DE102015110522B4 - Process for the production of blanks with internal channels - Google Patents

Abstract

Method for producing metal components having an internal channel structure comprising at least two similar plate-shaped parts with internal channels, with the following successive method steps:
i) introducing a surface channel structure into a plate pairing, and positioning the plates to each other,
ii) joining the plates to form a metallic component having a channel structure inside the component,
iii) threading a cutting wire into the channel structure of the component after an exposure of the channel ends by separating the frontal regions of the component,
iv) further processing of the channel structure of the component by means of wire EDM for the production of the final channel inner walls.

Description

All documents cited in the present application are incorporated by reference in their entirety into the present disclosure (= incorporated by reference in their entirety).

The present invention relates to a method for the manufacture of blanks with internal channels.

State of the art:

The prior art is on DE 10 2010 035 606 A1 . DE 10 2011 005 830 A1 . DE 102 49 724 B4 . DE 103 58 201 A1 and DE 196 23 148 C2 , referenced.

According to the current state of the art, the penetrations of the component required for threading a cutting wire can be done by standard drilling, various deep hole drilling methods (eg with or without tool rotation in opposition to the tool, as well as the option of fully automated real-time bore recording including measures for countermeasure) or erosion processes (sink EDM or drilling) are produced. However, these are bound to typical process limits (ratio between diameter and bore length, as well as the bore center profile as a function of the drilling depth). The current state of the art for the preparation of penetrations with small diameter in relation to the bore length with high demands on the precision with respect to the Bohrungsmittenverlaufes (as in the production of Startlochkanälen which are to be further processed by wire EDM usually the case) is mainly based on EDM drilling and deep hole drilling Method for introducing start hole channels. Recent developments in the field of wire erosion have led to an increase in the machining length to meanwhile 2500 mm, so that the currently used methods for starting hole production, especially in the production of channels with small cross sections in the range of a few millimeters to reach their limits.

Task:

The object of the present invention is to provide a new method that uses alternative techniques and is not limited by the process limitations of the prior art. Likewise, new components are to be obtained, which can not be produced with the previous method. Last but not least, uses or applications of the new process, the new components and the components produced using the new method should be found.

Solution:

This object is achieved by a method for the production of blanks with internal channels, comprising introducing a surface channel structure into a plate pairing, joining the plates to form a closed channel structure, threading a cutting wire into the channel structure, further processing by means of wire EDM for the production of the final channel inner wall, respectively manufactured components and the corresponding uses.

Definition of terms:

In the context of the present invention, all quantities are, unless stated otherwise, to be understood as weight data. In the context of the present invention, the expression "and / or" includes both any and all combinations of the elements listed in the respective list. HIP in the context of the present invention means "hot isostatic pressing". In the context of the present invention, the term EB welding is understood to mean electron beam welding. "Electron beam welding" and "diffusion welding", "HIP / hot isostatic pressing" and "wire erosion" are conventional methods and are used within the scope of the present invention in the usual way.

Detailed description:

In the following description and in the following drawings, the same parts in description and the drawings are designated by the same numerals. The drawings are not necessarily to scale. For the sake of clarity and ease of illustration, some features of the invention may be exaggerated in size or in schematic form, and accordingly, some details of conventional or known elements may not be presented.

The present invention relates to a method for the production of blanks with the aim of producing thermally highly resilient or highly stressed components. These blanks are flat plates with internal channels, which run in a plane. The method according to the invention relates to the technology used for introducing the channels into the flat plates.

• i) Einbringen einer oberflächigen Kanalstruktur in eine Plattenpaarung, sowie Positionieren der Platten zueinander,
• ii) Fügen der Platten zur Bildung eines metallischen Bauteiles mit einer Kanalstruktur im Inneren des Bauteiles,
• iii) Einfädeln eines Schneiddrahtes in die Kanalstruktur des Bauteiles nach einem Freilegen der Kanalenden durch Abtrennen der stirnseitigen Bereiche des Bauteiles,
• iv) Weiterbearbeitung der Kanalstruktur des Bauteiles mittels Drahterodieren zur Herstellung der finalen Kanalinnenwände.

Method for producing metal components having an internal channel structure comprising at least two similar plate-shaped parts with internal channels, with the following successive method steps:

• i) introducing a surface channel structure into a plate pairing, and positioning the plates to each other,
• ii) joining the plates to form a metallic component having a channel structure inside the component,
• iii) threading a cutting wire into the channel structure of the component after an exposure of the channel ends by separating the frontal regions of the component,
• iv) further processing of the channel structure of the component by means of wire EDM for the production of the final channel inner walls.

An embodiment of the present invention is disclosed in 1 shown.

Although the method of the present invention is in principle suitable for all metals, however, the chipping capability for channel production (step i), the weldability for joining the half-plates (step ii) and the erodibility (step iii and step iv) of the respective material must be present.

