WO2023097987A1 - 一种轴承用三维梳齿状凹槽阵列表面及制备方法 - Google Patents

一种轴承用三维梳齿状凹槽阵列表面及制备方法 Download PDF

Info

Publication number
WO2023097987A1
WO2023097987A1 PCT/CN2022/093605 CN2022093605W WO2023097987A1 WO 2023097987 A1 WO2023097987 A1 WO 2023097987A1 CN 2022093605 W CN2022093605 W CN 2022093605W WO 2023097987 A1 WO2023097987 A1 WO 2023097987A1
Authority
WO
WIPO (PCT)
Prior art keywords
bearing
comb
sample
groove array
shaped groove
Prior art date
Application number
PCT/CN2022/093605
Other languages
English (en)
French (fr)
Inventor
刘成龙
郭峰
巨斌
栗心明
白清华
Original Assignee
青岛理工大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 青岛理工大学 filed Critical 青岛理工大学
Publication of WO2023097987A1 publication Critical patent/WO2023097987A1/zh

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/66—Special parts or details in view of lubrication
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/583—Details of specific parts of races
    • F16C33/585—Details of specific parts of races of raceways, e.g. ribs to guide the rollers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
    • F16C33/30—Parts of ball or roller bearings
    • F16C33/58—Raceways; Race rings
    • F16C33/64—Special methods of manufacture

Definitions

  • the invention belongs to the technical field of anti-friction and wear reduction of rolling bearings, and relates to a surface and a preparation method for realizing directional flow of lubricant, enhancing lubrication, and reducing bearing friction, especially a three-dimensional comb-shaped groove array surface for bearings and a preparation method.
  • the three-dimensional comb-tooth groove array (3d-CTG) surface is used as a virtual rib to enhance the oil collection of the bearing, and the synergistic effect of the geometric shape of the comb teeth and the wettability gradient of the chemical coating is used to achieve the effect of oil collection enhancement.
  • Bearings are known as mechanical joints.
  • the maintenance of an effective lubricating oil film in the bearing can reduce friction and reduce wear.
  • excessive supply of lubricant will cause additional bearing temperature rise and waste of resources; while reducing oil supply, lubrication
  • Most of the lubricant in the raceway is squeezed and distributed on both sides of the lubricating raceway, which does not form an effective lubrication supply.
  • it will be thrown out of the lubricating track due to centrifugal force and inertial force, which cannot be effectively separated.
  • the purpose of the present invention is to overcome the shortcomings of the prior art, design and provide a three-dimensional comb-shaped groove array surface for bearings and a preparation method, and use the virtual rib formed by the comb-shaped groove array to act on the self-oil-collecting reinforced bearing , to overcome the defects of oil cut-off caused by centrifugal action and creeping action between the rolling elements and the contact surface, by regulating the distribution of lubricant in the bearing, the lubrication efficiency of the bearing under the condition of limited oil supply is enhanced and the surface is prevented from being damaged, so that the contact parts Under the condition of limited oil supply, the friction pair can effectively use the oil collection capacity of the lubricating raceway to obtain sufficient lubricating oil to form full-film lubrication, and finally obtain the optimal tribological performance, achieve controllable lubrication process, and improve lubrication
  • the purpose of agent use efficiency is to overcome the shortcomings of the prior art, design and provide a three-dimensional comb-shaped groove array surface for bearings and
  • the surface of the three-dimensional comb-shaped groove array for bearings in the present invention includes a comb-shaped groove array and an oleophobic layer.
  • the oleophobic layer is arranged on the surface of the comb-shaped groove array.
  • Each groove is a comb-like structure, and the depth of the groove gradually changes from 0.2 to 2.5 ⁇ m from the bottom to the top of the tooth.
  • the oil layer adopts a PTFE film with a thickness of 30 ⁇ m, and the contact angle of the PTFE film reaches 140°.
  • the tips of the combs point to the center of the bearing raceway and are evenly distributed along the rolling center of the bearing.
  • the surface of the three-dimensional comb-shaped groove array prepared by the present invention is prepared by a femtosecond processing system.
  • the main structure of the femtosecond processing system includes a femtosecond laser light source 1, an aperture 2, a mirror 3, a half mirror 4, an objective lens 5, Sample 6, micromotor 7 and precision three-dimensional translation stage 8, sample 6 is connected with micromotor 7 and placed on precision three-dimensional translation stage 8, precision three-dimensional translation stage 8 controls sample 6 to move in XYZ three directions, objective lens 5 Placed directly above the sample 6, the femtosecond laser light source 1, the aperture 2 and the reflector 3 are arranged on the same horizontal plane, the reflector 3 is arranged directly above the objective lens 5, and a half mirror is arranged between the reflector 3 and the objective lens 5 4.
