Surface machining method and surface machining system for high-hardness workpiece and diamond grinding head

Abstract

The embodiment of the invention provides a surface machining method and system for a high-hardness workpiece and a diamond grinding head. The surface machining method comprises the steps that S1, rough grinding machining is conducted on the surface of a workpiece through a diamond grinding head, so that the machining allowance of 0.2 mm-0. 3 mm is formed on the surface of the workpiece, and meanwhile, the hardness of the surface of the workpiece is reduced to 500 HV-550 HV; s2, a standard tool is adopted for conducting fine trimming machining on the surface of the workpiece machined in the step S1, and the machining allowance of 0.02-0.05 mm is reserved after machining; s3, the surface of the workpiece machined in the step S2 is subjected to fine trimming machining again through a fine trimming cutter, so that the workpiece reaches the standard structure size, and the surface roughness is Raut; and 0.1 [mu] m.

Description

Technical Field

[0001] This application relates to the field of precision machining technology, and more specifically, to a surface machining method for high-hardness workpieces, a surface machining system for high-hardness workpieces, and a diamond grinding head. Background Technology

[0002] With the development of high-end consumer electronics, medical devices, and aerospace, new materials with high hardness and high strength, such as amorphous zirconium and titanium alloys, are being used more and more widely. These materials have high initial surface hardness and excellent corrosion resistance and mechanical properties, but their high hardness and high chemical reactivity also bring severe processing challenges.

[0003] When CNC machining such high-hardness workpieces, the first process—roughing (or roughing)—faces the most prominent challenges. Traditional methods directly use standard carbide or high-speed steel tools for roughing. However, due to the extremely high surface hardness of the workpiece, the tools experience severe rapid wear, chipping, and even tool sticking due to material adhesion during cutting. This not only increases the tooling cost in the roughing process but also forces a significant reduction in cutting speed and feed rate to protect the tool, resulting in low roughing efficiency and becoming a bottleneck in the entire machining process.

[0004] To address the tool wear problem during the roughing stage, existing technologies typically employ two approaches: one is to frequently replace the tool, which directly increases production costs and affects machining continuity; the other is to conservatively reduce cutting parameters, which, while slightly extending tool life, comes at the cost of production efficiency, making it difficult to guarantee the economy and timeliness of mass production.

[0005] Therefore, in the roughing stage, how to effectively handle extremely high-hardness materials while maintaining a high-efficiency and economical material removal rate has become a pressing technical challenge in this field. Solving this problem is also a prerequisite for providing a stable and controllable processing foundation for subsequent finishing. Summary of the Invention

[0006] One objective of this application is to provide a new technical solution for a surface machining method and system for high-hardness workpieces and a diamond grinding head, aiming to solve the defects of rapid tool wear, low machining efficiency and poor surface quality in the surface machining of high-hardness workpieces in the prior art.

[0007] In a first aspect, embodiments of this application provide a surface machining method for a high-hardness workpiece, wherein the initial surface hardness of the workpiece is ≥600HV, and the surface machining method includes the following steps under continuous spraying of cutting fluid: Step S1, rough grinding: Use a diamond grinding head with a grit size of 100#~120# to perform rough grinding on the surface of the workpiece, so that the surface of the workpiece forms a machining allowance of 0.2mm~0.3mm, and at the same time, reduce the surface hardness of the workpiece to 500HV~550HV. Step S2, First finishing: Use standard tools to finish the surface of the workpiece after step S1, and retain a machining allowance of 0.02mm~0.05mm after machining; Step S3, Second finishing: The surface of the workpiece after step S2 is finished again using a finishing tool to make the workpiece reach the standard structural dimensions and the surface roughness Ra<0.1μm.

[0008] Optionally, the diamond grinding head has a T-shaped structure, including an integrally formed abrasive part and a tool holder; wherein the tool holder is used for detachable connection with the clamping device of the processing equipment, the abrasive part is cylindrical, the side of the cylinder forms a processing area for rough grinding, and the surface of the processing area is provided with an electroplated coating containing diamond abrasive grains.

[0009] Optionally, the surface of the abrasive part is provided with an electroplated coating, the electroplated coating containing diamond abrasive grains with a particle size of 100#~120#.

[0010] Optionally, the substrate material of the abrasive part is high-speed steel.

[0011] Optionally, in step S1, the roughing grinding process is achieved by making the cylindrical side of the abrasive part perform continuous reciprocating motion in a direction parallel to the workpiece surface.

[0012] Optionally, in step S1, the process parameters for the rough grinding process are: rotational speed 15000r / min~20000r / min, feed rate 2000mm / min~3000mm / min, and depth of cut 0.1mm~0.15mm.

[0013] Optionally, in step S2, the process parameters for the first finishing process include: spindle speed of 6000rpm~10000rpm, feed rate of 1200mm / min~1500mm / min, and depth of cut of the side cutting edge of 0.1mm~0.12mm.

[0014] Optionally, in step S3, the process parameters for the second finishing process include: spindle speed of 8000rpm~10000rpm, feed rate of 900mm / min~1000mm / min, and depth of cut of the side cutting edge of 0.02mm~0.05mm.

[0015] Optionally, the cutting fluid is a solution diluted with water, with a concentration of 15% to 20%.

[0016] Optionally, the workpiece is made of amorphous zirconium or titanium alloy.

[0017] Secondly, embodiments of this application provide a diamond grinding head, which is used for rough grinding in surface machining methods for high-hardness workpieces. The diamond grinding head includes: Tool holders, used for connection to the clamps of machining equipment; and, The frosted part is connected to the tool holder and has an overall T-shaped structure; The substrate of the abrasive part is made of high-speed steel and is cylindrical. The side of the cylinder forms a processing area for rough grinding, and the surface of the area is provided with an electroplated coating containing diamond abrasive grains with a particle size of 100#~120#.

