Summary of the invention
It in view of the deficiencies of the prior art, can the present invention provides a kind of laser shock peening method of variable incident angle degree
It realizes the surface Hardening Treatment of the small space structures such as turbine disc mortise, promotes the uniformity that strengthening effect is distributed in shock zone.
To achieve the above object, the present invention adopts the following technical scheme:
A kind of laser shock peening method of variable incident angle degree, comprising the following steps:
S101, the shape feature according to parts to be processed strengthening region, judge minimum laser incident angle, determine incidence angle
Spend range;
The laser parameters such as S102, initial option pulse width, spot size, are hung down according to the mechanical attribute of part material
Required laser energy under the conditions of straight incidence;
S103, it determines the respective pulses energy chosen needed for different laser incident angles, and judges minimum incident angle item
Whether laser energy needed for part is within the reachable technical indicator of laser;
If laser energy needed for S104, minimum incident angle condition is in laser up in technical indicator, it is determined that be added
The movement routine of work part determines the overlap joint rule of different shape hot spot;
S105, shock peening operation is carried out by incidence angles degree using the pulse laser of different-energy.
Further, laser beam is incident on region to be fortified from parts to be processed both ends of the surface respectively in the step S101
It is processed, and equal from the minimum laser incident angle of both ends of the surface incidence, guarantees to handle to entire region to be fortified
When selected minimum laser incident angle be maximum value.
Further, in the step S103 can by oblique incidence shock peening region carry out laser energy compensation with
Reach the processing intensity under the conditions of vertical incidence, passes through formula E=E0/ sin α, it may be determined that choosing needed for different laser incident angle α
The respective pulses energy taken.
Further, if laser energy needed for minimum incident angle is more than the reachable technology of laser in the step S103
Index, can be reselected in the optional range of laser parameter the pulse width suitable for parts to be processed, spot size and
Laser energy under the conditions of vertical incidence finally to strengthen the maximum laser energy of position in laser for minimum incident angle
Allow using within section.
Further, the movement routine that parts to be processed is determined in the step S104 includes that laser-impact processing originates in
The minimum incident angle position in region to be processed is then carried out to both ends of the surface direction with the incident angle of continuous improvement, In respectively
After completing intensive treatment from laser light incident initial position to a side end face, parts to be processed and laser beam need to be readjusted
The intensive treatment from minimum incident angle position to another side end face of laser is completed in relative position.
Further, the overlap joint rule for different shape hot spot being determined in the step S104 includes connecting adjacent spots intersection point
The length ratio of the length of line and the short axle in oval irradiation face is defined as hot spot overlapping rate, and the hot spot overlapping rate is becoming incident
The laser impact intensified of angle remains unchanged in the process.
A kind of beneficial effect of the laser shock peening method of variable incident angle degree provided by the invention is:
Change laser incident angle in real time based on Working position, is adjusted by laser energy strong to the processing of oblique incidence position
Degree compensates, and the part region to be fortified for solving the small space structures such as turbine disc mortise cannot achieve the skill of laser vertical incidence
Art problem, while can keep the consistency of laser-impact intensity during strengthening the hardly possible machining area such as tenon tooth tooth root, mention
Rise the uniformity of residual compressive stress distribution.
A kind of embodiment: laser shock peening method of variable incident angle degree.
A kind of laser shock peening method of variable incident angle degree, specific steps include:
S101: according to the shape feature of parts to be processed strengthening region, judge minimum laser incident angle αmin, determine
Penetrate angular extensions alphamin90 ° of≤α <;
Wherein, the purpose of this step is to test the form parameter in region to be fortified, determines adjacent parts to light beam incidence
Influence degree obtains maximum minimum laser incident angle αmin, so that it is determined that the variation range of laser incident angle.Citing comes
It says, usual tenon groove structure is there are two types of the distribution modes of turbine disk circumferencial direction, i.e., tongue-and-groove is axial parallel (vertical with end face with wheel disc
Directly) and not parallel, the tongue-and-groove tooth root of two types wheel disc is when selecting minimum laser incident angle with different approach.
Fig. 2 is turbine disc mortise tooth root region schematic diagram, and since transition arc radius is smaller between tenon tooth, which has tight
The stress concentration phenomenon of weight.During carrying out laser impact intensified to tongue-and-groove tooth root region, it is assumed that only exist opposite site
Laser light incident generation is blocked, then the selection of minimum laser incident angle is as shown in Figure 3,4.Fig. 3,4 middle tenon grooves are respectively provided with
With the axial parallel and not parallel feature of wheel disc, 1,6 be wheel side surface, and 2,7 be region to be fortified, and 3,8 be to laser light incident
The region opposite site to be fortified for blocking influence is generated, 4,9 be laser light incident light beam, and 5,10 be special for portion structure to be fortified
Levy the maximum minimum laser incident angle chosen.
It is understood that laser beam is incident on region to be fortified from wheel disc both ends of the surface respectively and is added in this step
Work, and it is equal from the minimum laser incident angle of both ends of the surface incidence, this ensure that being handled to entire region to be fortified
When selected minimum laser incident angle be maximum value.
S102: the laser parameters such as initial option pulse width, spot size are hung down according to the mechanical attribute of part material
Required laser energy E under the conditions of straight incidence0;
Wherein, it treats for strengthening region, there are the optional ranges of the laser parameters such as pulse width, spot size for default
(this programme default uses circular light spot), the acquirement of parameter is based on shape and structure feature and properties of material mechanics etc..Due to only
Having when induced with laser shock wave can lead to the plastic deformation of material surface, laser-impact surface peening effect just will appear, because
This can obtain the teachings of required laser parameter according to Mechanical Properties of Materials etc..The parameters such as laser energy in this step
Laser impact intensified practical experience can be obtained by theoretical calculation or technical staff by obtaining, herein without specifically limiting
It is fixed.
