WO2018194482A1

WO2018194482A1 - An additive manufactured part with an embedded gauge and an additive manufacturing method thereof

Info

Publication number: WO2018194482A1
Application number: PCT/RU2017/000250
Authority: WO
Inventors: Dmitry Leonidovich NESTERENKO; Mikhail Sergeevich GRITCKEVICH
Original assignee: Siemens Aktiengesellschaft
Priority date: 2017-04-19
Filing date: 2017-04-19
Publication date: 2018-10-25

Abstract

An additive manufactured part and a method for manufacturing the part are presented. The part includes a base portion, a gauge-cavity portion and a top portion, each of which includes one or more additively manufactured successive layers. Additionally, the gauge-cavity portion includes a gauge integrated therewithin. In the part the gauge-cavity portion is sandwiched between the base portion and the top portion. A gauge connector configured to communicate gauge data projects out from a surface of the part or is accessible from a surface of the part through an opening. The part when being manufactured by additive manufacturing is inserted with the gauge following halting of the additive manufacturing. The manufacturing of remaining portions, i.e. the top portion, of the part is resumed after placing the gauge into a cavity formed in the gauge-cavity portion of the part that was formed on top of the base portion before halting manufacturing.

Description

AN ADDITIVE MANUFACTURED PART WITH AN EMBEDDED GAUGE AND AN ADDITIVE MANUFACTURING METHOD THEREOF

The present invention relates to additive manufacturing (AM) and in particular to parts manufactured by AM with a gauge embedded therewithin and methods of additive manufacturing thereof .

Monitoring of vital parts of machines such as industrial machines, energy-converting machinery, high-speed transport, etc. on a real-time basis is a critical issue in modern industry. Whether monitored manually or automatically, numerous gauges (sensors/detectors) are used for monitoring of various characteristics of machine parts, for example by using a thermocouple to monitor temperature, using a strain gauge to monitor stress-strain state, using various sensors to monitor structural integrity or health, etc. Most of the gauges that require physical contact with the part that is to be monitored to acquire data are placed on a surface of the part that is to be monitored.

The requirement for installation of the gauge on external surface of the part has several disadvantages. One of the disadvantages is that such gauges cannot be mounted on relatively moving parts that might come into contact. Such moving parts may brush against each other and the gauges placed on the surface may get damaged. Another disadvantage is that gauges cannot be mounted on parts that work under aggressive conditions for example where external surface of the gauge is exposed to or subjected to extremely high temperatures, acidic/alkaline environments, extreme highspeed gas flow, etc. Yet another disadvantage is the construction and size of machine's part, for example in hardly accessible parts of the machine, or machine parts whose surfaces are covered by another part located on top of the part to be monitored, etc. Furthermore, the gauges in some cases due to functionality of the part, for example in a turbine blade, cannot be mounted on the surface of the blade as it may degrade the efficiency of the blade. Other aerodynamic parts of machines may also have the same problem for example in an aircraft fan.

In the aforementioned situations where it may not be possible or may not be advisable to mount or place the gauge on the surface of the part, various work around techniques are used today such trying to monitor through contact-less data collection, or machining the parts to create slots for mounting the gauges in the body as opposed to the surface of the part. However, the contact- less data collection may not be viable or reliable for parameters or characteristics of the part that are best acquired by using contact-based gauges. Furthermore, machining for example drilling a hole in the part and then inserting the gauge into the whole requires a considerable amount of post manufacturing processing and may deteriorate the part or destroy it completely.

Thus, monitoring of vital parts of various machines on a real-time basis where contact-based data acquisition by the gauge is desired is a challenge and therefore a technique is required that enables installation of gauges in a machine part for contact-based data acquisition and that does not compromise functionality or life of the part or require post manufacturing processing such as machining.

The object of the present invention is to provide a technique, more particularly a method and a part, that enables installation of gauges in a machine part for contact- based data acquisition and that does not compromise functionality or life of the part or require post manufacturing processing such as machining. The above objects are achieved by an additive manufacturing method according to claim 1 of the present technique, and by an additive manufactured part according to claim 8 of the present technique . In a first aspect of the present technique, an additive manufacturing method is presented. The additive manufacturing method, hereinafter also referred to as the AM method or simply as the method, is used to manufacture a part on a build platform of a build chamber of an additive manufacturing system. In the method, first, a base portion of the part is manufactured. The base portion is manufactured by additively adding one or more successive layers, i.e. by additive layer manufacturing. Thereafter, in the method a gauge-cavity portion of the part is manufactured onto the base portion. The gauge-cavity portion is manufactured by additively adding one or more successive layers, i.e. by additive layer manufacturing. The gauge-cavity portion is formed such that the gauge-cavity portion includes a cavity for receiving a gauge to be integrated into the part. Subsequently, the gauge is placed into the cavity of the gauge-cavity portion of the part. Finally in the method, a top portion of the part is manufactured onto the gauge-cavity portion. The top portion is manufactured by additively adding one or more successive layers, i.e. by additive layer manufacturing. The gauge is placed in the cavity such that a gauge connector projects out from the cavity or is accessible from a surface of the part through an opening of the cavity.