[0018] Thirdly, embodiments of this application provide a surface processing system for high-hardness workpieces, the surface processing system comprising: A workpiece clamping and driving device is used to fix and drive the workpiece to be processed, wherein the workpiece is a high-hardness workpiece; The diamond grinding head as described in claim 10 is used to perform rough grinding on the surface of the workpiece to form a machining allowance of 0.2 mm to 0.3 mm on the surface of the workpiece and reduce the surface hardness to 500 HV to 550 HV. A standard cutting tool is used to perform the first finishing on the surface of the workpiece after rough grinding, and to retain a machining allowance of 0.02mm to 0.05mm after machining. A finishing tool is used to perform a second finishing process on the surface of the workpiece after the first finishing process, so that the workpiece reaches the standard structural dimensions and obtains a surface roughness Ra < 0.1 μm; and, A cutting fluid supply device is used to continuously spray cutting fluid into the contact area between the cutting tool and the workpiece surface. The cutting fluid is a water-diluted solution with a concentration of 15% to 20% to achieve cooling and chip removal during the machining process.

[0019] The beneficial effects of this application are as follows: The high-hardness workpiece surface machining method provided in this application employs a diamond grinding head with a specific grit size (100#~120#) to perform rough grinding on the surface of a high-hardness workpiece. This efficiently removes material while significantly reducing the workpiece surface hardness from ≥600HV to 500HV~550HV. This effectively overcomes the problems of rapid tool wear, chipping, and forced parameter reduction affecting machining efficiency caused by excessively hard material during the roughing stage. This surface machining method, based on efficient and stable roughing, provides a pre-treated surface with significantly reduced hardness and uniform, controllable allowance for subsequent finishing. Furthermore, through a series of finishing processes, the workpiece achieves standard structural dimensions while consistently obtaining a high-precision surface with a surface roughness Ra < 0.1μm, thus achieving a synergistic improvement in machining efficiency, tool life, and final product quality.

[0020] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0022] Figure 1 This is one of the toolpath diagrams of a surface machining system for high-hardness workpieces according to an embodiment of this application; Figure 2 This is a second schematic diagram of the toolpath for a surface machining system for high-hardness workpieces according to an embodiment of this application. Figure 3 This is a side view and a detailed view of the abrasive part of the diamond grinding head according to an embodiment of this application. Attached image description: 11. Grinding section; 12. Tool holder; 2. Processing equipment. Detailed Implementation

[0024] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0025] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0026] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0027] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0028] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0029] The following description, in conjunction with the accompanying drawings, details a surface processing method and system for high-hardness workpieces, as well as a diamond grinding head, provided in the embodiments of this application.

[0030] According to one embodiment of this application, a surface machining method for a high-hardness workpiece is provided, wherein the initial surface hardness of the workpiece is ≥600HV, and the surface machining method includes the following steps under continuous spraying of cutting fluid: Step S1, rough grinding: Use a diamond grinding head with a grit size of 100#~120# (or 100 mesh~120 mesh) to perform rough grinding on the surface of the workpiece, so that the surface of the workpiece forms a machining allowance of 0.2mm~0.3mm, and at the same time, reduce the surface hardness of the workpiece to 500HV~550HV. Step S2, First finishing: Use standard tools to finish the surface of the workpiece after step S1, and retain a machining allowance of 0.02mm~0.05mm after machining; Step S3, Second finishing: The surface of the workpiece after step S2 is finished again using a finishing tool to make the workpiece reach the standard structural dimensions and the surface roughness Ra<0.1μm.

[0031] The surface machining method for high-hardness workpieces provided in this application is characterized by a three-step process: rough grinding with a diamond grinding head (or roughing), semi-finishing with standard tools (i.e., the first finishing), and finishing with a finishing tool (i.e., the second finishing). This surface machining method is highly suitable for machining high-hardness, difficult-to-cut materials, such as amorphous zirconium and titanium alloys, with an initial surface hardness of not less than 600 HV.

[0032] The surface processing method for high-hardness workpieces provided in this application embodiment features a novel design in step S1, the roughing grinding stage. Instead of the traditional surface processing method of directly cutting with conventional standard tools, a diamond grinding head (including diamond abrasive grains with a grit size of 100#~120#) with a grit size of 100#~120# (where "#" represents mesh, a unit of abrasive grit size) is used as the roughing tool in the roughing grinding process. The optimized grit size range ensures that the diamond abrasive grains possess sufficient cutting strength to efficiently remove material while avoiding excessive surface damage to the workpiece due to overly coarse grit.

[0033] In the rough grinding stage of step S1, a high spindle speed of 15000r / min~20000r / min and a high feed rate of 2000mm / min~3000mm / min can be used, along with a precision depth of cut of 0.1mm~0.15mm, to achieve efficient and stable rough grinding of the high-hardness workpiece surface. This roughing process not only quickly removes material from the workpiece surface, but also promotes beneficial changes in the surface structure of the high-hardness workpiece through the micro-cutting and crushing action of diamond abrasive grains, thereby reducing the surface hardness from the initial ≥600HV to a more easily machinable range of 500HV~550HV, thus laying the foundation for subsequent progressive finishing processes.

[0034] The roughing grinding process described in this application has the following advantages: First, the continuous spraying of cutting fluid during the roughing grinding process effectively controls the overall temperature rise of the workpiece, preventing materials such as amorphous zirconium from crystallizing due to temperatures exceeding 400°C; second, the diamond grinding head has extremely high hardness and good chemical stability, fundamentally avoiding the adhesion phenomenon that easily occurs between active materials such as amorphous zirconium and traditional tool materials (such as high-speed steel or cemented carbide), ensuring the cleanliness and integrity of the machined surface.