S103: pass through formula E=E0/ sin α determines the respective pulses energy chosen needed for different laser incident angle α,
And whether laser energy needed for judging minimum incident angle condition is within the reachable technical indicator of laser;If so, into
S104;If it is not, then terminating process;
Wherein, this step, which is established, has obtained the laser minimum incident angle α in region to be fortified in S101, S102minAnd it hangs down
Required laser energy E when straight incident0On the basis of.Default can be by carrying out laser energy benefit to oblique incidence shock peening region
It repays to reach the processing intensity under the conditions of vertical incidence.The laser spoke in region to be fortified that minimum incident angle need to be used to be processed
Product of showing up is maximum and energy loss is most, is the active position of maximum laser energy.Theoretical calculation acquisition is carried out by formula
Maximum laser energy is in laser impact intensified system within the coverage of laser, is just able to achieve the complete of parts to be processed
Strengthen in region.
, can it is worth noting that, if the maximum laser energy mentioned in this step is beyond the reachable technical indicator of laser
With reselected in the optional range of laser parameter that S102 is mentioned the pulse width suitable for parts to be processed, spot size with
And laser energy under the conditions of vertical incidence, finally to strengthen the maximum laser energy of position in laser for minimum incident angle
Device allows using within section.
S104: determining the movement routine of parts to be processed, determines the overlap joint rule of different shape hot spot;
Wherein, it is incident to provide a kind of laser impact intensified change for turbine disk-like accessory tongue-and-groove characteristic area for this step
Angle movement routine.In the movement routine, laser-impact processing originates in tongue-and-groove tooth root and the minimum of machining area is waited to enter
Angle position is penetrated, is then carried out respectively to both ends of the surface direction with the incident angle of continuous improvement.Fig. 5 be using variable incident angle degree into
When row is laser impact intensified, the movement routine schematic diagram of turbine disk-like accessory tongue-and-groove characteristic area, 11 be that laser is relatively to be fortified
The moving line in region, 12 be the movement routine of parts to be processed required by realizing the moving line, and 13 be area to be fortified
Domain laser irradiation shape obtained under the conditions of the part movement routine.
It is worth noting that, need to be adjusted again after completing the intensive treatment from laser light incident initial position to a side end face
The relative position of whole parts to be processed and laser beam is completed from the strong of minimum incident angle position to another side end face of laser
Change processing.
In addition, the laser irradiation shape based on the region to be processed obtained under the conditions of the movement routine of the parts to be processed
Shape, this step additionally provide a kind of overlap joint rule of different irradiation shape hot spots.Laser beam is oblique when being mapped to region to be processed
It irradiates shape and changes into the ellipse being elongated by circle, wherein the length of the short axle in oval irradiation face is vertical equal to laser
The diameter in circle irradiation face when incident.To keep the consistent of region processing intensity to be fortified, laser-impact processing surface is reduced
Degree of roughness and the uniformity for improving residual stress distribution, the present invention pass through two crosspoints in control adjacent spots overlapping regions
Line length formulate it is a kind of suitable for it is different irradiation shape hot spots overlap joints rule, with the length of adjacent spots intersection point line
It is remained unchanged in the process as light with the length ratio of the short axle in oval irradiation face in the laser impact intensified of variable incident angle degree
Spot overlaps foundation.For example, Fig. 6 shows the shape for irradiating face when laser beam is incident on region to be fortified with different angle
Shape, wherein a is the length of the short axle in oval irradiation face, and a ' is the length of the line of two crosspoint of adjacent spots, hot spot overlap joint
The numerical value of rate η can determine by controlling the ratio of a ' and a, i.e. η=(a '/a) × 100%.
S105: shock peening operation is carried out by incidence angles degree using the pulse laser of different-energy.
Wherein, this step requires that movement routine and the difference angle of parts to be processed has been determined by S104 the method
The overlapping rate of incident laser facula is spent, and each needed for region to be fortified under conditions of meeting the hot spot overlapping rate
The incident angle of laser beam has also obtained.
It is worth noting that, this step also defaults the operation in the presence of programming setting reinforcement process, for laser impact intensified
For system, it is laggard in parts fixation that the Pulsed Laser Parameters, mechanical arm carry the needs such as motion profile of parts to be processed
Line program setting, finally according to setting program, system is automatically performed impact process.Reinforcement process herein more refers to will be quantitative
The program setting that the conditions such as the laser pulse parameters of selection are implemented on specific part.
For laser impact intensified whole process, there is also shock peening operate before region absorbed layer to be fortified with
The coating procedure of restraint layer, this step default region to be fortified and related pretreatment, the material choosing of absorbed layer and restraint layer are completed
It selects and applies technique here without specifically limiting.
It is understood that this step is carried using mechanical arm, parts to be processed is mobile to carry out region different location to be fortified
Laser-impact processing when, (i.e. point-by-point processing) is carried out using the mobile laser-impact once of mechanical arm by the way of once.
Fig. 7 is the laser-impact for carrying out turbine disc mortise tooth root region using the method for variable incident angle degree in practical applications
When processing, the schematic diagram of turbine disk motion profile.In figure, laser beam to the incidence of tooth root region originate in wheel disc both ends of the surface it
Between position, mechanical arm carried the turbine disk and moved with the path that rotates clockwise of approximation, completed from laser light incident start bit
It sets to the intensive treatment of a side end face.
The above is presently preferred embodiments of the present invention, but the present invention should not be limited to embodiment and attached drawing institute public affairs
The content opened both falls within protection of the present invention so all do not depart from the lower equivalent or modification completed of spirit disclosed in this invention
Range.