Step i) can be carried out such that the channel structure is incorporated only in one of the plates of the plate pair (variant ia-1), or in both plates (variant ia-2). An introduction of channels in only one of the two plates (ia-1) can reduce the processing costs. Variant ia-2) allows on the one hand to edit the two plate halves so that the channels exactly above the other, resulting in a double channel depth compared to the variant ia-1). On the other hand, this also allows the two plate halves to be processed so that the channels do not overlap, resulting in twice the number of channels. Whether variant ia-1) or ia-2) is advantageous results depending on the application, depending on the overall geometry of the assembly and determining the plastic deformation HIP parameters (pressure, temperature and duration).

The processing of the half-plates in step i) can be carried out by any method suitable for working out channel structures from the plates. The method used is selected among others according to criteria of economy. In a variant of the present invention, the processing in step i) takes place by means of milling. Step i) may further as step ib), the cleaning of the contact surfaces z. B. with chemical process in preparation for the joining process. Furthermore, ic) positioning of the two half-plates in the desired position to each other is included. In the type of design of the superficial channel structure selected for step i), the consideration of the component requirements / design as well as the parameters of the later used joining method are decisive with regard to the expected plastic deformation of the channels (see step ii). In a variant, it is advantageous not to carry out the channel structure as far as the peripheral end plate edges, since a closed cavity for applying the gas pressure to the contact surface is advantageous and in some embodiments necessary for the HIP process used later for joining. In a variant, the channels should be connected to each other via transverse channels, as this allows the evacuation of the internal cavity before joining the plate pairing via a central vacuum port. In such a variant is in 2 shown. In some embodiments, bores for dowel pins for positioning are advantageously provided or incorporated. What such a plate pairing can look like after optional cleaning (ib) and positioning (ic) is described in 3 shown.

The joining in step ii) takes place in a variant of the present invention stepwise in two steps with two welding processes: First, in this variant, the edges are stapled in places, then the clamping device removed and finally the edges around along the parting plane of the two half-plates connected iia). Such an approach is in 4 illustrated. The cut AA in 4 shows that the circumferential weld does not yet make a full connection, the inner area of the plate pairing is not yet joined here. For the production of the circumferential weld, an EB process is ideally used in this variant, since this is carried out in a vacuum chamber. Also, the heat input compared to other methods is low. The effective depth of the circumferential weld is to be chosen as low as possible in a variant in order to keep the heat input into the component and thus the delay low. Nevertheless, the seam must simultaneously meet the requirement of vacuum tightness. Immediately following the circumferential weld, the vacuum connection within the EB chamber is closed with a stopper at the existing vacuum, which can be automatically positioned and welded using EB technology. This ensures that the vacuum in the inner channel structure is maintained.

Now follows the joining process of the entire contact surface also inside the component, step iib). For this purpose, a HIP method is used in a variant of the present invention, wherein a high isostatic pressure from the outside (therefore avoiding distortion of the assembly) causes at a high temperature diffusion processes in the contact surfaces of the components, resulting in a full connection. The illustrative 5 again shows a section AA with an indication of the HIP atmosphere and the diffusion weld in the interior of such a component.

Thereafter, the processing step iii), the threading of a cutting wire in the channel structure. For this purpose, the frontal areas of the component are separated, so that the ends of the channels are exposed for threading the cutting wire. Such an approach is in 6 shown.

After threading of the cutting wire in the respective channel, the finishing of the channel inner wall by means of wire eroding, processing step iv). For this purpose, the component must be aligned without contact in relation to the cutting wire, in order to exclude a short circuit during EDM machining.

• in Schritt i) zunächst die Halbplatten durch Fräsen vorbereitet, dann werden die Halbplatten vor dem Fügen entsprechenden zueinander positioniert,
• in Schritt ii) – die Halbplatten mittels Diffusionsschweissen (HIP) gefügt, wobei je nach Ausführung eine Deformation der Außenkontur des Rohteils inklusive der Kanäle und Kanalstege erfolgen kann,
• in Schritt iv) – die deformierten Bereiche des Rohteiles können dann durch entsprechende Ausführung eines Drahterodierprozesses entfernt werden, und – es resultiert ein finales Bauteil mit im Verhältnis zur Stegbreite großen Kanalquerschnitt.

In a variant of the present invention

• in step i) first prepares the half-plates by milling, then the half-plates are positioned corresponding to each other before joining,
• in step ii) - the half-plates are joined by means of diffusion bonding (HIP), whereby, depending on the design, a deformation of the outer contour of the blank including the channels and channel webs can take place,
• in step iv) - the deformed areas of the blank can then be removed by appropriate execution of a wire EDM process, and - results in a final component with respect to the web width large channel cross-section.

One possible approach is in 8th illustrated.

