METHOD FOR MANUFACTURING A COMPONENT STRUCTURE

Abstract

A method for producing a component structure of two components includes subjecting the components to beam energy for melting in a contact region. A variation of beam current is set to melt the components in the contact region over a defined component depth less than the perpendicular distance between sides of the contact region. A defined beam current pulse is periodically imparted to the variation of the beam current, to melt the components at least approximately over the entire perpendicular distance between the sides of the contact region and to produce in the region of the second side weld regions of a weld root of the weld connecting the components projecting from the contact region and form a pattern which representative of a weld quality. Between the weld regions there is no melting of the components in the region between the defined component depth and the second side.

Claims

1. A method for producing a component structure of at least two components to be welded to one another in certain regions, at least in a contact region, by means of beam welding, in which, by defined setting of a beam current, the components are subjected to beam energy from a first side of the contact region of the components that is facing the energy input in the direction of an opposite second side of the contact region, and are melted at least in certain regions in the contact region, wherein a variation of the beam current is set such that the components are melted in the contact region, from the first side in the direction of the second side, over a defined component depth (Hdef) that is less than the perpendicular distance between the sides, characterized in that a defined beam current pulse is periodically imparted to the variation of the beam current, in order to melt the components in certain regions at least approximately over the entire perpendicular distance between the sides of the contact region and to produce in the region of the second side weld regions of a weld root of the weld connecting the components that project out of the contact region and form a pattern which is representative of a weld quality, while between the weld regions there is no melting of the components in the region between the defined component depth (Hdef) and the second side.

2. The method according to claim 1, wherein the unpulsed variation of the beam current is predetermined in dependence on the perpendicular distance between the sides of the contact region, the variation of the beam current being raised as the distance increases.

3. The method according to claim 1, wherein the energy that is additionally input in each case into the components by the beam current pulses is set in a controlled manner in dependence on the electrons that completely penetrate the components.

4. The method according to claim 3, wherein a sensor system for determining the electrons that completely penetrate the components and the result of which is output to an evaluation unit is arranged on the second side.

5. The method according to claim 1, wherein the current intensity of the beam current is increased by a defined constant offset value for a defined operating time during the imparting of a beam current pulse to the variation of the beam current, starting from the value at the time of the unpulsed beam.

6. The method according to claim 1, wherein the beam current pulse imparted to the unpulsed variation of the beam current is produced by periodically generating a number of defined individual beam current pulses over a defined operating time.

7. The method according to claim 1, wherein the course of the unpulsed beam current is empirically determined in a reference process.

8. The method according to claim 1, wherein the current intensity of the beam current pulses is chosen in dependence on the materials to be melted of the components in the contact region in such a way that the weld regions on the side that is facing away from the energy input do not exceed a predefined amount.

9. The method according to claim 1, wherein the components are welded to one another by means of electron beam welding and/or laser beam welding.

10. The method according to claim 1, wherein the assessment of the weld quality takes place in an automated manner on the basis of the determined pattern of the weld regions and comparative data stored for this in a memory unit.

11. A computer program with computer-executable program coding instructions for implementing the method according to claim 1 when the computer program is run on a computer.

12. The computer program product, in particular a nonvolatile computer-readable data storage medium, with a computer-executable computer program according to claim 11.

13. A component structure with at least two components welded to one another in certain regions in a contact region by means of beam welding, wherein the components have on a side of the contact region that is facing away from the energy input during the beam welding weld regions of a weld root of a weld connecting the components to one another that project out of the contact region and form a pattern which is representative of a weld.

14. The component structure according to claim 13, wherein the weld regions are spaced apart from one another to a defined extent in the welding direction and are of substantially the same size, the weld root between the weld regions lying between a side that is facing the energy input and the side of the contact region that is facing away from the energy input.

