Component manufacturing and external inspection

Abstract

A method is provided that includes providing a preform part (20). The preform part includes a blind opening (36) on an exterior of the preform part. The exterior of the preform part is machined to obtain a machined part (64). The exterior of the machined part is inspected to determine a characteristic of the machined part. The characteristic of the machined part is related to the blind opening. A determination is made whether a characteristic of the machined part meets a criterion based on the characteristic of the machined part.

Description

Technical Field

[0001] (Reference to Related Applications) This application claims priority to U.S. Patent Application No. 17 / 204,556, filed on March 17, 2021, which is hereby incorporated by reference in its entirety. (Technical Field) The present disclosure generally relates to the manufacture and inspection of components having one or more internal features.

Background Art

[0002] Liquid flow-through cooling plates include one or more internal passages. During manufacture, a cooling plate preform may be formed using one or more known manufacturing techniques. This cooling plate preform may include one or more defects on the outside of the preform. To remove these defects, one or more surfaces of the cooling plate preform may be machined flat. However, depending on the type and size of the defect, such machining may cause one or more sidewall materials of the internal passages to become overly thin or be completely removed, thereby rendering the cooling plate unusable. To identify excessive machining, an inspection process such as a computed tomography (CT) scan may be performed on the cooling plate to identify the location of the internal passages within the cooling plate and / or measure the thickness of the sidewalls of the cooling plate. However, such inspection processes can be costly and / or time-consuming.

[0003] In the art, there is a need for improved methods for manufacturing and inspecting components having one or more internal features.

Summary of the Invention

[0004] According to an aspect of the present disclosure, a manufacturing method is provided. During this method, a preform part is prepared. The preform part includes a blind opening on the outside of the preform part. The outside of the preform part is machined to obtain a machined part. The outside of the machined part is inspected to determine the characteristics of the machined part associated with the blind opening. It is determined whether the characteristics of the machined part meet the criteria based on the characteristics of the machined part.

[0005] According to another aspect of the present disclosure, another manufacturing method is provided. During this method, a preform part is provided. The preform part includes an opening, a preform outer surface, and an opening end face. The opening extends into the preform part from the preform outer surface to the opening end face. The preform part is machined to obtain a machined part with a machined outer surface. The machined part includes a part of the opening. A part of the opening extends into the machined part from the machined outer surface to the opening end face. The distance from the machined outer surface to the opening end face is measured. It is determined whether the characteristics of the machined part meet the criteria based on the distance from the machined outer surface to the opening end face.

[0006] According to still another aspect of the present disclosure, another manufacturing method is provided. During this method, a preform part is provided. The preform part includes an inspection feature part. The outside of the preform part is machined to obtain a machined part. The machined part is visually inspected to determine the characteristics of the machined part related to the inspection feature part. It is determined whether the invisible features of the machined part meet the criteria based on the characteristics of the machined part.

[0007] The inspection feature part may be configured as an opening or a protrusion, or may include an opening or a protrusion in other cases.

[0008] The preform part may be additively manufactured. The preform outer surface may be a non-planar outer surface. The machined outer surface may be a planar outer surface.

[0009] The feature of the machined part may be the distance from a passage within the machined part to the machined outer surface.

[0010] The characteristic of the machined part may be the presence of at least a part of a blind opening in the machined part.

[0011] Determining may include determining whether the feature of the machined part meets the criteria when the machined part includes at least a part of a blind opening.

[0012] Determining may include determining that the feature of the machined part does not meet the criteria when the machining of the preform part completely removes the blind opening.

[0013] The machined part may include at least a part of a blind opening. The characteristic of the machined part may be the depth of at least a part of the blind opening.

[0014] Determining may include determining that the feature of the machined part meets the criteria when the depth of at least a part of the blind opening included in the machined part is greater than or equal to a certain value.

[0015] Determining may include determining that the feature of the machined part does not meet the criteria when the depth of at least a part of the blind opening included in the machined part is less than a certain value.

[0016] The feature of the machined part may be the dimension of the machined part.

