阅读说明：本技术 一种基于激光诱导击穿光谱的熔覆工艺调控方法 (Cladding process regulation and control method based on laser-induced breakdown spectroscopy ) 是由 董群雄 杨剑 于 2020-10-22 设计创作，主要内容包括：本发明公开了一种基于激光诱导击穿光谱的熔覆工艺调控方法,属于激光增材制造工艺控制领域,该装备检测组件设有：激光熔覆头,熔覆光纤激光器,机器人,脉冲激光器等；所述光谱收集探测器与数据分析装置相连,脉冲激光器,光谱收集探测器与控制器相连；利用该装置对熔覆过程中的进粉量、扫描速度、离焦量、激光功率、保护气体量进行全方位的控制。本发明基于激光诱导击穿光谱技术和红外测温仪相结合的解决方案,实现了激光熔覆过程中的参数自动优化,而且激光熔覆系统以及红外测温仪对于环境要求较低,可以在环境较为复杂的工厂中监测实时的结果,进而实现精确的反馈调节,进而降低加工成本,提高修复的在利用率,减少经济损失。(The invention discloses a cladding process regulating and controlling method based on laser-induced breakdown spectroscopy, which belongs to the field of laser additive manufacturing process control, and the equipment detection assembly is provided with: laser cladding heads, cladding fiber lasers, robots, pulsed lasers, and the like; the spectrum collection detector is connected with the data analysis device, and the pulse laser and the spectrum collection detector are connected with the controller; the device is used for controlling the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount in the cladding process in an all-round way. The invention realizes the automatic optimization of parameters in the laser cladding process based on the solution combining the laser-induced breakdown spectroscopy technology and the infrared thermometer, has lower environmental requirements of the laser cladding system and the infrared thermometer, can monitor real-time results in factories with more complex environments, further realizes accurate feedback adjustment, further reduces the processing cost, improves the utilization rate of repair, and reduces the economic loss.)

1. A cladding process regulating and controlling method based on laser-induced breakdown spectroscopy comprises the following steps:

the method comprises the following steps: establishing: extracting process parameters with high yield, characteristic spectral line time domain variation and temperature field variation data according to experimental data of a certain company, and establishing a database;

step two: preparing a laser cladding experiment: setting initial processing parameters and placing a cladding sample;

step three: monitoring: laser-induced breakdown spectroscopy and an infrared thermometer are used for monitoring a spectral signal and an infrared temperature in a cladding process in real time on line and transmitting data to a computer;

step four: and (3) judging: the computer establishes an intensity curve of the characteristic spectral line intensity and the temperature in the cladding process, judges whether the characteristic spectral line and the temperature are stable, if so, enters a sixth step, otherwise, enters a fifth step;

step five: adjusting: comparing the two curves obtained in the fourth step with the existing data in the database, and according to the empirical process parameters: feeding back and adjusting five process parameters of powder feeding amount, scanning speed, defocusing amount, laser power and protective gas amount, continuously processing, and entering the sixth step;

step six: and (6) ending.

2. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: the process parameters with high yield and the temperature field change in the step one are a database which is stored and established according to the prior working condition and requirements.

3. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: the laser cladding system comprises a laser cladding head, a robot, a laser controller, a demonstrator, a powder feeding device and a laser cladding light path transmission system; the robot is connected with the laser cladding head, the laser cladding head is connected with the laser controller, the laser cladding light path transmission system is integrated in the laser cladding head, the spatial position of the robot is controlled through the demonstrator, and the processing route of the laser cladding head is further controlled; the powder feeder is connected with the laser cladding head, and further supplies gas and powder in the processing process.

4. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: thirdly, the laser-induced breakdown spectroscopy and the infrared thermometer are used for real-time detection, a pulse laser is fixed on a laser cladding laser and forms a 45-degree angle with the laser cladding laser, and a sample piece is burned along with the laser cladding laser in the cladding process to excite plasma; the spectrometer sets integration time and average times, a spectral collection detector is used for collecting characteristic spectral signals in the cladding process after plasma is excited, the characteristic spectral signals are transmitted to the spectrometer for light splitting and then subjected to photoelectric conversion, and a spectrogram is transmitted to a computer to establish a time domain spectrogram of a characteristic spectral line; the infrared thermometer sets acquisition time, transmits temperature data to a computer, and establishes a temperature field data graph.

5. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: and step four, comparing the time domain spectrogram and the temperature field with an existing database after the time domain spectrogram and the temperature field are established, if the time domain spectrogram and the temperature field curve are stable, continuing processing, and if the time domain spectrogram and the temperature field curve are abnormal, entering step five.

6. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: and step four, comparing the real-time parameters with the existing data in the database, and adjusting the powder feeder, the laser controller and the demonstrator by using the existing parameters in the database to optimize the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount.

7. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: the laser cladding system parameters in the second step, laser wavelength 200 and 2800nm, power 1-10000W, continuous pulse laser, scanning speed 0-30mm/s, powder feeding amount 0-200g/min, and powder feeding gas flow 0.1-0.4m³H, defocusing amount is 10-50 mm.

8. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: the laser-induced breakdown spectroscopy parameters in the third step are that the wavelength of the pulse laser is 250-1100nm, the laser energy is 50-50000mj, and the repetition frequency is 1-50 Hz.

9. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: and step three, the processing technology in the real-time feedback optimization cladding process comprises that a spectrometer, an infrared thermometer, a laser controller, a powder feeder and a demonstrator adopt closed-loop PID control.

10. The cladding process regulating and controlling method based on the laser-induced breakdown spectroscopy, as recited in claim 1, is characterized in that: and fourthly, optimizing process parameters including powder feeding amount, scanning speed, defocusing amount, laser power and protective gas amount.

Technical Field

The invention discloses a cladding process regulating and controlling method based on laser-induced breakdown spectroscopy, and belongs to the field of laser additive manufacturing process control.

Background

In the field of laser material increase, a laser cladding technology is a green and cost-saving advanced remanufacturing surface engineering technology, and is characterized in that a metal alloy or other types of materials are deposited on a substrate to realize metallurgical bonding between a coating and the substrate material, so that a cladding layer with no holes, fine crystal grain microstructure and good mechanical property is obtained. The cladding layer has low dilution and has metallurgical physical and chemical properties with the matrix, thereby achieving the aim of repairing the surface of a sample or modifying the surface of the sample, meeting the requirement of the specific properties of the surface of a material and saving a large amount of material cost, and the laser cladding technology has very wide application prospect.

With the rapid development of scientific technology, the laser cladding technology is also improved, but in the cladding process, the technological parameters are the results summarized in the past. However, deviation occurs in the cladding process due to the influence of temperature, environment, equipment precision and the like, and the yield is reduced. These many uncontrollable factors affect the performance of the cladding layer and lack an effective means for real-time on-line monitoring and real-time optimization of feedback process parameters. Under the above circumstances, it is shown that the real-time monitoring feedback optimization field of the laser cladding technology is still in an attempt stage, and a large technical blank is left, especially in the process control in the cladding process, so that for the above reasons, a related effective monitoring means is urgently needed at the present stage to improve the application value of the laser cladding technology.

In order to solve the defects of the prior art, the invention carries out online monitoring on the temperature signal in the cladding process by exciting the plasma body by the pulse laser to generate the optical signal, and further obtains the time domain spectral line of the characteristic spectral line and the change condition of the temperature field to carry out online monitoring. In the cladding process, when the spectral line and the temperature field change abnormally, data in the database are called in time for comparison, parameters of a laser cladding system are automatically adjusted in real time, the cladding process is controlled, the yield of cladding layers is improved, the cost is effectively reduced, and high-quality, controllable and high-precision laser cladding processing is realized.

Disclosure of Invention

Technical problem to be solved

In order to overcome the defects in the prior art, the invention provides a cladding process regulating method based on laser-induced breakdown spectroscopy. The invention carries out online monitoring on the temperature signal in the cladding process by exciting the plasma to generate the optical signal by the pulse laser, thereby obtaining the time domain spectral line of the characteristic spectral line and carrying out online monitoring on the change condition of the temperature field. In the cladding process, when the spectral line and the temperature field change abnormally, data in the database are called in time for comparison, parameters of a laser cladding system are automatically adjusted in real time, the cladding process is controlled, the yield of cladding layers is improved, the cost is effectively reduced, and high-quality, controllable and high-precision laser cladding processing is realized.

