Probe and strengthening treatment method thereof

Abstract

The invention provides a probe and a strengthening treatment method thereof, and the strengthening treatment method comprises the step of manufacturing a hardened layer on the surface of a probe tip, and the manufacturing of the hardened layer comprises the following steps: an electron beam quenching step: adopting an electron beam with the acceleration voltage of 60-80kV and the beam density of 5 * 10 < 3 >-1 * 10 < 4 > W / cm < 2 > to bombard the surface of the probe tip after focusing through an electromagnetic lens, the local area is heated to the temperature above the material phase transition temperature within 0.1 s or less, the cooling rate of 103-104 DEG C / s is achieved through matrix self-cooling, and a metastable-state martensite structure with the high dislocation density is formed; through the synergistic effect of electron beam parameters (60-80 kV acceleration voltage, 5 * 10 < 3 >-1 * 10 < 4 > W / cm < 2 > specific beam density) and self-cooling quenching, the technical problems of insufficient micro-area strengthening precision, insufficient hardness performance of a hardened layer, machining deformation and the like in the prior art are solved, according to the scheme, the abrasion loss of the needle tip can be effectively reduced, the service life is prolonged, subsequent machining deformation correction is not needed, and the production cost is reduced. And the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of probe technology, and in particular to a probe and a strengthening treatment method thereof. Background Art

[0002] The existing mature technology is as follows Figure 1 The probe shown has a needle tip made of a precious metal material with higher hardness that is different from the needle body. This material is expensive, much harder than gold, and is inconsistent with the needle body material, which increases the complexity of the process. The industry is researching solutions to the above-mentioned needs and pain points, but the following technical limitations still exist: Laser quenching: Traditional laser quenching is unable to meet the requirements of precision measurement because the heat-affected zone is too wide (>200μm), which causes the tip area (<50μm) to be easily deformed by heat (bending >0.1mm / mm). Chemical plating / electroplating: The coating hardness is insufficient (usually <800HV), and stress concentration is easily generated at the interface; Conventional electron beam processing: The synergistic effect of beam density and cooling rate is not optimized, the martensite conversion rate is less than 70% or microcracks may occur, and overall quenching requires subsequent machining to correct deformation (taking time > 30 minutes / piece). High-frequency induction heating positioning accuracy is only ±50μm and energy conversion efficiency is less than 40%, which increases processing steps and is costly. Summary of the Invention

