Laser compound processing and modifying method of no-recasting-layer micro deep-hole

Abstract

The invention discloses a laser combined machining and profile modification method of a micro deep borehole without a recast layer. The method of the invention includes the following steps: first, a micro deep cooling borehole of a turbine blade is roughly machined by high power laser or electric sparks, and the like; the allowance for finish of the aperture is more than the thickness of the recast layer produced by using the machining method; and femtosecond laser is used for the secondary finish machining and profile modification of the micro deep cooling borehole; while femtosecond impulse laser is used for performing the finish machining and profile modification of the primarily machined micro deep borehole, under the precondition of guaranteeing the laser energy acting with the recast layer of a workpiece is higher than the ablation threshold of the material, a light beam is inclined for certain angle according to the spiral drilling mode; and the recast layer of the internal wall of the borehole is machined to remove erosion and profile modification by combining the method of lengthening the focal depth by a long focus lens. The concept of the combined machining method and the specific machining technology are used for solving the high-efficiency and high-precision machining problems of micro deep borehole groups of turbine blades.

Description

technical field [0001] The invention relates to a laser composite processing and shape modification method, in particular to a laser composite processing and shape modification method for micro-deep holes without a recast layer. Background technique [0002] A gas turbine is a rotary impeller power mechanical device that converts the heat energy generated by the combustion of gas or liquid fuel (such as natural gas, fuel oil) into mechanical work. It is widely used in energy, aviation, transportation, national defense and other fields. and the key major equipment for the development of the aviation industry. High-temperature turbine blades are located in the part of the gas turbine with the highest temperature (above 1400°C), the most complex stress, and the harshest environment. Its value accounts for nearly 50% of the total product and is a key component of the gas turbine. As the thrust and thrust-to-weight ratio requirements of large gas turbines continue to increase, t...

AI Technical Summary

Problems solved by technology

However, the hole walls processed by EDM and high-power lasers have poor smoothness, taper, and poor hole roundness, especially on the hole walls. The main factor for the development of blade micro-cooling hole processing technology, so it is mainly used for turbine stator blade processing at present

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