The method of the present technique has several advantages over the conventionally known techniques. Since the gauge is embedded into the part, and the part is the same component or the part of the machine that is to be monitored, the gauge is resistant to possible contact, and consequent damage, by another relatively moving part. Furthermore, in the part manufactured by the method of the present technique, the gauge being embedded into the part is shielded from aggressive external environment such as high temperatures, acidic/alkaline environment, extreme high-speed gas flow, etc., and thus reliability and lifetime of the gauge is increased. Furthermore, the part manufactured by the method of the present technique may, when installed in its functional position for example the machine, a hardly accessible or non-accessible part and still monitoring of the part is possible. Since the gauge is embedded within the part, the presence of the gauge does not interfere with aerodynamics of the part and thus efficiency of the part so manufactured is indifferent to the physical effects of the gauge. Furthermore, since the part made by the method of the present technique has the gauge embedded within it, any need to perform post manufacture fabrications such as machining to insert gauges is obviated.

In an embodiment of the method, after being placed into the cavity, the gauge is heated up positioned within the cavity by using an energy beam arrangement. The energy beam arrangement may be the same energy beam arrangement that is used to additively manufacture the layers of the gauge-cavity portion. As a result of the heating of the gauge, the gauge adheres to walls of the cavity.

In another embodiment of the method, the cavity is such that the gauge is form-fitted into the cavity when being placed into the cavity. Thus the gauge fits in snugly within the cavity and does not create gaps or air pockets with the part. Furthermore, due to snugly fitting into the cavity the adhesion of the gauge to the walls of the cavity is enhanced.

In another embodiment of the method, the successive layers of the base portion, the gauge-cavity portion and the top- portion are formed by one of Selective Laser Melting (SLM) , Selective Laser Sintering (SLS) , Direct Metal Laser Sintering (DMLS) , Direct Energy Deposition (DED) , Direct Metal Deposition (DMD) , Laser Melting Deposition (LMD) , and Fuse Deposition Modeling (FDM) . The aforementioned additive manufacturing techniques are well known and thus the method of the present technique may be implemented with ease .

In another embodiment of the method, the successive layers of the base portion, the gauge-cavity portion and the top- portion are formed from one of powdered metallic material, polymer material, ceramic material, and a combination thereof. Thus different types of materials may be used to manufacture the part .

In another embodiment of the method, the gauge placed in the cavity is one of a structural integrity sensor, a strain gauge, a thermocouple. Thus parts having one of the aforementioned gauges are formed by the present method.

In another embodiment, the method includes creating a 3D model template, for example a CAD model, of the part to be manufactured. The 3D model template is designed by 3D modeling of the part to be produced sans the gauge to be placed and then introducing a representation of the cavity into the 3D model.

In another aspect of the present technique, an additive manufactured part is presented. The additive manufactured part, hereinafter referred to as the AM part or simply as the part, includes a base portion, a gauge-cavity portion and a top portion. The base portion of the part includes one or more additively manufactured successive layers. The gauge- cavity portion includes one or more additively manufactured successive layers and a gauge integrated therewithin. The top portion includes one or more additively manufactured successive layers. Furthermore, in the part the gauge-cavity portion is sandwiched between the base portion and the top portion. Additionally, the gauge is concealed within a surface of the part; however a gauge connector configured to communicate gauge data projects out from the surface of the AM part or is accessible from the surface of the AM part through an opening on the surface .

The AM part of the present technique being embedded into the part is resistant to any contact based damage and is shielded from aggressive external environment such as high temperatures, acidic/alkaline environment, extreme high-speed gas flow, etc. and thus has better reliability and lifetime as compared to a gauge placed on the surface of a similar part. Furthermore, the part even if, when installed in its functional position for example the machine, forming a hardly accessible or non-accessible part still monitoring of the part is possible. Furthermore, the gauge does not alter the shape or the contour of the AM part, thus efficiency of the part affected by a non-optimal change in the shape or the contour of the part remains undisturbed by the presence of the gauge. Furthermore, any need to perform post manufacture fabrications such as machining to install the gauge are obviated since the gauge is pre-inserted into the part.