[0003] In order to solve the technical problems of insufficient micro-area strengthening precision, insufficient hardness performance of hardened layer and processing deformation in the prior art, the present invention proposes a probe and a strengthening treatment method thereof. The electron beam parameters (60-80 kV acceleration voltage, 5×10 3 ~1×10 4 W / cm 2 The synergistic effect of specific beam current density) and self-cooling quenching solves the technical problems of insufficient micro-area strengthening accuracy, insufficient hardness performance of the hardened layer, and processing deformation in the existing technology. This solution can effectively reduce the wear of the needle tip, extend the service life, and does not require subsequent machining to correct deformation, thereby reducing production costs. In order to achieve the above object, the technical solution of the present invention is as follows: In one aspect, the present invention provides a probe strengthening method, comprising: manufacturing a hardened layer on the surface of a formed and hardened needle tip, wherein the manufacturing of the hardened layer comprises the following steps: Electron beam quenching steps: using an accelerating voltage of 60-80 kV and a beam current density of 5 × 10 3 ~1×10 4 W / cm 2The electron beam is focused by an electromagnetic lens and bombards the probe tip surface, causing the local area to heat up to above the material phase transition temperature within ≤0.1s, and the substrate self-cooling is used to achieve 10 3 ~10 4 ℃ / s cooling rate, forming a metastable martensite structure with high dislocation density. The present invention proposes a probe and a strengthening treatment method thereof, by adjusting the electron beam parameters (60-80 kV acceleration voltage, 5×10 3 ~1×10 4 W / cm 2 The synergistic effect of specific beam current density) and self-cooling quenching solves the technical problems of insufficient micro-area strengthening accuracy, insufficient hardness performance of the hardened layer, and processing deformation in the existing technology. This solution can effectively reduce the wear of the needle tip, extend the service life, and does not require subsequent machining to correct deformation, thereby reducing production costs. As a preferred technical solution, in the electron beam quenching step, the needle tip includes: a formed and hard beryllium copper alloy needle tip, the beryllium copper alloy needle tip is heated to 780-850°C to reach the β phase region, the electron beam bombards the needle tip surface, causing the local area to austenitize within ≤0.1s, and through self-cooling of the matrix, the supersaturated β phase is transformed into α' phase martensite, and the hardness is increased to 45-50HRC. As a preferred technical solution, the manufacture of the hardened layer includes the following steps: an aging precipitation strengthening step, which includes the following steps: aging treatment at 300-350°C for 2-3 hours to precipitate nano-scale γ-phase strengthening particles in the α'-phase martensite, thereby increasing the hardness to 52-55HRC. As a preferred technical solution, the manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step comprises the following steps: Adjust the parameters of electron beam energy density and scanning speed so that the depth of the hardened layer satisfies the following formula: In the formula, k is the thermal diffusion constant of the material, E is the energy density of the electron beam, and d is the depth of the hardened layer; The electron beam spot diameter is dynamically controlled. A sharp focus beam spot is used during shallow hardening, so that the electron beam spot diameter D is ≤ 100 μm, and the edge thermal effect is compensated by the energy attenuation of the electron beam spot edge. As an optimal technical solution, in the hardening layer depth control step, dynamic power compensation is implemented at the starting and / or ending position of the scanning path, and the power is automatically reduced by 10% to 15% to suppress the thermal accumulation effect, ensuring that the depth deviation of the entire area is ≤±5μm. As an optimal technical solution, parameters are set based on phase change temperature field simulation, and the specific heat capacity and density parameters of the probe tip material are input through the heat conduction model to predict the temperature distribution with a target depth error of ≤±10μm. As a preferred technical solution, a pulse modulation step is adopted for a beryllium copper probe tip with a thickness of 0.05 to 0.2 mm, and the pulse modulation step specifically includes the following steps: An intermittent heat source is applied to a beryllium copper needle tip with a thickness of 0.05 to 0.2 mm. The heat input is controlled by adjusting the synergistic relationship between the pulse frequency and the duty cycle to prevent the hardened layer from penetrating deeply into the substrate. As a preferred technical solution, the manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step further comprises real-time monitoring