Sample holder for resin mounting techniques, and related method for embedding a sample into a resin mount

Abstract

The present invention relates to a sample holder (100) for embedding a sample (1) into a resin mount (2), said sample holder (100) comprising a main frame (101) provided with an inner hollow (102) configured to house at least a portion of the sample (1), said sample holder (100) being fully containable in a housing (301) of a mounting machine (300) used for embedding the sample (1) into a resin mount (2), wherein said main frame (101) is configured to partition the housing (301) of the mounting machine (300) into a first portion (301a) and a second portion (301b), and wherein said main frame (101) is further configured to fill said first portion (301a) of the housing (301) when the sample holder (100) is inserted in the mounting machine (300). The present invention also relates to a method (200) for embedding a sample (1) into a resin mount (2), in particular a sample (1) of a coated wire, said method (200) comprising the following phases: - placing (220) the sample (1) in a housing (301) of a mounting machine (300); - covering (230) said sample (1) with a resin material, in particular until filling said housing (301) of the mounting machine (300); - creating (240) a rigid resin mount (2) of resin material embedding the sample (1). According to the present invention, said phase (220) of placing the sample (1) in a housing (301) of a mounting machine (300) is carried out by means of the following steps: - inserting (222) the sample (1) in an inner hollow (102) of a main frame (101) of a sample holder (100); - placing (224) the sample holder (100), with the sample (1) inserted in the inner hollow (102) of the main frame (101), in said housing (301) of the mounting machine (300).

Description

[0001] SAMPLE HOLDER FOR RESIN MOUNTING TECHNIQUES, AND RELATED

[0002] METHOD FOR EMBEDDING A SAMPLE INTO A RESIN MOUNT

[0003] DESCRIPTION

[0004] The present invention relates to the field of sample (or probe) holders for resin mounting techniques (i.e., hot or cold mounting techniques), said sample holder being configured for performing an evaluation test, in particular a quality test, on a sample, for example a sample of a coated wire (i.e., a wire coated with a layer of coating material). Therefore, the preset invention relates to a sample holder for embedding a sample into a resin mount according to claim 1. Moreover, the present invention relates to a related method for embedding a sample into a resin mount.

[0005] Specifically, the present invention relates to a device and a method for optimizing a technique known as "metallographic mounting" used for embedding different types of samples into a resin mount (e.g., a sample of a coated wire).

[0006] In the wire coating industry, it is a common practice to perform a number of evaluation tests on a produced coated wire in order to guarantee a predetermined level of quality of said coated wire.

[0007] In particular, for many applications, it is of paramount importance to guarantee a certain level of accuracy with regard to the geometrical properties of the coating layer applied on the wire. For example, the width, the uniformity, the symmetricity, etc., of the coating layer applied on the wire usually need to meet with a certain number of predetermined requirements.

[0008] For the sake of quality control and assurance, it is a common practice in the wire coating industry to extract a certain number of samples from each batch of newly produced coated wires in order to analyze them, in particular performing on them a set of quality tests or checks.

[0009] In particular, one of the most important tests or checks on the geometrical properties of the coating layer is carried out by means of the so called "crosssection" procedure.

[0010] According to such a procedure, one or more cross-sections of a coated wire are usually exposed for examination by simply cutting one or more samples out of the coated wire in order to measure the geometrical properties of the coating layer applied on the wire. In operation, a cross-section of a coated wire (i.e., a sample of a coated wire) is then embedded or mounted into one or more resin mounts, by means of a hot mounting press or of a cold mounting press.

[0011] In hot mounting, a housing (also referred to as mounting chamber) or a mold (usually cylindrical in shape) comprised in a mounting press is filled to a predetermined level with a raw resin material (usually in the form of grains or dust) until covering a sample, in particular a sample of a coated wire; said resin material liquefies and embeds the sample when the mold is heated and subjected to a moderate pressure.

[0012] Cold mounting typically involves the process of embedding a sample in a mounting medium at ambient or low temperatures without the need for heat and pressure. The mounting medium usually comprises a compound of synthetic resins (such as, for example, epoxy, polyester, acrylic, etc.) that, when mixed together in the mold along with one or more hardening chemicals, ensures proper curing and adhesion of the embedded sample (for example, by means of exothermic polymerization reactions).

[0013] In both the above processes (i.e., hot mounting and cold mounting), at the end of such resin mounting process, the sample is embedded into a rigid mount of resin material.

[0014] In order to guarantee a certain level of precision during the examination of the sample, the surface of a cross-section of a coated wire is rendered available for examination (e.g., by transversally cutting the coated wire) in such a way as to form a predetermined angle with respect to the linear direction (or development) of the wire; more specifically, the surface of the cross-section of the coated wire is exposed for examination in such a way as to be substantially orthogonal with said linear direction of the wire.