[0035] After step S1 is completed, a margin of 0.2mm to 0.3mm is reserved on the surface of the workpiece, providing a reliable dimensional reference and process tolerance for the subsequent two finishing processes (i.e., steps S2 and S3). The entire roughing grinding process in this application, aided by continuous cooling, lubrication, and chip removal of the cutting fluid, further ensures process stability and surface integrity.

[0036] In the first finishing stage of step S2, based on the workpiece surface with reduced hardness after the treatment in step S1, a standard tool (such as a carbide end mill) is used for machining. Since the surface hardness of the workpiece has decreased from an initial ≥600HV to 500HV~550HV, the mechanical load and wear on the standard tool used in step S2 are significantly reduced during cutting, thus significantly extending tool life while maintaining high cutting efficiency. Step S2 further removes material and improves the workpiece shape accuracy, while also leaving a allowance of 0.02mm~0.05mm on the workpiece surface. This step S2 in this application plays a crucial role: it effectively eliminates machining marks and surface inhomogeneities that may remain from the rough grinding stage, and improves the dimensional and positional accuracy of the workpiece to a level close to the final requirements, laying a good foundation for subsequent finishing.

[0037] In step S3, the second finishing stage, a finishing tool is used to perform a second fine machining on the workpiece surface after step S2. Based on the significant reduction in workpiece surface hardness and dimensional pre-refinement achieved in the preceding steps S1 and S2, this stage can focus on achieving ultimate geometric accuracy and surface integrity. Ultimately, the structural dimensions of the workpiece accurately meet design standards, and key functional surfaces achieve a smooth machined surface with a surface roughness Ra < 0.1 μm, thus fully meeting the stringent requirements of high-end applications for appearance and tactile performance.

[0038] The principle of the surface machining method of this application is as follows: a diamond grinding head is used to replace the traditional standard cutting tool to perform rough machining on the surface of the workpiece. The removal of high-hardness materials is achieved through the micro-cutting and motion control of diamond abrasive grains. This method not only overcomes the problems of rapid tool wear, chipping and sticking caused by the high hardness and chemical activity of the material, but also significantly reduces the generation of burrs. Thus, while efficiently completing the roughing, it provides a surface with reduced surface hardness and uniform allowance for subsequent finishing.

[0039] In summary, the processing method provided in this application systematically overcomes a series of technical bottlenecks in the processing of high-hardness workpieces by constructing a process flow of efficient roughing with diamond grinding head to reduce hardness → stable semi-finishing with standard tool → precision forming with finishing tool. This process flow is as follows: high-efficiency roughing with diamond grinding head to reduce hardness → stable semi-finishing with standard tool → precision forming with finishing tool. Ultimately, it achieves a balance between processing efficiency, tool cost and product quality.

[0040] The high-hardness workpiece surface processing method provided in this application achieves the following beneficial effects through the above-described three-step process (steps S1 to S3): Using diamond grinding heads with specific grit sizes for roughing fundamentally overcomes the problems of rapid wear and easy chipping that traditional cutting tools tend to encounter when machining workpieces with high hardness (such as those initially requiring ≥600HV).

[0041] The roughing process not only removes material, but more importantly, it significantly reduces the surface hardness of the workpiece to 500HV~550HV. This removes a major obstacle to subsequent semi-finishing and finishing using standard tools, reduces tool wear during the finishing stage, and ensures the economy and stability of the entire process.

[0042] The surface finishing method of this application is carried out under continuous spraying of cutting fluid. In particular, the sufficient cooling during the roughing grinding stage effectively controls the grinding temperature rise, avoids the risk of crystallization caused by overheating of high-hardness materials such as amorphous zirconium, and reduces the adhesion between the material and the tool.

[0043] The surface finishing method provided in this application, through a progressive processing of roughing → semi-finishing → finishing, can stably obtain an ultra-high surface finish with a surface roughness Ra < 0.1μm while ensuring that the workpiece dimensions accurately meet the standards, thus satisfying the stringent quality requirements of high-end products.

[0044] The surface processing method provided in this application is mainly designed to address the processing challenges of high-hardness workpieces (such as materials with an initial surface hardness of not less than 600 HV, such as amorphous zirconium and titanium alloys). This method systematically solves problems such as rapid tool wear, chipping, tool sticking, and difficulty in guaranteeing surface quality during the processing of these materials through a continuous process of roughing with a diamond grinding head, semi-finishing with standard tools, and final finishing with a finishing tool.

[0045] Building upon this, the surface processing method is also applicable to workpieces exhibiting both high hardness and thin-walled structural characteristics. Such high-hardness, thin-walled workpieces (e.g., wall thickness below 2 mm, even 0.5 mm or less) are more sensitive to external forces and heat input during processing, and traditional processing methods easily lead to deformation and dimensional instability. This application, through the synergistic optimization of the surface processing method and processing tools, achieves efficient material removal while significantly reducing cutting forces and grinding heat, thus providing a reliable solution for the stable and precise machining of high-hardness, thin-walled workpieces.

[0046] In some examples of this application, the diamond grinding head has a T-shaped structure, including an integrally formed abrasive part 11 and a tool holder 12; wherein, the tool holder 12 is used to connect with the processing equipment 2 (see processing equipment 2 for details). Figure 1 and Figure 2 The clamping device is detachably connected, and the abrasive part 11 is cylindrical, with its cylindrical side forming a processing area for rough grinding of the workpiece surface.