(II) technical scheme

The invention adopts the following technical scheme:

the method comprises the following steps: according to the experimental data of a certain company, extracting the data of the process parameters, the characteristic spectral line time domain variation and the temperature field variation with high yield, and establishing a database.

Step two: preparing a laser cladding experiment, setting initial processing parameters, and placing a cladding sample.

Step three: and laser-induced breakdown spectroscopy and an infrared thermometer are used for monitoring a spectrum signal and an infrared temperature in the cladding process in real time on line and transmitting data to a computer.

Step four: and (4) establishing an intensity curve of the characteristic spectral line intensity and the temperature in the cladding process by the computer, judging whether the characteristic spectral line and the temperature are stable, if so, entering the step six, and otherwise, entering the step five.

Step five: comparing the two curves obtained in the fourth step with the existing data in the database, and according to the empirical process parameters: and (5) performing feedback adjustment on five process parameters of the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount, continuing processing, and entering the step six.

Step six: and finishing the processing.

Further, the process parameters and temperature field variation with high yield in the step one are stored and established as a database according to the previous working conditions and requirements.

Further, the laser cladding system in the second step comprises a laser, a robot, a laser controller, a demonstrator, a powder feeding device and a laser cladding spectrum transmission system.

And further, the laser-induced breakdown spectroscopy and the infrared thermometer are used for real-time detection, the pulse laser is fixed on the laser cladding laser and forms a 45-degree angle with the laser cladding laser, and the sample piece is burned and excited by the laser cladding laser in the cladding process. The spectrometer sets integration time and average times, a spectrum collection detector is used for collecting characteristic spectrum signals in the cladding process after the plasma is excited, the characteristic spectrum signals are transmitted to the spectrometer for light splitting and then subjected to photoelectric conversion, and a spectrogram is transmitted to a computer to establish a time domain spectrogram of the characteristic spectrum. The infrared thermometer sets acquisition time, transmits temperature data to a computer, and establishes a temperature field data graph.

And further, comparing the time domain spectrogram and the temperature field with an existing database after the time domain spectrogram and the temperature field are established, and if the time domain spectrogram and the temperature field curve are stable, continuing processing. And if the abnormality exists, entering the step five.

And further, comparing the real-time parameters with the existing data in the database, and adjusting the powder feeder, the laser controller and the demonstrator by using the existing parameters in the database to optimize the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount.

Further, the laser cladding system parameters of the second step are laser wavelength of 200-³H, defocusing amount is 10-50 mm.

Further, the laser induced breakdown spectroscopy parameters of the third step include a pulse laser wavelength of 250-1100nm, a laser energy of 50-50000mj, and a repetition frequency of 1-50 Hz.

And further, the processing technology in the real-time feedback optimization cladding process in the third step comprises that the spectrometer, the infrared thermometer, the laser controller, the powder feeder and the demonstrator adopt closed-loop PID control.

Further, the optimized process parameters in the fourth step include powder feeding amount, scanning speed, defocusing amount, laser power and protective gas amount.

(III) advantageous effects

Compared with the prior art, the invention has the following beneficial effects:

the invention carries out on-line monitoring on the temperature signal in the cladding process by exciting the plasma to generate the light signal by the pulse laser, thereby obtaining the time domain spectral line of the characteristic spectral line and carrying out on-line monitoring on the change condition of the temperature field. In the cladding process, when the spectral line and the temperature field change abnormally, the data in the database are timely called for comparison, the parameters of the laser cladding system are automatically adjusted in real time, the cladding process is controlled, the yield of a cladding layer is improved, the cost is effectively reduced, and high-quality, controllable and high-precision laser cladding processing is realized.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a block diagram of the flow structure of the present invention;

FIG. 3 is a time domain diagram of the temperature field measured in this embodiment;

FIG. 4 is a time-domain spectrogram of the characteristic spectrum obtained by measurement in the present embodiment;

FIG. 5 illustrates some of the parameters in the database according to the present invention;

FIG. 6 is a schematic diagram of the process optimization of the present invention

In the figure: the device comprises a spectrum collection detector-1, an infrared temperature measurement module-2, a pulse laser-3, a computer-4, a laser cladding head-5, a powder feeder-6, a cladding fiber laser-7, a controller-8, a robot-9, a sample stage-10 and a spectrometer-11.