• – Tiefen zu Durchmesserverhältnis: Die neue Kombination der Verfahrensschritte ermöglicht die Herstellung von Kanälen in einem im Vergleich zur Längenausdehnung kleinen Querschnitt, ähnlich wie beispielsweise Tieflochbohrverfahren. Es ist mit dem erfindungsgemäßen Verfahren die Realisierung von Tiefen- zu Durchmesserverhältnissen von 1000 und mehr vorstellbar, welche mit anderen Verfahren gemäß Stand der Technik kaum herstellbar wären. In 7 wird der Stand der Technik, sowie die vorliegenden Erfindung diesbezüglich dargestellt; es ist die realisierbare Bohrtiefe über dem Bohrungsdurchmesser aufgetragen. Die eingezeichneten Grenzen der einzelnen Verfahren sind hierbei fließend und als Näherungswerte anzusehen. Der Bereich der Standardbohrverfahren beschreibt Tiefen- zu Durchmesserverhältnisse, bei denen keine besonderen Maßnahmen erforderlich sind, um die entsprechende Bohrung zu realisieren. Anspruchsvollere Tiefen- zu Durchmesserverhältnisse erfordern Sonderverfahren wie Tiefloch- und Erodierbohren. Die in 7 dargestellten Punkte (1), (2) und (3) entstammen verschiedenen Versuchsergebnissen zum Stand der Technik. Das mit der vorliegenden Erfindung mögliche Potential ist in der Figur durch das Feld „HIP Schweißen + Draht-Erodieren der Zone C repräsentiert. Die Punkte in der Figur repräsentieren dabei: (1) = 1600 mm Tiefe bei 10 mm Durchmesser, Tieflochbohren ohne Gegendrehung des Werkstückes; (2) = 850 mm Tiefe bei 1,6 mm Durchmesser, Erodier-Bohren; (3) =: 4000 mm Tiefe bei 10 mm Durchmesser, Vollautomatisch gesteuertes Tieflochbohren
• – Hohe Flexibilität bei der Querschnittsgeometrie der Kanäle: Die Kanäle können durch den Drahterodierprozess mit einer beliebigen Geometrie der Querschnittsfläche gefertigt werden, somit ist beispielsweise die Herstellung von rechteckigen Kanälen mit einem Querschnitt von 2 mm × 2 mm in einer Länge von 2000 mm möglich.
• – Geringere Toleranzen von oberflächigen Abtragsverfahren anstatt Bohrungsmittenverlauf: Ein weiterer Vorteil besteht darin, dass die Kanaloberfläche im Rohzustand von außen (z. B. mit einem Fräsverfahren) eingebracht wird und somit kein Verlauf von der idealen Kanalachse, wie bei Bohrverfahren typisch, auftritt. Dadurch tritt anstelle des Bohrungsmittenverlaufes nun die Herstelltoleranz von Frästeilen. Die Präzision bei der Herstellung von Frästeilen liegt im Bereich von hundertstel Millimetern und ist außerdem im Gegensatz zum bisherig betrachteten Bohrungsverlauf nicht tiefen- bzw. ortsabhängig. So kann nun beispielsweise ein Kanal von 2 mm Tiefe und 2000 mm Länge eingefräst werden. Hierbei würde sich die Lagetoleranz der Kanaloberfläche durch die Einbringung mittels Fräsen im Bereich von hundertstel Millimetern bewegen. Nach dem Stand der Technik wäre bei einem Tieflochbohren selbst mit gegenläufiger Werkstückdrehung eine höhere Abweichung zu erwarten.
• – Reduktion der Produktionskosten/Eignung für Serienfertigung: Die Reduktion der Produktionskosten/Eignung für Serienfertigung in großer Stückzahl ist ein weiterer Vorteil der Technologie: Es können eine Vielzahl von Kanälen in einem Bauteil für die Endbearbeitung mittels Drahterodieren hergestellt werden. Eine detaillierte Prozessoptimierung vorausgesetzt, kann auch der Arbeitsaufwand beim Drahterodieren durch gezielte Vorbereitung der Rohkanäle minimiert werden. Zudem sind durch erstellen von Computer-gestützen Fräsprofilen beliebige viele gleiche Bauteile in Serie herstellbar.
• – Hohe Flexibilität bei der Gestaltung der Bauteile: Nach der erfolgten Diffusionsschweißung zur Herstellung der Rohkanäle ist das Verhältnis zwischen lichter Weite und Stegbreite der Kanäle nicht mehr an feste Gesetzmäßigkeiten (z. B. homogene Druckverteilung während Diffusionsschweißen der Kanäle in der finalen Geometrie) gebunden. Somit kann praktisch jedes beliebige Verhältnis zwischen Steg und Kanal durch das Drahterodieren hergestellt werden. Auch kann die Kanalhöhe, Querschnittsfläche und Stegbreite innerhalb einer Komponente flexibel variiert werden. Auch ist die Realisierung von sich überkreuzenden Kanälen in einer Ebene ist möglich.
• – Prozesssicherheit: Bedingt durch Eigenspannungen im Grundmaterial kann beim Startlochbohren mit größeren Eindringtiefen mit verhältnismäßig geringem Bohrdurchmesser (im Millimeterbereich bei mehreren hundert Millimetern Bohrtiefe) ein nicht gewollter Fehlverlauf der Bohrung entstehen, welcher lokal auftritt. Somit kann bei den herkömmlichen Verfahren in der geplanten Anwendung zur Fertigung von beispielsweise Cooling Plates bei einer Anzahl von 30 Kanälen (2 × 30 Startlöchern von zwei gegenüberliegenden Stirnseiten) der Fehlverlauf eines einzelnen Startlochkanales dazu führen, dass das komplette Rohbauteil nicht verwendet werden kann. Wird die Platte jedoch aus zwei Halbschalen gefügt, kann vor dem Fügen jede Kanalhälfte einzeln vermessen, und ggf. im Rahmen von Qualitätssicherungsmaßnahmen ausgesondert werden.
• – Hohe Präzision der Kanalgeometrie: Durch den HIP-Druck entstandene Deformierungen der Kanäle können durch nachfolgendes Drahterodieren wieder entfernt bzw. ausgeglichen werden. Auch kann im Verhältnis zur Stegbreite ein großer Kanalquerschnitt gefertigt werden. Eine illustrative Darstellung einer entsprechenden Variante ergibt sich aus 8.