[0017] The feature of the machined part may be the thickness of the side wall of the machined part.

[0018] The feature of the machined part may be the distance between a passage within the machined part and the outer surface of the machined part.

[0019] Preparing the preform part may include additive manufacturing of the preform part.

[0020] Machining may include machining the outer surface of the preform of the preform part to provide a machined outer surface to the machined part. At least a part of the blind opening may extend from the machined outer surface into the machined part.

[0021] The preform outer surface may be a non-planar outer surface. In addition or alternatively, the machined outer surface may be a planar outer surface.

[0022] The machined part may include at least a part of the blind opening, the opening end face, and the internal passage. At least a part of the blind opening may extend vertically in the machined part to the opening end face. The side surface of the internal passage may be aligned in a direction perpendicular to the opening end face.

[0023] The machined part may include at least a part of the blind opening, the opening end face, and the internal passage. At least a part of the blind opening may extend vertically in the machined part to the opening end face. The side surface of the internal passage may be offset in a direction perpendicular to the opening end face.

[0024] The machined part may be configured as a heat exchanger or may be a part of a heat exchanger.

[0025] The blind opening may be configured as a stepped opening or may include a stepped opening in other cases.

[0026] This disclosure may include any one or more of the individual features disclosed above and / or below, alone or in any combination thereof.

[0027] The foregoing features and operations of the present invention will become more apparent in view of the following description and the accompanying drawings.

Brief Description of the Drawings

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DETAILED DESCRIPTION OF THE INVENTION

[0047] The present disclosure includes a method for manufacturing a component with one or more internal features. Each of these internal features is partially or fully disposed inside the manufactured component. Thus, the internal features may not be visible from the outside of the manufactured component and / or may not be easily accessible for inspection. Accordingly, the manufacturing method of the present disclosure may include techniques / processes for inspecting and / or obtaining information associated with the internal features from the outside of the manufactured component without, for example, requiring costly and / or time-consuming imaging processes (such as X-ray scans, computed tomography (CT) scans, etc.).

[0048] FIG. 1 is a flowchart of a method 1000 for manufacturing a component with at least one internal feature. For simplicity of explanation, the manufactured component is hereinafter described as a heat exchanger, and the internal feature is hereinafter described as an internal passage. Examples of heat exchangers include, but are not limited to, heat exchanger plates (e.g., liquid flow-through cold plates), heat spreaders, radiators, and sections / modules of modular heat exchangers. The heat exchanger can be configured as a liquid-to-liquid heat exchanger, a gas-to-liquid heat exchanger, and / or a gas-to-gas heat exchanger. However, the present disclosure is not limited to the manufacture of such typical heat exchangers or to their use. For example, in other embodiments, the manufacturing method 1000 may be performed to manufacture a fluid container (e.g., a tank) or a fluid conduit. Also, the present disclosure is not limited to embodiments in which the internal feature is an internal passage. For example, in other embodiments, the internal feature may alternatively be an internal cavity, an internal core, a part of the manufactured component with different porosities and / or densities, or any other type of volume and / or element that is at least partially or completely disposed within the manufactured component, or that includes these. Such manufactured components can be used for various applications, such as, without limitation, mobile devices (e.g., land vehicles, ships, aircraft, spacecraft, projectiles, missiles, etc.), sensor systems, communication systems, and control systems.

[0049] In step 1002, a preform 20 of the manufactured component is provided. A schematic perspective view of the preform component 20 is illustrated in FIG. 2. This preform component 20 has on the outside opposing longitudinal sides 22 and 24, opposing transverse sides 26 and 28, and opposing vertical sides 30 and 32. The preform component 20 extends longitudinally (e.g., along the x-axis) between the longitudinal sides 22 and 24. The preform component 20 extends transversely (e.g., along the y-axis) between the transverse sides 26 and 28. The preform component 20 extends vertically (e.g., along the Z-axis) between the vertical sides 30 and 32.

[0050] The preform part 20 of FIG. 2 includes at least one internal passage 34 (internal feature), and the ends of the passage 34 are visible in FIG. 2. Also, the preform part 20 of FIG. 2 includes at least one inspection opening 36 (e.g., recess, groove, channel, notch, dimple, etc.).