Detailed Description

The first embodiment is as follows:

referring to fig. 1-5, the present invention provides a method for controlling a cladding process based on laser-induced breakdown spectroscopy, which includes at least one set of computer, at least one set of laser cladding system, at least one set of laser-induced breakdown spectroscopy equipment, and at least one set of infrared thermometer; the laser cladding system breaks down a pulse laser in the spectrum system through mechanical clamping laser induction, and the infrared thermometer is fixed on a sample table through a bolt and connected to a computer through RS 485; the computer loads the set database.

The laser cladding system comprises:

laser cladding head: the laser cladding device is used for optical path transmission, outputs laser for cladding experiment and clamps a pulse laser;

the robot comprises: the clamping device is used for clamping the laser cladding head;

a laser controller: the laser power for laser cladding is adjusted;

a demonstrator: the laser cladding head is used for adjusting the working track of the robot so as to control the processing track and the processing height of the laser cladding head;

powder feeding device: the device is used for controlling the powder conveying amount and the shielding gas carrying amount in the laser cladding process;

laser cladding light path transmission system: the laser guide device is used for controlling the guide of the laser and realizing the output of high-power laser.

The laser-induced breakdown spectroscopy system comprises:

a pulse laser: used for ablating a sample to generate plasma and form an optical signal.

Optical path transmission: for controlling the pulsed laser path and the spot size.

A spectrometer: the CCD photoelectric conversion device is used for receiving plasma optical signals, separating the light into discrete spectrums, and conducting the discrete spectrums to the CCD for photoelectric conversion to generate a spectrogram.

A cladding process regulating method based on laser-induced breakdown spectroscopy comprises the following specific steps:

firstly, a laser cladding laser is started to preheat, then, broken blades of a TC11 titanium alloy integral blade disc are cleaned by absolute ethyl alcohol and then are placed on a sample processing table, at the moment, a demonstrator is used for compiling a robot motion track, a motion height and laser starting time according to the repairing requirement, and then, a laser cladding laser is started to preheat, and finally, the laser cladding laser is started to repair the broken blades of the titanium alloy integral blade disc, and the broken blades are placed on the sample processing tableSetting initial processing parameters: laser power 3000W, defocusing amount 20mm, powder feeding speed 50g/min, and powder feeding airflow 0.1m³H, the scanning speed is 2 mm/s; then starting the relevant laser induced breakdown spectroscopy equipment and the infrared thermometer for correction, wherein the laser induced breakdown spectroscopy system and the infrared thermometer are in a preparation state; starting a laser cladding system after the preparation is finished; and laser-induced breakdown spectroscopy and an infrared thermometer are used for monitoring the spectrum signal and the infrared temperature in the cladding process in real time on line and transmitting the data to a computer. Establishing an intensity curve of the characteristic spectral line intensity and the temperature in the cladding process by the computer, judging whether the characteristic spectral line and the temperature are stable, if so, processing till finishing, otherwise, comparing the two obtained curves with the existing data in the database, and according to the empirical process parameters: and (4) performing feedback adjustment on five process parameters of the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount, and continuing processing until the processing is finished.

The solution scheme of the invention based on the combination of the laser-induced breakdown spectroscopy technology and the infrared thermometer realizes the automatic optimization of parameters in the laser cladding process, and the laser cladding system and the infrared thermometer have lower requirements on the environment, so that the real-time result can be monitored in a factory with a more complex environment, and further the accurate feedback regulation is realized, thereby reducing the processing cost of the aircraft bladed disk, improving the reuse rate of the aircraft bladed disk and further improving the application potential of the laser cladding technology.