[0047] In this example of the application, the diamond grinding head adopts an integrally formed T-shaped structure, the main body of which is a rigid whole consisting of a cylindrical abrasive part 11 and a tool holder 12 perpendicularly connected thereto.

[0048] Cylindrical abrasive section 11: As a machining part that directly performs rough grinding, its cylindrical side surface is a working area, i.e., a machining area, coated with a diamond coating. The cylindrical side surface of this abrasive section 11 constitutes a cylindrical side cutting edge for cutting.

[0049] In one specific embodiment of this application, see [reference needed]. Figure 3 The diameter of the frosted part 11 is 9mm and the height is 11mm. The base material of the frosted part 11 can be high-speed steel.

[0050] Tool holder 12: As a clamping part, its axis intersects perpendicularly with the axis of the abrasive part 11, forming a T-shaped connection. This arrangement allows the cylindrical side surface (i.e., the cylindrical side edge) of the abrasive part 11 to be used for lateral rough grinding (or rough machining), increasing the effective machining range.

[0051] The integrated design of the tool holder 12 and the grinding part 11 perpendicularly intersecting forms a short cantilever, high-rigidity mechanical structure. This structure can effectively resist the radial cutting force generated during lateral grinding, and is particularly suitable for the stringent requirements of tool rigidity in the machining of high-hardness workpieces.

[0052] The cutting force is directly transmitted from the abrasive part 11 to the tool holder 12 through the T-connection, which reduces vibration and deformation and provides structural guarantee for achieving a stable depth of cut of 0.1mm to 0.15mm.

[0053] The cylindrical grinding section 11 and its T-shaped arrangement make it particularly suitable for performing planar milling or contour roughing in the side-cutting direction, enabling efficient use of the entire cylindrical side surface for large-mass grinding. In addition, the geometric space formed by the connection between the cylindrical shape and the T-shape facilitates the flow of cutting fluid and the removal of chips, helping to control the grinding temperature.

[0054] In summary, the structural design of this T-shaped integrated diamond grinding head, through the rigid combination of the cylindrical grinding section and the vertical tool holder, has been optimized in terms of both geometry and mechanical properties for efficient and stable roughing of high-hardness materials. It is a key tool to ensure the effective implementation of the aforementioned processing method.

[0055] In some examples of this application, the surface of the abrasive portion 11 is provided with an electroplated coating, the electroplated coating containing diamond abrasive grains with a particle size of 100#~120#, see [link to relevant documentation]. Figure 3 The part indicated by the dashed circle on the right side of the middle section.

[0056] In this example of the application, an electroplating coating containing diamond abrasive grains is formed on the outer surface of the abrasive part 11 by an electroplating process. This is a key technical feature for achieving efficient and stable roughing grinding of the diamond grinding head.

[0057] Specifically, the electroplating process involves firmly embedding and fixing selected diamond abrasive grains with a particle size in the range of 100# to 120# (100 mesh to 120 mesh) into an electroplated coating deposited on the surface of the substrate (the substrate material of the abrasive part 11 is, for example, high-speed steel). The particle size of the diamond abrasive grains can be any specific value within this range, such as 100# (100 mesh), 105# (105 mesh), 110# (110 mesh), 115# (115 mesh), 116# (116 mesh), or 120# (120 mesh), and other particle size values ​​within this range are also applicable.

[0058] The bonding force generated by the electroplating process tightly binds the diamond abrasive grains within the electroplated coating in a mechanically embedded manner. This bonding method provides extremely high coating adhesion and grain retention, ensuring that the diamond abrasive grains are not easily detached under rotational speeds, such as 15,000 r / min to 20,000 r / min, and under intense friction conditions. This guarantees the service life and processing stability of the diamond grinding head during long-term, high-load roughing grinding operations.

[0059] The 100#~120# (100 mesh~120 mesh) grit size range selected in this application is an optimized range. Diamond abrasive grain sizes within this range ensure that each grain possesses sufficient cutting edge strength and material removal capability for efficient roughing grinding, while avoiding excessively coarse grit that could cause deep damage to the workpiece surface or leave deep grooves that are difficult to remove in subsequent processes. This guarantees the process requirement of a 0.2mm~0.3mm allowance after roughing grinding, enabling reliable coverage of roughing marks during finishing.

[0060] As a high-hardness material, diamond abrasive grains are the primary force in directly cutting and altering the microstructure of high-hardness workpiece surfaces. Simultaneously, its extremely high chemical stability fundamentally avoids the adhesion phenomenon (i.e., tool sticking) that easily occurs between reactive materials such as amorphous zirconium and traditional tool materials (such as high-speed steel and cemented carbide), thus ensuring the cleanliness and integrity of the machined surface and eliminating the risk of premature tool failure.

[0061] Furthermore, the distribution density of abrasive grains in the coating can be controlled through electroplating, forming microscopic chip-holding spaces. This facilitates the penetration of cutting fluid into the grinding zone, promptly removing grinding heat and expelling fine chips, effectively helping to control workpiece temperature rise (for materials such as amorphous zirconium, preventing the risk of crystallization exceeding 400°C is crucial), and maintaining the sharp cutting edge of the grinding head.

[0062] In some examples of this application, the base material of the frosted part 11 is high-speed steel.

[0063] In this example of the application, the substrate of the abrasive part 11 is made of high-speed steel. High-speed steel is an alloy tool steel with high hardness, good wear resistance, and sufficient toughness. As the substrate of the abrasive part, it provides physical support for the firm adhesion of the diamond coating on the surface. This material ensures that the grinding head has excellent overall rigidity, capable of withstanding the mechanical load and impact brought about by the high speed and large depth of cut during rough grinding. At the same time, its good machinability also facilitates the manufacture of the grinding head into the required complex structures such as T-shaped shapes. The use of a high-speed steel substrate ensures key performance while taking into account the manufacturing cost and process feasibility of the tool.

