RU2727339C1 - Method for outputting audio information about the technological process of electron-beam action - Google Patents

Abstract

FIELD: metrology.SUBSTANCE: invention relates to metrology, in particular to methods of metrological assessment of processes occurring during thermal treatment of metals. Method of outputting audio information about a process involves attaching a flexible waveguide to the object to be processed, attaching an accelerometer on the waveguide and processing information using a computer. Accelerometer signal is recorded in form of time dependences of current values of signals in two frequency ranges from the beginning of exposure to the moment of amplitude drop of signals to the level of background noise. Envelopes of obtained relationships are selected, which are stretched in time by 50 or more times. As frequency ranges, in which time dependencies of current values of signals from the accelerometer are recorded, selecting those ranges in which, according to experimental data, the signal effective amplitude undergoes the greatest changes from pulse to pulse, new envelopes are used as modulating functions for corresponding selected carrier signals, modulated signals are differentiated amplified and separately supplied to a two-channel sound-reproducing device for action on the right and left ear of the operator accordingly.EFFECT: shorter time and higher accuracy of setting operating modes of process equipment.1 cl, 4 dwg

Description

The invention relates to mechanical engineering, mainly to heat treatment of metals and alloys in a vacuum chamber by electron beams in the form of short pulses, and can be used to control the resulting indicators of the process of heat treatment of surfaces, in particular, surface alloying.

From the prior art, methods for outputting sound (vibration) information about phase transformations accompanying a thermal effect are known, consisting in the fact that the boundaries of phase transitions are determined using an acoustic emission sensor attached to the sample being processed (1. RF Patent No. 2433190, IPC C21D 1 / 55; G01N 29/00; C21D 1/04. Publ. Bulletin No. 31, dated 10.11.2011; 2. Vyunenko Yu.N., Chernyaeva EV Features of acoustic emission during martensitic transformations in TiNi alloy. // Bulletin Tambov University. Series: natural and technical sciences. T. 21, No. 31. 2016. P. 917-921).

The main disadvantage of these analogs is that they are designed for processing signals on a computer and displaying the results on a monitor for visual observation by the operator. However, this method presupposes a high level of operator qualifications and sophisticated decision-making algorithms regarding the controlled process taking place in the vacuum chamber. To create decision-making algorithms for numerous processes taking place in a vacuum chamber with a wide range of materials and modes, a preliminary research cycle is required for each variant of combinations of the processed material and processing modes. Large time costs and high requirements for the qualifications of personnel lead to the fact that such methods are used only for scientific research. As a result, production quality control of processing processes in vacuum chambers is mainly carried out based on the results of the analysis of the quality of the products obtained. This disadvantage affects the quality of the products obtained and the time required to select rational processing modes. But even with the selected modes, there is a random scatter in the parameters of the supplied electronic pulses that trigger the required reaction in samples in different volumes. Without methods of operational control, it is impossible to assess and make an adequate decision on further actions (repeat processing, change technological modes).

The closest to the proposed method in terms of the number of common essential features and the achieved technical result - the prototype - is a method for monitoring phase transformations in the metal when its temperature changes, which consists in the fact that a waveguide is connected to the workpiece that goes beyond the processing zone, on which the sensor is fixed oscillations, the information from which is processed using a computer (Vorontsov V.B., Zhuravlev D.V. Relationship between the structure of acoustic emission signals during crystallization of A1 and the mechanism of the formation of a solid phase from a melt. // Bulletin of Novgorod State University, No. 67. 2012. P . 8-13).

The main disadvantage and technical problem of the known technical solution is that it is not intended to promptly inform the personnel servicing the vacuum chamber in production conditions. This well-known solution is intended for research work by highly qualified personnel who are well versed in the method of mathematical processing of vibration signals and can read graphic information on the monitor screen. As such information accumulates and compares it with the results of the analysis of the quality indicators of the treated surfaces (for example, the uniformity of the coating with the alloying film, the depth of its penetration into the surface layer, the number of microcracks, etc.), a recommendation for rational processing modes (the power of the electronic pulse, number of pulses, gas environment, etc.). The operator of a production plant with an electron gun is not familiar with vibration diagnostics methods, but he has the usual skills of perceiving sound information. The human ear is able to perceive frequency and amplitude changes in a sound signal, its modulation. Comparing these changes with the results of determining the quality indicators of the surface layer of the processed parts, the operator can independently develop connections between the parameters of organoleptic perception (loudness and modulation features in different frequency ranges, the ratio of signal amplitudes in different ranges) with the processing results. As a result, he will be able to independently assess the ongoing processes in the vacuum chamber and make decisions on changing the processing modes. This is the same as how an experienced driver judges the condition of the motor from changes in the accompanying noise.