  • the external CCD is on the same level as the semi-mirror 4.
  • the CCD is connected to the femtosecond laser light source 1 and the aperture 2 respectively.
  • the computer is connected.
  • the movement accuracy of the precise three-dimensional translation stage 8 of the present invention is 0.1 mm.
  • the femtosecond laser light source 1 of the present invention has a wavelength of 1040nm, an average power of 40W, and a laser energy of 50 ⁇ J; the femtosecond laser light source 1 passes through the diaphragm 2, the mirror 3, the half mirror 4 and the objective lens 5 to reach the sample in sequence 6.
  • the spot diameter reaching the sample 6 is 10um.
  • the micromotor 7 of the present invention rotates 5 degrees every 16 seconds, the sample 6 is an inner ring of a rolling bearing, and the objective lens 5 is an eight-fold objective lens.
  • a femtosecond laser is used to etch grooves of a certain depth on the bearing surface, and then the PTFE film is embossed and bonded to the surface of the inner ring of the bearing, and then the laser is adjusted. Focus position, make the focus focus on the lower surface of the PTFE film, and scan the same pit position repeatedly. Under the action of laser ablation heating, the surface of the inner ring of the bearing will produce ripple-like characteristic stripes and the film will instantly vaporize. After gasification, part of the polymer material is adsorbed to the mechanical surface in the pit, and a super-oleophobic PTFE surface is obtained inside the pit.
  • the specific process is as follows:
  • Pre-etching depth Assemble the sample 6 cleaned in S1 with the micro-motor 7 and install it on the precision three-dimensional translation stage 8. After laser etching at the same position for 16 seconds, the main shaft rotates 5 degrees. The etching depth is based on the selected Different oleophobic materials are selected between 0-5 ⁇ m, and the exhaust system is used to remove gasified metals and organic materials during the preparation process to avoid material deposition;
  • Film transfer preparation select a PTFE film that is sufficient to cover the surface of the sample, use a small amount of liquid resin adhesive to fill the etching position of the bearing inner ring in S2, and use a vacuum degassing device to remove the inner ring of the bearing and the PTFE film prepared in S2. close fit;
  • Film transfer preparation first put the sample of the laminated film in S3 into the precision three-dimensional translation stage 8, and move the focus of the laser to make the lower surface and rigid surface of the film clearly visible. At this time, repeat the step S2 for etching, each time After scanning, increase the laser focus position by 10 ⁇ m, and scan 3 times in total, so that the surface of the inner ring of the rolling bearing is coated with a uniform oleophobic PTFE film, and the average energy of a single scan is selected as the attenuated energy of 10 ⁇ J.
  • the laser energy in this step varies according to the thickness of the film material. (Laser energy is 50 ⁇ J).
  • the present invention uses the comb-tooth-shaped groove array surface as the virtual rib of the inner ring of the rolling bearing to enhance the flow control of the lubricant.
  • the comb-tooth-shaped groove array surface distributes the comb-tooth-shaped groove array structure on both sides of the bearing raceway, At the same time, the comb tooth area is endowed with oleophobic properties.
  • the oleophobic part can effectively regulate the lubricant and prevent the loss of lubricant.
  • the invention utilizes a femtosecond laser to process groove arrays on both sides of the inner ring track, and then uses a PTFE film to perform ablation treatment, so that a layer of super-oleophobic PTFE coating is adsorbed on the surface of the groove, and the contact angle reaches 140°. Etching forms an oleophilic area that still maintains the original surface characteristics of the inner ring.
  • the contact angle of the oleophilic area is less than 10°, which can lock the lubricating oil and make the lubricating oil form a uniform lubricating oil film in the middle of the prepared virtual rib; sparse teeth
  • the groove array increases the potential energy barrier for the expansion of the liquid lubricant, and the comb-like texture also increases the backfilling ability of the lubricant.
  • the surface presents an uneven cluster-like micro-nano structure, which can lock the lubricating oil. At the same time, it can play an oleophobic effect.
  • the present invention uses a full bearing torque measuring instrument to measure the bearing torque at different rotational speeds on the surface of the prepared three-dimensional comb-shaped groove array.
  • the film-forming performance of the rib sample and the ordinary sample, the film-forming experiment adopts a reciprocating motion module, the stroke is 10mm, the lubricating oil is PAO4, the dosage is 0.5 ⁇ L, the load is 30N, and the speed range is 1-4Hz; in the film-forming experiment and torque measurement experiments, there is limited lubricating oil between the friction pairs, and the lubricant is evenly distributed in the lipophilic area.