[0015] At the end of such a process, the specimen (i.e., the sample of the coated wire) is embedded into a resin mount (also called "resin shell" or "resin armor" in the rest of the present description) which typically comes in the shape of a small cylinder. In order to allow the analysis of the coated wire, at least part of the specimen embedded into such resin mount is directly exposed and made available for inspection (that is, the cross-section of the coated wire is exposed on at least one side of the mount cylinder); to this end, one side of the sample mount is usually grinded and polished so as to clearly expose the surface of the cross-section of the coated wire for inspection. The exposed surface of the cross-section of the coated wire is then examined by means, for example, of an optical and / or an electronic microscope.

[0016] One of the main benefits of mounting a sample, in particular a sample of a coated wire, into a resin mount is to ease the handling of small specimens, so as to increase the reliability and the repeatability of the analysis on such kind of specimens.

[0017] Moreover, such resin mounting techniques (i.e., hot or cold mounting techniques) bring about a number of benefits, which include providing protection of the sample, easy handling of the sample, capability of housing several small samples in one mount, and so on.

[0018] On the other hand, the techniques of hot or cold mounting bring about a number of challenges.

[0019] In fact, as most of the resins used in the hot or cold mounting techniques require the use of a "mounting press", it is often difficult to keep the sample steady during the pressing phase; as a consequence, at the end of the hot or cold mounting process, the sample is often incorrectly positioned inside the resin mount (also called shell or resin armor), with the undesired result of incorrectly exposing a wrong cross-section of the sample for analysis.

[0020] In the particular case of coated wires, it is desirable that the angle between the cross-section of the coated wire and the linear direction of the wire is within a predetermined value; in particular, the surface of the cross-section of the coated wire is often required to be substantially orthogonal to the linear direction of the coated wire. As already explained, it is often not straightforward to keep the sample at the right angle within the resin mount during the process of hot or cold mounting.

[0021] Although it is known in the art to use probe holders, such as metal or plastic fixation clips (or clamps, springs, etc..) in order to keep the sample steady, such approach does not guarantee acceptable results. On the one hand, plastic clips usually brake when subjected to high pressure, thus leaving the sample completely free to move within the resin armor during the mounting process; on the other hand, metal clips may deteriorate the surface of the sample, therefore rendering the analysis of the sample unreliable. For example, due to its softness, the coating material laid around the wire can be easily deformed by the metal clip, thus worsening the accuracy of the geometrical measurements of the coating layer. Furthermore, metal clips are also uncapable of maintaining an elongated object in a steady position under high pressure.

[0022] Another problem related to the techniques of hot and cold mounting is the great quantity of resin needed to create each resin mount with respect to the modest volume of the samples. Furthermore, most of the resins employed for mounting samples cannot be re-used after finishing the analysis of the sample; sample mounts are then usually archived or, more often, destroyed after the analysis.

[0023] In this frame, the main object of the present invention is to provide a sample (or probe) holder for resin mounting techniques (i.e., hot or cold mounting techniques), in particular for performing evaluation tests on a sample of a coated wire, wherein said sample holder is so designed as to overcome the drawbacks of the techniques of hot and cold mounting known in the state of the art.

[0024] In particular, one object of the present invention is to provide a sample holder configured for optimizing the techniques of resin mounting (i.e., hot or cold mounting). In this respect, the probe holder according to the present invention aims at keeping any kind of elongated specimen, like a coated wire (i.e., a wire coated with a layer of coating material), in a steady and predetermined position even when subjected to high pressures, for example during a pressing phase carried out in the "hot mounting" technique. Another object of the present invention is to provide a sample holder capable of preventing any deformation of the surface of the sample or specimen during the resin mounting process (in particular, during the pressing phase of hot mounting). Another object of the present invention is to optimize a resin mounting process in the wire coating field. In particular, according to one aspect of the present invention, a sample of a coated wire can be mounted in a resin mount without any deformation of the coating material laid around the wire. Further, according to an aspect of the present invention, a sample of coated wire can be embedded into a resin mount according to a predetermined position; for example, a sample of a coated wire can be mounted according to a predetermined angle between the surface of the cross section of the wire exposed for inspection and the linear direction of the wire.

[0025] Another object of the present invention is to reduce the amount of resin needed to mount a sample, in particular by means of hot mounting.

[0026] Another object of the present invention is to provide a probe holder capable of being employed multiple times over multiple samples; in particular, it is an object of the present invention to provide a sample holder configured to ease the removal of the resin mount from the sample holder so as to allow using the sample holder multiple times.

[0027] In view of achieving these objects, the present invention relates to a sample (or probe) holder embedding a sample, in particular a sample of a coated wire, into a a resin mount, according to resin mounting techniques (i.e., hot or cold mounting), said sample holder having all the features indicated in the annexed claim 1. The present invention also relates to a method for embedding a sample, in particular a sample of a coated wire, into a resin mount.