The objective of the invention is to equip the operator with sound information about the technological process of electron-beam impact on the part for monitoring and prompt response to changes in the quality of the processes in the vacuum chamber during the implementation of the technological process of surface alloying in order to promptly respond to deviations in the quality of the process being implemented and to reduce the development time rational technological modes.

The technical result is a reduction in the time for mastering the technology of processing new materials and an increase in the accuracy of tuning the operating modes of technological equipment that determine the parameters of electronic pulses and the effectiveness of their impact on the surface of the part, and an increase in the quality of products of electron-beam processing due to timely correction of the technological process.

The problem is solved, and the claimed result is achieved by the fact that in the method of outputting sound information about the technological process of electron-beam impact on the surface of the workpiece, which consists in attaching a flexible waveguide to the object being processed, extending beyond the vacuum chamber through a vacuum input, fixing it on the accelerometer waveguide, and processing information from the latter with the help of a computer, the signal received from the accelerometer is recorded in the form of time dependences of the current signal values in two frequency ranges from the beginning of exposure to the moment the signal amplitude drops to the background noise level, envelopes of the obtained dependences are distinguished, which are stretched in time by 50 or more times, forming new envelopes, for a lower frequency range select the frequency of the carrier signal in the range from 50 to 1000 Hz, for another range the frequency of the carrier signal is taken two or more times higher, as the frequency ranges in which the time is recorded variable dependences of the current values \ u200b \ u200bof signals from the accelerometer, select those ranges in which, according to experimental data, the effective signal amplitude undergoes the greatest changes from pulse to pulse with varying processing conditions and for random reasons, new envelopes are used as modulating functions for the corresponding selected carrier signals, modulated the signals are differentially amplified and separately fed to a two-channel sound reproducing device to influence the operator's right and left ear, respectively.

The invention is illustrated by images, which show:

in fig. 1 is a diagram of the installation of equipment that implements the proposed method for recording and analyzing vibration signals from the accelerometer, arising after an electronic pulse, and converting them into an audio signal affecting the operator's hearing organs;

in fig. 2 is an example of recording a vibration pulse that arose after the filing of an electronic pulse filtered in the 10-19 kHz band, and its envelope;

in fig. 3 is an example of a new envelope after being stretched 100 times and a view of a quasi-harmonic signal modulated by a new envelope;

in fig. 4 is an example of two quasi-harmonic signals generated in accordance with the proposed method, supplied to the operator's hearing organs.

The method for outputting sound information about the technological process of electron-beam impact on the surface of the workpiece consists in attaching a flexible waveguide to the object being processed, extending outside the vacuum chamber through a vacuum input, fixing the accelerometer on the waveguide and processing information from the latter using a computer, and the signal received from the accelerometer are recorded in the form of time dependences of the current values of signals in two frequency ranges from the beginning of exposure to the moment the amplitude of the signals falls to the level of background noise, the envelopes of the obtained dependences are isolated, which are stretched in time by 50 or more times, forming new envelopes; for a lower frequency range, the frequency is selected carrier signal in the range from 50 to 1000 Hz, for another range, the frequency of the carrier signal is taken two or more times higher, as the frequency ranges in which the time dependences of the current values of the signals from the accelerometer are recorded, those range zones in which, according to experimental data, the effective signal amplitude undergoes the greatest changes from pulse to pulse with varying processing conditions and for random reasons, the new envelopes are used as modulating functions for the corresponding selected carrier signals, the modulated signals are differentially amplified and separately fed to a two-channel sound reproducing device for exposure to the right and left ear of the operator, respectively.

In accordance with the invention, FIG. 1 shows an example of a circuit that implements the hardware part of the proposed method, where a waveguide 2 made of flexible wire contacts the processed sample 1, the opposite end of which is connected to a receiving plate 3, on which an accelerometer 4 is installed, the output of which is connected to a preamplifier 5 connected to an analog amplifier 6, at the output of which an analog-to-digital converter (ADC) 7 is installed, the data of which is stored using a computer 8 for subsequent processing and formation of a two-channel acoustic display of the vibration signal, which is differentially fed to headphones 9 having channel amplification and balancing devices used by the operator ...

FIG. 2 shows an example of a vibration signal 10, resulting from the application of an electronic pulse to the processed sample 1. The example shows the form of a pulse with a duration of 50 ms after filtering with a 10-19 kHz bandpass filter. The envelope 11 for signal 10 was constructed by sequentially calculating the effective amplitude values over short time intervals (in this case, 4 μs intervals were taken). The length of the time slices determines the details of the signal, described by the envelope. A very detailed description does not make sense, since the human ear does not distinguish them, the crude description loses essential details. A peak envelope can be constructed in the same way, where the maximum value is allocated for each segment.