Description

[0031] Further advantages and advantageous developments of the invention emerge from the patent claims and the exemplary embodiment that is described in principle with reference to the drawing:

[0032] in which:

[0033] FIG. 1a to FIG. 1e show in each case a schematized partial sectional view of a component structure of at least two components to be welded to one another in a contact region by means of beam welding during various phases of the beam welding process;

[0034] FIG. 2 shows a schematic variation of the beam current over the advancement path;

[0035] FIG. 3 shows a further partial sectional view of the component structure in the region of the weld to be produced by means of the beam welding process, the weld root of which lies within the contact region;

[0036] FIG. 4 shows a representation corresponding to FIG. 3 with a weld region of the weld root of the weld connecting the components that projects out of the contact region;

[0037] FIG. 5 shows a three-dimensional view of the component structure with a number of weld regions arranged on the side that is facing away from the energy input; and

[0038] FIG. 6 shows a further sectional view of the component structure according to FIG. 1e along a sectional plane running in the direction of the weld.

[0039] FIG. 1a to FIG. 1e show in each case a sectional view of a component structure 1 with two components 3, 4 to be connected to one another in a contact region 2 by means of an electron beam welding process. In this present case, the component 3 is a shaft collar, which is produced for example from a steel material and is to be connected to the component 4, which is configured for example as a turbine disc wheel of a jet engine and consists for example of a high temperature resistant nickel-based alloy. During the beam welding process, the components 3, 4 are moved in the direction of advancement X with respect to an electron beam 5, in order to be able to present a continuous welding process. By defined setting of the beam current, the components 3 and 4 are subjected during the beam welding process to beam energy from a first side 6 of the contact region 2 of the components 3, 4 that is facing the energy input in the direction of an opposite second side 7 of the contact region 2, and is increasingly melted in the contact region 2 as the operating time increases. In this respect, FIG. 1a to FIG. 1e show successive operating states of the component structure 1 before, during and after the welding process.

[0040] In FIG. 1a, and unwelded and not melted operating state of the components 3, 4 is represented. As a difference from this, the components 3, 4 in the operating state that is shown in FIG. 1b are melted in certain regions by the beam-side energy input in a region that is facing the side 6. With increasing energy input into the components 3, 4 during the beam welding process, the melted region of the components 3, 4 increases from the side 6 in the direction of the second side 7 of the contact region 2, as shown more specifically in FIG. 1c and FIG. 1d, until the contact region 2 is melted over the entire height H. In this case, not only is the material of the components 3, 4 liquefied but in addition to liquid material in the contact region 2 there also forms between liquid material regions 11, 12 a so-called vapour cavity 13, in which vaporous material of the components 3, 4 is arranged.

[0041] In addition, FIG. 1e shows the weld 8 that has been produced by beam welding and solidified, by way of which the components 3 and 4 are connected to one another to the desired extent. The production of the weld 8 over the entire height H takes place within a few milliseconds. In this case, the welding is carried out by means of electron beam welding, preferably in a vacuum, in order to avoid undesired interactions between the components 3 and 4 and the oxygen-containing surroundings. During the beam welding process, the beam current is set to a such a level that the components 3 and 4 are welded or connected to one another by way of a weld 8 extending over the entire perpendicular distance H between the sides 6 and 7.

[0042] However, in particular in the case of the present combination of materials to be welded, this cannot be readily put into practice, since beam welding processes are generally highly dynamic joining processes and sagging of welding material out of the contact region 2 has to be avoided to achieve a high welding quality.

[0043] For this reason, the variation of the beam current IB is set for a time to the extent shown in FIG. 2 in such a way that, in the contact region 2, the components 3 and 4 are only melted from the first side 6 in the direction of the second side 7 to the extent represented in turn in FIG. 3 over a defined component height Hdef, which is less than the perpendicular distance H between the sides 6 and 7.

[0044] Since in the case of the so-called welding-in that is represented in a schematized form in FIG. 3, in which the weld root 10 of the weld 8 is arranged within the contact region and running between the sides 6 and 7, the weld quality is not verifiable by means of test methods that do not destroy the material, and neither material-destructive testing of the weld quality of the weld 8 is possible nor can reworking of the weld 8 be carried out from the second side 7, in particular in the case of unfavourable or small component geometries of the components 3 and 4, an additional beam current pulse is imparted to the variation of the beam current IB in the way represented in FIG. 2 as from a defined advancement path value L1 over a defined advancement path, and consequently over a defined operating time in the millisecond range. By means of this beam current pulse, the components 3 and 4 are temporarily melted to the extent shown in FIG. 4 over the entire perpendicular distance H between the sides 6 and 7 of the contact region 2, and weld regions 9 of the weld root 10 of the weld 8 connecting the components 3 and 4 that in each case project out of the contact region 2 are produced and form a pattern which is representative of the weld quality in the way explained more precisely later.

