A method for improving the interface strength of cold spray additives and a method for extending shaft parts
By performing multiple processing and cold spraying on the cold spray additive interface, the problems of cracks and peeling inside the coating are solved, and the interface strength and service life of the components are improved.
Patent Information
- Application Number
- CN202211240701.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-11
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2042-10-11
AI Technical Summary
In the existing cold spraying technology, cracks or peeling are prone to occur inside the coating, resulting in thermal damage to the parts, thick tissue, and degradation of performance.
By performing primary processing of the additive interface of the parts to be processed to increase the area, secondary processing to increase the roughness, and cold spraying is performed on the interface after secondary processing, adjusting the cold spraying angle to ensure that the jet direction is parallel to the direction of the extension of the texture. Finally, the coating is processed overall to improve interface strength.
It effectively improves interface strength, extends the service life of parts, avoids cracks and peeling inside the coating, and improves load bearing capacity.
Smart Images
Figure CN115747784B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of cold spraying technology, and in particular to a method for improving the interface strength of cold spraying additives and a method for extending shaft parts. Background Art
[0002] At present, cold spray technology has the characteristics of unlimited coating thickness and high additive efficiency. It has the potential to be widely used in aerospace, steel, petroleum, ocean, military and other fields. It has gradually developed into a rapid additive manufacturing technology and has attracted much attention from the industry. The interface is the bonding area between the substrate and the reinforcement. The coating interface strength is one of the important indicators for evaluating the coating quality. The strength of the interface strength will directly affect the service safety and life of equipment parts.
[0003] In the related technology, the method to improve the interface bonding strength is to use remelting technology to process the formed coating, but this method has some defects. The uneven heat distribution during remelting will induce residual stress and produce cracks inside the coating. In severe cases, the coating may peel off. Some materials are sensitive to high temperatures, and high-temperature remelting will cause thermal damage to the parts, resulting in coarse structure and reduced performance. Summary of the invention
[0004] The embodiments of the present invention provide a method for improving the interface strength of cold spray additives and a method for extending shaft parts to solve the problems in the related art of cracks or even peeling off inside the coating, and thermal damage to the parts resulting in coarse structure and reduced performance.
[0005] In a first aspect, a method for improving the strength of a cold spray additive interface is provided, which comprises the following steps: performing a primary processing on the additive interface of a part to be processed to increase the area of the additive interface; performing a secondary processing on the additive interface to improve the roughness of the additive interface; and cold spraying the additive interface after the secondary processing.
[0006] In some embodiments, the processing of the additive interface includes: increasing the area of the additive interface by changing the angle of the additive interface.
[0007] In some embodiments, before the additive interface is processed once, the method further includes: determining the angle at which the additive interface needs to be changed according to the stress characteristics of the part to be processed.
[0008] In some embodiments, the secondary processing of the additive interface includes: processing lines on the additive interface, and the extension direction of the lines is perpendicular to the axis of the part to be processed.
[0009] In some embodiments, before cold spraying the additive interface after secondary processing, it also includes: adjusting the cold spraying angle so that the jet direction of the cold spraying is parallel to the extension direction of the texture.
[0010] In some embodiments, after cold spraying the additive interface after secondary processing, the method further includes: integrally processing the outside of the coating, and the processing direction is parallel to the force direction of the part to be processed.
[0011] In a second aspect, a method for extending shaft parts is provided, which comprises: performing a primary processing on the end of the part to be processed and forming a conical surface to increase the area of the additive interface; performing a secondary processing on the conical surface to improve the roughness of the conical surface; and performing cold spraying on the conical surface after the secondary processing.
[0012] In some embodiments, the secondary processing of the conical surface includes: processing threads on the conical surface, and the extension direction of the threads is perpendicular to the axis of the part to be processed.
[0013] In some embodiments, before cold spraying the conical surface after secondary processing, the method further includes: adjusting the cold spraying angle so that the jet direction of the cold spraying is parallel to the extension direction of the thread.
[0014] In some embodiments, the exterior of the coating is processed as a whole based on the original outer cylindrical surface of the part to be processed, and the processing direction is parallel to the force direction of the part to be processed.
[0015] The beneficial effects brought about by the technical solution provided by the present invention include:
[0016] The embodiments of the present invention provide a method for improving the strength of a cold spray additive interface and a method for extending shaft parts. Since the additive interface is mainly used to transfer loads and will be subject to shear force, the area of the additive interface is increased and the roughness of the additive interface is improved through secondary design of the additive interface, which can effectively improve the bearing capacity of the interface and thereby improve the interface strength. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0018] Figure 1 The present invention is a flow chart of the method for improving the interface strength of cold spray additives.
[0019] Figure 2 It is a schematic diagram of the structure of the additive interface of the shaft parts extension method of the present invention after one-time processing;
[0020] Figure 3It is a schematic diagram of the structure after secondary processing of the additive interface of the shaft parts extension method of the present invention;
[0021] Figure 4 It is a schematic structural diagram of the parts to be processed after cold spraying in the method for lengthening shaft parts of the present invention;
[0022] Figure 5 It is a schematic structural diagram of the parts to be processed after supplementary processing in the method for lengthening shaft parts of the present invention.