FIG. 3 shows a new envelope 12 after being stretched 100 times the initial envelope 11 and a quasi-harmonic signal 13 modulated by a new envelope 12. Inset 14 shows an enlarged section of a quasi-harmonic signal modulated by a new envelope and a carrier signal with a constant frequency (in this case 70 Hz).

FIG. 4 shows an example of two quasi-harmonic signals formed to sound vibration signals in two frequency ranges (two frequency ranges were selected: 10-19 kHz and 19-40 kHz). The new envelopes modulate the carrier signals at 70 Hz for 10-19 kHz and 250 Hz for 19-40 kHz. The loudness of quasi-harmonic signals is leveled for their comfortable perception by the operator, while differential listening with different ears. Differential gain is preset based on experiments with typical signals from a particular process. This approach provides maximum information content for each channel. Differential gain is used to balance the signals in different channels. A signal that initially has a relatively small amplitude can be highly informative. To improve its perception against the background of the signal of another channel, balancing is required (usually such a device is present in stereo equipment). For the initial setting of the channel balance, you can align the maxima of the quasi-harmonic signals for typical process conditions.

The method of acoustic monitoring of electron beam technology in vacuum chambers is carried out as follows. Referring to FIG. 1, a flexible waveguide 2 is outputted from the vacuum chamber, which is mechanically connected to the sample to be processed 1. For output from the vacuum chamber, the waveguide section is sealed. The opposite end of the waveguide 2 is connected to the receiving plate 3, on which an accelerometer 4 is installed, the output of which is connected to a preamplifier 5 connected to an analog amplifier 6, at the output of which an analog-to-digital converter (ADC) 7 is installed, the data of which is stored by a computer 8 for subsequent processing and formation of an acoustic display of the vibration signal, which is fed to the headphones 9 used by the operator.

Practice has shown that the duration of the vibration signal that occurs after the irradiation of the part is about 50 ms. The main signal energy is concentrated in an even shorter section, sometimes reaching 15 ms. If such a signal is applied to the operator's headphones, he will hardly be able to estimate only the pulse amplitude. In fact, the human ear can distinguish many shades of the signal, including changes in amplitude and frequency composition, but only with a sufficient duration of the analyzed pulse (this is 5-10 seconds). With experience, the operator can audit the progress of the process by ear and react in time to unwanted deviations. When the composition of the processed materials changes, the operator may not wait for the researchers to test various processing modes, but independently determine a suitable combination of varied modes by ear, comparing them with the subsequent results of the analysis of the quality of the obtained surfaces (after being removed from the vacuum chamber).

However, simply stretching the signal of the original impulse in time is not the best option, since in this case all frequencies included in the spectrum of the vibration signal (mainly the natural frequencies of the channel connecting the workpiece to the accelerometer) will be reduced by the same number of times as the time is increased pulse. It turns out that many frequencies will be concentrated on a small low-frequency interval, which were previously distributed in a frequency range 100-200 times larger (with a long waveguide, the main vibration energy is concentrated at frequencies up to 20-30 kHz). The result is a noise signal in which it is difficult to make out the individual components. It should also be borne in mind that miniature acoustic equipment transmits the lowest frequencies worse. A lower threshold of about 40 Hz appears. In this regard, in the proposed method, it was decided to select two frequency ranges from the composition of the vibration signal and to influence different ears of the operator by their sound display. To do this, the original signal is filtered for these frequency ranges, and initial envelopes (graph 11 in Fig. 2) are constructed for each range. The initial envelopes are stretched to the required time scale (100-200 times), for each range, its own carrier harmonic signal is selected, which should be modulated by a new (stretched) envelope. Thus, two quasi-harmonic signals are obtained (example 13 in Fig. 3), which are then differentially amplified and launched into different operator headphones. In this case, the operator is affected not by a complex noise signal, but by a simplified one, consisting of two quasi-harmonic components, shades (amplitude, modulation, the ratio of amplitudes in different ranges at different points in time), the changes of which a person is able to catch. The converted signal is launched into the headphones with some delay (less than one second), determined by the conversion time in the computer, which does not affect the time for further decision making by the operator.