[0064] In some examples of this application, in step S1, the roughing grinding process is achieved by making the cylindrical side surface of the abrasive portion 11 perform a continuous reciprocating motion in a direction parallel to the workpiece surface, see [reference needed]. Figure 1 and Figure 2 The toolpath is shown in the image.

[0065] In this example of the application, the roughing grinding described in step S1 is achieved by a cylindrical side cutting edge formed on the cylindrical side surface of the abrasive portion 11 of the diamond grinding head, which performs a continuous reciprocating motion in a direction parallel to the workpiece surface. This processing method has the following characteristics: The reciprocating path can avoid the uneven surface quality that may be caused by unidirectional cutting, thereby achieving stable and consistent removal of high-hardness workpiece surfaces.

[0066] Side-cutting makes it easier to control the contact area and cutting thickness between the diamond abrasive grains and the workpiece surface. Combined with the intermittent entry and exit of the grinding edge during reciprocating motion, it facilitates the full penetration of cutting fluid into the grinding zone, timely removal of grinding heat and effective chip discharge, thereby significantly reducing local temperature rise and thermal stress. This is especially helpful in preventing the risk of crystallization due to overheating in materials such as amorphous zirconium.

[0067] This method places the main cutting force direction within the tangent plane of the workpiece surface, which can reduce the axial impact and deformation tendency on the workpiece structure, while also helping to maintain the overall rigidity of the tool system during machining.

[0068] In some examples of this application, in step S1, the process parameters for the rough grinding process are: rotational speed 15000r / min~20000r / min, feed rate 2000mm / min~3000mm / min, and depth of cut 0.1mm~0.15mm.

[0069] In this example of the application, the process parameters for the roughing grinding process described in step S1 are optimized as follows: rotational speed 15000 r / min to 20000 r / min, feed rate 2000 mm / min to 3000 mm / min, and depth of cut 0.1 mm to 0.15 mm. This parameter combination is a synergistic solution specifically designed for the efficient machining of high-hardness (≥600 HV) materials using diamond grinding heads.

[0070] The high rotational speed ensures that the diamond abrasive grains have sufficient cutting speed to effectively penetrate the surface layer of high-hardness materials. The high feed rate combined with a moderate depth of cut achieves a high material removal rate while ensuring that each abrasive grain bears a reasonable load, thus significantly improving roughing efficiency. At the same time, this depth of cut range is specially limited to achieve a balance between high-efficiency grinding and controllable grinding force and grinding heat. This helps maintain the rigidity of the process system, suppress vibration, and provides conditions for the continuous spraying of cutting fluid to fully cool the grinding zone and remove chips in a timely manner. This synergistically achieves an effective reduction in the surface hardness of the workpiece (to 500HV~550HV) and provides a stable and uniform pre-formed surface for subsequent finishing.

[0071] In some examples of this application, in step S2, the process parameters for the first finishing process include: spindle speed of 6000rpm~10000rpm, feed rate of 1200mm / min~1500mm / min, and depth of cut of the side cutting edge of 0.1mm~0.12mm.

[0072] In this example of the application, the process parameters for the first finishing (or semi-finishing) step S2 are optimized and set within a specific range, specifically including: spindle speed of 6000 rpm to 10000 rpm, feed rate of 1200 mm / min to 1500 mm / min, and depth of cut of 0.1 mm to 0.12 mm. The parameter range in this example is designed based on the following considerations: At this stage (i.e., step S2), the workpiece surface hardness has been reduced from ≥600HV to 500HV~550HV through step S1, creating favorable conditions for subsequent finishing. The moderate range of spindle speed and feed provided in this example, combined with a small depth of cut, can effectively control cutting force and cutting heat while ensuring high material removal efficiency, thereby reducing the wear of standard tools (such as carbide end mills) and maintaining good machining stability and dimensional control accuracy.

[0073] In one specific embodiment of this application, a preferred parameter combination within this range can be used, which includes a spindle speed of 8000 rpm, a feed rate of 1500 mm / min, and a side cutting depth of 0.1 mm. This set of parameters can further balance machining efficiency and surface quality, forming a uniform and smooth transition surface while efficiently removing the main body portion with the 0.2 mm to 0.3 mm allowance reserved in step S1, and precisely leaving a trace allowance of 0.02 mm to 0.05 mm, providing an ideal processing basis for the fine finishing in step S3.

[0074] The parameterization scheme provided in this example is one of the process guarantees that this step can achieve the finishing effect of connecting the preceding and following steps while ensuring machining economy (reducing tool wear).

[0075] In some examples of this application, in step S3, the process parameters of the second finishing process include: spindle speed of 8000rpm~10000rpm, feed rate of 900mm / min~1000mm / min, and depth of cut of the side cutting edge of 0.02mm~0.05mm.

[0076] In this example of the application, the process parameters for the second finishing process (i.e., final finishing) in step S3 are limited to the following range: spindle speed of 8000 rpm to 10000 rpm, feed rate of 900 mm / min to 1000 mm / min, and depth of cut of 0.02 mm to 0.05 mm. This parameter range is specifically set based on the condition that the workpiece surface has undergone high-level pre-finishing after step S2, retaining only a very small allowance of 0.02 mm to 0.05 mm. By combining a relatively high spindle speed, a low feed rate, and a small depth of cut, it is possible to achieve precise and stable removal of the remaining allowance while maintaining low cutting force and heat, thereby simultaneously ensuring final dimensional accuracy and surface finish.

