A method for detecting microscale irregular surface structures

Abstract

The application relates to the technical field of laser melting forming, in particular to a method for detecting micron-level special-shaped surface structures, which comprises the following steps: step 1, producing standard samples in the same batch in a part processing process, the special-shaped structure size and distribution of the surface of the standard samples are completely consistent with those of other parts; step 2, manufacturing a standard block; step 3, comparing the roughness of the standard sample to be detected and the standard block; step 4, using a three-dimensional profilometer to count the number of special-shaped structures in the standard block specification range at different positions of the standard sample, and comparing the number with that of the standard block; and step 5, according to the comparison results of the roughness and the number of convex structures, determining whether the micron-level special-shaped surface structures meet the design standards. The application has the advantages of reliable principle, strong operability and economy, can effectively detect the effectiveness of the textured structure of an ion thruster discharge chamber part, ensure that the ion thruster discharge chamber can effectively inhibit the peeling of the redundant material film layer, and ensure the reliability of the long-life ion thruster at the end of the service life.

Description

Technical Field

[0001] This application relates to the field of laser melting and forming technology, and more specifically, to a method for detecting micron-scale irregular surface structures. Background Technology

[0002] Spacecraft rely on propulsion systems to achieve functions such as position holding, attitude control, orbit transfer, deep space exploration propulsion, and drag-free control. Electric propulsion directly converts electrical energy into the kinetic energy of the propellant through electrothermal / electrostatic / electromagnetic methods. Space electric propulsion is internationally recognized as the most advanced propulsion technology, significantly reducing the amount of propellant carried. Whether or not electric propulsion is used has become an important indicator of a spacecraft's advancement and competitiveness. Ion thrusters, also known as ion engines, use electrical energy to ionize the propellant and accelerate it out, thereby generating thrust. Ion thrusters are a type of space electric propulsion technology, characterized by low thrust and high specific impulse. They are widely used in space propulsion. Their specific principle involves first ionizing the gaseous propellant, then accelerating and ejecting the ions under a strong electric field. The reaction force propels the satellite for attitude adjustment or orbit transfer missions. Compared to traditional chemical propulsion, ion thrusters require less propellant mass and are the most suitable for long-distance travel among practical propulsion technologies. An ion thruster is a power unit that provides power to a spacecraft. Its performance is measured by thrust, specific impulse, and efficiency. Usually, under the condition of ensuring thrust and specific impulse, efficiency is used to evaluate its performance.

[0003] During operation, the discharge chamber components of the ion thruster are in a plasma environment. Low-potential components in the discharge chamber are sputtered and etched by the plasma, producing excess material. This excess material is deposited inside the discharge chamber to form a film. Once the film reaches a certain thickness, it will fall off and into the discharge chamber, affecting the insulation performance between the thruster electrodes.

[0004] The texturized structure of the discharge chamber can effectively suppress the shedding of the film layer formed by foreign matter in the discharge chamber. However, the textured structure is extremely small and cannot be directly detected by mechanical means. If a method for detecting the effectiveness of the textured structure of the discharge chamber components cannot be summarized, the ability of the textured structure in the discharge chamber to retain foreign matter film layers cannot be guaranteed. Once the textured structure fails, the long-life performance of the thruster will decline, making it unable to complete the on-orbit satellite mission and leading to mission failure. Summary of the Invention

[0005] This application provides a method for detecting micron-level irregular surface structures, which can ensure the effectiveness of micron-level irregular surface structures and improve the lifespan and reliability of thrusters at the end of their lifespan.

[0006] To achieve the above objective, a method for detecting micron-scale irregular surface structures includes the following steps:

[0007] Step 1: Produce standard samples from the same batch during the part processing. The dimensions and distribution of the irregular structures on the surface of the standard samples are completely consistent with those of other parts. Step 2: Fabricate standard blocks. Step 3: Compare the roughness of the standard sample to be tested with that of the standard block. Step 4: Use a three-dimensional profilometer with 50x optical magnification to count the number of irregular structures within the specification range of the standard block at different positions of the standard sample and compare it with the standard block. Step 5: Based on the comparison results of roughness and the number of protrusions, determine whether the micron-level irregular surface structure meets the design standard.

[0008] Furthermore, in step 1, the height of the irregular structure on the surface of the standard sample is 150-250 μm, and the spacing between the structures is 200 μm. u m.

[0009] Furthermore, in step 2, the standard block is a sample with an irregular surface structure that has been experimentally verified.

[0010] Furthermore, in step 2, the material of the standard block is the same as the material of the standard sample to be tested.

[0011] Furthermore, in step 2, the standard block has a size of 10mm × 10mm and a thickness of 0.5mm.

[0012] Furthermore, in step 3, when comparing the roughness of the standard sample to be tested with that of the standard block, the roughness evaluation parameter adopts the profile arithmetic mean deviation.

[0013] Furthermore, in step 4, when comparing the number of protrusions, the error is ≤ ±10.