[0028] Further objects, features, and advantages of the present invention will become apparent from the following detailed description and from the annexed drawings, which are supplied by way of non-limiting explanatory example, wherein:

[0029] Fig. la shows a perspective view of a first embodiment of a sample holder for embedding a sample, in particular a sample of a coated wire, into a resin mount according to the present invention;

[0030] Fig. lb shows a front top view of the sample holder of Fig. la;

[0031] Fig. 1c shows a perspective view of an optional component of the sample holder according to the first embodiment of the present invention;

[0032] Fig. Id shows a perspective view of an exemplary realization of the first embodiment of the sample holder according to the present invention;

[0033] Fig. le shows a perspective view of the first embodiment of the sample holder according to the present invention, wherein said sample holder comprises a sample, in particular a coated wire;

[0034] Fig. 2a shows a perspective view of a second embodiment of the sample holder according to the present invention, wherein said second embodiment of the sample holder comprises a sample, in particular a coated wire;

[0035] Fig. 2b shows a front top view of the sample holder of Fig. 2a;

[0036] Fig. 2c shows a perspective view of an exemplary realization of the second embodiment of the sample holder according to the present invention;

[0037] Fig. 3a shows a perspective view of the sample holder according to the present invention, wherein said sample holder is shown in combination with an optional further element;

[0038] Fig. 3b shows a front lateral view of the sample holder and of the optional further element of Fig. 3a;

[0039] Fig. 3c shows a longitudinal cross-section of the sample holder and of the optional further element of Fig. 3a;

[0040] Fig. 4a shows a perspective view of a resin mount obtained with a sample holder according to the present invention, wherein said resin mount is shown before an optional grinding and / or polishing phase;

[0041] Fig. 4b shows a perspective view of the resin mount of Fig. 4a, wherein said resin mount is shown after an optional grinding and / or polishing phase;

[0042] Fig. 5 shows a diagram of a method for embedding a sample, in particular a sample of a coated wire, into a resin mount according to the present invention;

[0043] Fig. 6a shows a perspective view of an exemplary hot mounting machine; Fig. 6b, 6c, and 6d show a cross section side view of an exemplary hot mounting machine at different stages of the hot mounting process;

[0044] Fig. 6e shows an enlargement of a housing of the exemplary hot mounting machine during a step of the method according to the present invention.

[0045] In the following description, various specific details are illustrated aiming at a thorough understanding of examples of one or more embodiments. The embodiments can be implemented without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the embodiments. The reference to "an embodiment" in the context of this description indicates that a particular configuration, structure or characteristic described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as "in an embodiment", possibly present in different places of this description do not necessarily refer to the same embodiment. Moreover, particular conformations, structures or characteristics can be combined in a suitable manner in one or more embodiments and / or associated with the embodiments in a different way from that illustrated here, for example, a characteristic here exemplified in relation to a figure may be applied to one or more embodiments exemplified in a different figure.

[0046] The references illustrated here are only for convenience and do not therefore delimit the field of protection or the scope of the embodiments.

[0047] In the annexed figures from la to le, reference 100 generally designates a first embodiment of a sample (or probe) holder for embedding a sample 1 into a resin mount (designated with reference 2 in figures 4a and 4b) according to the present invention. In the annexed figures, the sample 1 to be analyzed comprises a sample 1 of a coated wire (i.e., a wire coated with a layer of coating material); however, it is evident that the teachings of the present invention may also apply to a sample of a different kind.

[0048] The sample holder 100 comprises a main frame 101 provided with an inner hollow 102 configured to contain at least a portion of the sample 1 of the material to be analyzed (e.g., a coated wire).

[0049] Advantageously, the main frame 101 of the sample holder 100 has a shape and / or dimensions similar to the resin mount 2 created by a predetermined mounting machine (designated with reference number 300 in Figs. 6a-6e) used for embedding the sample 1 in a resin mount 2, in particular said mounting machine 300 being used according to hot or cold mounting techniques known in the state of the art. For example, the sample holder 100 may be configured to ensure a tight fit when inserted in a housing (designated with reference number 301 in Figs. 6a-6e) of said mounting machine 300; the sample holder 100 can be therefore configured to precisely fit within the housing 301 of the mounting machine 300 thus providing minimal clearance between the surface of the housing 301 and the external surface of the sample holder 100. As better explained in the rest of the present description, this feature brings about the technical effect of minimizing the amount of resin material (designated with reference number 3 in figures 6d) required to create the sample mount (that comprises the sample 1 and the resin material 3).

[0050] In particular, as the housing 301 or mold of a (hot or cold) mounting machine 300 is typically shaped in a cylindrical fashion, the main frame 101 may have a substantially cylindrical shape as well. In this respect, it must be noted that a typical resin mount (i.e., a resin mount known in the state of the art) is a cylinder which has a diameter of 30mm and a height of 10 mm; however, any suitable shape of the main frame 101 is clearly within the scope of the present invention (e.g., rectangular or square cuboid).