[0077] In one specific embodiment of this application, a typical parameter combination within this range is used: a spindle speed of 8000 rpm, a feed rate of 1000 mm / min, and a side cutting depth of 0.02 mm. This set of parameters has been verified to effectively suppress cutting temperature rise during the final forming of materials such as amorphous zirconium, avoiding microstructural changes or dimensional deviations caused by heat accumulation, thereby consistently achieving the machining requirement of surface roughness Ra < 0.1 μm.

[0078] This parameter scheme, in conjunction with continuous cutting fluid cooling throughout the process, forms the technological basis for achieving high-precision, low-damage final finishing, ensuring that the workpiece achieves standard structural dimensions while maintaining excellent surface integrity.

[0079] In some examples of this application, the cutting fluid is a solution diluted with water with a concentration of 15% to 20%.

[0080] In this example of the application, the cutting fluid is a solution diluted with water with a concentration controlled within the range of 15% to 20%. At this concentration, the cutting fluid can achieve a balance between cooling, lubrication, and rust prevention. Specifically, a concentration of 15% to 20% provides sufficiently high specific heat capacity and thermal conductivity, effectively removing the large amount of cutting heat generated by high-speed grinding and subsequent finishing of the diamond grinding head under continuous spraying conditions, thereby controlling the temperature rise of the workpiece. This is crucial for preventing thermal crystallization of materials such as amorphous zirconium (critical temperature above 400°C). Simultaneously, the solution within this concentration range has suitable viscosity and surface activity, which can both fully wet the grinding zone, reduce the friction and adhesion tendency between the diamond abrasive grains and the workpiece surface, and effectively penetrate and carry away fine chips, maintaining the cleanliness of the machining area.

[0081] If the concentration of the cutting fluid is below the range in this example, it may result in insufficient cooling and lubrication performance, while if it is too high, it may increase costs and easily leave residues on the surface of the equipment and workpiece.

[0082] In some examples of this application, the workpiece material is amorphous zirconium or titanium alloy.

[0083] In this example of the application, the surface processing method is applicable to difficult-to-machine materials such as amorphous zirconium or titanium alloys, which have high hardness and high strength.

[0084] Taking amorphous zirconium (Zr-based amorphous alloy) as an example, its initial surface hardness is typically ≥600 HV, exhibiting extremely high wear and corrosion resistance. However, it also presents unique challenges such as a significant tendency for work hardening, severe tool wear, and the risk of crystallization at certain temperature rises (e.g., exceeding 400℃). Titanium alloys are similarly known for their high strength, poor thermal conductivity, and high chemical reactivity, which can easily lead to tool adhesion. The surface processing method described in this application systematically addresses the challenges posed by these material characteristics by employing a diamond grinding head for efficient roughing while simultaneously reducing surface hardness, combined with a process of full-process cooling and graded finishing. The high hardness and chemical stability of the diamond grinding head solve the problems of rapid tool wear and tool adhesion; the optimized grinding process and cooling effectively control the processing heat input, avoiding material crystallization or unfavorable phase transformations; and finally, through a finishing process, dimensional accuracy and mirror-level surface quality meeting the requirements of high-end applications are achieved. Therefore, this method provides a practical solution for the precise, stable, and economical processing of such high-performance materials.

[0085] The surface processing method for high-hardness workpieces provided in this application will be described in detail below through Example 1.

[0086] Example 1 This embodiment 1 provides a surface machining method for high-hardness workpieces, specifically using a shell workpiece made of amorphous zirconium with an initial surface hardness ≥600HV as the machining object. The surface machining method is performed under continuous spraying of a cutting fluid with a concentration of 15%~20% (diluted by cutting fluid and pure water in a specific ratio), following steps 100 to 300: Step 100, Rough Grinding: The workpiece surface is rough ground using a 100# (or 100 mesh) diamond grinding head. The diamond grinding head has a T-shaped structure, with its abrasive section being cylindrical. The abrasive section has a diameter of 9mm and a height of 11mm, and is made of high-speed steel. The surface of the abrasive section is coated with an electroplated coating containing diamond abrasive grains. The rough grinding parameters are set as follows: spindle speed 15000rpm, feed rate 2000mm / min, depth of cut 0.1mm, and a planar milling reciprocating toolpath. After rough grinding, a uniform machining allowance of 0.3mm is formed on the workpiece surface, and the surface hardness decreases from the initial ≥600HV to 500HV~550HV, resulting in the roughened surface of the product.

[0087] Step 200, First Finishing (or Semi-Finishing): Using a standard tool, perform semi-finishing on the surface of the roughed workpiece to obtain a semi-finished product. The semi-finishing parameters are set as follows: spindle speed 8000 rpm, feed rate 1500 mm / min, and side cutting depth 0.1 mm. Step 200 further removes material and improves shape accuracy. The measured allowance remaining on the workpiece surface after machining is 0.02 mm.

[0088] Step 300, Second Finishing (or Finishing): The workpiece surface after semi-finishing is further finished using a finishing tool. The finishing parameters are set as follows: spindle speed 8000 rpm, feed rate 1000 mm / min, and depth of cut 0.02 mm. After this finishing process, all structural dimensions of the workpiece meet the specified standard tolerances. The surface roughness is measured using a surface roughness tester and meets the design requirement of Ra < 0.1 μm.

[0089] Through steps 100 to 300 above, this embodiment 1 achieves efficient and stable processing of high-hardness amorphous zirconium workpieces, effectively reducing tool wear while obtaining high dimensional accuracy and excellent surface quality.

[0090] Comparative Example To verify the superiority of the surface processing method proposed in this application, a typical direct cutting process in the prior art was used to process the same amorphous zirconium workpiece as in Example 1. All processing steps were carried out under the condition of continuous spraying of the same concentration of cutting fluid.