[0051] Referring to FIG. 3, the internal passage 34 can have an inlet 38 and an outlet 40. The internal passage 34 of FIG. 3 extends within the preform part 20 along the centerline 42 of the internal passage 34 between the inlet 38 and the outlet 40. The internal passage 34 and its centerline 42 may include one or more straight portions 44-46. The internal passage 34 and its centerline 42 may further or alternatively include one or more non-straight portions 48 and 50 (e.g., curved portions, arched portions, serpentine portions, meandering portions, etc.). Thereby, the internal passage 34 and its centerline 42 may follow a serpentine trajectory within the preform part 20 (see also FIG. 12). However, the present disclosure is not limited to such typical internal passage configurations.

[0052] Referring to FIG. 4, the inspection opening 36 may be configured as a blind opening. The inspection opening 36 of FIG. 4 extends partially into the preform part 20, for example, from the preform outer surface 52 of the preform part 20 to the opening end face 54 of the preform part 20. The preform outer surface 52 of FIG. 4 is disposed on (e.g., on, adjacent to, or proximate to) the second vertical side surface 32 of the preform part 20. The opening end face 54 is disposed vertically between the vertical side surfaces 30 and 32 of the preform part 20. The opening end face 54 is disposed at a vertical distance 56 away from the preform outer surface 52 (e.g., along the Z-axis). This vertical distance 56 defines the vertical depth of the inspection opening 36 within the preform part 20.

[0053] The preform component 20 may be formed by additive manufacturing using an additive manufacturing apparatus. The term "additive manufacturing" may describe a process in which one or more components are formed by the accumulation and / or fusion of materials together, usually in an alternating layer method. For example, layers of powder material are placed and then sequentially solidified with each other to form the component(s). The term "solidify" is used herein to describe the process in which the material is sintered and / or otherwise melted so that separate particles or droplets of the sintered and / or melted material fuse together. Examples of additive manufacturing processes include the laser powder bed fusion (LPBF) process and the electron beam powder bed fusion (EB-PBF) process. Examples of additive manufacturing apparatuses include the laser powder bed fusion (LPBF) device and the electron beam powder bed fusion (EB-PBF) device. Of course, various other additive manufacturing processes and devices are known in the art, and the present disclosure is not limited to any particular one of them. Further, the present disclosure is not limited to the additive manufacturing formation process. For example, the preform component 20 may be formed further or alternatively by casting and / or machining.

[0054] The preform part 20 may include one or more defects. The term "defect" may describe an artifact from the preform part forming process that can be addressed (e.g., removed and / or otherwise modified) in subsequent step(s) of the manufacturing method 1000. For example, when the preform part 20 is additive manufactured, one or more or all of the layers of material forming the preform part 20 may be exposed to a non-uniform temperature difference, either separately or collectively, throughout. For example, referring to FIG. 5, the end 58 of the newly solidified layer 60 may cool faster than, for example, the middle / central portion(s) 62 of the newly solidified layer 60. This non-uniform cooling may cause the newly formed layer 60 to distort (e.g., cup, "potato chip", etc.). Thus, the preform outer surface 52 of FIGS. 2 and 4 may have a non-planar (e.g., non-flat) geometric shape. The preform outer surface 52 may be, for example, a curved (e.g., cup-shaped) or wavy outer surface. Of course, the preform part 20 may further or alternatively include various other types of defects.

[0055] In step 1004, the preform part 20 is machined to obtain a machined part 64 (see FIG. 6). At least a portion (or all) of the preform outer surface 52 (see FIG. 2) is, for example, face milled, milled, and / or otherwise machined to provide the machined part 64 with a machined outer surface 52' at the second vertical side surface 32' (see FIG. 6). This machined outer surface 52' may have a planar geometric shape. The machined outer surface 52' of FIG. 6 is, for example, a flat outer surface. Thereby, the machining step 1004 may remove the curvature and / or waviness of the outer surface from the preform part 20 (e.g., remove artifact(s) of the forming process). Of course, one or more additional portions of the preform part 20 (e.g., one or more of the surfaces at the sides 22, 24, 26, 28, and / or 30) may also be at least partially or fully machined to obtain the machined part 64.