and control, including: The infrared thermometer monitors surface temperature fluctuations in real time and automatically adjusts the power of the generated electron beam when the temperature fluctuation exceeds a threshold; The eddy current sensor detects the hardness gradient and feeds back to correct the beam density parameters. As a preferred technical solution, the manufacturing of the hardened layer further comprises the following steps: a quenching stress elimination step, wherein the quenching stress elimination step comprises: The low temperature tempering stress relief step comprises the following steps: Low-temperature tempering is performed in the temperature range of 150-200°C, and the holding time is adjusted in a gradient of 30-90 minutes according to the thickness of the workpiece, so that the martensite decomposes into tempered martensite and releases the lattice distortion stress; Use a vacuum tempering furnace with a temperature control accuracy of ±2°C and slowly cool to below 50°C at a cooling rate of ≤10°C / min; And / or, the aging synergistic stress relief step comprises the following steps: A beryllium copper alloy needle tip containing 1.6% to 2.0% beryllium is first pre-aged at 110°C to 130°C for 1 to 3 hours to stabilize the martensitic substructure, and then subjected to main aging at 320°C to 340°C for 2 to 4 hours. During the aging treatment, coherent strain generated by precipitates within the grains offsets the quenching stress. And / or, the static pressure shaping and composite stress relief step comprises the following steps: For workpieces with a curvature > 0.1 mm / mm after quenching, apply a static pressure correction force of 5 to 10 N / mm before tempering and maintain it for 8 to 12 minutes to offset the quenching stress through the correction stress. On the other hand, the present invention also provides a probe, comprising: a probe tip and a hardened layer processed according to any of the probe strengthening treatment methods described above, wherein the hardened layer is located on the surface of the probe tip, and the hardness of the hardened layer is 52 to 55 HRC. The present invention provides a probe and a method for strengthening the probe, which has the following beneficial effects: 1) The present invention provides a probe and a strengthening treatment method thereof, which is a secondary processing on the needle tip surface that has been formed and is in a hard state, and the electron beam parameters (60-80kV acceleration voltage, 5×10 3 ~1×10 4 W / cm 2 The synergistic effect of the specific beam current density and self-cooling quenching solves the technical problems of the existing technology, such as insufficient micro-area strengthening precision, insufficient hardness of the hardened layer, and processing deformation. This solution can effectively reduce the wear of the needle tip, extend the service life, and eliminate the need for subsequent machining to correct deformation, thereby reducing production costs. 2) The present invention provides a probe and a processing method thereof. The present invention uses a 60-80 kV accelerating voltage in combination with an electromagnetic lens to compress the electron beam spot diameter to the submicron level (<50 μm), thereby overcoming the defect of the laser quenching heat affected zone being too wide (>200 μm); at the same time, the 5×10 3 ~1×10 4 W / cm 2 The beam density ensures that the heat energy only acts on the surface of the needle tip, and the thickness deviation of the hardened layer is ≤±5μm. The precision is increased by 80% compared with chemical plating, which improves the micro-area strengthening accuracy. The substrate of the present invention realizes a cooling rate of 103-104°C / s by self-cooling, and forms a dislocation density greater than 10 5 / m 2 The martensitic structure has a hardness of 45 to 50HRC; short-term heating of ≤0.1s inhibits grain coarsening and avoids micro-crack defects caused by traditional electron beam treatment; This application uses electron beam bombardment without mechanical stress, and non-contact processing to eliminate the positioning error (±50μm) of high-frequency induction heating. At the same time, the substrate conducts heat to achieve rapid cooling, and the needle tip curvature is less than 0.01mm / mm, eliminating the traditional process of 30min / piece grinding; This synergistic effect can effectively reduce the amount of needle tip wear, extend the service life, and eliminate the need for subsequent machining to correct deformation, thereby reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 A schematic diagram of the structure of a probe provided by an existing mature process in the background technology; Figure 2 A schematic structural diagram of a probe (cantilever needle) provided by the present invention; Figure 3 A schematic structural diagram of a probe provided by the present invention (straight needle); Among them, 1-probe; 2-needle tip. DETAILED DESCRIPTION The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. like Figure 1As shown, the present invention provides a probe strengthening