[0091] The specific steps of the surface finishing method used in the comparative example are as follows: (1) Rough grinding: Instead of using a diamond grinding head, a standard carbide end mill was used to perform conventional rough milling on the workpiece surface. To prevent tool chipping, the machining parameters were reduced during this process: the spindle speed was set to 3000 rpm, the feed rate was set to 500 mm / min, and the depth of cut was set to 0.05 mm. After machining, a machining allowance of approximately 0.3 mm was left on the workpiece surface. Testing showed that the surface hardness of the workpiece did not decrease significantly and remained at ≥600 HV.

[0092] First finishing (semi-finishing): The first finishing was performed using a new standard carbide tool. The machining parameters were set as follows: spindle speed 5000 rpm, feed rate 800 mm / min, and side cutting depth 0.08 mm. Significant tool wear occurred during this process, resulting in uneven surface quality and barely achieving the required 0.02 mm allowance.

[0093] Second finishing: A second finishing process was performed using a finishing tool. The machining parameters were set as follows: spindle speed 7000 rpm, feed rate 700 mm / min, and side cutting depth 0.02 mm. Due to the extremely high and uneven hardness of the roughened surface, tool wear intensified during the finishing process, resulting in unstable dimensional tolerance control of the final workpiece. The surface roughness Ra value ranged from 0.2 μm to 0.3 μm, failing to consistently meet the requirement of Ra < 0.1 μm.

[0094] Comparison and conclusions between Example 1 and the comparative example: The comparative example required at least two replacements of carbide end mills due to tool wear during the roughing stage. The entire process involved high tool costs, and the roughing efficiency was only about 1 / 10 of that of Example 1, which was very low.

[0095] The roughing process in the comparative example failed to reduce the surface hardness of the workpiece, causing the subsequent finishing tools to operate under extremely high hardness conditions. This is the root cause of short tool life, poor and unstable final surface quality. The final workpiece surface roughness in the comparative example was far worse than that in Example 1.

[0096] As can be clearly seen from the comparative examples, for materials such as amorphous zirconium with an initial hardness ≥600HV, without employing the key steps of roughing with a diamond grinding head and reducing hardness, even with subsequent two finishing passes (gradually refinishing with machining allowance), the core technical challenges of rapid tool wear, low processing efficiency, and difficulty in achieving the required surface quality cannot be solved. This demonstrates the necessity and advancement of the three-step process for roughing and reducing hardness with a diamond grinding head proposed in this application.

[0097] According to another embodiment of this application, a diamond grinding head is provided for rough grinding in a surface machining method for high-hardness workpieces. The diamond grinding head includes the following components, see below. Figures 1 to 3 : Tool holder 12, for connection to the clamp of machining equipment 2; and, The abrasive part 11 is connected to the tool holder and has an overall T-shaped structure; The substrate of the abrasive part 11 is made of high-speed steel and is cylindrical. The side of the cylinder forms a processing area for rough grinding, and the surface of the processing area is provided with an electroplated coating containing diamond abrasive grains. The particle size of the diamond abrasive grains is 100#~120#.

[0098] This application provides a diamond grinding head for the aforementioned surface finishing method. The diamond grinding head has a T-shaped integrated structure, consisting of a tool holder 12 and an abrasive section 11, wherein: Tool holder 12 is used with machining equipment 2 (see See) Figure 1 and Figure 2 The clamps, such as standard clamps for machine tool spindles (e.g., hydraulic tool holders or spring collets), provide a reliable connection, ensuring good dynamic balance and clamping rigidity at high speeds.

[0099] The abrasive section 11 is a functional part that directly participates in rough grinding. Its base is made of high-speed steel to provide the necessary overall strength and toughness.

[0100] The core technical feature of the diamond grinding head in this application is that its abrasive part 11 has a cylindrical structure and its surface is coated with a composite coating containing diamond abrasive grains through an electroplating process, and the grit size of the selected diamond abrasive grains is limited to a specific range of 100#~120# (100 mesh~120 mesh). This design enables the diamond grinding head to possess the following properties: Extremely high hardness and wear resistance: derived from diamond abrasive grains, it can directly and efficiently cut materials with an initial hardness ≥600HV.

[0101] Strong abrasive grain bonding strength: The electroplating process ensures that the diamond abrasive grains are firmly embedded in the coating, which can withstand the high loads brought by high speed (15000r / min~20000r / min) and large depth of cut (0.1mm~0.15mm) and prevent the grains from falling off prematurely.

[0102] Optimized cutting and heat dissipation characteristics: The 100#~120# (100 mesh~120 mesh) particle size ensures cutting efficiency while also facilitating the penetration of cutting fluid and chip removal to a certain extent, thus helping to control the grinding temperature rise.

[0103] According to another embodiment of this application, a surface processing system for high-hardness workpieces is provided, the surface processing system comprising: A workpiece clamping and driving device is used to fix and drive the workpiece to be processed, wherein the workpiece is a high-hardness workpiece; The diamond grinding head described above is used to perform rough grinding on the surface of the workpiece to form a machining allowance of 0.2 mm to 0.3 mm on the surface of the workpiece and reduce the surface hardness to 500 HV to 550 HV. A standard cutting tool is used to perform the first finishing on the surface of the workpiece after rough grinding, and to retain a machining allowance of 0.02mm to 0.05mm after machining. A finishing tool is used to perform a second finishing process on the surface of the workpiece after the first finishing process, so that the workpiece reaches the standard structural dimensions and obtains a surface roughness Ra < 0.1 μm; and, A cutting fluid supply device is used to continuously spray cutting fluid into the contact area between the cutting tool and the workpiece surface. The cutting fluid is a water-diluted solution with a concentration of 15% to 20% to achieve cooling and chip removal during the machining process.