[0014] The present invention provides a method for detecting micron-scale irregular surface structures, which has the following beneficial effects:

[0015] This application is based on a reliable principle, is highly operable, and economical. It can effectively detect the effectiveness of the textured structure of the discharge chamber components of the ion thruster, ensuring that the discharge chamber of the ion thruster can effectively suppress the shedding of the foreign matter film layer and ensure the reliability of the long-life ion thruster at the end of its life. Attached Figure Description

[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0017] Figure 1 This is a schematic diagram of an ion thruster application component provided according to an embodiment of this application;

[0018] Figure 2This is a schematic diagram of the micron-scale irregular surface structure to be detected according to an embodiment of this application;

[0019] Figure 3 This is a schematic diagram of the structure of a standard block provided according to an embodiment of this application; Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0023] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0024] In addition, the term "multiple" should mean two or more.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] like Figure 1-3 As shown in the embodiments of this application, the method for detecting micron-scale irregular surface structures includes the following steps:

[0027] Step 1: During the part processing, produce standard samples of the same batch. The dimensions and distribution of the irregular structure on the surface of the standard sample are completely consistent with those of other parts.

[0028] Step 2: Create standard blocks;

[0029] Step 3: Compare the roughness of the standard sample to be tested with that of the standard block;

[0030] Step 4: Using a three-dimensional profilometer with 50x optical magnification, count the number of irregular structures within the specification range of the standard block at different positions of the standard sample, and compare them with the standard block.

[0031] Step 5: Based on the comparison results of roughness and the number of protrusions, determine whether the micron-scale irregular surface structure meets the design standards.

[0032] Specifically, the discharge chamber of the long-life ion thruster is composed of 3D-printed titanium alloy parts, a grid cylinder, and an anode cylinder. The overall parts and the textured structure of their inner surfaces are fabricated using selective laser melting. The textured structure of the inner surface consists of an array of micron-sized irregular surface structures, with a minimum of 400,000 irregular structures per part, making direct detection impossible. The method for detecting micron-sized irregular surface structures provided in this application involves setting up a standard block of experimentally verified irregular surface structures and comparing the roughness and number of protrusions between the sample to be tested and the standard block, thereby determining whether the micron-sized irregular surface structure meets the design standards.

[0033] Furthermore, in step 1, the height of the irregular structure on the surface of the standard sample is 150-250 μm, and the spacing between the structures is 200 μm. Since the minimum gap between the electrodes inside the ion thruster is 1 mm, to ensure that the deposits falling off between the irregular surface structures will not affect the insulation between the electrodes, and considering the ability of the irregular structure parts to accommodate deposits, the height of the irregular structure of the parts is designed to be 150-250 μm, the spacing between the structures is 200 μm, and the size of the standard sample is 40 mm × 40 mm. According to different design requirements, the dimensions of the irregular structure of the parts and the test can be adjusted.

[0034] Furthermore, in step 2, the standard block is a sample with an irregular surface structure that has been experimentally verified.

[0035] Furthermore, in step 2, the material of the standard block is the same as the material of the standard sample to be tested.

[0036] Furthermore, in step 2, the standard block has a size of 10mm × 10mm and a thickness of 0.5mm.

[0037] Specifically, the standard block is a standard sample that has been actually tested and whose number and shape of irregular structures per unit area meet the design requirements in step 1. The material of the standard block is exactly the same as the material grade of the standard sample to be tested, and the thickness of the standard block is the same as the thickness of the part and the accompanying furnace sample. At the same time, since the size of the irregular structure is too small, in order to improve the testing efficiency of the part, the standard block is preferably 10mm×10mm.

[0038] Furthermore, in step 3, when comparing the roughness of the standard sample to be tested and the standard block, the roughness evaluation parameter adopts the profile arithmetic mean deviation. If the roughness of the standard sample to be tested and the standard block are within ±2μm, they are considered qualified.

[0039] Furthermore, in step 4, when comparing the number of protruding structures, the error must be ≤ ±10. In this embodiment, a three-dimensional profilometer with 50x optical magnification is used to count the number of irregular structures at different locations (10mm × 10mm, i.e., within the standard block size range) of the standard sample, totaling 3 locations. When comparing the number of irregular structures, the error must be ≤ ±10. When the number of irregular structures at all 3 locations meets the tolerance requirements, the distribution of irregular structures meets the design requirements. If the statistical data at any one location exceeds the tolerance, it indicates that the distribution of irregular structures does not meet the design requirements, meaning that the part's ability to suppress the shedding of excess material or its ability to contain deposits is insufficient, and the part is unqualified.

[0040] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for detecting micron-scale irregular surface structures, characterized in that, Includes the following steps: Step 1: During the part processing, produce standard samples of the same batch. The dimensions and distribution of the irregular structure on the surface of the standard sample are completely consistent with those of other parts. The height of the irregular structure on the surface of the standard sample is 150-250 μm, and the spacing between the structures is 200 μm. Step 2: Create standard blocks; The standard block is a specimen with an irregular surface structure that has been tested and verified. The material of the standard block is the same as the material of the standard sample to be tested. The standard block has dimensions of 10mm × 10mm and a thickness of 0.5mm; Step 3: Compare the roughness of the standard sample to be tested with that of the standard block; When comparing the roughness of the standard sample to be tested with that of the standard block, the roughness evaluation parameter is the profile arithmetic mean deviation. Step 4: Using a three-dimensional profilometer with 50x optical magnification, count the number of irregular structures within the specification range of the standard block at different positions of the standard sample, and compare them with the standard block. When comparing the number of protruding structures, the error is ≤ ±10; Step 5: Based on the comparison results of roughness and the number of protrusions, determine whether the micron-scale irregular surface structure meets the design standards.

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