treatment method, comprising: manufacturing a hardened layer on the surface of a needle tip 2 that has been formed and is in a hard state, and manufacturing the hardened layer includes the following steps: Electron beam quenching steps: using an accelerating voltage of 60-80 kV and a beam current density of 5 × 10 3 ~1×10 4 W / cm 2 The electron beam is focused by an electromagnetic lens and bombards the probe tip surface, causing the local area to heat up to above the material phase transition temperature within ≤0.1s, and the substrate self-cooling is used to achieve 10 3 ~10 4 ℃ / s cooling rate, forming a metastable martensite structure with high dislocation density. The high dislocation density and supersaturated beryllium atoms in the martensite structure form a metastable structure, which provides a basis for subsequent aging strengthening. The present invention proposes a probe strengthening treatment method, which uses electron beam parameters (60-80 kV acceleration voltage, 5×10 3 ~1×10 4 W / cm 2 The synergistic effect of specific beam current density) and self-cooling quenching solves the technical problems of insufficient micro-area strengthening accuracy, insufficient hardness performance of the hardened layer, and processing deformation in the existing technology. This solution can effectively reduce the wear of the needle tip, extend the service life, and does not require subsequent machining to correct deformation, thereby reducing production costs. Preferably, an electron beam generator generates a high-speed electron stream (with an energy of up to tens of keV) which is focused by an electromagnetic lens and then bombards the surface of the material. The kinetic energy of the electrons is converted into heat energy through electron-atom collisions, causing the local temperature to rise rapidly to above the phase transition point of the material. In the electron beam quenching step, the needle tip comprises: a beryllium copper alloy needle tip, which is heated to 780-850° C. to reach the β phase region. The electron beam bombards the needle tip surface, causing the local region to austenitize within 0.1 s or less. Through self-cooling of the matrix, the supersaturated β phase is transformed into α' phase martensite, and the hardness is increased to 45-50 HRC. The beryllium copper alloy needle tip is heated to 780-850℃ (β phase region) to fully dissolve the beryllium atoms in the copper matrix and form a supersaturated β solid solution, which provides a basis for the subsequent martensitic phase transformation. Electron beam bombardment (≤0.1s) causes the needle tip surface to instantly heat up to above the phase transformation point, and the β phase transforms into austenite with a face-centered cubic structure, while inhibiting grain coarsening. The matrix is cooled naturally (10 3 ~10 4 ℃ / s cooling rate) forces the supersaturated β phase to transform into α' martensite in a non-diffusion shear manner, producing a high dislocation density structure (>10 15 / m 2); the high-density dislocation structure of the α' phase martensite increases the hardness to 45-50HRC, significantly enhancing wear resistance; the staggered structure of the acicular martensite effectively hinders dislocation slip, making the needle tip less likely to collapse or permanently deform under contact stress; local strengthening only changes the surface structure (depth ≤ 50μm), and the matrix still retains the high conductivity of beryllium copper, ensuring the stability of probe signal transmission. Preferably, the manufacturing of the hardened layer includes the following steps: an aging precipitation strengthening step, wherein the aging precipitation strengthening step includes the following steps: aging treatment at 300-350°C for 2-3 hours to precipitate nano-scale γ-phase strengthening particles in the α'-phase martensite, thereby increasing the hardness to 52-55HRC, which is 30%-40% higher than the original state (35-40HRC); The aging temperature of 300-350℃ provides sufficient thermal activation energy to promote the diffusion and aggregation of beryllium atoms in the α' phase martensite to form nano-scale γ phase (chemical formula is CuBe) strengthening particles; the heat preservation time of 2-3 hours ensures that the diameter of the γ phase particles is controlled at 10-20nm (optimal strengthening size). If it is too short, the precipitation is insufficient, and if it is too long, the particles will coarsen (>30nm) and weaken. The γ phase particles and the martensite matrix produce a 4.5% lattice mismatch, which triggers a strong coherent strain field and increases the hardness from 45-50HRC to 52-55HRC. Preferably, the manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step comprises the following steps: Adjust the parameters of electron beam energy density and scanning speed so that the depth of the hardened layer satisfies the following formula: In the formula, k is the thermal diffusion constant of the material, E is the energy density of the electron beam, and d is the depth of the hardened layer; Adjust the scanning speed to 200~300mm / s and the beam density