Some advantages of the present invention are:

• - Depth to diameter ratio: The new combination of process steps enables the production of channels in a small compared to the longitudinal extent cross-section, similar to, for example, deep hole drilling. It is with the inventive method the realization of depth to diameter ratios of 1000 and more conceivable that would be difficult to produce with other methods according to the prior art. In 7 the prior art, as well as the present invention in this regard is shown; the realizable drilling depth is plotted over the bore diameter. The marked boundaries of the individual methods are fluent and approximate. Standard boring methods describe depth to diameter ratios where no special measures are required to make the appropriate hole. Challenging depth to diameter ratios require special procedures such as deep hole and EDM drilling. In the 7 Points (1), (2) and (3) taken from various prior art test results. The potential possible with the present invention is represented in the figure by the field "HIP welding + wire erosion of zone C." The points in the figure represent: (1) = 1600 mm depth at 10 mm diameter, deep hole drilling without counter rotation of the workpiece; (2) = 850 mm depth at 1.6 mm diameter, erosion drilling; (3) =: 4000 mm depth at 10 mm diameter, fully automatic controlled deep hole drilling
• - High flexibility in the cross-sectional geometry of the channels: The channels can be made by the wire erosion process with any geometry of cross-sectional area, thus, for example, the production of rectangular channels with a cross section of 2 mm × 2 mm in a length of 2000 mm is possible.
• Another advantage is that the channel surface in the raw state is introduced from the outside (eg with a milling method) and thus no course from the ideal channel axis, as typical in drilling methods, occurs. As a result, the manufacturing tolerance of milled parts now occurs instead of the Bohrungsmittenverlaufes. The precision in the production of milled parts is in the range of hundredths of a millimeter and, in contrast to the previously considered bore course, is not dependent on depth or location. For example, a channel of 2 mm depth and 2000 mm length can now be milled. Here, the position tolerance of the channel surface would move by the introduction by milling in the range of hundredths of a millimeter. According to the prior art, a higher deviation would be expected in a deep hole drilling even with opposite workpiece rotation.
• - Reduction of production costs / Suitability for mass production: The reduction of production costs / suitability for mass production in large quantities is another advantage of the technology: It can produce a multitude of channels in a component for the final processing by means of wire EDM. Provided that a detailed process optimization is provided, the workload involved in wire erosion can be minimized through targeted preparation of the raw channels. In addition, by creating computer-supported milling profiles any number of the same components in series can be produced.
• - High flexibility in the design of the components: After the diffusion welding for the production of the raw channels, the ratio between clear width and web width of the channels is no longer subject to regular laws (eg homogeneous pressure distribution during Diffusion bonding of the channels in the final geometry). Thus, virtually any ratio between land and channel can be made by wire eroding. Also, the channel height, cross-sectional area and web width can be flexibly varied within a component. Also, the realization of intersecting channels in one plane is possible.
• - Process reliability: Due to residual stresses in the base material can occur at start hole drilling with larger penetration depths with relatively small bore diameter (in the millimeter range at several hundred millimeters drilling depth) unwanted misalignment of the bore, which occurs locally. Thus, with the conventional methods in the planned application for manufacturing cooling plates, for example, with a number of 30 channels (2 × 30 start holes from two opposite end faces), the failure of a single start hole channel can result in failure to use the complete shell part. However, if the plate is assembled from two half-shells, each half of the channel can be individually measured prior to joining and, if necessary, rejected within the scope of quality assurance measures.
• - High precision of the channel geometry: Deformations of the channels caused by the HIP pressure can be removed or compensated by subsequent wire EDM. Also, in relation to the web width, a large channel cross-section can be made. An illustrative representation of a corresponding variant results from 8th ,