In an embodiment of the AM part, the gauge is adhered to the gauge-cavity portion of the part. Thus the gauge is fixedly attached and chances of falling out of the gauge from within the part are reduced.

In another embodiment of the AM part, the gauge is one of a structural integrity sensor, a strain gauge, a thermocouple. Thus, the structural integrity or health, the strain, or the temperature of the part may be easily monitored. There may be more than one gauges present in the part. The multiple gauges may be same or different type of gauges. In another embodiment of the AM part, the successive layers are formed of one of powdered metallic material, polymer material, ceramic material, and a combination thereof. Thus, parts made from different material are available.

In another embodiment, the AM part is a turbine blade and the gauge is a structural integrity sensor or a strain sensor. In the turbine blade it is possible to identify any damage after blade-off event when the gauge is a structural integrity sensor. Furthermore, in the turbine blade it is possible to monitor stress-strain state of the blade on a real-time basis. This can be achieved in parts that have gauges that are commonly surface-based since the gauges being surface based are prone to damage by the aggressive conditions of operation, and furthermore placement of the surface-based gauges significantly degrades blade aerodynamics and affects efficiency and over-all balance.

In another embodiment, the AM part is a bolt and the gauge is a strain sensor. The bolts, for example studs, screws, may be used for connecting vital parts, for example flanges of turbine casing and rotor. The embedded strain gauge allows monitoring of stress-strain state of these critical bolts, and thus indicated the stress-strain state of the turbine parts where these bolts are installed.

The present technique is further described hereinafter with reference to illustrated embodiments shown in the accompanying drawing, in which:

FIG 1 schematically illustrates an additive manufacturing system;

FIG 2 presents a flow chart representing an additive manufacturing method of the present technique; FIG 3 schematically illustrates an exemplary embodiment of manufacturing of a base portion of the part to be manufactured by the method of FIG 2 ;

FIG 4 schematically illustrates an exemplary embodiment of manufacturing of a gauge-cavity portion of the part at a stage in the method of FIG 2 and subsequent to the manufacturing of FIG 3 ;

FIG 5 schematically illustrates an exemplary embodiment of a gauge placed in the gauge-cavity portion of the part at a stage in the method of FIG 2 and subsequent to the manufacturing of FIG 4 ;

FIG 6 schematically illustrates an exemplary embodiment of initial step of manufacturing of a top portion of the part a stage in the method of FIG 2 and subsequent to the stage of FIG 5;

FIG 7 schematically illustrates an exemplary embodiment of an additive manufactured part obtained as a result of the method of FIG 2;

FIG 8 schematically illustrates another exemplary embodiment of the additive manufactured part;

FIG 9 schematically illustrates an embodiment of the gauge wherein the gauge is a structural integrity sensor;

FIG 10 schematically illustrates another embodiment of the gauge wherein the gauge is a strain gauge; and

FIG 11 schematically illustrates yet another embodiment of the gauge wherein the gauge is a thermocouple; in accordance with aspects of the present technique.

Hereinafter, above-mentioned and other features of the present technique are described in details. Various embodiments are described with reference to the drawing, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments. It may be noted that the illustrated embodiments are intended to explain, and not to limit the invention. It may be evident that such embodiments may be practiced without these specific details.

It may be noted that in the present disclosure, the terms "first", "second", etc. are used herein only to facilitate discussion, and carry no particular temporal or chronological significance unless otherwise indicated.

It may also be noted that terms such as "front," "back," "top," "bottom," "side, "short," "long," "up," "down," and "below" used herein are merely for ease of description and refer to the orientation of the elements or components as shown in the figures. It should be understood that any orientation of the elements or components described herein is within the scope of the present invention.

FIG 1 schematically represents an additive manufacturing system 80. The system 80 generally includes a part building module 10, also known as the build chamber 10, in which a part 1 is build by additive manufacturing (AM) for example by SLM or SLS processes. The build chamber 10 is a container for example a box shaped or barrel shaped container and having a top side of the container open. FIG 1 represents such a container having side walls 11, 12 and a bottom surface 15. The side walls 11, 12 and the bottom surface 15 together define a space in which the part 1 is built. The AM system builds the part 1 by addition of layer after layer, i.e. by successively adding layers, by a suitable AM process. A powder metal material 7 is provided by a powder storage module 20, also known as the feed cartridge 20, that stores the powdered metal material 7, hereinafter also referred to as the powder 7. The powder 7 in the feed cartridge 20 is stored in an open top container having side walls 21, 22 and a bottom 26. The bottom 26 is placed on top of a piston 28 that makes the bottom 26 slide or move in Z direction, as represented by the co-ordinate system shown in FIG 1.