Example two:

referring to fig. 1-5, the present invention provides a method for controlling a cladding process based on laser-induced breakdown spectroscopy, which includes at least one set of computer, at least one set of laser cladding system, at least one set of laser-induced breakdown spectroscopy equipment, and at least one set of infrared thermometer; the laser cladding system breaks down a pulse laser in the spectrum system through mechanical clamping laser induction, and the infrared thermometer is fixed on a sample table through a bolt and connected to a computer through RS 485; the computer loads the set database.

The laser cladding system comprises:

laser cladding head: the laser cladding device is used for optical path transmission, outputs laser for cladding experiment and clamps a pulse laser;

the robot comprises: the clamping device is used for clamping the laser cladding head;

a laser controller: the laser power for laser cladding is adjusted;

a demonstrator: the laser cladding head is used for adjusting the working track of the robot so as to control the processing track and the processing height of the laser cladding head;

powder feeding device: the device is used for controlling the powder conveying amount and the shielding gas carrying amount in the laser cladding process;

laser cladding light path transmission system: the laser guide device is used for controlling the guide of the laser and realizing the output of high-power laser.

The laser-induced breakdown spectroscopy system comprises:

a pulse laser: used for ablating a sample to generate plasma and form an optical signal.

Optical path transmission: for controlling the pulsed laser path and the spot size.

A spectrometer: the CCD photoelectric conversion device is used for receiving plasma optical signals, separating the light into discrete spectrums, and conducting the discrete spectrums to the CCD for photoelectric conversion to generate a spectrogram.

A cladding process regulating method based on laser-induced breakdown spectroscopy comprises the following specific steps:

firstly, a laser cladding laser is started to preheat, then a large fan gate stator blade of an aircraft engine is cleaned by absolute ethyl alcohol and then placed on a sample processing table, at the moment, a demonstrator is used for compiling a robot motion track, a motion height and laser starting time according to the requirement of repair, and then initial processing parameters are set: the laser power is 2500W, the defocusing amount is 10mm, the powder feeding speed is 30g/min, and the powder feeding air flow is 0.2m³H, the scanning speed is 4 mm/s; then starting the relevant laser-induced breakdown spectroscopy equipment and the infrared thermometer for correction, wherein the laser-induced breakdown spectroscopy system and the infrared thermometer are in a preparation state; starting a laser cladding system after the preparation is finished; laser induced breakdown spectroscopy, infrared thermometer real-timeAnd monitoring the spectral signal and the infrared temperature in the cladding process on line, and transmitting the data to a computer. Establishing an intensity curve of the characteristic spectral line intensity and the temperature in the cladding process by the computer, judging whether the characteristic spectral line and the temperature are stable, if so, processing till finishing, otherwise, comparing the two obtained curves with the existing data in the database, and according to the empirical process parameters: and (4) performing feedback adjustment on five process parameters of the powder feeding amount, the scanning speed, the defocusing amount, the laser power and the protective gas amount, and continuing processing until the processing is finished.

The solution scheme of the invention based on the combination of the laser-induced breakdown spectroscopy technology and the infrared thermometer realizes the automatic optimization of parameters in the laser cladding process, and the laser cladding system and the infrared thermometer have lower requirements on the environment, so that the real-time result can be monitored in a factory with a more complex environment, and further the accurate feedback regulation is realized, thereby reducing the processing cost of the large fan gate stator blade of the aircraft engine, improving the reutilization rate of the large fan gate stator blade of the aircraft engine, and further improving the application potential of the laser cladding technology.

The control mode of the invention is controlled by manually starting and closing the switch, the wiring diagram of the power element and the supply of the power source are common knowledge in the field, and the invention is mainly used for protecting the method, so the control mode and the wiring arrangement are not explained in detail in the invention.

While there have been shown and described what are at present considered to be the fundamental principles and essential features of the invention and advantages thereof, it will be apparent to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, but is capable of other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description of the embodiments is for clarity only, and those skilled in the art should make the description as a whole, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.