• – Mit Hilfe des erfindungsgemäßen Verfahrens können thermisch hochbelastete Komponenten für Fusionsreaktoren, wie beispielsweise die First Wall von Brut-Blankets oder HCPB TBMs sowie interne Komponenten wie beispielsweise Cooling Plates (vgl. beispielsweise H. Neuberger, et al., KIT INDUCED ACTIVITIES TO SUPPORT FABRICATION, ASSEMBLY AND QUALIFICATION OF TECHNOLOGY FOR THE HCPB-TBM, Fusion Engineering and Design, Volume 86, Issues 9–11, October 2011, Pages 2039–2042) hergestellt werden.
• – Kalter Strahlungsschild: Die Technologie der vorliegenden Erfindung kann für ebene oder gebogene Strahlungsschilde verwendet werden, wenn zur Wärmeabfuhr ein hoher Kanalinnendruck gefordert ist. Die Umformbarkeit von Platten mit innenliegender Kanalstruktur wurde bereits erfolgreich demonstriert.
• – Herstellung von Brennkammerwänden: Bei sehr hohen thermischen Belastungen von Brennkammerwänden ist eine Kühlung erforderlich. Hierfür kann das erfindungsgemäße Verfahren zur Herstellung von Halbzeugen mit innenliegenden Hochdruckkanälen verwendet werden. Hierbei kann eine hohe Präzision bezüglich der verbleibenden Wandstärke zwischen dem Kanalinnenraum und dem Inneren der Brennkammer erreicht werden. Diese sorgt für eine homogene Temperaturverteilung. Somit kann die durch die Warmfestigkeit der umgebenden Kammerwände begrenzte Prozesstemperatur innerhalb des Brennraumes nahe der Einsatzgrenze des Werkstoffes gefahren werden. Eine dünne Wandstärke zwischen Brennraum und Kanalinnenwand von ca. 1,5 mm (Toleranzbereich ca. +/–10%) kann realisiert werden, was zu einer sehr hohen Wärmeabfuhrkapazität führt. Auch bieten die mit der erfindungsgemäßen Verfahrenskombination HIP/Erodieren hergestellten ebenen Halbzeuge eine große Flexibilität bezüglich Weiterverarbeitungsmöglichkeiten. Die zunächst ebenen Halbzeuge die mit der HIP/Erodier-Verfahrenskombination hergestellt sind, können beispielsweise, wie bereits erwähnt, durch Umformprozesse (mittels Rundbiegemaschine, Gesenkumformverfahren) und Verschweißen zu Röhren mit innenliegenden Kanalstrukturen für eine Umlaufkühlung weiterverarbeitet werden. Auch eine Weiterverarbeitung einer gefertigten Röhre zur Optimierung der Geometrie (z. B. erforderlich für Herstellung thermischer Strömungsmaschinen) mittels weiterer Umformtechnik (z. B. Innen-Hochdruck-Umformung IHU) ist möglich. Entsprechende Umform- und Schweißverfahren zur Herstellung und Verbindung von Platten mit Kanälen wurden bereits durchgeführt und erfolgreich demonstriert.
• – Ein Schema zur Herstellung eines Werkstücks (Umlaufkühlung mit strömungstechnisch optimierter Geometrie) ist in 9 wiedergegeben.
• – Partielle Gehäusekühlung: Die Technologie der vorliegenden Erfindung kann auch zur Herstellung von Gehäusesegmenten mit aktiver Kühlung genutzt werden. Entsprechende Platten können in ein Gehäuse oder eine Baugruppe mit thermischer Belastung an erforderlicher Stelle (vgl. Brennkammerwand) direkt eingeschweißt werden. Auch eine Innenauskleidung von Bereichen mit erhöhter thermischer Last mit ebenen oder gebogenen Platten ist möglich Beispielhafte Darstellungen für diese Anwendungsmöglichkeit sind in 10 illustriert.
• – Rohr mit axialer Anordnung der (Kühl-)Kanäle: Das erfindungsgemäße Verfahren kann auch dazu genutzt werden, Röhren in Segmentbauweise herzustellen, die mit Kanälen in axialer Richtung versehen sind.
• – Ansicht 1 in 11 zeigt die Anordnung mehrerer Startlöcher für nachfolgende Bearbeitung mit Drahterodieren in einer Ebene, sie wurden mit den Verfahrensschritten i) und ii) hergestellt. Ansicht 2 von 11 stellt die Stirnseite des Bauteiles dar, wobei die Lage der Startlöcher im Verhältnis zu den durch Drahterodieren herzustellenden Kanaloberflächen gezeigt ist. Ansicht 3 von 11 demonstriert das Rohteil mit fertig geschnittenen Kanälen, Ansicht 4 lässt ein fertiggestelltes Segment nach dem Herausschneiden der Außenkontur erkennen. Das Zusammenfügen mehrerer Segmente zu einem kompletten Rohr mit einem geeigneten Schweißverfahren (z. B. EB) ist in Ansicht 5 von 11 illustriert. Eine Abwandlung dieser Variante basiert auf der Vollanbindung der Kontaktflächen innerhalb der Einzelsegmente in den Kanalebenen sowie dem gleichzeitigen Fügen aller Einzelsegmente miteinander in einem Arbeitsgang mit HIP Technologie. Hierbei ist jedoch die Verwendung eines Hüllkörpers erforderlich um die Krafteinleitung zwischen den Einzelsegmenten zu realisieren. In 12 wird schrittweise ein mögliches Vorgehen dargestellt. Je nach detaillierter Gestaltung der Positionierung der Segmente vor dem HIP Prozess sowie der Ausführung der Umhüllung ist auch eine Variante mit geöffneten Kanalenden während des HIP Prozesses (ohne vorheriges umlaufendes Fügen der Halbschalen jedes Segments) möglich.