[0056] The machined part 64 in FIG. 6 may include at least a part (or all) of the inspection openings 36 from the preform part 20. FIG. 7A illustrates an embodiment in which the machined part 64 includes all of the inspection openings 36. FIGS. 7B and 7C illustrate embodiments in which the machined part 64 includes a part of the inspection openings 36.

[0057] In step 1006, the outside of the machined part 64 is inspected. Referring to FIG. 8, this inspection is performed to determine at least one (e.g., external) characteristic of the machined part 64 associated with / related to the inspection opening 36.

[0058] The inspection opening characteristic may be whether all or at least a part of the inspection opening 36 still exists within the machined part 64. The presence (or absence) of the inspection opening 36 within the machined part 64 may be determined, for example, via a visual inspection of the outside of the machined part 64, more particularly its machined outer surface 52'. This visual inspection may be performed manually (e.g., via the human eye) by a human inspector. The visual inspection may also or alternatively be performed using an inspection system (e.g., an automatic camera inspection system). However, the manufacturing method 1000 is not limited to the typical visual inspection techniques described above.

[0059] The inspection opening characteristic may also or alternatively be the dimension 56' (e.g., vertical depth) of the inspection opening 36 (e.g., the remaining inspection opening portion) within the machined part 64 (or indicative thereof). The dimension 56' of the remaining inspection opening 36 within the machined part 64 may be determined using a manual inspection device (e.g., a set of measuring calipers). The dimension 56' of the inspection opening 36 may also or alternatively be determined using an inspection system, e.g., an automatic contact or non-contact inspection system. This may be, but is not limited to, a coordinate measuring machine (CCM) or an (e.g., white or blue) optical measuring system. However, the manufacturing method 1000 is not limited to the typical dimension inspection techniques described above.

[0060] In step 1008, it is determined whether at least one feature of the machined part 64 meets or does not meet a (for example, design and / or manufacturing) standard. The determination of whether the feature meets the standard may be made based on the inspection opening characteristics of the machined part 64.

[0061] The feature of the machined part may be a dimension or other internal characteristic of the machined part 64. For example, the feature may be the thickness 68 of the side wall 70 of the machined part 64, or alternatively, may indicate or be related to the thickness 68 of the side wall. The side wall 70 in FIG. 8 extends vertically between the machined outer surface 52' and the peripheral boundary 72 of the internal passage 34 and at least partially forms it. The thickness 68 of the side wall may be measured as the (for example, shortest and / or vertical) vertical distance from the machined outer surface 52' to the internal passage 34 and its peripheral boundary 72. However, the manufacturing method 1000 is not limited to the typical features of the machined parts described above.

[0062] The features of the machined part are related to the inspection opening 36. For example, the inspection opening 36 may be spatially arranged at a known position close to the internal passage 34 (internal feature). Also, the inspection opening 36 may be configured (e.g., size, arrangement, etc.) to provide information regarding the internal passage 34 (internal feature). For example, referring to FIG. 9A, the opening end face 54 may be aligned perpendicular to (e.g., along the Z-axis) the peripheral boundary 72 (e.g., vertical side face) of the internal passage 34 (internal feature). Alternatively, referring to FIG. 9B, the opening end face 54 may be offset vertically (along the Z-axis) by a known vertical distance 74 from the peripheral boundary 72 (e.g., side face) of the internal passage 34 (internal feature). The opening end face 54 of FIG. 9B is arranged vertically (along the Z-axis) between, for example, the peripheral boundary 72 (e.g., side face) of the internal passage 34 and the machined outer surface 52'. By arranging the opening end face 54 (e.g., referring to FIGS. 9A or 9B) at a known (e.g., perpendicular) position with respect to the internal passage 34 (internal feature) and its peripheral boundary 72 (e.g., side face), the position of the peripheral boundary 72 (e.g., side face) can be determined by knowing the depth of the inspection opening 36 within the machined part 64. Thus, information regarding the internal passage 34 (internal feature) can be determined by inspecting the outside of the machined part 64 without using, for example, costly and / or time-consuming imaging processes (e.g., X-ray scan, computed tomography (CT) scan, etc.).