When the piston 28 moves upwards in the Z direction, i.e. in a direction 29, the powder 7 from the container 20 is raised above and outside the container 20. The powder 7 is then spread as top surface 9 of a bed 8 of the powder 7 in the build chamber 10 by using a powder spreading mechanism 30 which evenly spreads a thin layer of the powder 7 on the build chamber 10, in a direction 39. Usually the layer spread has a thickness of few micrometers, for example between 20 μτα and 100 μτη.

The build chamber 10 binds the bed 8 of powdered metal material 7 limiting the bed 8 by the side walls 11, 12 and the bottom surface 15. The build chamber 10 also includes a build platform 16, and the bottom surface 15 of the container of the build chamber 10 is formed by the build platform 16, also known simply as the platform 16. The platform 16 receives and supports the bed 8 of powdered metal material 7, and optionally also a workpiece (not shown) when the part 1 is intended to be built on the workpiece. The workpiece, if and when used, is positioned on the platform 16 embedded within the bed 8. The platform 16 is placed on top of a piston 18 that makes the platform 16 slide or move in Z direction, as represented by the co-ordinate system shown in FIG 1.

When the piston 18 moves downward in the Z direction, i.e. in a direction 19, the bed 8 is lowered thereby creating a space at surface 9 of the container of the build chamber 10 to accommodate the layer that is spread by the spreading mechanism 30. The layer so spread by the spreading mechanism 30 forms the surface 9 of the bed 8 and also covers a surface of the workpiece, if any is present.

It may be noted that although in FIG 1 only one feed cartridge 20 and associated powder spreading mechanism 30 have been depicted, in most of the AM systems 80 there are generally two such feed cartridges 20 and associated powder spreading mechanisms 30, one on each side of the build chamber 10. The system 80 also includes an energy beam arrangement 40. The energy beam arrangement 40 generally has an energy source 41 from which an energy beam 42 such as a Laser beam 42 or an electron beam 42 is generated, and a scanning mechanism 44 that directs the beam 42 to specific selected parts of the surface 9 of the powder bed 8 to melt or sinter the selectively scanned portions to form portions of the part 1. The specific portions of the surface 9 to which the beam 42 is directed are referred to as scanned. The selections of portions that are to be scanned by the beam 42 by action of scanning mechanism 44 are based on a 3D model, for example a CAD model, of the part 1 that has to built. The 3D model is designed or acquired before the AM process is implemented to build the part 1.

The build chamber 10, the feed cartridge 20, the spreading mechanism 30, and the energy beam arrangement 40 are well known in the art of additive manufacturing thus not described herein in further details for the sake of brevity.

After portions of a first layer are scanned on the surface 9 of the bed 8, a portion of the part 1 is formed. Besides the portions of the first layer that were sintered or melted, the remaining portions of the first layer are present in adjoining area of the sintered or melted portions and now form part of the powder bed 8. Thereafter, the platform 16 is lowered in the direction 19 along with the portion of the part 1 that was formed and the existing bed 8 of powdered metal material 7. Consequently, a space on top of the bed 8 is generated. The space so generated is same as the thickness of the next layer, or successive layer, which is to be spread on the powder bed 8. Thereafter a new layer is spread by using the spreading mechanism 30 and the powder 7 provided by the feed cartridge 20. The generated space accommodates the new layer of powdered metal material 7 which now forms the surface 9 of the powder bed 8. Portions of the surface 9 of the new layer of powdered metal material 7 are then selectively scanned by the energy beam arrangement 40 to melt or sinter the selectively scanned portions onto the previously formed portions of the part 1. The AM process is repeated as aforementioned by adding sintering or melting portions of the surface 9 of the bed 8, lowering the platform 16, spreading a next new layer to form surface of the bed 8, and scanning portions of the surface 9, thereby additively adding successive layers to form parts or portions of the part 1.

Hereinafter, in reference to FIG 2 an additive manufacturing method 100, also referred to as the AM method 100, of the present technique has been explained. The AM method 100 may be implemented by using the AM system 80 as shown in FIG 1 and explained hereinabove. Different successive stages of the AM method 100 are shown schematically in FIGs 3, 4, 5 and 6 to finally complete manufacturing of the part 1 shown in FIGs 7 and 8. The AM method 100, is explained hereinafter using FIG 2 in combination with FIGs 3 to 11.

