DD143146A2 - PROCESSES AND DEVICES FOR PROCESS STABILIZATION WHEN WORKING WITH CHARGING JET RADIATORS - Google Patents

Abstract

The invention relates to the control and process dependent Control of the effect of high-energy charged-particle beams Material according to patent 139 102. Under the respective conditions of technological process should be throughout the process measurable information about the interaction between the high-energy carrier beam and involved in the process Matter won and for control and process-dependent regulation be used. According to the invention, the ion backscattering and / or Ion penetration current in the electron beam method and the Electron backscatter and / or electron penetration current in Ion beam method measured and their DC component and / or amplitude, frequency or mean of the AC component individually or linked together to the control and / or Process control used. The procedure and the associated Facilities serve in extension of the main patent application in particular the improvement of the control and regulation accuracy as well in processes with. high beam power ». - Figure -

Description

21290

Method and devices for process stabilization when working with charged-particle beams

Field of application of the invention

The invention relates to a method and devices for the determination, adjustment, control and process-dependent control of the effect of high- energy carrier beams on material according to Pa ^^ t idJ-fCZ, in particular for welding, cutting, melting, spraying, sputtering, evaporation and material processing «

Characteristic of the known technical solutions

After Pak ^ -t 139Yc ??, it is already known that only certain charge carriers and / or energy spectra and / or frequency spectra of the litter, workpiece or penetration current are selected to obtain processinfoxinations for control and control variables. " At the

Electron beam welding using the electron flow as Prozeßmeßgröße, this procedure has been found to beam powers of about * 10 kV / "proven at a further increase in Strahlkraftmrde that the required accuracy decreases»

Object of the invention

The invention provides a method and a device which, under the respective conditions of the technological process, allow the irradiation of high-energy carrier radiation during the course of the process to be determined, controlled and process-dependent, even at higher beam power regulate"

Bas essence of the invention

The invention has for its object to develop a method and facilities that it possible ~ under the particular conditions of the technological process, during the course of the process measurable information about the interaction between the high-energy carrier beam and involved in the process

Matter to be achieved * The measuring signals should permit conclusions to be drawn as to the effect of the charged particle beam on the substance and thus to determine, adjust, control and process-dependent control of this effect. "The pedal-dependent control is intended to be within given limits even with time-dependent changes of the geometry of the electron optical system of the beam quay a stabilization of the

21290

Ensuring the effect of the charged particle beam on the material · The process should also be ensured in the radiated beam power range as well as for all technological processes with high-energy carrier beams.

According to the invention, the object is achieved by measuring the electron backscatter and / or ion penetration current in the case of electron beam methods and the electron backscattering and / or electron transfer current in ion beam methods and their direct current component and / or amplitude and / or frequency and / or pulse length of the alternating current component and / or their mean, which according to the invention in each case have a typical characteristic depending on the individual process parameters, which exactly reflects the interaction between the high-energy carrier beam, the matter involved in the process as well as the respective currently present process conditionsj for process control of the effect of the charge carrier beam on the Yierkstoff be used,

Devices for carrying out the method according to the invention are determined by obtaining the backscattering, penetration current. It is necessary that the obtained Prozeßmeßsignale even when. Changes in the angular distribution of Mckstreu- and Durchdringungsstromes the interaction z? / Ischen the high-energy carrier beam, the matter involved in the process and the respective, currently present process conditions exactly reflect and their own Time constant of the Meßsignalerfassungssysterne negligible is low »For this purpose, it is expedient to use for the Eückstreustrom a flat, sufficiently large Kreisringauffänger.mit small bore diameter, the spatially

between beam gun and Y / erkstück is arranged so that the electron-optical axis of the gun perpendicular to the catcher plane passes through the center · For the penetration current, it is expedient to use a flat, sufficiently large catcher j is spatially arranged in the beam path to the workpiece so in that the electron-optical axis of the ray gun is perpendicular to the catcher plane through its center »

In the case of electron beam processes, the collectors receive a certain negative potential with respect to ground, so that electrons are largely repelled by the collector as a function of the potential level, but ions are absorbed. In ion beam processes, the collectors receive a certain positive potential with respect to ground, so that, depending on the potential level, ions are largely repelled by the collector, but electrons are attracted. "

For this purpose, it is expedient to connect the catcher respectively via a low-impedance DC voltage source and a low-impedance, inductance sannen resistor with appropriate polarity and negligible low voltage dex voltage source to ground and the low, dropping at the Widerstand Prozeßmeßspannung a sufficiently high-impedance broadband amplifier, preferably one as integrated Circuit operated operational amplifier, supply and pay particular attention to low-capacitance construction and switching,

embodiment

The invention will be explained in more detail below with reference to an exemplary embodiment. In the associated drawing

