Device and method for impacting and strengthening fastening hole through ring laser

Abstract

The invention discloses a device and method for impacting and strengthening a fastening hole through ring laser. The device is arranged above a laser impacting and strengthening object provided with a fastening hole and comprises an inner concave cone lens provide with a center hole, a focusing lens provide with a center hole, an outer convex cone lens and a focusing lens, which are sequentially and coaxially arranged from top to bottom; the lenses are arranged on an optical lens adjusting frame; the lenses are coaxially arranged with the fastening hole; a ring laser beam with diameter larger than the aperture of the center hole of the inner concave cone lens is axially incident from the upper side of the inner concave cone lens. The device disclosed by the invention can spatially separate the ring laser beam, couple the separated ring laser beams into a new ring laser beam and regulate the spatial energy distribution of the new ring laser beam to improve the bearable laser power density, and the ring laser beam is used for impacting, strengthening, regulating and controlling the residual stress distribution on the surrounding of the fastening hole end so as to further improve the fatigue performance of the fastening hole. The device disclosed by the invention is capable of increasing the utilization rate of laser pulse energy, simple to operate and convenient to promote and use.

Description

technical field [0001] The invention relates to a device for laser shock strengthening of fastening holes, in particular to a device and method for converting circular laser beams into circular laser beams to realize shock strengthening of fastening holes. Background technique [0002] Laser shock strengthening technology uses nanosecond pulsed laser to generate plasma shock wave effect on the surface of the material, and introduces the residual compressive stress layer by causing micro-plastic deformation on the surface of the material, thereby improving the fatigue performance of metal parts. Usually, the laser shock strengthening can only be carried out after the surface of the material should be arranged with an absorbing layer (aluminum foil tape or black paint, etc.) and a constraining layer (deionized water, etc.). Laser shock strengthening is a general surface strengthening technology. Laser shock strengthening can be used for key fatigue parts or key fatigue parts o...

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Problems solved by technology

[0003] From the above, the disadvantages of the existing laser shock peening method for fastening holes are: ①. The circular laser beam is used to strengthen the fastening hole coaxially. Since there is no material in the fastening hole, the effect on the fastening The laser energy at the hole position is severely limited in the size of the fastening hole that can be strengthened without changing the laser output energy; ②. When a large residual compressive stress value is required, the laser acting on the surface around the fastening hole end The power density is also higher, but the greater the laser power density, the more serious the deformation of the edge of the fastening hole, the fatigue performance is not used, so the laser power density and the deformation of the edge of the fastening hole are contradictory

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