The objective of the method 100 is to manufacture the part 1. Two alternate exemplary embodiments of the part 1 are depicted in FIGs 7 and 8. The part 1 is a part, for example a turbine blade, bolt, etc, that has a gauge 50 embedded with the part 1, i.e. the gauge 50 is not present on any external surface of the part 1 but embedded or buried within the body of the part 1. The gauge 50 an instrument, that measures and provides data, referred to as the gauge data, of the amount, level, or other parameters of the part 1. For example the gauge 50 is any sensor or detector that gathers information on one or more parameters physical aspects of the part 1, for example a temperature, a structural integrity, and/or a strain of the part 1. Although in the present disclosure only one gauge 50 has been depicted to be embedded in the part 1, as shown in FIGs 7 and 8, it is well within the scope of the present technique that multiple gauges 50 may be embedded within the part 1 forming a part or portion of the part 1. Furthermore since the part 1 is formed by AM method 100 of FIG 2 and as generally explained in FIG 1, it is referred to as an additive manufactured part 1.

The additive manufactured part 1, hereinafter referred to as the AM part 1 or simply as the part 1, includes a base portion 2, a gauge-cavity portion 4 and a top portion 6, as depicted in FIG 7. It may be understood that the base portion 2, the gauge-cavity portion 4 and the top portion 6 are integral portions or sections of the part 1 and are not separate pieces .

As shown in FIG 7, the base portion 2 of the part 1 includes one or more additively manufactured successive layers (not shown) . The gauge-cavity portion 4 includes one or more additively manufactured successive layers (not shown) and a gauge 50 integrated therewithin i.e. within the gauge-cavity portion 4 and consequently within the part 1. The top portion 6 includes one or more additively manufactured successive layers (not shown) . The gauge-cavity portion 4 is sandwiched between the base portion 2 and the top portion 6, and consequently the gauge 50 is concealed within a surface 3 of the part 1. However, a gauge connector 55 either projects out from the surface 3 of the AM part 1 as shown in FIG 7, or is accessible from the surface 3 of the AM part 1 through one or more openings, for example holes 99, on the surface 3 of the part 1. The gauge connector 55 is basically a data communicating means that transmits the gauge data to outside of the part 1. The gauge connector 55 for example may be, but not limited to, a wire. The gauge connector 55 may be connected to a controller and/or to a display. The data acquired or generated by the gauge 50 embedded within the part 1 is communicated to the controller and/or to the visual display via the gauge connector 55 directly or through additional such connectors joint in-between the gauge connector 55 and the controller and/or the display.

The gauge 50 is embedded in the part 1 by adhesion obtained from form-fitting or snug fitting of the gauge 50 into an inside of the part 1 or by affixing the gauge 50 to the material of the part 1 for example by gluing. The gauge 50 may also be fixed to the inside of the part 1 by solidification of the material, for example the powder 7, around the gauge 50 to form-fit the gauge 50. The material from which the part 1 is formed may be powdered metallic material 7, polymer material, ceramic material, and a combination thereof. Thus the gauge is fixedly attached to the inside of the part 1.

The gauge 50 is one of a structural integrity sensor 51 as shown in FIG 9, a strain gauge as shown in FIG 10, or a thermocouple as shown in FIG 11.

The structural integrity sensor 51 is used for monitoring of structural integrity i.e. structural continuity and/or health of the part 1, for example by detecting any cracks or micro- cracks that may be present in the part 1. The structural integrity sensors 51 may be a fiber optics based sensor, a foil based sensor, a vacuum tube based sensor, and so on and so forth. The structural integrity sensor 51 is used to measure a parameter for example an electrical current or characteristics of an optical wave that is received as an output of the structural integrity sensor 51 when an input electric current or light is introduced into structural integrity sensor 51. The output of the structural integrity sensor 51, i.e. in other words sensor behavior, changes if the structural integrity sensor 51 i.e. a wire, a tube, a optical fiber forming the structural integrity sensor 51 loses its continuity due to damage experienced as a result of deformity or damage suffered by the part 1 that is being investigated or monitored. For example, metal foil based structural integrity sensor 51 lose the electric current introduced into the structural integrity sensor 51, vacuum tube based structural integrity sensor 51 shows a pressure rise, and optic fiber based structural integrity sensor 51 depicts a change of the optical phase difference between two light waves with the same frequency that were introduced into the structural integrity sensor 51.