21290 8

A schematic representation of the catcher and its spatial arrangement in electron beam welding as well as the principle of control and. Processing of the process measurement signals shown ·

The electron beam generated by the beam gun 1, the jet current intensity Is strikes the surface of the arranged at a working distance a workpiece 2 of thickness s, which moves relative to the electron beam with the welding speed vs "By appropriate adjustment of the individual process parameters thereby creates a weld" on the Workpiece 2 is at a distance IR a flat Kreisringauf catcher 3 for the fuückstreustrom IH arranged such that the electron-optical axis of the beam gun 1 extends perpendicular to the Auffängerebene through the center. The outer diameter of the collector 3 is 200 roms and the bore diameter is about twice the jet diameter · The one with Isola ·? gates / j. Attached catcher 3 is a low impedance voltage source SQt ₃ and a resistance H ~ of about 10 to 100Jt. connected to ground. The adjustable with the potentiometer P ^ negative potential level for the catcher 3 is dependent on the process conditions and is on average 300 Y · On resistance E ", a voltage drop is measured, which is directly proportional to the ion backcurrent IJ ^ · Under the Yterkstück 2 is at a distance 1-n a planar square catcher he 5 arranged on the penetrating current L ₀ on insulators 4 such that the electron optical axis of the beam gun 1 perpendicular to the catcher plane passes through the center of «The edge length of the catcher 5 is for example 60 mm« The catcher 5 is about a low-impedance voltage source SQ ^ and a resistance EW of about 10 to 100

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connected to ground · The adjustable with the potentiometer P ^ negative potential level for the catcher 5 is dependent on the process conditions and usually lower than for the interceptor 3 · in the resistor R ^ a voltage drop is measured, which is directly proportional to the ion penetration current iJpJ *

ro The ion backscatter or ion penetration current Ip ---; 2η " ¹ * proportional measurement voltage is amplified by an operational amplifier OY with 10 kSL input s / _s and a bandwidth of * 0 to 0 _s 5 MHz and directly or via a low-pass filter TPFj bandpass filter 3PF or H ₀ chppass filter HPF an iünplituden- Voltage converter ASV /, frequency-voltage converter FSW, pulse width voltage converter LSW and / or a mean value generator fed MWB whose time constant is only a few milliseconds.

The voltage corresponding to the respective direct current and / or the amplitude, frequency and / or pulse length of the alternating current component and / or the mean value is displayed by an analog or digitally operating voltmeter SM sur control and / or as controlled variable X in an analog or digitally operating electronic bowler , preferably a process computer P _p5 in a single or more slanted Hegel circle by comparison with the reference variable W and the provision of the manipulated variable Y, which according to the on-line tr ah welding process engages "processed" for "the Process control and process control required characteristics are previously determined in experiments

Claims (4)

212908 claim for invention 1. A method for detection, adjustment, control and process-dependent control of the effect of high-energy carrier radiation on material, especially for welding, cutting, melting, spraying, sputtering, evaporation and for material processing according to patent Ί3> $ 4ΟΖ _f preferably for process stabilization at higher beam power CHARACTERIZED IN THAT, in electron beam processes, the ion backscatter and / or ion permeation current and, in ion beam processes, the electron backscatter and / or electron penetration current is preferably measured, the DC component and / or amplitude and / or frequency and / or pulse length of the current component and / or their mean value can be used for process controlc 2. Device for determining, setting, control and process-dependent control of the effect of high-energy charge carrier beams on material according to item 1, characterized by the fact that for the Bückstreustrom (I _R ) a flat, sufficiently large circular collecting it (3) with a small bore diameter spatially between the gun (1) and workpiece (2) is arranged so that the electron-optical axis of the beam gun (1) extends perpendicular to the catcher plane through the collector center. 3 "device for determining, setting, control and process-dependent control of the effect of high-energy carrier beams on Y / erkstoff after item 1, ge characterized in that for the penetration current a flat, sufficiently large-scale catcher (5) spatially in the beam path to the workpiece (2) is arranged such that the electron-optical axis is perpendicular to the Auffanger- level through the Auffängerniittelpunkt · 4 »Device for determination, adjustment, control and process-dependent control of the effect of high-energy carrier beams on" workpiece according to items 1 to 3, characterized in that the interceptors (3; 5) each have a low-ohmic DC voltage source (SQ _R ) and a niederohmigen, low-inductance Resistor (R ~) with appropriate polarity and negligible interference voltage of the Sparuaimgsquelle are connected to ground, the low at the resistor (R _R ) sloping Prozeßmeßspannung each with a high-impedance broadband amplifier, preferably an executed as an integrated circuit operational amplifier (OY) is coupled For this 1 page drawings