CN102747197B - Technological parameter real-time monitoring method for laser shock peening process - Google Patents

Abstract

The invention discloses a technological parameter real-time monitoring method for a laser shock peening process. The method comprises the following steps: 1) arranging a first glass plate on a laser output light path of a laser device, wherein an included angle between the first glass plate and the laser output light path is 75-85 DEG, and carrying out laser shock peening by the laser transmitted through the first glass plate and output by the laser device; 2) arranging a second glass plate on a light path formed by reflecting the laser output by the laser device by the first glass plate, wherein an included angle between the light path and the second glass plate is 75-85 DEG; arranging an energy meter on a light path transmitted by the second glass plate; and arranging a photoelectric probe on a light path reflected by the second glass plate; and 3) transmitting the laser energy information acquired by the energy meter and laser pulse width information acquired by the photoelectric probe to a processing system. According to the present invention, corresponding laser energy and pulse width effected on a target body are obtained through on-line detection of reflected laser energy and laser pulse width, thereby realizing real-time monitoring on technological parameters of the laser shock peening process.

Description

A kind of laser impact intensified process parameter real time monitoring method

Technical field

The present invention relates to a kind of laser impact intensified process parameter real time monitoring method.

Background technology

Reiforcing laser impact technology is a kind of novel material surface treatment process, the plasma shockwave that it utilizes intense laser beam to produce, at material surface, produce certain thickness unrelieved stress layer, and change surfacing weave construction, thereby improve antifatigue, the wear-resistant and resistance to corrosion of metallic substance.

Compare with the reinforcing process such as shot-peening in the past, laser impact intensified have outstanding advantages such as noncontact,, unrelieved stress layer depth strong without heat affected zone, controllability and strengthening effect be remarkable.On the absorption layer that a branch of high-energy-density laser radiation is adhered at target body material surface, absorption layer absorbing laser energy generates rapidly high pressure plasma, the high pressure of plasma generation suffer restraints layer effect can not decay very soon, be subject to High Pressure, material surface can produce shockwave and to internal communication, due to the yield strength of pressure over material, the part material of shock wave can produce viscous deformation, at material surface, form the unrelieved stress with certain distribution, these residual stress distribution can effectively stop the generation of surface crack.Thereby material is subject to High Pressure can produce certain phase transformation and forms hardened layer simultaneously, improves surperficial resistance to corrosion.

In reiforcing laser impact technology, pulsed laser energy parameter and pulsewidth parameter have directly determined to act on the pressure characteristic of material surface, thereby have determined the effect of final shock peening.Shock peening parameter in the past determine and the assessment of strengthening effect be all while utilizing laser apparatus to dispatch from the factory to parameter, rather than the result of Real-Time Monitoring.

For laser apparatus, the energy that every pulse laser beam carries and pulse width and factory-said value are all difference to some extent, in order to assess accurately the relation between laser impact intensified parameter and strengthening effect, must carry out Real-Time Monitoring to beam energy and pulsewidth waveform.

In addition, laser apparatus single-shot energy and adjusting by regulating the multistage pump energy of laser apparatus and delay time to regulate, generally do not there is linear regulation relation.This just makes the research of studying strengthening effect under particular energy be difficult to realize, necessary by laser single-shot energy in certain laser impact intensified process of device Real-Time Monitoring and two parameters of pulse width, thus set up the quantitative relationship between multistage pump energy, delay time and Laser output processing parameter.

Summary of the invention

The problem existing for prior art, the object of the present invention is to provide a kind of laser impact intensified process parameter real time monitoring method and system, can realize the Real-Time Monitoring of single-shot beam energy and pulse width in laser impact intensified process, for the relation between assessment reinforcing process parameter and Effect of Laser Shock Processing provides favourable detection means and method.

A kind of laser impact intensified process parameter real time monitoring method of the present invention comprises the steps:

1) angle with this laser apparatus output light path being set in the Laser output light path of laser apparatus is first sheet glass of 75 ~ 85 °, and the laser of described laser apparatus output sees through described the first sheet glass target body is carried out to shock peening;

2) angle with this light path being set in the light path through described the first sheet glass reflection at the laser of described laser apparatus output is second sheet glass of 75 ~ 85 °, through in the light path of this second sheet glass transmission, energy meter is being set, laser energy for acquisition of transmission, in the light path of this second sheet glass reflection, photoelectric probe is set, for gathering the laser pulse width of reflection;

3) the laser energy information of described energy meter collection and the laser pulse width information of described photoelectric probe collection send treatment system to, through converting, obtain acting on laser energy and pulse width on target body.

