A Laser Shock Hardening Method for Surfaces of Small Pitch Gears

Abstract

The invention relates to a laser surface shock strengthening technology, and in particular to a laser shock strengthening method for a small-pitch gear surface. The method can be expanded into surface strengthening of a small-pitch spline male die and a fine-pitch thread. The method is characterized in that clearances among teeth of a gear are filled with transparent fillers prepared by mixing materials in ratio, and the clearances are full of the transparent fillers in order to form a column body by the gear and the transparent fillers; then an aluminum foil is adhered to the column surface to be used as an energy absorbing layer; the gear surface can be subjected to large-area overlapping laser shock treatment under the condition that running water is used as a limiting layer. The method has the advantages that the clearances among the teeth of the gear are fully filled with the transparent fillers, and the tops of the teeth of the gear and the transparent fillers can form a smooth column surface, thus the large-area overlapping laser shock treatment can be conveniently carried out for the gear, and as a result, the laser shock strengthening effect can be greatly improved; and after the shock treatment, the transparent fillers in the clearances among the teeth of the gear can be easily removed, so that the demand of mass production can be met.

Description

technical field [0001] The invention relates to laser surface shock strengthening technology, in particular to a laser shock strengthening method for the surface of small pitch gears, and the method can be extended to the surface strengthening of small pitch spline punches and small pitch threads. Background technique [0002] Laser shock strengthening is a new type of surface strengthening technology. The super strong shock wave formed by the strong laser on the metal surface causes severe plastic deformation on the metal surface, induces deep residual compressive stress and refines the grains, and significantly improves the surface properties of metal parts. , compared with other technologies, it has high pressure (shock wave pressure reaches GPa-TPa level), high energy (peak power reaches GW level), ultra-fast (tens of nanoseconds) and ultra-high strain rate (up to 10 7 the s -1 ) four distinctive features, is one of the advanced manufacturing methods under extreme condi...

AI Technical Summary

Problems solved by technology

But for spline punches and gear parts with small tooth pitch, the laser beam diameter is 2-8mm. When the spline punch or transmission gear tooth pitch is less than 10mm, the laser beam radiates to the side first, and the absorbing layer pasted on the side Absorbing laser energy produces gasification to form plasma, which shields the laser beam from radiating downward to the alveolar, and the alveolar part cannot be strengthened

In addition, when a large area is impacted, the absorbent layer in the overlapping area is prone to warping and peeling off

Therefore, the general laser shock peening method cannot realize the overall strengthening of the surface of such workpieces, which seriously weakens the performance of the workpiece surface after laser shock peening.

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