Some, but not all possible applications of the present invention are described below:

• Thermally highly stressed components for fusion reactors, such as the first wall of breeding blankets or HCPB TBMs and internal components such as cooling plates (cf., for example, H. Neuberger, et al., KIT INDUCED ACTIVITIES TO SUPPORT FABRICATION , ASSEMBLY AND QUALIFICATION OF TECHNOLOGY FOR THE HCPB-TBM, Fusion Engineering and Design, Volume 86, Issues 9-11, October 2011, Pages 2039-2042).
• - Cold radiation shield: The technology of the present invention can be used for plane or curved radiation shields, if a high internal channel pressure is required for heat dissipation. The formability of plates with internal channel structure has already been successfully demonstrated.
• - Production of combustion chamber walls: Cooling is required for very high thermal loads on combustion chamber walls. For this purpose, the inventive method for the production of semi-finished products with internal high-pressure channels can be used. In this case, a high precision with respect to the remaining wall thickness between the channel interior and the interior of the combustion chamber can be achieved. This ensures a homogeneous temperature distribution. Thus, the limited by the heat resistance of the surrounding chamber walls process temperature can be driven within the combustion chamber near the application limit of the material. A thin wall thickness between combustion chamber and channel inner wall of about 1.5 mm (tolerance range about +/- 10%) can be realized, resulting in a very high heat dissipation capacity. Also, the flat semifinished products produced by the method combination HIP / EDM according to the invention offer great flexibility with regard to further processing options. The initially flat semi-finished products which are produced using the HIP / EDM process combination can, for example, be further processed by forming processes (by means of a round bending machine, die-forming process) and by welding into tubes with internal channel structures for circulation cooling. A further processing of a manufactured tube to optimize the geometry (eg, necessary for the production of thermal turbomachines) by means of further forming technology (eg, internal high pressure forming IHU) is also possible. Corresponding forming and welding processes for the production and connection of plates with channels have already been carried out and successfully demonstrated.
• - A scheme for the production of a workpiece (circulation cooling with aerodynamically optimized geometry) is in 9 played.
• Partial Case Cooling: The technology of the present invention may also be used to fabricate housing segments with active cooling. Corresponding plates can be welded directly into a housing or a module with thermal load at the required location (see combustion chamber wall). Also, an inner lining of areas with increased thermal load with flat or curved plates is possible. Exemplary representations for this application are in 10 illustrated.
• - Tube with axial arrangement of the (cooling) channels: The inventive method can also be used to produce tubes in segmental construction, which are provided with channels in the axial direction.
• - View 1 in 11 shows the arrangement of several starting holes for subsequent processing with wire erosion in a plane, they were prepared with the method steps i) and ii). View 2 of 11 represents the front of the component, the position of the starting holes being shown in relation to the channel surfaces to be produced by wire eroding. View 3 from 11 demonstrates the blank with cut channels, view 4 shows a finished segment after cutting out the outer contour. The joining of several segments into a complete pipe with a suitable welding process (eg EB) is in view 5 of 11 illustrated. A modification of this variant is based on the full connection of the contact surfaces within the individual segments in the channel levels as well as the simultaneous joining of all individual segments together in one operation with HIP technology. In this case, however, the use of an enveloping body is required in order to realize the introduction of force between the individual segments. In 12 a step-by-step approach is presented. Depending on the detailed design of the positioning of the segments before the HIP process as well as the design of the enclosure, a variant with open channel ends during the HIP process (without prior circumferential joining of the half-shells of each segment) is also possible.

It is possible within the scope of the present invention to connect a plurality of components produced according to the invention with one another, so that the resulting structures are larger than components which can be produced individually. In this way, for example, via plug connections and optionally subsequent sealing by welding o. Ä. Quasi arbitrarily long channel structures can be obtained.

An assembly of components with axially and circumferentially flowed through walls with suitable joining technology is possible.