[0051] In case the main frame 101 has a substantially cylindrical shape, the inner hollow 102 may be located substantially at the center of at least one of the bases of the cylindric main frame 101 and may extend substantially throughout the whole length / height of the main frame 101 (as shown in Fig. lb).

[0052] As particularly shown in Fig. Id, the main frame 101 may comprise a first body 101a and a second body 101b, wherein said first body 101a and second body 101b are configured to be combined together to form said main frame 101. The first body 101a and the second body 101b comprised in the frame 101 may be shaped, for example, as half cylinders configured to form a main frame 101 having a substantially cylindrical shape when said first body 101a and second body 101b are mounted together.

[0053] Moreover, at least one of said first body 101a and second body 101b comprises a slot 102a, 102b that forms said inner hollow 102. In the embodiment shown in figures from la to le, the first body 101a comprises a first slot 102a and the second body 101b comprises a second slot 102b, wherein said first slot 102a and second slot 102b cooperate in order to form said inner hollow 102; however, it is clear that the inner hollow 102 can also be formed in such a way to correspond to only one of said first slot 102a and second slot 102b (for example as it is shown in Fig. 2c, wherein the first slot 102a of the first body 101a substantially forms the entire inner hollow 102 of the sample holder 100).

[0054] The probe holder 100 according to the present invention may further comprise at least one fastening element 110 configured to hold together the first body 101a and the second body 101b and / or configured to hold in place the sample 1 of the material to be tested when housed in the inner hollow 102; for example, as shown in Fig. 1c, said at least one fastening element 110 may be a cotter pin.

[0055] Advantageously, at least one of the bases of the main frame 101 may comprise at least one superficial groove 103, 104 configured to contain (or to house) said at least one fastening element 110; in particular, said at least one superficial groove 103, 104 and said at least one fastening element 110 may be configured to cooperate in order to hold together the first body 101a and the second body 101b. As it can be seen from the attached figures la, lb, Id and le, preferably the main frame 101 comprises a first superficial groove 103 configured to contain a first fastening element 110 and a second superficial groove 104 configured to contain a second fastening element 110, in particular said first superficial groove 103 and second superficial groove 104 being substantially orthogonal to each other.

[0056] Figures 2a-2c show a second exemplary embodiment of the sample holder 100 according to the present invention, wherein said second embodiment comprises all the main features of the first embodiment.

[0057] In particular, the sample holder 100 according to the second embodiment comprises a main frame 101 provided with an inner hollow 102; moreover, the main frame 101 may further comprise a first body 101a, a second body 101b, and at least one fastening element 110.

[0058] In the second embodiment, said at least one fastening element 110 can be a screw configured to either hold together the first body 101a and the second body 101b, or to move apart the first body 101a from the second body 101b; moreover, the fastening element 110 according to the second embodiment brings about the indirect technical effect of holding in place the sample 1 when housed in the inner hollow 102. In fact, as the first body 101a and the second body 101b are tightly hold together by said at least one screw, the sample 1 results to be clamped against said first slot 102a and / or said second slot 102b and therefore tightly held in place in the inner hollow 102. Such technical effect is reached even though the fastening element 110 according to the second embodiment is not in direct contact with said sample 1.

[0059] In the first and in the second embodiment, the main frame 101 can be made of any material that can hold high temperatures and pressures, in particular of a hot mounting press. Advantageously, in order to ease the operations for freeing the sample holder 100 from the resin mount (and from the sample 1 embedded in said resin mount), the main frame 101 can be made, at least partially, of a material characterized by low adhesion with the resin; in this respect, the main frame 101 is preferably made in a plastic material, in particular Teflon® (and, therefore, also the first body 101a from the second body 101b).

[0060] Advantageously said at least one fastening element 110 can be made of plastic material (both in the first and in the second embodiment) such as, for example, Teflon®.

[0061] As previously explained, in Fig. 2c it is shown that the first slot 102a of the first body 101a substantially forms the entire inner hollow 102 of the sample holder 100; however, also in the second embodiment it is possible to form said inner hollow 102 by means of a first slot 102a obtained in the first body 101a and of a second slot 102b obtained in the second body 101b.

[0062] Figures from 3a to 3c show that the sample holder 100 according to the present invention may comprise a supporting element 120 configured to house at least a portion of the main frame 101 of the sample holder 100.

[0063] In this respect, the sample holder 100 may comprise at least one coupling element 121 configured to prevent any movement (in particular, a rotative movement) between said main frame 101 and said supporting element 120.

[0064] From Fig. 3c it can be observed that said at least one coupling element 121 comprises a pin configured to be inserted both in a first hole 105 of the main frame 101 and in a second hole 122 of the supporting element 120; however, it is clear that said at least one coupling element 121 may also be different from the one shown in Fig. 3c.