[0045] For this, in the present case the variation of the beam current IB is set as substantially constant up to the discrete advancement path value L1 and, on reaching the advancement path value L1, is raised from a current value IBL1 to the extent represented in FIG. 2 in a ramp-like manner to the reaching of a further advancement path value L2 up to a consequently corresponding current value IBL2, and up to an advancement path value L3 of the components 3 and 4 is left constantly at the current value IBL2.

[0046] As the advancement path L increases further, as from the advancement path value L3 the variation of the current value IB is lowered in turn in a ramp-like form in the direction of the first current value IBL1, and subsequently, as from the advancement path value L4, is again set constantly to this value. As from reaching a further discrete advancement path value L5, a further current beam pulse is in turn imparted to the variation of the current value IB, in order to produce a further weld region 9 projecting out of the contact region 2. In this case, the variation of the beam current IB at the discrete advancement path values L5 to L8 is set to the extent described in relation to the discrete advancement path values L1 to L4.

[0047] The last-described procedure brings about a pattern of the weld regions 9 that is shown more specifically in the region of the side 7 of the contact region 2 of the components 3 and 4 and in FIG. 5 and is formed by a multiplicity of weld regions 9 arranged evenly distributed over the circumference of the in the present case rotationally symmetrical configured components 3 and 4. In this case, the weld regions 9 are of substantially the same size and are spaced apart from one another approximately equally in the circumferential direction X.

[0048] In FIG. 6, a partial sectional view of the component structure 1 shown in FIG. 5 is shown along the course of the weld 8. It is evident from the representation according to FIG. 6 that the weld root 10 between the weld regions 9 on average lies in each case at a defined distance from the lower side within the contact region 2, and the welding between the components 3 and 4 has a welding-in depth from the first side 6 of the contact region 2 that ensures a desired high weld quality.

[0049] In the case of the beam welding process considered in the present case, the high voltage that is partly responsible for generating the electron beam is set as constant. In this case, an increase of the high voltage or the acceleration voltage brings about the effect that the electron energy increases and a stiffening of the electron beam is achieved.

[0050] The working vacuum that is present during the electron beam welding is likewise set to be as constant as possible, in order to achieve a low scattering of the electrons, and consequently to achieve a setting of the beam focus that is as sharp as possible. In addition, the working distance between the beam outlet of the welding installation and the first side 6 of the contact region 2 is predetermined in dependence on the high voltage that is set, and taking into consideration the fact that particularly sharp focusing of the electron beam becomes more difficult as the working distance increases.

[0051] In addition, the lens current of a magnetic lens is kept as constant as possible during the beam welding process, in order to be able to predetermine the electron beam welding with a defined focal length, and consequently with a defined position of the focal plane in relation to the component surface 6. Furthermore, the electron beam is moved with a small amplitude and average frequency, in order to be able to shape the melt bath, and consequently the weld profile, to the desired extent by way of a defined beam oscillation.

[0052] Since the welding speed on the one hand influences the productivity and on the other hand also has a significant influence on the welding metallurgy and the solidifying process of the melt of the components 3 and 4, the welding speed is in the present case likewise kept as constant as possible, in order to be able to operate the beam welding process with little control expenditure.

LIST OF DESTINATIONS

[0053] 1 Component structure [0054] 2 Contact region [0055] 3, 4 Component [0056] 5 Electron beam [0057] 6 First side of the contact region [0058] 7 Second side of the contact region [0059] 8 Weld [0060] 9 Weld region [0061] 10 Weld root [0062] 11, 12 Liquid material region [0063] 13 Vapor cavity [0064] H Perpendicular distance [0065] Hdef Defined component depth [0066] IB Beam current [0067] IBL1, IBL2 Discrete value of the beam current [0068] L Advancement path [0069] L1 bis L8 Discrete advancement value [0070] X Direction of advancement