to 5×10 3 ~8×10 3 W / cm 2 Parameter adjustment range (d = 50 ~ 100 μm): (E = 0.5 ~ 1.0 J / mm2); Energy density (E, J / mm 2 ) is positively correlated with depth (d, μm). The electron beam energy density is determined by the accelerating voltage (60-80 kV) and the beam current (0.1-0.3 mA). The scanning speed must be accurately matched using the power formula P=IU (where P is power, I is current, and U is voltage). The depth is inversely proportional to the scanning speed, decreasing with increasing scanning speed (for every 100 mm / s increase in speed, the depth decreases by approximately 30%), achieving a high-precision, low-deformation strengthening effect. Dynamically control the electron beam spot diameter. Use a sharp focus beam spot for shallow hardening, so that the electron beam spot diameter D is less than or equal to 100 μm. The edge thermal effect is compensated by the energy attenuation of the electron beam spot edge. At shallow depths (<100 μm), a sharp focused beam spot (D = 50-100 μm) is used to concentrate energy on the surface, reducing heat diffusion. By attenuating the energy at the edge of the beam spot by 15% to 20%, abnormal increase in depth due to energy concentration in the edge area can be avoided. Preferably, in the hardening layer depth control step, dynamic power compensation is implemented at the start and / or end position of the scanning path, and the power is automatically reduced by 10% to 15% to suppress the heat accumulation effect, ensuring that the depth deviation of the entire area is ≤±5μm; The power is automatically reduced by 10% to 15% at the start and / or end of the scan to compensate for the "heat accumulation effect" at the edge (to avoid the edge depth being more than 20% deeper than the center). The beam intensity is adjusted in real time through the machine tool linkage system to ensure that the depth deviation of the entire area is ≤±5μm. Preferably, the parameters are set based on the phase change temperature field simulation, and the specific heat capacity and density parameters of the probe tip material are input through the heat conduction model to predict the temperature distribution with an error of ≤±10μm at the target depth; A three-dimensional heat conduction model was established using finite element software (such as ANSYS Fluent), and the specific heat capacity of beryllium copper (380 J / (kg·K)), density (8.3 g / cm 3 ) and other parameters, predict the temperature distribution cloud map under different parameters, and accurately set the process parameters to make the target depth error ≤±10μm. Preferably, for a beryllium copper probe tip with a thickness of 0.05 to 0.2 mm, a pulse modulation step is adopted, and the pulse modulation step specifically includes the following steps: An intermittent heat source is applied to a beryllium copper needle tip with a thickness of 0.05 to 0.2 mm. The heat input is controlled by adjusting the synergistic relationship between the pulse frequency and the duty cycle to prevent the hardened layer from penetrating deeply into the substrate. For beryllium copper parts with a thickness of 0.05 to 0.2 mm, a pulse frequency of 100 to 500 Hz and a duty cycle of 20% to 50% are used. The total energy input is controlled by intermittent heating to prevent the hardened layer from penetrating the substrate. For example, when the duty cycle is reduced by 10%, the depth of the hardened layer decreases by about 15 μm. Single-pass scanning: Applicable to hardened layer depths <100μm. The linear speed uniformity of the path must be ≤±2% to avoid uneven hardened layer depth caused by speed fluctuations (e.g., a 10% speed change will result in a depth change of ±15μm). Preferably, the manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step further comprises real-time monitoring and control, including: The infrared thermometer monitors surface temperature fluctuations in real time and automatically adjusts the power of the generated electron beam when the temperature fluctuation exceeds a threshold; The eddy current sensor detects the hardness gradient and provides feedback to correct the beam density parameters; The infrared thermometer simultaneously monitors the needle tip surface temperature (accuracy ±10°C) during scanning. When the temperature fluctuation exceeds the ±20°C threshold, the power of the generated electron beam is automatically adjusted to ensure depth stability. After quenching, the eddy current sensor immediately detects the surface hardness gradient and feeds it back to the control system to correct the next scanning parameters (such as if the actual depth is 5% shallower than the target, the beam energy density is increased by 5%). A microhardness tester was used to measure the cross-section (at 10 μm intervals) and plot a hardness-depth curve. The hardened layer depth was defined as the thickness of the region with a hardness ≥ 45 HRC (the beryllium copper substrate has a hardness of 35-40 HRC). Statistical process control (SPC) analysis was used to control the fluctuation of the hardened layer depth to within ±5%. The above-mentioned hardening layer