[0063] If the machined part 64 includes the entire (or at least a part of) the inspection opening 36, it may be determined that sufficient material still exists between the internal passage 34 (internal feature) and the machined outer surface 52'. For example, since the entire (or at least a part of) the inspection opening 36 exists, it can be determined that the thickness 68 of the side wall is within the reference specifications. Accordingly, the machined part 64 may be identified / classified as meeting the criteria (e.g., conforming to the design tolerance / within the design tolerance). However, if the machined part 64 includes only a part of the inspection opening 36 or does not include the inspection opening 36 at all, it may be determined that the material existing between the internal passage 34 (internal feature) and the machined outer surface 52' is insufficient. For example, since only a part of the inspection opening 36 exists or does not exist at all, it can be determined that the thickness 68 of the side wall is outside the reference specifications. Accordingly, the machined part 64 may be identified / classified as not meeting the criteria.

[0064] If the depth of the inspection opening 36 within the machined part 64 is measured to be equal to or greater than a (e.g., predetermined design) value, it may be determined that sufficient material still exists between the internal passage 34 (internal feature) and the machined outer surface 52'. Accordingly, the machined part 64 may be identified / classified as meeting the criteria. However, if the depth of the inspection opening 36 within the machined part 64 is measured to be less than a (e.g., predetermined design) value, it may be determined that sufficient material does not exist between the internal passage 34 (internal feature) and the machined outer surface 52'. Accordingly, the machined part 64 may be identified / classified as not meeting the criteria.

[0065] In step 1010, the machined part 64 is marked and / or otherwise identified as meeting or not meeting the criteria. If the machined part 64 meets the criteria, the machined part 64 is identified for further downstream processing (e.g., further machining, finishing, and / or assembly). If the machined part 64 does not meet the criteria, the machined part 64 is identified for other processing (e.g., rework and / or disposal).

[0066] The machined part 64 may be identified by applying a marking (e.g., writing, label, etc.) on the machined part 64. The machined part 64 may also or alternatively be identified by placing the machined part 64 in an individual storage location, placing the machined part 64 on an individual shelf, etc. However, the manufacturing method 1000 is not limited to the aforementioned typical identification (e.g., marking) techniques.

[0067] Referring to FIG. 10A, one or more or all of the inspection openings 36 may have a circular cross-sectional shape, for example, when viewed perpendicular to the center line 76 of an individual inspection opening 36. Referring to FIGS. 10B and 10C, one or more or all of the inspection openings 36 may also or alternatively have a non-circular cross-sectional shape, for example, when viewed perpendicular to the center line 76 of an individual inspection opening. For example, the cross-sectional shape of the inspection opening may be substantially or exactly oval, elliptical, or polygonal (e.g., square, rectangular, etc.). However, the present disclosure is not limited to the aforementioned typical inspection opening configurations.

[0068] In some embodiments, referring to FIG. 4, the inspection opening 36 may be configured with a uniform depth (e.g., vertical distance 56). More specifically, the inspection opening 36 may extend vertically within the preform part 20 to a single opening end face 54.

[0069] In some embodiments, referring to FIGS. 11 and 12, one or more or all of the inspection openings 36 may be configured with varying depths (e.g., stepped depths). The inspection opening 36 of FIG. 12 is configured, for example, as a stepped opening. This inspection opening 36 extends vertically within the preform part 20 to a plurality of opening end faces 54A - C. The first end face 54A is disposed at a first vertical distance 56A (e.g., uniform) from the preform outer surface 52. Thus, a first rising face 55A extends vertically between the preform outer surface 52 and the first end face 54A. The second end face 54B is disposed at a second vertical distance 56B (e.g., uniform) from the preform outer surface 52. The second vertical distance 56B is longer than the first vertical distance 56A. Thus, a second rising face 55B extends vertically between the first and second end faces 54A and 54B. The third end face 54C is disposed at a third vertical distance 56C (e.g., uniform) from the preform outer surface 52. The third vertical distance 56C is longer than the second vertical distance 56B. Thus, a third rising face 55C extends vertically between the second and third end faces 54B and 54C.