A representation corresponding to this variant of the present invention results 13 ,

The present invention also relates to the use of the method according to the invention for the production of components for fusion reactors, cold radiation shields, combustion chamber walls, thermal turbomachines, segments for the target of the European Spallation Source (ESS) and housing segments with active cooling.

Last but not least, the present invention also relates to the use of the components produced by the process according to the invention for components for fusion reactors, components for cold radiation shields, components for the production of combustion chamber walls, components in thermal flow machines, components for the production of segments for the target of the ESS and components for Production of housing segments with active cooling.

The inventive method is essentially limited only by the size of the available HIP systems or the available wire EDM, for example, there are HIP systems on which you can weld at least components of about 3000 mm, as well as wire erosion, where you like components similar It is possible to process the size so that components of this type can be manufactured in accordance with the invention with a length of 3000 mm (length.) If larger systems are available, it is possible to produce larger components according to the invention.

The various embodiments and / or variants of the present invention, for. For example, but not limited to, those of the various dependent claims or variants mentioned in the description, they may be combined with each other in any manner.

Following is a description of the figures:

Fig. 1:

1 is a schematic drawing of the main process steps of the method according to the invention. In A a pair of plates with mirror-symmetrical channel structure is made (left side) with subsequent positioning of the plate pairing with channel structure inside (right side). In B the joining of the plate pairing to a solid component is shown. In C, the removal of the frontal areas is first illustrated (left side), the dashed lines denoting the sectional planes. On the right side, the components are shown after removing the frontal areas, wherein the cutout shows a perspective view of three channel openings and the arrow shows the threading direction for a cutting wire. In D, the further processing for the production of the final channel inner wall is illustrated, wherein the cutout represents a threaded cutting wire in a channel opening for the wire EDM.

Fig. 2:

2 shows a typical arrangement on a half plate of surface milled channels with cross connection / transverse channel (A), holes for dowel pins (B) and vent (C).

3:

3 shows a plate pairing after cleaning and positioning, with clamping devices for positioning.

4:

In 4 illustrates the all-round welding of the plate pairing and closure of the vacuum port, the lower half representing section AA of the upper half of the figure, and S denoting the depth of action of the welding process.

Fig. 5:

In 5 the diffusion welding of the plate pairing for joining the inner contact region is shown. The element J circled in the upper half of the figure is reproduced in detail in the lower half and shows the full connection in the joining surface.

Fig. 6:

In 6 the component is shown in the upper half with Kanalöffnugen exposed after removal of the frontal areas and illustrated in the lower half by means of the arrow, the insertion direction of the cutting wire for the subsequent wire EDM.

Fig. 7:

7 is a schematic representation of the prior art, wherein drilling depth over hole diameter, each in millimeters, various methods are plotted. The numbers represent various measured values of prior art methods. Zone A represents standard drilling techniques, Zone B deep hole drilling / EDM drilling and Zone C HIP welding + wire eroding.

Fig. 8:

In 8th Fig. 12 is a cross-sectional view of the component during various stages of processing. A shows the preparation of the half plates by milling. B shows the positioning of the half-plates before joining. C illustrates the joining, for example by means of diffusion welding (HIP), with a deformation of the outer contour of the blank, including the channels and channel webs occurs. D illustrates that the deformed areas (hatched areas) of the component are then removed, and E shows a cross section of the final component with a large channel cross-section relative to the land width.

Fig. 9:

9 shows an example of the application of the present invention in combination with further joining and forming steps. In the left part of the figure while the production of plates with obliquely (in an angle alpha) extending channels is illustrated. In the middle of the figure, the positioning and joining of the plate segments is illustrated to a tube and the right part of the figure, the forming of the in a fluidically optimized component, for example by means of hydroforming, indicated.

Fig. 10:

10 shows two examples of housing with partial cooling, wherein the partially cooled housing areas are marked by the bar marks.

Fig. 11:

In 11 a variant of the production of pipes with axially extending channels in the wall is illustrated. View 1 shows the arrangement of several starting holes for subsequent processing by means of wire EDM in one plane. View 2 shows a plan view of the face of the component, the position of the starting holes being shown in relation to the channel surfaces to be produced by wire eroding. View 3 demonstrates the blank with ready-cut channels, view 4 shows a finished segment after cutting out the outer contour. View 5 is an enlarged detail view of area A from that in the lower part of FIG 11 illustrated finished tube.

Fig. 12:

FIG. 1 illustrates another variant of the production of tubes with axially extending channels in the wall. In A, the production of inner and outer individual segments is shown, wherein the dashed line in the assembled workpiece represents a circumferential EB seam. In B, the positioning of the various individual segments is illustrated. C illustrates wrapping in a wrapper for HIP welding. D then shows the semifinished product after the HIP welding and E illustrates the finishing by means of wire EDM.

Fig. 13:

13 shows a workpiece with a combination of an axially flowed through area "ax" (left part of the component) and an area with circulating flow "around" (right part of the component).