[0065] In operation, the sample 1 (e.g., a sample 1 of a coated wire) is inserted in the inner hollow 102 of the sample holder 100; the sample 1 is then held steady by the inner hollow 102 and, advantageously, it may further be secured by said one or more fastening elements 110. In particular, in the first embodiment of the sample holder 100 shown in figures from la to le, said at least one fastening element 110 may be located within said at least one groove 103, 104. In this respect, it must be observed that the insertion of the sample 1 in the inner hollow 102 may be performed before or after the first body 101a and the second body 101b are mounted together to form the main frame 101.

[0066] The sample holder 100 (with the sample 1 inserted in the inner hollow 102) is then placed in a housing 301 of a mounting machine 300 and then covered by a resin material (e.g., in the form of grains or dust according to a hot mounting technique, and in the form of synthetic resins according to a cold mounting technique) until filling the housing 301 of the mounting machine 300.

[0067] As already explained, the resin material contained within the housing 301 of the mounting machine 300 is then: heated and pressed, according to hot mounting techniques, or cooled after an exothermic polymerization reaction of a mixture of resin and hardening chemicals according to cold mounting techniques, with the result of creating a rigid resin mount 2 of resin material embedding the sample 1.

[0068] In order to expose the surface of the sample 1 for allowing the examination of the sample 1, it is usually necessary to refine the resin mount 2 by removing some layers of resin, in particular by means of a grinder and a polisher. In this respect, as shown in figures le and 2a, before creating the resin mount 2 comprising the sample 1, the sample 1 can be advantageously placed in the sample holder 100 such that at least part of the sample 1 extends over (i.e., pops out from) the inner hollow 102 of the sample holder 100; to this end, the length of the inner hollow 102 may be configured according to length of the elongated sample. This configuration (shown in figures le and 2a) brings about the technical effect of easing the refining operations of the resin mount 2 as the process of grinding and polishing can be carried out on the side of the resin mount 2 where the sample 1 extends over the surface of the sample holder 100; this way, while still maintaining the sample 1 in a steady position (during the pressing phase according to hot mounting techniques, or during the cooling phase according to cold mounting techniques), the sample holder 100 does not interfere with the operations of grinding and polishing and the subsequent analysis of the exposed surface of the sample 1.

[0069] More specifically, the sample 1 can be a wire comprising a first section and a second section; according to an aspect of the present invention, the inner hollow 102 can be configured to contain said first section of the wire while allowing the second section of wire to extend over the main frame 101.

[0070] Figure 4a shows a resulting resin mount 2 before grinding and polishing; in this situation, the cross-section of the sample 1 is not exposed. Figure 4b shows the same resin mount 2 after grinding and polishing; in this situation, the cross-section of the sample 1 is exposed for examination.

[0071] After analyzing the sample 1, the sample holder 100 can be easily freed from the resin mount 2, so as to be re-used to create a new resin mount 2 for another sample 1. To this end, the sample holder 100 can be freed mechanically by simply forcing apart the first body 101a and the second body 101b; to this end, a mechanical tool, such as (for example) a mechanical lever, can be employed to force the first body 101a and the second body 101b apart. Alternatively, or in addition, the fastening elements may be configured to ease the operation of forcing apart the first body 101a from the second body 101b (for example, the screw element shown in Fig. 2a may be configured to move apart the first body 101a from the second body 101b).

[0072] It is advantageous that the size and the shape of the main frame 101 is designed with direct reference to the specific mold or housing 301 of the mounting machine 300 used for (hot or cold) mounting the sample 1. That is, the volume of the main frame 101 can be specifically configured to minimize the amount of resin needed for each resin mount 2, while leaving enough space for properly embedding the section of the elongated sample 1 extending over the inner hollow 102 of the main frame 101. For example, the main frame 101 can be designed to match with the shape of said mold or housing 301 of the (hot or cold) mounting machine 300. To this end, the main frame 110 of the sample holder 100 may be configured to ensure a tight fit when inserted in the housing 301 of said mounting machine 300; for example, the main frame 110 of the sample holder 100 can be configured to precisely fit within the housing 301 of the mounting machine 300 in order to provide minimal clearance between the surface of the housing 301 and the external surface of the sample holder 100.

[0073] According to an aspect of the present invention, the sample holder 100 is characterized by being fully containable in the housing 301 of a predetermined mounting machine 300 used for embedding the sample 1 into a resin mount 2; more specifically, when fully inserted in the housing 301 of the mounting machine 300, the sample holder 100 can be configured to entirely fill at least a first portion of the housing 301 (also referred to as a first volume), while leaving empty a second portion of it (also referred to as a second volume). In other words, the main frame 110 of the sample holder 100 can be configured to partition the housing 301 of the mounting machine 300 into at least a first portion and a second portion, said first portion of the housing 301 being entirely filled by the main frame 110 of the sample holder 100 (when the sample holder 100 is inserted in the housing 301).

