Pore wall laser peening compound expansion strengthening device and method thereof

Abstract

The invention provides a pore wall laser peening compound expansion strengthening device and a method thereof. The device comprises a laser generation device, a clamping chuck, a compound expansion core rod, a numerical control mobile working platform, a clamp and a control system; the clamping chunk is arranged on the top of the numerical control mobile working platform; the compound expansion core rod comprises a core rod front cone and a rear cone, the core rod front cone and the rear cone are hollowed-out, and one end of the rear cone extends into the clamping chunk; the other end of the rear cone is connected with the core rod front cone; a total-reflection mirror is arranged in the rear cone, a conical total-reflection mirror is arranged in the core rod front cone, and conical total-reflection mirror reflection light beams transmit the core rod front cone to form an annular laser band; a core rod working segment is arranged at the other end of the rear cone, the control system controls the numerical control mobile working platform to move, and the control system further controls the laser generation device and the clamping chuck. By means of the device and the method thereof,energy loss in a laser transmission process is reduced, and large-scale continuous peening strengthening can be achieved.

Description

technical field [0001] The present invention relates to the technical field of laser shot peening or extrusion strengthening, in particular to a device and method for hole wall laser shot peening combined extrusion strengthening. Background technique [0002] The connection between key aviation structural parts is mainly by screwing and riveting, and the existence of bolt holes and riveting holes will lead to material discontinuity, so there will be obvious stress concentration at the edge of the hole during the service process of the structural parts, especially in complex Under the applied load, the hole structure is prone to fatigue fracture failure, which will greatly reduce the safety, reliability and service life of the whole machine. Fatigue fracture is the main failure mode of aircraft structural parts. About 70% of the fatigue cracks in these failed structural parts originate from the connecting holes, and about 90% of the airframe accidents are caused by the failur...

AI Technical Summary

Problems solved by technology

Although the above-mentioned device has realized the strengthening of the hole wall, there are still some shortcomings: (1) the induced shock wave consumes a lot of energy through the reflection of the reflection cone, which reduces the strengthening effect on the hole wall; (2) the energy absorbing layer is in the There will be consumption during the impact process, and large-scale continuous shot peening cannot be realized; (3) The strengthening area of ​​the hole wall cannot be accurately controlled

[0005] The invention patent with the application number 201010510712.X "a method and device for laser shock strengthening of fastening holes" places the energy absorbing rod at a suitable position inside the fastening hole, and the laser pulse beam acts on the top of the energy absorbing rod to induce plasma The shock wave generated by the explosion acts on the inner wall of the fastening hole, thereby strengthening the fastening hole. However, after strengthening, the laser spot overlaps and produces pits of different degrees on the hole wall, which leads to an increase in the surface roughness of the material, which will to a certain extent Counteracts the contribution of residual stresses to extended fatigue life

The invention patent with the application number 201210456285.0 "Method and device for laser peening strengthening of the inner wall of medium and small diameter long tubes", although the ring laser beam is used to realize the laser shot peening treatment of the inner wall of medium and small diameter long tubes, the strengthening effect is not obvious , and the tube wall will have different degrees of pits and protrusions due to beam overlap, which will affect the overall smoothness and roughness of the tube wall

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