The strain gauge 52, as shown in FIG 10, are devices used to determine material strain due to the static and dynamic loads coming from internal and external sources such as mechanical or thermal stresses experienced by the part 1. As the part 1 is deformed for example by loading, the strain gauge 52 having specifically shaped foil such as shown in FIG 10, present within the part 1 undergoes a change in shape, and consequently a change of the electrical resistance occurs, which is measured with the use of a Wheatstone bridge circuit

(not shown) and a computerized data logger (not shown) . By estimating the change in electrical resistance of the strain gauge 52 a change in strain, and thus stress, experienced by the strain gauge 52 is estimated, which is indicative of the strain, and thus stress, of the part 1.

The thermocouple 53, as shown in FIG 11, is a temperature sensor that is used for the temperature measurements. The thermocouple 53 usually comprises of two conductors (made of different metals) joined together to form two junctions. One junction is connected to the part 1 by embedding therewithin and the other is connected to a known temperature body. If the temperatures of the part 1 and the known temperature body are different then at the junctions a potential difference is created, and a temperature of the part 1 is thereby calculated using temperature of the known temperature body and the potential difference.

A specific example of the part 1 and the gauge 50 is where the part 1 is a turbine blade and the gauge 50 is the structural integrity sensor 51 or the strain sensor 52.

Another specific example of the part 1 and the gauge 50 is where the part 1 is a bolt and the gauge 50 is the strain sensor 52. The part 1 is manufactured or built by the method 100 of FIG 2. The method of FIG 2 is explained hereinafter with reference to FIGs 3 to 6 that explain the manufacturing of the part 1, especially the embodiment of the part 1 shown in FIG 7. However, it may be appreciated by one skilled in the art that the embodiment of the part 1 shown in FIG 8 can also be manufactured by the method 100 of FIG 2.

In the method 100, in a step 105 a 3D model template, for example a CAD model, of the part 1 to be manufactured is created. In the event where the part 1 is being newly designed and the 3D model created does not include the gauge 50 in the model, then in the step 105, first in a step 102 a 3D modeling of the part 1 without the gauge 50 is performed. Thereafter, in the 3D model so created that does not have a representation of the gauge 50, in a step 104 the representation of a cavity within which the gauge 50 is to be placed is introduced. Thus as a result of the step 105, a 3D model of the part 1 to be build with the embedded gauge 50 is obtained. The 3D model, having the representation of the cavity for receiving the gauge 50, is thereafter used to manufacture the part 1. The 3D model is sectioned into a plurality of 2D slices. The 2D slices are grouped into at least three groups - first group having one or more 2D slices that together represent the base portion 2 of the part 1, second group having one or more 2D slices that together represent the gauge-cavity portion 4 of the part 1 and that includes the representation of the cavity for receiving the gauge 50, and third group having one or more 2D slices that together represent the top portion 6 of the part 1. In the subsequently performed steps of the method 100, the base portion 2, the gauge-cavity portion 4 and the top portion 6 of the part 1 are manufactured using the 2D slices of the first, the second and the third group, respectively.

In a step 110 the base portion 2 of the part 1 is manufactured. The base portion 2 is manufactured or formed by additively adding one or more successive layers, similar to as was explained hereinabove in reference to FIG 1. FIG 3 depicts the base portion 2 as manufactured by scanning, with the beam 42, the surface 9 of successively added layers onto the powder bed 8, and thus melting or sintering the powder 7 to form successive layers of the base portion 2. A surface of the base portion 2 so formed is depicted in FIG 3 using reference numeral 62 and a height of the powder bed 8 from the platform 16 is depicted using reference numeral 92.

Thereafter, as shown in FIG 2 in combination with FIG 4, in a step 120 the gauge-cavity portion 4 of the part 1 is manufactured onto the base portion 2, and more particularly on the surface 62 (shown in FIG 3) . As abovementioned the gauge-cavity portion 4 includes a cavity 5 for receiving the gauge 50 (not shown in FIG 4) that is to be integrated later into the part 1. The gauge-cavity portion 4 is manufactured or formed by additively adding one or more successive layers, similar to as was explained hereinabove in reference to FIGs 1 and 3. The cavity 5 may be formed by scanning portions of the surface 9 that are supposed to form walls of the cavity 5 and leaving a cavity volume between the walls un-scanned. Loose powder 7, i.e. un-scanned powder 7 may be present in the cavity 5 at this stage, which may need to be removed from the cavity 5 before the subsequent steps of the method 100. A surface of the gauge-cavity portion 4 so formed is depicted in FIG 4 using reference numeral 64 and a height of the powder bed 8 from the platform 16 is depicted using reference numeral 94. The height 94 is greater than the height 92 because of addition of successive layers of powder 7 during the step 120.