[0074] This way, when inserting the resin material into the housing 301 of the mounting machine 300 for covering the sample holder 100 with a resin material, the sample holder 100 inserted in the housing 301 prevents, at least partially, the first portion of the housing 301 to be filled with the poured resin; instead, as the second portion of the housing 301 is not engaged by the sample holder 100, the resin material poured in the housing 301 is allowed to embed the section of the elongated sample 1 extending over the inner hollow 102 towards the second portion of the housing 301.

[0075] Therefore, in the following of the present description there will be described in detail, also in connection with Fig. 5, a method 200 for embedding a sample 1, in particular a sample 1 of a coated wire, into a resin mount 2 according to the present invention.

[0076] The method 200 comprises the following phases:

[0077] 220 placing the sample 1 (e.g., a sample 1 of a coated wire) in a housing 301 (or mold) of a mounting machine 300;

[0078] 230 covering said sample 1 with a resin material (e.g.: in the form of grains or dust according to a hot mounting technique; in the form of synthetic resins according to a cold mounting technique), in particular until filling said housing 301 of the mounting machine 300;

[0079] 240 creating a rigid resin mount 2 of resin material embedding the sample 1.

[0080] In particular, said phase 240 of creating a rigid resin mount 2 of resin material embedding the sample 1 may be performed by means of one of the following steps:

[0081] 242 heating and pressing the resin material contained within the housing 301 of the mounting machine 300 (according to hot mounting techniques), or (alternatively)

[0082] 244 cooling a mixture of resin and hardening chemicals, in particular after an exothermic polymerization reaction of said mixture (according to cold mounting techniques).

[0083] The method 200 may further comprise a phase 260 of analyzing or examining the sample 1, for example by means of an optical and / or an electronic microscope. In this respect, said phase 260 of analyzing the sample 1 may be preceded by a phase 250 of refining the resin mount 2 by removing some layers of resin, in particular by means of a grinder and / or of a polisher, in order to expose a surface of the sample 1. In this respect, it must be noted that said refining phase 250 follows said phase 240 of creating a rigid resin mount 2.

[0084] According to the present invention, said phase 220 of placing the sample 1 in a housing 301 (or mold) of a mounting machine 300 is carried out by means of the following steps:

[0085] 222 inserting the sample 1 in an inner hollow 102 of a main frame 101 of a sample holder 100;

[0086] 224 placing the sample holder 100, with the sample 1 inserted in the inner hollow 102 of the main frame 101, in said housing 301 of the mounting machine 300.

[0087] In particular, said step 222 of inserting the sample 1 in said inner hollow 102 may be performed by means of a sub-step 223 of laying the sample holder 100 on a supporting element 120 configured to house at least a portion of the main frame 101 of the sample holder 100, in particular said sample holder 100 comprising at least one coupling element 121 preventing any movement (in particular, a rotative movement) between said main frame 101 and said supporting element 120.

[0088] Moreover, said phase 220 of placing the sample 1 in a housing 301 of a mounting machine 300 may be preceded by a phase 210 of making or producing the main frame 101 of the sample holder 100 in such a way to have a shape and / or dimensions that substantially matches (or corresponds to) the shape and / or the dimensions of said housing 301 of the mounting machine 300.

[0089] In particular, said phase 210 of making the main frame 101 may comprise the following steps: 212 producing said main frame 101 in such a way to comprise a first body 101a and a second body 101b, wherein at least one of said first body 101a and second body 101b comprises a slot 102a, 102b that forms said inner hollow 102;

[0090] 214 mounting or combining together said first body 101a and said second body 101b in order to form said main frame 101 and said inner hollow 102, in particular at least one fastening element 110 holding together the first body 101a and the second body 101b.

[0091] In this respect, it must be observed that said step 222 of inserting the sample 1 in the inner hollow 102 may be performed before or after said step 214 of mounting together the first body 101a and the second body 101b to form the main frame 101. According to a first embodiment of the present invention, said step 212 of producing said main frame 101 comprises a sub-step 213 of producing at least one of the bases of the main frame 101 in such a way to comprise at least one superficial groove 103, 104 configured to contain (or to house) said at least one fastening element 110. In this respect, said step 214 of mounting together said first body 101a and said second body 101b comprises a sub-step 215 of inserting said at least one fastening element 110 into said at least one superficial groove 103, 104 in order to hold together the first body 101a and the second body 101b, in particular said at least one fastening element 110 further cooperating with the inner hollow 102 for holding in place or clamping the sample 1.

[0092] Moreover, according to the present invention the phase 260 of analyzing the sample 1 may be followed by a phase 270 of freeing the sample holder 100 from the resin mount 2, so that said sample holder 100 can be re-used to create a new resin mount 2 for another sample 1. As already explained, said phase 270 of freeing the sample holder 100 may be performed mechanically by forcing apart the first body 101a and the second body 101b of the main frame 101, in particular employing a mechanical tool (such as, for example, a mechanical lever) to force apart the first body 101a and the second body 101b.