depth control step makes the hardening layer depth of the needle tip controllable, thereby improving the fatigue life of the probe needle tip, avoiding brittle fracture caused by stress mutation, increasing wear resistance, enhancing environmental tolerance and balancing cost efficiency. Preferably, the manufacturing of the hardened layer further comprises the following steps: a quenching stress elimination step, wherein the quenching stress elimination step comprises: The low temperature tempering stress relief step comprises the following steps: Low-temperature tempering is performed in the temperature range of 150-200°C, and the holding time is adjusted in a gradient of 30-90 minutes according to the thickness of the workpiece, so that the martensite decomposes into tempered martensite and releases the lattice distortion stress; Use a vacuum tempering furnace with a temperature control accuracy of ±2°C and slowly cool to below 50°C at a cooling rate of ≤10°C / min; And / or, the aging synergistic stress relief step comprises the following steps: A beryllium copper alloy needle tip containing 1.6% to 2.0% beryllium is first pre-aged at 110°C to 130°C for 1 to 3 hours to stabilize the martensitic substructure, and then subjected to main aging at 320°C to 340°C for 2 to 4 hours. During the aging treatment, coherent strain generated by precipitates within the grains offsets the quenching stress. And / or, the static pressure shaping and composite stress relief step comprises the following steps: For workpieces with curvature > 0.1 mm / mm after quenching, apply a static pressure correction force of 5 to 10 N / mm before tempering and maintain it for 8 to 12 minutes to offset the quenching stress through the correction stress; Preferably, the low-temperature tempering stress relief step activates dislocation movement by tempering temperature (150-200° C.), promotes the decomposition of martensite into tempered martensite, and releases lattice distortion stress (accounting for 60%-70% of the total stress). Low temperature tempering stress relief process parameters: Temperature: Select according to the hardness retention requirements. The best stress relief temperature for beryllium copper alloy needle tips is 180±5℃. When the temperature exceeds 220℃, the hardness begins to decrease, and the hardness decreases by 2~3HRC for every 10℃ increase. Time: Calculated according to the thickness of the workpiece, 30 minutes for 0.1mm thin sheets and 60-90 minutes for thicker pieces over 1mm. Too long a time will lead to grain boundary diffusion and slow down the improvement of stress relief efficiency. Cooling: Cool down to below 50℃ before taking out of the furnace (cooling rate ≤ 10℃ / min) to avoid secondary thermal stress. Equipment requirements: Use a high-precision vacuum tempering furnace (temperature control accuracy ±2°C) to prevent oxidation of the beryllium copper surface. The oxide layer will cause the stress concentration factor to increase by 15% to 20%. Preferably, the aging synergistic stress relief step is applicable to precipitation-hardened beryllium copper needle tips, particularly high-strength beryllium copper alloy needle tips (such as C17200) containing 1.6% to 2.0% beryllium. The volume expansion effect of the θ phase (CuBe) precipitated during the aging process is used to offset part of the quenching stress. Immediately after quenching, pre-aging is performed at 120°C for 2 hours to stabilize the martensitic substructure, and then the temperature is raised to 320-340°C for 3 hours. When precipitation strengthening is the same, the stress relief rate can reach more than 85%. During the aging treatment, the intragranular precipitates produce coherent strain, which interacts with the quenching stress to reduce the average stress value from 500MPa to 80-100MPa. Preferably, the static pressure shaping and composite stress relief step is applicable to workpieces with a curvature >0.1mm / mm after quenching. Static pressure shaping (pressure 5-10N / mm2) is performed at room temperature before tempering, and tempering is performed immediately after holding for 10 minutes. This can offset the shaping stress and quenching stress, and ultimately reduce the residual stress by more than 50%. A high-precision shaping fixture (positioning accuracy ±5μm) is used in conjunction with a laser vibrometer to monitor the stress release vibration signal during the shaping process. By eliminating the quenching stress mentioned above, the average residual stress of beryllium copper after electron beam quenching can be controlled within ±150MPa (ideal value ≤±100MPa), and the uniformity of stress distribution can be improved to more than 90%, effectively avoiding delayed cracking and long-term service failure caused by stress. On the other hand, Figure 1 As shown, the present invention also provides a probe, comprising: a probe tip 2 and a hardened layer (not shown) obtained by processing according to the probe strengthening treatment method as described in any of the above items, the hardened layer (not shown) is located on the surface of the probe tip 2, and the hardness of the