines as intelligent core components. As a load-bearing component, micro-devices are usually subjected to alternating loads such as heat and force, resulting in deformation, fracture, wear, and fatigue damage, resulting in failure of the microstructure, which leads to the failure of the entire micro-electromechanical system and machine. High requirements are put forward for wear resistance and fat...

AI Technical Summary

Problems solved by technology

For the microstructure manufacturing technology, it is mainly the microstructure forming process, such as silicon micromachining, LIGA, high energy beam etching, micro-EDM and micro-stamping, etc. During the production process, residual tensile stress is often generated on the surface of the microstructure. Affect the service life

[0003] A.H.Clauer and B.P.Fairand of Battlells Columbus Laboratory in the United States proposed in the patent U.S.4401477 "Laser shock processing" to irradiate the surface of parts with high-energy short-pulse laser to generate strong shock waves and form residual compressive stress in the surface layer to improve The method of mechanical properties of parts, but the laser shot peening method described in this patent is non-controllable, it cannot realize the online detection and judgment of the laser shot peening effect, and it is only applicable to macroscopic parts

In addition, P.P. Wu of General Electric Company of the United States proposed in the patent CN1754967 "system and method for monitoring laser shock treatment" to compare the spectral line broadening of the line spectrum around its emission peak during the laser shock process with the spectral line broadening of the limited line spectrum, To verify whether the operation of the laser shock system is reasonable. At the same time, the system realizes the monitoring and control of the shock wave pressure and intensity during the laser shock peening process, but the patent only monitors the pulse emission and the resulting shock wave pressure during the laser shock peening process. , does not address monitoring of induced residual compressive stresses in parts after impact

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