The step 110 and the step 120 may be performed by continuously scanning successive layers at the surface 9 of the bed 8 in the build chamber 10. After completion of the step 120, the continuous scanning of the surface 9 is halted. Thereafter, as shown in FIG 2 in combination with FIG 5, in^' a step 130 of the method 100 the gauge 50 is placed into the cavity 5 of the gauge-cavity portion 4. The gauge 50 may be placed such that the gauge 50 is limited within the cavity 5 and the gauge connector 55 extends out of the cavity 5 as shown in FIG 5, or alternatively (not shown) the gauge 50 may be placed such that the gauge 50 is limited within the cavity 5 and the gauge connector 55 is also limited within the cavity 5 but extends up to a boundary of the gauge-cavity portion 4 such that an end of the gauge connector 55 later forms part of the surface 3 of the part 1 when completely manufactured.

In an embodiment of the method 100, after being placed into the cavity 5 in the step 130, in a step 135 the gauge 50 is heated up while seated within the cavity 5 by using the energy beam arrangement 40 of FIG 1. The heating of the gauge 50 causes adherence of the gauge 50 or of parts of the gauge 50 to the walls of the cavity 5, for example by partially or completely melting or sintering the powder 7 which is heated up by the heated gauge 50. In another embodiment of the method 100, the cavity 5 is such that the gauge 50 is form- fitted into the cavity 5 in the step 130. The step 135 may follow after form-fitting the gauge 50 into the cavity 5.

Finally in the method 100, as shown in FIG 2 in combination with FIG 6, in a step 140 the top portion 6 of the part 1 is manufactured onto the gauge-cavity portion 4, and more particularly on the surface 64 (shown in FIG 5) . The top portion 6 is manufactured or formed by additively adding one or more successive layers, similar to as was explained hereinabove in reference to FIGs 1, 3 and 4. FIG 6 depicts one such layer 70 added on the surface 64 having the gauge 50 and the gauge connector 55 in position and forming portions of the surface 64. The layer 70 has a height 96. As a result of the formation of the top portion 6 the gauge 50 is embedded with the top portion 6 and the base portion 2, and more particularly within the gauge-cavity portion 4 sandwiched between the top portion 6 and the base portion 2.

After the completion of the step 140, the part 1 is removed from the bed 8 and includes the embedded gauge 50. In case where the gauge 50 was placed in the step 130 such that the gauge 50 was limited within the cavity 5 and the gauge connector 55 extended out of the cavity 5 as shown in FIG 5, the part 1 removed from the bed 8 has the gauge connector 55 projecting or hanging out or protruding out from the surface 3 of the part 1, as shown in FIG 7. In alternative case where the gauge 50 was placed in the step 130 such that the gauge 50 was limited within the cavity 5 and the gauge connector 55 was also limited within the cavity 5 but extended up to the boundary of the gauge-cavity portion 4, the part 1 removed from the bed 8 has the gauge connector 55 accessible from the surface 3 of the part 1 through the openings 99 of the cavity 5 , as shown in FIG 8.

While the present technique has been described in detail with reference to certain embodiments, it should be appreciated that the present technique is not limited to those precise embodiments. Rather, in view of the present disclosure which describes exemplary modes for practicing the invention, many modifications and variations would present themselves, to those skilled in the art without departing from the scope and spirit of this invention. The scope of the invention is, therefore, indicated by the following claims rather than by the foregoing description. All changes, modifications, and variations coming within the meaning and range of equivalency of the claims are to be considered within their scope.

List of Reference Characters

1 part

2 base portion

4 gauge-cavity portion

5 cavity in the gauge-cavity portion

6 top portion

7 powdered metal material

8 bed of powdered material

9 surface of the bed

10 build chamber

11 wall

12 wall

15 surface of the build platform

16 build platform

18 piston

19 direction of movement of the piston

20 powder feed module or feed cartridge

21 wall

22 wall

26 platform

28 piston

29 direction of movement of the piston

30 powder spreading mechanism

39 direction of powder spreading

40 energy beam arrangement

41 energy source

42 power beam

44 scanning mechanism

50 gauge

51 structural integrity sensor

52 strain gauge

53 thermocouple

55 gauge connector 62 surface of the base portion

64 surface of the gauge-cavity portion

70 layer of powdered metal material

80 AM system

99 opening

100 AM method

102 3D modeling of the part to be produced sans the gauge

104 introducing a representation of the cavity

105 creating 3D model template of the part

110 manufacturing the base portion of the part

120 manufacturing the gauge-cavity portion of the part

130 placing the gauge into the cavity

135 heating the gauge

140 manufacturing the top portion of the part

Claims

Patent Claims :