[0093] Figure 6a, 6b, 6c, and 6d show an exemplary mounting machine 300 (also referred to as mounting press 300) configured for hot mounting a sample 1 into a resin mount 2. The mounting machine 300 comprises a housing 301 (also referred to as mounting chamber 301) configured to entirely contain the sample holder 100. The mounting machine 300 may further comprise a pressing device 302 such as, for example, a piston stem, located inside the housing 301 and configured to exert a predetermined pressure inside it.

[0094] The mounting machine 300 may further comprise a heating system (not shown in Figure 6) for heating the housing 301 at a predetermined temperature.

[0095] Figures 6a and 6b show the mounting machine 300 during the step 224 of placing the sample holder 100, along with the sample 1 inserted in the inner hollow 102 of the main frame 101, into the housing 301 of the mounting machine 300; in particular, in order to ease the placement of the sample holder 100, the pressing device 302 may move upwards until reaching an opening of the housing 301. After placing the sample holder 100 on a pressure distribution plate of the pressing device 302 (e.g., a flat metal plate located at the top of the pressing stem 302), the pressing device 302 is moved downwards in order to drive the sample holder 100 inside the housing 301, as shown in Fig. 6c.

[0096] A predetermined quantity of resin material 3 is then inserted into the housing 301 until entirely covering the sample 1 and a mounting lid 303 is firmly closed over the opening of the housing 301. The pressing device 302 is therefore moved upwards along the housing 301 in order to exercise a predetermined pressure on the resin material 3. As already explained above, the sample holder 100 is configured to partition the housing 301 of the mounting machine 300 into a first portion 301a and a second portion 301b.

[0097] Fig. 6e shows an enlargement of the housing 301 during the step 242 (shown in Fig. 6d) of heating and pressing the resin material contained within the housing 301 of the mounting machine 300. According to an aspect of the present invention, the main frame 101 is configured to entirely fill the first portion 301a of the housing 301 so as to confine the resin material in the second portion 301b of the housing 301. Therefore, when the sample holder 100 is inserted in the mounting machine 300, the main frame 101 prevents the resin material 3 to enter into said first portion 301a of the housing 301.

[0098] The features and the functionalities of the sample holder 100 described in relation to the mounting machine 300 depicted in Figs. 6a-6d are equally applicable to any type of cold mounting machine 300 (not shown); the reference numbers indicated in Figs. 6a-6e in relation to the mounting machine 300 are hereby employed to designate one or more comparable components of a cold mounting machine 300.

[0099] For example, a typical cold mounting machine 300 comprises at least a housing 301 (also referred to as a mold) for containing the sample holder 100; as already described in relation to the mounting machine 300 depicted in Figs. 6a-6d, the main frame 101 of the sample holder 100 is configured to partition the housing 301 of the cold mounting machine 300 into a first portion 301a and a second portion 301b; in particular wherein the main frame is configured to fill said first portion 301a of the housing 301 of the cold mounting machine 300 when the sample holder 100 is inserted in the cold mounting machine 300.

[0100] It is therefore evident that the present invention may also relate to a system for embedding a sample 1 into a resin mount 2, wherein said system comprises a sample holder 100 and a mounting machine 300, as previously described.

[0101] The features of the sample holder 100 and of the method 200 for embedding a sample 1, in particular a sample 1 of a coated wire, into a resin mount 2 according to the present invention, as well as the advantages thereof, are apparent from the above description.

[0102] In fact, the provisions of the present invention allow to provide a sample holder 100 which is so designed as to overcome the drawbacks of the techniques of hot and cold mounting known in the state of the art.

[0103] In this respect, it must be observed that the provisions and the features of the sample holder 100 according to the present invention allow to optimize the techniques of resin mounting (i.e., hot or cold mounting), since said sample holder 100 aims at keeping any kind of elongated sample 1 or specimen, like a coated wire (i.e. a wire coated with a layer of coating material), in a steady and predetermined position even when subjected to high pressures, for example during a pressing phase carried out in the "hot mounting" technique.

[0104] The sample holder 100 according to the present invention also allows to prevent any deformation of the surface of the sample 1 or specimen during the resin mounting process (in particular, during the pressing phase of hot mounting); therefore, said sample holder 100 allows to optimize a resin mounting process in the wire coating field. In fact, a sample 1 of a coated wire can be mounted in the resin mount 2 without any deformation of the coating material laid around the wire. Moreover, a sample 1 of coated wire can be embedded into a resin mount 2 according to a predetermined position; in particular, according to the provisions of the present invention, a sample 1 of a coated wire can be mounted according to a predetermined angle between the surface of the cross section of the wire exposed for inspection and the linear direction of the wire.