Preferably, described the first sheet glass and the second sheet glass are the dull and stereotyped silica glass of thickness 1 ~ 3mm.

The present invention, by online laser energy and the laser pulse width detecting through reflection, through converting, obtains respective action laser energy and pulse width on target body, thereby has realized the Real-Time Monitoring of laser impact intensified process parameter.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention schematic diagram.

Embodiment

As shown in Figure 1, laser impact intensified process parameter method of real-time of the present invention comprises the steps:

1) angle with this laser apparatus 1 output light path being set in the Laser output light path of laser apparatus 1 is first sheet glass 2 of 80 °, and the laser of laser apparatus 1 output sees through 2 pairs of target bodys of the first sheet glass 7 and carries out shock peening;

2) angle with this light path being set in the light path through the first sheet glass 2 reflections at the laser of laser apparatus 1 output is second sheet glass 3 of 80 °, through in the light path of these the second sheet glass 3 transmissions, high frequency sound energy meter 5 is being set, laser energy for acquisition of transmission, in the light path of these the second sheet glass 3 reflections, nanosecond photoelectric probe 4 is set, for gathering the laser pulse width of reflection;

3) the laser pulse width information that the laser energy information that high frequency sound energy meter 5 gathers and nanosecond photoelectric probe 4 gather sends treatment system 6 to, obtains acting on laser energy and pulse width on target body 7, thereby realize on-line real time monitoring through converting.

In embodiments of the present invention, the first sheet glass 2 and the second sheet glass 3 are dull and stereotyped silica glass.

The laser that high-energy short-pulse laser 1 is launched is first through the first sheet glass 2, the thickness of the first sheet glass 2 is 2mm, the normal direction of the first sheet glass 2 and laser are 10 ° of angles, when the normal of the first sheet glass 2 and laser angle are less than 15 °, the one side emittance of sheet glass is 4%, if the energy of laser input is E, emittance is a, and the energy by transmission after 2 two faces of the first sheet glass is E _t=E (1-a) ², the energy of reflection is E _f=E-E (1-a) ²=aE (2-a), these energy are again through the second sheet glass 3, and final transmission potential is E _n=Ea (1-a) ²(2-a), the ENERGY E of final reflection _m=a ²e (2-a) ².

$\frac{E}{E_n}=\frac{1}{a{(1-a)}^2(2-a)}]\≈13.84$

$\frac{E_t}{E_n}=\frac{{(1-a)}^2}{a{(1-a)}^2(2-a)}\≈12.76$

E _nby high frequency sound energy meter 5, collected, data directly upload to treatment system 6, by being multiplied by gain factor, just can obtain the energy of Laser output and act on the energy on laser impact intensified target body 7.

E _mby nanosecond photoelectric probe 4, received, can catch laser pulse width, because pulse width can not change due to the decay of energy and the distance of propagation, so the pulsewidth collecting is exactly the pulsewidth of Laser output and acts on the pulsewidth on target body 7, the pulse width data recording uploads to treatment system 6 equally.

Like this, just can in laser-impact process, act on laser energy and pulse width on target body 7 by Real-Time Monitoring, thereby on the rule that affects of strengthening effect, provide the most effective test instrument for obtaining laser parameter.

Claims (1)

1. a laser impact intensified process parameter real time monitoring method, is characterized in that, comprises the steps:

1) angle with this laser apparatus output light path being set in the Laser output light path of laser apparatus is first sheet glass of 75～85 °, and the laser of described laser apparatus output sees through described the first sheet glass target body is carried out to shock peening; Wherein, the thickness of the first sheet glass is 2mm, when the normal of the first sheet glass and laser angle are less than 15 °, the one side emittance of the first sheet glass is 4%, if the energy of laser input is E, emittance is a, and the energy by transmission after 2 two faces of the first sheet glass is E _t=E (1-a) ²;

2) angle with this light path being set in the light path through described the first sheet glass reflection at the laser of described laser apparatus output is second sheet glass of 75～85 °, through in the light path of this second sheet glass transmission, energy meter is being set, laser energy for acquisition of transmission, in the light path of this second sheet glass reflection, photoelectric probe is set, for gathering the laser pulse width of reflection; Wherein, the energy through the first sheet glass back reflection is E _f=E-E (1-a) ²=aE (2-a), these energy are again through the second sheet glass, and final transmission potential is E _n=Ea (1-a) ²(2-a), the ENERGY E of final reflection _m=a ²e (2-a) ²;

3) the laser energy information of described energy meter collection and the laser pulse width information of described photoelectric probe collection send treatment system to, through converting, obtain acting on laser energy and pulse width on target body.