  • the tension drives the lubricant on both sides to migrate to the central area of the lubricating track, and the prepared three-dimensional
  • the inner ring on the surface of the comb-shaped groove array also has the effect of resisting centrifugal force on both sides of the bearing lubricating track due to the driving force of the coating on both sides.
  • the present invention has the following advantages and beneficial technical effects:
  • the present invention can play the transport and guiding role of the micro-nano groove array on the lubricating oil, can improve the constraint distribution of the lubricating oil on the friction pair of the contact parts, and can also play the role of the interface gradient force of the oleophobic coating , actively regulate the loss of lubricant;
  • the problems of lack of oil and difficult lubricant return in the bearing can be effectively solved.
  • the lubricating material Increased film formation and significantly reduced bearing torque;
  • the bearing with the surface of the three-dimensional comb-shaped groove array prepared by the present invention can make the lubricant migrate to the center of the lubricating track. Under the condition of limited oil supply, the bearing torque can be maintained at a low level, which greatly improves the performance of the bearing. service life and performance;
  • the bearing with the three-dimensional comb-like groove array surface prepared by the present invention can maintain a limited amount of lubricant between the bearing lubrication tracks under the condition of discontinuous oil supply, and at the same time, the oleophobic coating on both sides of the bearing The layer can reduce the agitation friction resistance of the lubricant and reduce the friction torque of the bearing.
  • Fig. 1 is a schematic diagram of the structure and principle of the femtosecond laser processing system involved in the present invention.
  • Fig. 2 is the torque measurement result of the surface bearing with three-dimensional comb-shaped groove array involved in the present invention.
  • Fig. 3 is the contact angle measurement result diagram of different surfaces involved in the present invention, wherein (a) is the contact angle of ordinary steel surface, and (b) is the contact angle of steel surface with PTFE.
  • Figure 4 is a comparison of film thicknesses of 2 ⁇ L lubricating oil PAO4 on different surfaces under the condition of a load of 30N according to the present invention, where (a) is the result of light interference, and the left side is the light interference of film thickness on the surface of the three-dimensional comb-shaped groove array The results, the right side is the optical interference result of ordinary surface film thickness; (b) is the film thickness profile.
  • Figure 5 is an electron micrograph of the PTFE coating on the surface of the bearing steel involved in the present invention, wherein (a) is the etched surface of the steel, and (b) is the surface of the PTFE oleophobic coating.
  • Fig. 6 is the result of the oil collection experiment on the surface of the inner ring of the bearing involved in the present invention, where (a) is the initial position of the oil drop on the inner ring of the bearing (left: surface with three-dimensional comb-shaped groove array; right: ordinary bearing), ( b) The distribution of oil droplets after the inner ring of the bearing rotates (left: surface with a three-dimensional comb-shaped groove array; right: ordinary bearing).
  • Fig. 7 is a surface structure diagram with a three-dimensional comb-shaped groove array involved in the present invention.
  • the surface of the three-dimensional comb-shaped groove array for bearings in this embodiment includes a comb-shaped groove array and an oleophobic layer, the oleophobic layer is arranged on the surface of the comb-shaped groove array, and each groove of the comb-shaped groove array is It is a comb-like structure, and the depth of the groove gradually changes from 0.2 to 2.5 ⁇ m from the bottom to the top of the tooth. 30 ⁇ m PTFE film, the contact angle of PTFE film reaches 140°.
  • the tips of the combs point to the center of the bearing raceway and are evenly distributed along the rolling center of the bearing.
  • the surface of the three-dimensional comb-shaped groove array is prepared by a femtosecond laser processing system.
  • the main structure of the femtosecond laser processing system includes a femtosecond laser light source 1, an aperture 2, a mirror 3, a half mirror 4, Composed of objective lens 5, sample 6, micromotor 7 and precision three-dimensional translation stage 8, sample 6 is connected with micromotor 7 and placed on precision three-dimensional translation stage 8, and precision three-dimensional translation stage 8 controls sample 6 to move in XYZ three directions , the objective lens 5 is placed directly above the sample 6, the femtosecond laser light source 1, the diaphragm 2 and the reflective mirror 3 are arranged on the same horizontal plane, the reflective mirror 3 is arranged directly above the objective lens 5, and a half The half-mirror 4, the external CCD and the half-mirror 4 are on the same horizontal plane, the CCDs are respectively connected to the femtosecond laser light source 1 and the diaphragm 2, the femtosecond laser light source 1, the
  • the movement accuracy of the precise three-dimensional translation stage 8 in this embodiment is 0.1mm.