[0070] Each of the opening end faces 54A, 54B, 54C may be associated with a corresponding attribute. For example, if all of the opening end faces 54A - C are present (e.g., visible) after the machining step 1004, the machined part may be determined to meet the criteria. If each of the opening end faces 54B and 54C are present (e.g., visible) after the machining step 1004, the machined part may also be determined to meet the criteria. It should be noted that if each of the opening end faces 54B and 54C are still present, a part of the step 57A that defined the original opening end face 54A and the rising face 55B may still be present. The presence of at least a part of this step 57A / rising face 55B may indicate that the surface 54B is in its original shape. If a part of the step 57B that defined the original opening end face 54B and the rising face 55C is machined and removed during the machining step 1004, the machined part may be determined not to meet the criteria. However, the present disclosure is not limited to the foregoing typical end face / step attribute assignments.

[0071] In some embodiments, referring to FIGS. 13 and 14, one or more or all of the inspection openings 36 may be respectively disposed within the raised portions of the preform part 20. The inspection openings 36 of FIGS. 13 and 14 are arranged, for example, within a raised rim portion 59 that partially or completely extends around the outer peripheral portion of the preform part 20. The machined part may be inspected using the inspection openings 36 within the raised rim portion 59 using the method 1000 described above. And following the inspection step 1006, the (for example, remaining / unmachined portion of) the raised rim portion 59 may be left or machined and removed.

[0072] In FIGS. 15 and 16, a machined part 64 (manufactured part) is illustrated as a heat exchanger plate 78 (for example, a cooler plate). This machined part 64 includes a plurality of inspection openings 36 at various locations along the machined outer surface 52'. Each of these inspection openings 36 is configured to provide information about individual portions of one or more internal passages 34 (internal features) within the machined part 64, as described above.

[0073] Referring to FIG. 17, one or more additional parts 80 (for example, electronic devices) may be attached to the machined part 64. The additional parts 80 may be attached, for example, to the machined outer surface 52'.

[0074] Referring to FIG. 18, a plurality of machined parts 64 may be assembled to provide a heat exchanger system 82 or otherwise arranged together. However, the present disclosure is not limited to such a typical heat exchanger system or to the manufacture of heat exchange parts as described above.

[0075] In some embodiments, referring to FIG. 19, one or more of all the inspection openings 36 may be replaced with inspection protrusions 36', respectively. This inspection protrusion 36' may be essentially the opposite of the aforementioned inspection opening 36. The inspection protrusion 36' may be, for example, a rib, pedestal, step, or any other protrusion having one or more (e.g., known) criteria (e.g., geometric shape, dimensions, etc.). The inspection protrusion 36' in FIG. 19 protrudes vertically by a known vertical distance 56' from the outer surface 52 of the preform to the distal end surface 54' of each individual inspection protrusion 36'. This inspection protrusion 36' may be used in method 1000 in a manner similar to the inspection opening 36. For example, if at least a part of this inspection protrusion 36' remains after the machining step 1004, it may be determined that the machined part meets the criteria. Of course, following the inspection step 1006, the inspection protrusion 36' may be completely removed from the machined part.

[0076] Although various embodiments of the present disclosure have been described, as will be apparent to those skilled in the art, many more embodiments and implementation modes are possible within the scope of the present disclosure. For example, the disclosure described herein includes several aspects and embodiments including specific features. These features may be described individually, but it is within the scope of the present disclosure that some or all of these features may be combined with any one of the aspects and remain within the scope of the present disclosure. Therefore, the present disclosure should not be limited except when considering the appended claims and their equivalents.