[0105] Another advantage of the present invention consists in the fact that said sample holder 100 and method 200 allow to reduce the amount of resin needed to embed a sample 1 into a resin mount 2, in particular by means of hot mounting. This is achieved by designing the sample holder 100 according to the present invention so as to match with the shape and / or dimensions of the housing of the mounting machine 300; this way, the final mount comprises a first portion where the sample holder 100 is only partially embedded by any resin and a second portion whereas the sample 1 (extending over the inner hollow 102 of the sample holder 100) is embedded into a resin mount 2. The resulting mount brings about all the benefits of a traditional resin mount (entirely made by resin) but with considerable savings in terms of resin employed.

[0106] A further advantage of the present invention consists in the fact that said sample holder 100 is capable of being employed multiple times over multiple samples 1; in fact, the sample holder 100 according to the present invention can be easily detached from the resin mount 2, in particular when the analyzing phase 260 of the sample 1 is finished.

[0107] The sample holder 100 and the method 200 described herein by way of example may be subject to many possible variations without departing from the novelty spirit of the inventive idea; it is also clear that, in the practical implementation of the invention, the illustrated details may have different shapes or be replaced with other technically equivalent elements.

Claims

CLAIMS1. A sample holder (100) for embedding a sample (1) into a resin mount (2) by means of a mounting machine (300), said sample holder (100) comprising a main frame (101) provided with an inner hollow (102) configured to contain at least a portion of the sample (1), said sample holder (100) being fully containable in a housing (301) of said mounting machine (300), wherein said main frame (101) is configured to partition the housing (301) of the mounting machine (300) into a first portion (301a) and a second portion (301b), and wherein said main frame (101) is further configured to fill said first portion (301a) of the housing (301) when the sample holder (100) is inserted in the mounting machine (300).

2. A sample holder (100) according to claim 1 wherein said main frame (101) is further configured to prevent a resin material (3) to fill said first portion (301a) of the housing (300) when the sample holder (100) is inserted in the mounting machine (300).

3. A sample holder (100) according to one or more of the previous claims, wherein said sample (1) is a wire comprising a first section and a second section, said inner hollow (102) being configured to house said first section of the wire and to allow said second section of the wire to extend over the main frame (101) into said second portion (301b) of the housing (301) of the mounting machine (300).

4. Sample holder (100) according to one or more of the previous claims, characterized in that said main frame (101) has a substantially cylindrical shape and said inner hollow (102) is located substantially at the center of at least one of the bases of the cylindric main frame (101), in particular said inner hollow (102) extending substantially throughout the whole length / height of the main frame (101).

5. Sample holder (100) according to one or more of the previous claims, characterized in that said main frame (101) comprises a first body (101a) and a second body (101b), wherein said first body (101a) and second body (101b) are configured to be combined together to form said main frame (101) and wherein atleast one of said first body (101a) and second body (101b) comprises a slot (102a), (102b) that forms said inner hollow (102).

6. Sample holder (100) according to claim 5, characterized in that it comprises at least one fastening element (110) configured to hold together the first body (101a) and the second body (101b) and / or configured to hold in place the sample (1) when housed in the inner hollow (102).

7. Sample holder (100) according to claim 6, characterized in that at least one of the bases of the main frame (101) comprises at least one superficial groove (103, 104) configured to contain said at least one fastening element (110).

8. Sample holder (100) according to one or more of claims 5 and 6, characterized in that said at least one fastening element (110) is a screw, in particular made of plastic material.

9. Sample holder (100) according to one or more of the previous claims, characterized in that said main frame (101) is made in a plastic material, in particular Teflon®.

10. A system for embedding a sample (1) into a resin mount (2), wherein said system comprises a sample holder (100) according to one or more of claims from 1 to 9 and a mounting machine (300).

11. A method (200) for embedding a sample (1) into a resin mount (2) by means of a sample holder (100) according to one or more of the claims from 1 to 11, in particular a sample (1) of a coated wire, said method (200) comprising the following phases: placing (220) the sample (1) in a housing (301) of a mounting machine (300); covering (230) said sample (1) with a resin material, in particular until filling said housing (301) of the mounting machine (300); creating (240) a rigid resin mount (2) of resin material embedding the sample (1), said method (200) being characterized in that said phase (220) of placing the sample (1) in a housing (301) of a mounting machine (300) is carried out by means of the following steps:inserting (222) the sample (1) in an inner hollow (102) of a main frame (101) of said sample holder 100; placing (224) the sample holder (100), with the sample (1) inserted in the inner hollow (102) of the main frame (101), in said housing (301) of the mounting machine (300).

12. Method (200) according to claim 11, characterized in that said phase (260) of analyzing the sample (1) is followed by a phase (270) of freeing the sample holder (100) from the resin mount (2) in order to reuse said sample holder (100) to create a new resin mount (2) for another sample (1), in particular said phase (270) of freeing the sample holder (100) being performed mechanically by forcing apart the first body (101a) and the second body (101b) of the main frame (101).

Images