The choice of two frequency ranges in which the original signal is filtered is done in advance. It is determined by the composition of the natural frequencies of the vibration observation channel, the distribution of the pulse power over the frequency range and the frequencies at which the signal amplitude undergoes the greatest changes from pulse to pulse with varying processing conditions and due to random factors accompanying electron-beam processing. The frequency range should not be too narrow due to the appearance in this case of an instability of the signal amplitude; the most acceptable width of the frequency range is a range of the order of one octave. The selection of the best ranges is based on experimental data. In the example of FIG. 4 shows two quasi-harmonic signals formed for sounding two frequency ranges, in which the greatest changes in amplitude occurred with variations in the working pulses of the electron gun.

The choice of the carrier frequencies of harmonic signals is also made in advance and is guided by the human perception of these signals and their distinguishability when sounding together. For good discernibility, it is necessary that the carrier frequencies differ by a factor of two or more (for this reason, the frequency range is divided into octaves). The perception of each quasi-harmonic signal by different operator ears improves the distinguishability of the features of their variations for different reasons. In this case, the carrier frequency is selected for the lowest frequency range (for example, 70 Hz), for the other channel, the frequency is taken two or more times higher. This does not exclude an orientation towards taking into account the wishes of the operator. In the given case, the second carrier frequency was 250 Hz.

FIG. Figures 2 and 3 show step by step the sequence of signal conversion in one of the selected frequency ranges (10-19 kHz). These data were taken from the results of experimental processing of vibration signals during electron-beam irradiation of a steel plate coated with an NbHf film. As a result of the irradiation, a chemical reaction was initiated with the formation of the nitride phase (NbHf) N. For sounding the process, two frequency bands of 10-19 and 19-40 kHz were chosen. Conversions in the 10-19 kHz band are shown in FIG. 2 and 3, the same transformations were done for the second band. Frequencies of 70 and 250 Hz were chosen as carrier frequencies. To improve the perception of sound at a frequency of 250 Hz, before being fed into the headphones, the corresponding quasi-harmonic signal was amplified 6 times to equalize the maximum values of the amplitudes of both signals. As a result, quasi-harmonic pulses with a duration of 5 seconds were obtained (graphs 15 and 16 in Fig. 4), where at the very beginning sounds at a frequency of 250 Hz are distinguished, then sounds at a low frequency predominate, modulated by the wavy nature of martensitic transformation processes.

Taking into account the foregoing, it can be concluded that the task set - to equip the operator with sound information about the technological process of electron-beam exposure to the part for monitoring and prompt response to changes in the quality of the processes in the vacuum chamber during the implementation of the surface alloying technological process - has been solved, and the claimed technical result - a reduction in the time for mastering the technology of processing new materials and an increase in the accuracy of tuning the operating modes of technological equipment that determine the parameters of electronic pulses and the effectiveness of their impact on the surface of the part, and an increase in the quality of products of electron-beam processing due to timely correction of the technological process - are achieved

The analysis of the claimed technical solution for compliance with the conditions of patentability showed that the features indicated in the independent claim are essential and interconnected with the formation of a stable set of necessary features unknown on the priority date from the prior art, sufficient to obtain the required synergistic (over-sum) technical result.

Thus, the above information indicates the fulfillment of the following set of conditions when using the claimed technical solution:

- an object that embodies the claimed technical solution, in its implementation, refers to electrophysical processing methods, in particular to electron beam processing in vacuum chambers;

- for the claimed object in the form as it is characterized in the independent clause of the following formula, the possibility of its implementation is confirmed using the means and methods described above in the application and / or known from the prior art at the priority date;

- an object that embodies the claimed technical solution, when implemented, is capable of achieving the technical result perceived by the applicant.

Consequently, the claimed object meets the criteria of patentability "novelty", "inventive step" and "industrial applicability" under the current legislation.

Claims (1)

A method for outputting sound information about the technological process of electron-beam impact on the surface of the workpiece, which consists in attaching a flexible waveguide to the object being processed, extending beyond the vacuum chamber through a vacuum input, fixing the accelerometer on the waveguide and processing information from the latter using a computer, characterized in that the signal received from the accelerometer is recorded in the form of time dependences of the current signal values in two frequency ranges from the beginning of exposure to the moment the signal amplitude falls to the level of background noise, the envelopes of the obtained dependences are selected, which are stretched in time by 50 or more times, forming new envelopes, for more of the low-frequency range, the frequency of the carrier signal is selected in the range from 50 to 1000 Hz; for another range, the frequency of the carrier signal is taken two or more times higher, as the frequency ranges in which the time dependences of the current values of signals from the accelerator are recorded meter, select those ranges in which, according to experimental data, the effective signal amplitude undergoes the greatest changes from pulse to pulse with varying processing conditions and for random reasons, new envelopes are used as modulating functions for the corresponding selected carrier signals, modulated signals are differentially amplified and separately supplied on a two-channel sound-reproducing device to influence the operator's right and left ear, respectively.

Images