Method of absorbing shock waves of nanosecond impulse laser shock strengthened titanium alloy thin blade

Abstract

The invention discloses a method of absorbing shock waves of a nanosecond impulse laser shock strengthened titanium alloy thin blade. When laser shock strengthening treatment is carried out on the side and edge of the titanium alloy thin blade, shock waves is exported from the side edge and the back surface of the blade by means of a special shock wave energy absorption device, so that shock deformation of the thin blade is controlled and the strengthening effect is enhanced; by mounting a trap device on the back surface of a to-be-strengthened blade, a technical breakthrough of shock strengthening on the surface of the thin blade is achieved by means of an existing laser shock strengthening technology, so that the method is easy to operate and high in feasibility; existing equipment can be directly refit, so that the defects that the strengthening effect is poor as a result of power reduction and pulse width reduction by means of laser shock strengthening of an existing thin blade andstrain is formed inside as a result of double-sided shock strengthening are overcome. The method of carrying out shock strengthening on the side edge of the titanium alloy thin blade by adopting nanosecond impulse laser, the energy of which is 2-5J and the spot diameter of which is 1-2mm, is a critical core technology for strengthening the thin blade, and is good in strengthening effect and suitable for being popularized and used.

Description

technical field [0001] The invention specifically relates to a method for shock wave absorption of titanium alloy thin blades strengthened by nanosecond pulsed laser shock. Background technique [0002] Advanced high-thrust-to-weight ratio aero-engines are developing towards light weight and integration, and their compressors / fans widely use titanium alloy thin blades, which are prone to high-cycle vibration fatigue fractures under the action of alternating loads such as centrifugal force and air excitation force during use , seriously affecting flight safety. [0003] Laser shock strengthening is an important technical means to improve the high-cycle fatigue performance of aero-engine components. It is listed by the US Department of Defense as one of the 76 key technologies of the fourth-generation fighter engine. Power (>1GW / cm2) laser induces the mechanical effect of plasma shock wave (>1GPa), causing plastic deformation of metal materials with ultra-high strain ra...

AI Technical Summary

Problems solved by technology

However, for laser shock strengthening of titanium alloy thin blades, there is a typical "thin" problem. This is because the energy carrier of laser shock strengthening is a shock wave, which propagates into the material and causes plastic deformation, forming a residual compressive stress field and tissue changes. The law directly determines the distribution characteristics of the residual stress field

However, the titanium alloy blade is relatively thin, and its edge thickness is less than 1mm ( figure 2 ), while the shock wave travels deeper, and strongly reflects and couples at the back of the blade ( image 3 ), a complex wave system is formed inside the blade, it is difficult to form a uniform gradient residual compressive stress field, and at the same time, the thin blade produces macroscopic deformation, which does not meet the design requirements

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