hardened layer is 52~55HRC. The present invention proposes a probe, which is configured to 3 ~1×104 W / cm 2 The synergistic effect of specific beam current density) and self-cooling quenching solves the technical problems of insufficient micro-area strengthening accuracy, insufficient hardness performance of the hardened layer, and processing deformation in the existing technology. This solution can effectively reduce the wear of the needle tip, extend the service life, and does not require subsequent machining to correct deformation, thereby reducing production costs. The probe provided by the present invention includes: a cantilever needle (such as Figure 2 As shown), straight needle (as Figure 3 Probes of any shape or form are within the protection scope of this application. Example 1 like Figure 1 As shown, the present invention provides a probe strengthening treatment method, comprising: manufacturing a hardened layer on the surface of the needle tip, wherein the manufacturing of the hardened layer comprises the following steps: Electron beam quenching step: The formed and hardened beryllium copper alloy tip is heated to 850℃ to reach the β phase region, and an acceleration voltage of 80kV and a beam current density of 1×10 4 W / cm 2 The electron beam is focused by an electromagnetic lens and bombards the surface of the beryllium copper alloy tip, causing the local area to heat up to above the material phase transition temperature within ≤0.1s, causing the local area to austenitize within ≤0.1s, and achieving 10 4 ℃ / s cooling rate, the supersaturated β phase transforms into α' phase martensite, obtaining a metastable martensite structure with high dislocation density, and the hardness increases to 50HRC (500HV); Aging precipitation strengthening step: Aging treatment is performed at 350°C for 3 hours to precipitate nano-scale γ-phase strengthening particles in the α' phase martensite, and the hardness is increased to 55HRC (570HV). Example 1 also provides a probe, comprising: a beryllium copper alloy needle tip and a hardened layer (not shown) obtained by processing according to the above-mentioned probe strengthening treatment method, wherein the hardened layer (not shown) is located on the surface of the beryllium copper alloy needle tip. Comparative Example 1 Comparative Example 1 provides a probe comprising a beryllium copper alloy needle tip, wherein the beryllium copper alloy needle tip does not have the hardening layer prepared in Example 1. Experimental methods The performance of the probe tips obtained in Example 1 and Comparative Example 1 was tested using the following experimental means: Comparative Example 1: Test Method for Hardness of Beryllium-Copper Alloy Tip Without Hardened Layer: Knupp Microhardness Test (Bidirectional Indentation Method); Key Parameters / Standards: Load 1-1000 gf, Indentation Major / Minor Axis Ratio ≈ 7:1 (ASTM E384); Example 1 Test of the tip hardness of beryllium copper alloy after the electron beam quenching step Experimental method: Micro Vickers hardness vertical section method (continuous indentation from the surface to the substrate), key parameters / standards: load 0.3-1 kgf, critical hardness value 550 HV (ISO 2639); Example 1 Test of the needle tip hardness value of beryllium copper alloy after the aging precipitation strengthening step Experimental method: Microindentation hardness retest (avoid matrix interference), key parameters / standards: Rockwell B / C scale is prohibited for thin-walled parts, and the micro-Vickers method is used; The tensile strength test of the beryllium copper alloy tip of the probe of Example 1 and Comparative Example 1 was carried out using the following experimental methods: microscale tensile test (custom tip fixture), strain rate 0.5 mm / min, extensometer accuracy ±0.1 μm (ASTM E8 / E8M); Wear loss test of the beryllium copper alloy tip of the probe in Example 1 and Comparative Example 1 Experimental method: Grinding wheel friction test (load 50N, SiC grinding wheel grit #120), load 50N, wear loss measurement by weight loss method (ASTM G65). The performance of the beryllium copper alloy probe tips obtained in Example 1 and Comparative Example 1 was tested using the above experimental methods and the experimental data are as follows: From Table 1, we can observe that in Example 1, the beryllium copper alloy needle tip surface is coated with a hardened layer (not shown), and the hardness value and tensile strength are greatly improved compared with Comparative Example 1 in which the beryllium copper alloy needle tip surface is not coated with a hardened layer (not shown), and the wear weight loss is greatly reduced, which proves that the hardness of the beryllium copper alloy needle tip of the probe provided by Example 1 is significantly improved, and the strength and wear resistance are greatly improved. It will be appreciated that the present invention is described through some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are subject to various changes or equivalent substitutions. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope protected by the present invention.