Claims

Step 1: Prepare a preform part, wherein the preform part includes a blind opening on the outside of the preform part, and prepare the preform part; Step 2: Machine the outside of the preform part to obtain a machined part; Step 3: Inspect the outside of the machined part to determine the characteristics of the machined part, wherein the characteristics of the machined part include the presence of at least a part of the blind opening in the machined part or the depth of at least a part of the blind opening, and determine the characteristics of the machined part; Step 4: Determine whether the internal features of the machined part meet the design or manufacturing criteria based on the characteristics of the machined part. The manufacturing method includes the above steps. Manufacturing method. Claim 2 The determination in step 4 includes determining that the internal features of the machined part meet the criteria when the machined part includes at least a part of the blind opening. The method according to claim 1. Claim 3 The determination in step 4 includes determining that the internal features of the machined part do not meet the criteria when the machining of the preform part completely removes the blind opening. The method according to claim 1. Claim 4 The determination in step 4 includes determining that the internal features of the machined part meet the criteria when the depth of at least a part of the blind opening included in the machined part is greater than or equal to a certain value. The method according to claim 1. Claim 5 The determination in step 4 includes determining that the internal features of the machined part do not meet the criteria when the depth of at least a part of the blind opening included in the machined part is less than a certain value. The method according to claim 1. Claim 6 The internal features of the machined part include the dimensions of the machined part. The method according to claim 1. Claim 7 The internal features of the machined part include the thickness of the side wall of the machined part. The method according to claim 1. Claim 8 The internal features of the machined part include the distance between the passage in the machined part and the outer surface of the machined part. The method according to claim 1. Claim 9 The step of preparing the preform part in step 1 includes additive manufacturing of the preform part. The method according to claim 1. Claim 10 Said machining includes machining the preform outer surface of the preform part to provide a machined outer surface to the machined part, At least a part of said blind opening extends from said machined outer surface into the machined part, the method according to claim 1.

11. Said preform outer surface is a non-planar outer surface, or At least one of said machined outer surfaces is a planar outer surface, The method according to claim 10.

12. Said machined part includes at least a part of said blind opening, an opening end face, and an internal passage, Said at least a part of said blind opening extends vertically from the outside of said preform part into the machined part up to said opening end face, The side surface of said internal passage is aligned in a direction perpendicular to said opening end face, The method according to claim 1.

13. Said machined part includes at least a part of said blind opening, an opening end face, and an internal passage, Said at least a part of said blind opening extends vertically from the outside of said preform part into the machined part up to said opening end face, The side surface of said internal passage is displaced in a direction perpendicular to said opening end face, The method according to claim 1.

14. Said blind opening includes a stepped opening, the method according to claim 1.

15. Preparing a preform part, wherein said preform part includes an opening, a preform outer surface, and an opening end face, said opening extending from said preform outer surface into said preform part up to said opening end face, preparing said preform part, Machining said preform part to obtain a machined part with a machined outer surface, said machined part including a part of said opening, said part of said opening extending from said machined outer surface into said machined part up to said opening end face, machining said preform part, Measuring the distance from said machined outer surface to said opening end face, Determining whether the internal features of said machined part meet the criteria for design or manufacture based on said distance from said machined outer surface to said opening end face, Manufacturing method.

16. Said preform part is additive manufactured, Said preform outer surface is a non-planar outer surface, The machined outer surface is a flat outer surface. The method according to claim 15. **Claim 17** The method according to claim 15, wherein the internal feature of the machined part indicates the distance from a passage in the machined part to the machined outer surface. **Claim 18** Providing a preform part, wherein the preform part includes an inspection feature part, and the inspection feature part includes an opening or a protrusion, providing the preform part; machining the outside of the preform part to obtain a machined part; visually inspecting the machined part to determine the characteristics of the machined part, wherein the characteristics of the machined part include the presence of at least a part of the opening or the protrusion or the depth of at least a part of the opening or the protrusion in the machined part, determining the characteristics of the machined part; determining whether an invisible internal feature of the machined part meets the criteria of design or manufacture based on the characteristics of the machined part. Manufacturing method.

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