The invention will now be further elucidated with reference to the following non-limiting examples.

Examples:

• – Die Kanäle kollabieren nicht während dem Diffusionsschweißprozess.
• – Nach dem Verschweißen und Wiederöffnen der Stirnseiten kann ein Schneiddraht auf einer Erodiermaschine eingefädelt werden.

The method of the present invention was first performed on a test component having the full length of a HCPB TBM Cooling Plate and 30 start hole channels (full width of the component). By means of this test component it was shown that the core points of the invention function:

• The channels do not collapse during the diffusion welding process.
• - After welding and reopening the end faces, a cutting wire can be threaded on an EDM machine.

To demonstrate the complete process chain for the process combination of HIP and wire erosion, a component was produced which contains typical design features of a HCPB TBM Breeder Zone Cooling Plate. The component had a channel length of about 850 mm, a total of 30 channels, arranged at regular intervals along the entire component width of about 200 mm. The selected cross-section of the starting holes for later erosion processing was rectangular with 2 mm channel height (1 mm depth per half plate) and 1 mm channel width (hydraulic diameter = 4 × A / U = 4 × 2/6 = 1.333 mm). Thus, a ratio of L = 800 mm / dh = 1.333 mm = 600 results. Such a ratio would not be achievable with conventional standard methods, on the condition that the deviation of the ideal axis of the bore would not be outside the rectangular later channel contour of 2.6 mm × 4.5 mm may lie. The plate had channels along the length direction which were connected by transverse channels at the top and bottom. These transverse channels served to evacuate the channels during the joining of the plates in the electron beam welding chamber. The peripheral edge area of the plate was free of channels.

The procedure was as follows:

• - milling the channel structure / surface conditioning: To achieve the surface specifications, the appropriate milling tools and roughness requirements for the contact surfaces were adopted.
• - Cleaning the contact surfaces / positioning: A chemical cleaning process was used to clean the contact surfaces to be joined. This method was selected for reasons of reproducibility and verifiability by means of EDX analysis (comparison of the surface before and after cleaning) and the already applied cleaning processes such. As plasma cleaning, cleaning by acetone or dry ice cleaning preferred. After cleaning, the plates were positioned over dowel pins and mounted with clamps to prevent re-contamination of the contact surfaces during shipping and storage prior to further processing. The stapling was released only after stitching the half plates in the EB welding chamber.
• - Stapling and welding of the plate pairing: The plate pairing was delivered after cleaning for stapling and welding. After stapling, the stapling was removed and performed circumferentially around a weld with a penetration of about 8 mm. Thereafter, the assembly was left in the EB chamber and evacuated the now enclosed inner channels via a previously introduced vent hole for several hours. To support the evacuation process, the plate was superficially heated with the electron beam of the low power plant. Thereafter, the evacuation well was sealed with a stopper.
• - HIP process with subsequent tempering: The HIP process was determined using parameters that correspond to previous experiments (eg 1/8 and 1/4 of the total component size of the HCPB TBM First Wall) in terms of temperature history. However, the process pressure could be significantly increased and maintained for a longer time due to the significantly better ratio between channel and web width within the plate pairing. After the HIP process, another two-step heat treatment was performed (austenitizing and tempering the component).
• - Removal of the frontal areas: For further processing of the component by wire EDM, but also for the first preliminary assessment of the production result, the removal of the frontal areas was required. After separation, the channel ends were exposed.

The continuity of the thus prepared channels was checked by threading a thin wire (0.3 mm in diameter) through the channels. The check revealed that wires could be pushed through all channels. Thus, it has been proved that the technology of the present invention works to introduce start-up holes for subsequent EDM by diffusion bonding.

Claims (6)

A method for producing metallic components with an inner channel structure of at least two similar plate-shaped parts with internal channels with the following sequential method steps: i) introducing a surface channel structure into a plate pairing, and positioning the plates to each other, ii) joining the plates to form a metallic component with a channel structure inside the component, iii) threading a cutting wire into the channel structure of the Components after exposing the channel ends by separating the frontal regions of the component, iv) further processing of the channel structure of the component by means of wire EDM for the production of the final channel inner walls. A method according to claim 1, characterized in that in step i) the channel structure is incorporated in one of the plates of the plate pair, or in both plates A method according to claim 1 or 2, characterized in that the processing of the half-plates in step i) by means of milling. Method according to one of claims 1 to 3, characterized in that the joining in step ii) is carried out first by electron beam welding around along the parting plane of the two half-plates and subsequent hot isostatic pressing of the plates. Method according to one of claims 1 to 4, characterized in that in step ii) the frontal areas of the component are exposed after welding by means of milling, wire EDM or sawing with subsequent grinding. Use of the metal components produced by a method according to one of claims 1 to 5 with an internal channel structure for components for fusion reactors, for cold radiation shields, for the production of combustion chamber walls, in thermal turbomachines and for the production of housing segments with active cooling.

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