[0104] This embodiment of the application provides a surface machining system for implementing the aforementioned processing method. Its design focuses on the coordinated configuration of functional components and the systematic assurance of key process conditions. This surface machining system is a solution to the challenging problem of machining high-hardness workpieces, and mainly includes: Diamond grinding head: As a core component, it mainly undertakes the key tasks of efficient rough grinding and reducing the surface hardness of the workpiece.

[0105] Standard tools and finishing tools: Under optimized hardness conditions, semi-finishing and final precision forming are completed sequentially.

[0106] Workpiece clamping and driving device: Provides stable and reliable clamping for high-hardness workpieces to be machined, in order to cope with the high cutting forces in the machining of high-hardness materials.

[0107] Cutting fluid supply device: By continuously spraying a specific cutting fluid with a concentration of 15%~20%, it provides the necessary cooling, lubrication and chip removal conditions for the entire machining process (especially the high-heat roughing stage). This is the key to controlling the temperature rise of the workpiece, preventing thermal damage to the material (such as crystallization of amorphous zirconium), and ensuring machining stability.

[0108] The surface processing system described in this application integrates specialized tools, graded finishing strategies, and a controlled process environment to form a complete solution. This ensures, at both the hardware and process levels, that the surface processing method can be executed efficiently, stably, and economically, ultimately achieving high-quality processing of high-hardness workpieces.

[0109] The specific implementation of the surface processing system for high-hardness workpieces in this application can refer to the various embodiments of the diamond grinding head and the surface processing method for high-hardness workpieces described above. Therefore, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0110] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0111] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A surface processing method for high-hardness workpieces, characterized in that, The initial surface hardness of the workpiece is ≥600HV, and the surface processing method under continuous cutting fluid spraying includes the following steps: Step S1, rough grinding: Use a diamond grinding head with a grit size of 100#~120# to perform rough grinding on the surface of the workpiece, so that the surface of the workpiece forms a machining allowance of 0.2mm~0.3mm, and at the same time, reduce the surface hardness of the workpiece to 500HV~550HV. Step S2, First finishing: Use standard tools to finish the surface of the workpiece after step S1, and retain a machining allowance of 0.02mm~0.05mm after machining; Step S3, Second finishing: The surface of the workpiece after step S2 is finished again using a finishing tool to make the workpiece reach the standard structural dimensions and the surface roughness Ra<0.1μm.

2. The surface processing method according to claim 1, characterized in that, The diamond grinding head has a T-shaped structure, including an integrally formed abrasive part and a tool holder; wherein, the tool holder is used for detachable connection with the clamping device of the processing equipment, and the abrasive part is cylindrical, the cylindrical side of which forms a processing area for rough grinding of the workpiece surface.

3. The surface processing method according to claim 2, characterized in that, The surface of the abrasive part is provided with an electroplated coating, which contains diamond abrasive grains with a particle size of 100#~120#.

4. The surface processing method according to claim 2 or 3, characterized in that, The base material of the abrasive part is high-speed steel.

5. The surface processing method according to claim 2, characterized in that, In step S1, the roughing grinding process is achieved by making the cylindrical side of the abrasive part perform continuous reciprocating motion in a direction parallel to the surface of the workpiece.

6. The surface processing method according to claim 1, characterized in that, In step S1, the process parameters for rough grinding are: rotational speed 15000r / min~20000r / min, feed rate 2000mm / min~3000mm / min, and depth of cut 0.1mm~0.15mm.

7. The surface processing method according to claim 1, characterized in that, In step S2, the process parameters for the first finishing process include: spindle speed of 6000rpm~10000rpm, feed rate of 1200mm / min~1500mm / min, and depth of cut of the side cutting edge of 0.1mm~0.12mm.

8. The surface processing method according to claim 7, characterized in that, In step S3, the process parameters for the second finishing process include: spindle speed of 8000rpm~10000rpm, feed rate of 900mm / min~1000mm / min, and depth of cut of the side cutting edge of 0.02mm~0.05mm.

9. The surface processing method according to claim 1, characterized in that, The cutting fluid is a solution diluted with water, with a concentration of 15% to 20%.

10. A diamond grinding head, characterized in that, The diamond grinding head is used for rough grinding in surface machining methods for high-hardness workpieces, and the diamond grinding head includes: Tool holders, used for connection to the clamps of machining equipment; and, The frosted part is connected to the tool holder and has an overall T-shaped structure; The substrate of the abrasive part is made of high-speed steel and is cylindrical. The side of the cylinder forms a processing area for rough grinding, and the surface of the processing area is provided with an electroplated coating containing diamond abrasive grains with a particle size of 100#~120#.

11. A surface processing system for high-hardness workpieces, characterized in that, include: A workpiece clamping and driving device is used to fix and drive the workpiece to be processed, wherein the workpiece is a high-hardness workpiece; The diamond grinding head as described in claim 10 is used to perform rough grinding on the surface of the workpiece to form a machining allowance of 0.2 mm to 0.3 mm on the surface of the workpiece and reduce the surface hardness to 500 HV to 550 HV. A standard cutting tool is used to perform the first finishing on the surface of the workpiece after rough grinding, and to retain a machining allowance of 0.02mm to 0.05mm after machining. A finishing tool is used to perform a second finishing process on the surface of the workpiece after the first finishing process, so that the workpiece reaches the standard structural dimensions and obtains a surface roughness Ra < 0.1 μm; and, A cutting fluid supply device is used to continuously spray cutting fluid into the contact area between the cutting tool and the workpiece surface. The cutting fluid is a water-diluted solution with a concentration of 15% to 20% to achieve cooling and chip removal during the machining process.

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