1. An additive manufacturing method (100) for manufacturing a part (1) , the method (100) comprising: - manufacturing (110) a base portion (2) of the part (1) , wherein the base portion (2) is manufactured (110) by additively adding one or more successive layers;

- manufacturing (120) a gauge-cavity portion (4) of the part (1) onto the base portion (2) , wherein the gauge-cavity portion (4) is manufactured (120) by additively adding one or more successive layers, and wherein the gauge-cavity portion

(4) comprises a cavity (5) for receiving a gauge (50) to be integrated into the part (1) ;

- placing (130) the gauge (50) into the cavity (5) of the gauge-cavity portion (4) of the part (1) ; and

- manufacturing (140) a top portion (6) of the part (1) onto the gauge-cavity portion (4), wherein the top portion (6) is manufactured (140) by additively adding one or more successive layers;

wherein the gauge (50) is placed in the cavity (5) such that a gauge connector (55) projects out from the cavity (5) or is accessible from a surface (3) of the part (1) through an opening (99) of the cavity (5) . 2. The method (100) according to claim 1, further comprising:

heating (135) the gauge (50) by an. energy beam arrangement (40) , after placing (130) the gauge (50) into the cavity (5) , to adhere the gauge (50) to walls of the cavity

(5) .

3. The method (100) according to claim 1 or 2, wherein the cavity (5) is such that the gauge (50) is form-fitted into the cavity (5) in placing (130) the gauge (50) into the cavity (5) .

4. The method (100) according to any of claims 1 to 3, wherein the successive layers of the base portion (^'2) , the gauge-cavity portion (4) and the top-portion (6) are formed by one of Selective Laser Melting (SLM) , Selective Laser Sintering (SLS) , Direct Metal Laser Sintering (DMLS) , Direct Energy Deposition (DED) , Direct Metal Deposition (DMD) , Laser Melting Deposition (LMD) , and Fuse Deposition Modeling (FDM) .

5. The method (100) according to any of claims 1 to 4, wherein the successive layers of the base portion (2) , the gauge-cavity portion (4) and the top-portion (6) are formed from one of powdered metallic material (7) , polymer material, ceramic material, and a combination thereof.

6. The method (100) according to any of claims 1 to 5, wherein the gauge (50) placed in the cavity (5) is one of a structural integrity sensor (51) , a strain gauge (52) , and a thermocouple (53) .

7. The method (100) according to any of claims 1 to 6, comprising creating (105) a 3D model template of the part (1) to be manufactured, wherein the 3D model template includes a representation of the cavity (5) .

8. An additive manufactured part (1) comprising:

- a base portion (2) of the part (1) , wherein the base portion (2) comprises one or more additively manufactured successive layers;

- a gauge-cavity portion (4) of the part (1) , wherein the gauge-cavity portion (4) comprises one or more additively manufactured successive layers and a gauge (50) integrated therewithin; and

- a top portion (6) of the part (1) , wherein the top portion (6) comprises one or more additively manufactured successive layers; wherein the gauge-cavity portion (4) of the part (1) is sandwiched between the base portion (2) and the top portion (6) and wherein the a gauge connector (55) configured to communicate gauge data projects out from a surface (3) of the part (1) or is accessible from a surface (3) of the part (1) through an opening (99) on the surface (3) .

9. The additive manufactured part (1) according to claim 8, wherein the gauge (50) is adhered to the gauge-cavity portion (4) of the part (1) .

10. The additive manufactured part (1) according to claim 8 or 9, wherein the gauge (50) is one of a structural integrity sensor (51) , a strain gauge (52) , and a thermocouple (53) .

11. The additive manufactured part (1) according to any of claims 8 to 10, wherein the successive layers are formed of one of powdered metallic material (7) , polymer material, ceramic material, and a combination thereof.

12. The additive manufactured part (1) according to claim 8 or 9, wherein the part (1) is a turbine blade and the gauge

(50) is a structural integrity sensor (51) or a strain sensor

(52) .

13. The additive manufactured part (1) according to claim 8 or 9, wherein the part (1) is a bolt and the gauge (50) is a strain sensor (52) .