[0023] Numbers in the figure:
[0024] 1. Additive interface after primary processing; 2. Additive interface after secondary processing; 3. Parts to be processed after cold spraying; 4. Parts to be processed after supplementary processing. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0026] The embodiments of the present invention provide a method for improving the interface strength of cold spray additives and a method for extending shaft parts, which can solve the problems in the related art of cracks or even peeling off inside the coating, and thermal damage to parts resulting in coarse structure and reduced performance.
[0027] See also Figure 1-Figure 5 As shown, a method for improving the interface strength of cold spray additive provided by an embodiment of the present invention may include the following steps:
[0028] S1. Processing the additive interface of the part to be processed once to increase the area of the additive interface.
[0029] S2. Perform secondary processing on the additive interface to improve the roughness of the additive interface.
[0030] S3. Cold spraying the additive interface after secondary processing.
[0031] In this embodiment, by performing secondary design on the additive interface, the area of the additive interface is increased, and the roughness of the additive interface is improved, which can effectively improve the bearing capacity of the interface and thus improve the interface strength. Cold spraying is performed on the processed additive interface to improve the coating quality and extend the service life of the components.
[0032] See also Figure 2As shown, in some optional embodiments, the processing of the additive interface may include: increasing the area of the additive interface by changing the angle of the additive interface. In this embodiment, the area is increased by changing the angle of the additive interface. For example, if the part to be processed is a flat plate, the additive interface can be processed into an inclined surface, or if the part to be processed is a cylindrical part, the additive interface can be processed into a cone, which is convenient for processing. In other embodiments, the area of the additive interface can be increased by other means. The area of the additive interface can be increased by changing the shape of the additive interface, such as changing a plane to a curved surface or a polygon.
[0033] See also Figure 2 As shown, in some embodiments, before the additive interface is processed once, it can also include: determining the angle that the additive interface needs to change according to the stress characteristics of the part to be processed. In this embodiment, according to the stress characteristics of the part to be processed, such as better fatigue resistance and bending resistance, the processing angle of the additive interface can be larger, thereby increasing the area of the additive interface while ensuring the strength of the part to be processed.
[0034] See also Figure 3 As shown, in some optional embodiments, the secondary processing of the additive interface may include: processing lines on the additive interface, and the extension direction of the lines is perpendicular to the axis of the part to be processed. In this embodiment, according to the force direction of the processed part, the interface is roughened by turning, scraping, etc. The lines are perpendicular or nearly perpendicular to the force direction, which can avoid interface contamination caused by sandblasting, achieve close bonding between the coating and the substrate, and further enhance the load-bearing capacity of the interface; wherein, if the part to be processed is cylindrical and is mainly subjected to axial tensile load, the extension direction of the lines is perpendicular to the axis of the part to be processed. If the part to be processed is of other shapes, the extension direction of the lines can also be other directions.
[0035] See also Figure 3 As shown, in some embodiments, before cold spraying the additive interface after secondary processing, it can also include: adjusting the cold spray angle so that the cold spray jet direction is parallel to the extension direction of the texture. In this embodiment, the cold spray angle is parallel to the extension direction of the texture, that is, parallel to the angle bisector of the texture, so that the cold spray jet can directly hit the bottom of the texture to form a hole-free combination, effectively reduce the porosity, and improve the interface strength.
[0036] See also Figure 4 and Figure 5As shown, in some embodiments, after the cold spraying of the additive interface after the secondary processing, it can also include: overall processing of the outside of the coating, and the processing direction is parallel to the force direction of the part to be processed. In this embodiment, the surface integrity and dimensional accuracy are controlled by supplementary processing, and the fatigue characteristics of the part are significantly improved while ensuring the function of the part. The processing direction is consistent with the force direction of the part to be processed to avoid early damage caused by stress concentration.
[0037] Specifically, a method for improving the interface strength of cold spray additive provided by an embodiment of the invention includes four steps: interface macro-shape design, interface micro-morphology design and processing, cold spray additive process parameter adjustment and optimization, and supplementary processing to achieve final part size and surface integrity control.
[0038] 1. Macro-shape design of the interface
[0039] According to the stress characteristics of the parts, the interface angle is appropriately changed to increase the interface area.
[0040] 2. Interface micro-morphology design and processing
[0041] According to the force direction of the parts, the interface is roughened by turning, scraping and other methods. The texture is perpendicular or nearly perpendicular to the force direction, and the roughness is controlled to Ra5-12um.
[0042] 3. Optimization and adjustment of cold spray additive process parameters
[0043] Adjust the spraying angle of cold spray additive, make the jet direction parallel to the bisector of the angle of the micro-morphology groove, and carry out cold spray additive to ensure the dense interface and reduce the interface porosity.
[0044] 4. Supplementary processing to achieve final size and surface integrity control of parts
[0045] After the spraying and additive manufacturing is completed, the parts are processed as a whole to ensure the size of the parts and the integrity of the surface. There is no visible overcutting and scratches. The processing lines are as consistent as possible with the force direction to avoid stress concentration caused by the processing lines and early fracture.