Claims

1. A probe strengthening treatment method, characterized in that: include: A hardened layer is manufactured on the surface of the needle tip that has been formed and is in a hard state. The manufacturing of the hardened layer includes the following steps: Electron beam quenching steps: using an accelerating voltage of 60-80 kV and a beam current density of 5 × 10 3 ~1×10 4 W / cm 2 The electron beam is focused by an electromagnetic lens and bombards the probe tip surface, causing the local area to heat up to above the material phase transition temperature within ≤0.1s, and the substrate self-cooling is used to achieve 10 3 ~10 4 ℃ / s cooling rate, forming a metastable martensite structure with high dislocation density.

2. The probe strengthening method according to claim 1, wherein: In the electron beam quenching step, the needle tip includes: a formed and hard beryllium copper alloy needle tip, the beryllium copper alloy needle tip is heated to 780-850°C to reach the β phase region, the electron beam bombards the needle tip surface, causing the local area to austenitize within ≤0.1s, and through self-cooling of the matrix, the supersaturated β phase is transformed into α' phase martensite, and the hardness is increased to 45-50HRC.

3. The probe strengthening method according to claim 1 or 2, characterized in that: The manufacturing of the hardened layer includes the following steps: an aging precipitation strengthening step, which includes the following steps: aging treatment at 300-350°C for 2-3 hours to precipitate nano-scale γ phase strengthening particles in the α' phase martensite and increase the hardness to 52-55HRC.

4. The probe strengthening method according to claim 1, wherein: The manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step comprises the following steps: Adjust the parameters of electron beam energy density and scanning speed so that the depth of the hardened layer satisfies the following formula: In the formula, k is the thermal diffusion constant of the material, E is the energy density of the electron beam, and d is the depth of the hardened layer; The electron beam spot diameter is dynamically controlled. A sharp focus beam spot is used during shallow hardening, so that the electron beam spot diameter D is ≤ 100 μm, and the edge thermal effect is compensated by the energy attenuation of the electron beam spot edge.

5. The probe strengthening method according to claim 4, characterized in that: In the hardening layer depth control step, dynamic power compensation is implemented at the start and / or end position of the scanning path, and the power is automatically reduced by 10% to 15% to suppress the thermal accumulation effect, ensuring that the depth deviation of the entire area is ≤±5μm.

6. The probe strengthening method according to claim 1, wherein: Based on the phase change temperature field simulation and setting parameters, the specific heat capacity and density parameters of the probe tip material are input through the heat conduction model to predict the temperature distribution at the target depth with an error of ≤±10μm.

7. The probe strengthening method according to claim 1, wherein: For a beryllium copper probe tip with a thickness of 0.05 to 0.2 mm, a pulse modulation step is adopted, and the pulse modulation step specifically includes the following steps: An intermittent heat source is applied to a beryllium copper needle tip with a thickness of 0.05 to 0.2 mm. The heat input is controlled by adjusting the synergistic relationship between the pulse frequency and the duty cycle to prevent the hardened layer from penetrating deeply into the substrate.

8. The probe strengthening method according to any one of claims 4 to 7, characterized in that: The manufacturing of the hardened layer further comprises the following steps: a hardened layer depth control step, wherein the hardened layer depth control step further comprises real-time monitoring and control, including: The infrared thermometer monitors surface temperature fluctuations in real time and automatically adjusts the power of the generated electron beam when the temperature fluctuation exceeds a threshold; The eddy current sensor detects the hardness gradient and feeds back to correct the beam density parameters.

9. The probe strengthening method according to claim 3, wherein: The manufacturing of the hardened layer further comprises the following steps: a quenching stress elimination step, wherein the quenching stress elimination step comprises: The low temperature tempering stress relief step comprises the following steps: Low-temperature tempering is performed in the temperature range of 150-200°C, and the holding time is adjusted in a gradient of 30-90 minutes according to the thickness of the workpiece, so that the martensite decomposes into tempered martensite and releases the lattice distortion stress; Use a vacuum tempering furnace with a temperature control accuracy of ±2°C and slowly cool to below 50°C at a cooling rate of ≤10°C / min; And / or, the aging synergistic stress relief step comprises the following steps: A beryllium copper alloy needle tip containing 1.6% to 2.0% beryllium is first pre-aged at 110°C to 130°C for 1 to 3 hours to stabilize the martensitic substructure, and then subjected to main aging at 320°C to 340°C for 2 to 4 hours. During the aging treatment, coherent strain generated by precipitates within the grains offsets the quenching stress. And / or, the static pressure shaping and composite stress relief step comprises the following steps: For workpieces with a curvature > 0.1 mm / mm after quenching, apply a static pressure correction force of 5 to 10 N / mm before tempering and maintain it for 8 to 12 minutes to offset the quenching stress through the correction stress.

10. A probe, characterized in that: include: A probe tip and a hardened layer obtained by processing according to the probe strengthening method according to any one of claims 1 to 9, wherein the hardened layer is located on the surface of the probe tip and has a hardness of 52 to 55 HRC.

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