[0046] See also Figure 2-Figure 5 As shown, a method for extending shaft parts provided by an embodiment of the present invention may include:
[0047] S1. The end of the part to be processed is processed once and a conical surface is formed to increase the area of the additive interface. Specifically, the shaft parts are subjected to torsion and axial tensile loads. They are pre-treated before spraying, and the end of the shaft to be extended is made into a cone to increase the bonding area between the coating and the substrate.
[0048] S2. Perform secondary processing on the conical surface to improve the roughness of the conical surface. Specifically, considering the processing properties, rough threading can be performed on the conical surface of the substrate to achieve the required roughness of the interface between the substrate and the coating.
[0049] S3. Cold spraying is performed on the conical surface after secondary processing. Specifically, a workpiece is manufactured by completing a spraying operation on a substrate.
[0050] See also Figure 3 As shown, in some embodiments, the secondary processing of the conical surface may include: processing threads on the conical surface, and the extension direction of the threads is perpendicular to the axis of the part to be processed. In this embodiment, shaft parts are subjected to torsion and axial tensile loads, the main stress direction is axial, and torsion is an auxiliary load. The thread processing is perpendicular to the main load direction, which can further improve the interface bearing capacity.
[0051] See also Figure 3 As shown, in some embodiments, before cold spraying the conical surface after secondary processing, it can also include: adjusting the cold spraying angle so that the jet direction of the cold spraying is parallel to the extension direction of the thread. In this embodiment, the spraying angle is parallel to the extension direction of the thread, and the jet can be directly sprayed to the bottom of the thread groove to ensure a dense interface and reduce interface porosity.
[0052] See also Figure 4 and Figure 5 As shown, in some embodiments, the outer part of the coating is processed as a whole with the original outer cylindrical surface of the part to be processed as a reference, and the processing direction is parallel to the force direction of the part to be processed. In this embodiment, the supplementary processing after spraying is based on the original outer cylindrical surface of the long axis to process the cold sprayed additive body, and the surface roughness value is not higher than Ra1.6, ensuring that the part size meets the design requirements.
[0053] The principles of a cold spraying additive interface strength improvement method and a shaft parts extension method provided in an embodiment of the present invention are as follows:
[0054] According to the load mode of the parts, the interface between the additive body and the substrate is designed to increase the interface area, which can effectively enhance the interface load-bearing capacity; non-sandblasting methods are used to process the interface micro-morphology to achieve roughening of the substrate interface, avoid interface contamination caused by sandblasting, achieve close bonding between the coating and the substrate, and make the processing lines perpendicular to the load direction, which can further improve the interface bearing capacity; the macro-spraying angle parameters are associated with the micro-roughness morphology, and the spraying angle is parallel to the bisector of the micro-groove angle of the interface, optimizing the sandblasting coarsening random morphology shielding interference and inclusion contamination, so that the cold spray jet can directly hit the bottom of the micro-groove, achieving higher strength and smaller porosity to form a hole-free bond; supplementary processing controls surface integrity and dimensional accuracy to ensure part function while significantly improving part fatigue characteristics.
[0055] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.
[0056] It should be noted that, in the present invention, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.
[0057] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.
Claims
1. A method for improving the interface strength of cold spray additives, characterized in that: It includes the following steps: Performing a processing on the additive interface of the part to be processed so as to increase the area of the additive interface; Performing secondary processing on the additive interface to improve the roughness of the additive interface; cold spraying the additive interface after secondary processing; The one-time processing of the additive interface comprises: By changing the angle of the additive interface, the area of the additive interface is increased; Before the additive interface is processed once, the method further includes: Determining the angle at which the additive interface needs to be changed according to the stress characteristics of the part to be processed; The secondary processing of the additive interface includes: Processing lines on the additive interface, wherein the extending direction of the lines is perpendicular to the axis of the part to be processed; Before cold spraying the additive interface after secondary processing, the method further comprises: Adjusting the cold spraying angle so that the cold spraying jet direction is parallel to the extension direction of the texture; After the cold spraying of the additive interface after the secondary processing, the method further comprises: The exterior of the coating is processed as a whole, and the processing direction is parallel to the force direction of the part to be processed.
2. A method for improving the interface strength of cold spray additives for shaft parts, characterized in that: It includes: The end of the part to be processed is processed once and a conical surface is formed to increase the area of the additive interface; Performing secondary processing on the conical surface to improve the roughness of the conical surface; cold spraying the conical surface after secondary processing; The secondary processing of the conical surface comprises: Processing a thread on the conical surface, wherein the extending direction of the thread is perpendicular to the axis of the part to be processed; Before cold spraying the cone surface after secondary processing, the method further comprises: Adjusting the cold spraying angle so that the jet direction of the cold spraying is parallel to the extension direction of the thread; The outer part of the coating is processed as a whole based on the original outer cylindrical surface of the part to be processed, and the processing direction is parallel to the force direction of the part to be processed.