  • the wavelength of the femtosecond laser light source 1 described in this embodiment is 1040nm, the average power is 40W, and the laser energy is 50 ⁇ J; Sample 6, the spot diameter reaching sample 6 is 10 ⁇ m.
  • the micromotor 7 described in this embodiment rotates 5 degrees every 16 seconds, the sample 6 is an inner ring of a rolling bearing, and the objective lens 5 is an eight-fold objective lens.
  • the steps are as follows:
  • Pre-etching depth Assemble the sample 6 cleaned in S1 with the micro-motor 7 and install it on the precision three-dimensional translation stage 8. After laser etching at the same position for 16 seconds, the main shaft rotates 5 degrees. The etching depth is based on the selected Different oleophobic materials are selected between 0-5 ⁇ m, and the exhaust system is used to remove gasified metals and organic materials during the preparation process to avoid material deposition;
  • Film transfer preparation select a PTFE film that is sufficient to cover the surface of the sample, use a small amount of liquid resin adhesive to fill the etching position of the bearing inner ring in S2, and use a vacuum degassing device to remove the inner ring of the bearing and the PTFE film prepared in S2. close fit;
  • Film transfer preparation first put the sample of the laminated film in S3 into the precision three-dimensional translation stage 8, and move the focus of the laser to make the lower surface and rigid surface of the film clearly visible. At this time, repeat the step S2 for etching, each time After scanning, increase the laser focus position by 10 ⁇ m, and scan 3 times in total, so that the surface of the inner ring of the rolling bearing is coated with a uniform oleophobic PTFE film. The average energy of a single scan is selected as 10 ⁇ J. The laser energy in this step varies according to the thickness of the film material (laser energy 40 ⁇ J); and take out the sample for performance testing;
  • Oleophobic characterization using disc bearing steel of the same material: use a contact angle measuring instrument to test the contact angles of the uncoated sample and the coated sample in S4, and measure the same volume of lubricating oil drop on the disc test The static contact angle of the sample surface, the amount of lubricating oil is 5 ⁇ L, lubricating oil selects PAO4 base oil, in order to verify the oleophobic effect of the sample after coating, its result is as shown in Figure 3;
  • the structure of the self-oil-collecting bearing prepared in this example is to etch a layer of comb-like micro-nano structure with a certain roughness gradient and a certain geometric shape on the surface of the inner ring of the bearing.
  • the oil layer is ablated to the surface of the sample, so that the contact angle can have oleophobic properties, and the contact angle of the oleophobic layer reaches 140°, and a small amount of resin adhesive is coated on the etched position, which is conducive to the adhesion of PTFE.
  • the same position is etched again, and the PTFE film is adhered to the position of the groove array at the same time, and a super-oleophobic and slipping PTFE coating is prepared.
  • the microstructure of the PTFE coating is shown in Figure 5, and the remaining track positions are ordinary
  • the lipophilic area on the steel surface, the lipophilic area can lock the lubricating oil, so that the lubricating oil can be continuously distributed in the prepared lipophilic track, and the oleophobic coating on both sides can well limit the expansion of the lubricating oil to both sides ;
  • the tooth tip of the comb-shaped micro-nano structure faces the center of the bearing track, and the roughness gradually increases from the tooth tip to the tooth root. to the effect of transport towards the center of the orbit.
  • the self-oil-collecting bearings prepared in Example 1 are subjected to a bearing torque test and a lubrication film-forming test using a bearing torque testing machine and an photoelasto-hydrodynamic oil film measurement test machine, respectively, and the self-oil-collecting bearings and untreated bearings are tested The results were compared.
  • the lubricating oil in the film forming experiment was PAO4, the dosage was 0.5 ⁇ L, the load was 30N, the speed range was 0-80mm/s, and the test sample was a glass block with the same texture and PTFE coating; in the bearing torque test bench
  • the bearing torque measurement experiment was carried out on the bearing, the load used was 280N, the speed range was 500-2500rpm, the lubricating oil was PAO4, and the dosage was 5 ⁇ L.
  • the microstructure of the surface of the prepared bearing steel sample 5 was observed by scanning electron microscopy, as shown in Figure 5.
  • the nanostructure of the oleophobic region at the boundary between the oleophobic region and the oleophobic region can inhibit the flow of lubricating oil in the oleophilic region, and can effectively prevent the lubricant from creeping;
  • Lubricating oil the lubricant is evenly distributed in the lipophilic area, when the friction pair moves relative to each other, the tension drives the lubricant on both sides to migrate to the central area of the lubrication track, and the virtual rib in the prepared self-oil-collecting bearing removes and strengthens the lubricant Migrating to the center of the lubricating track, and due to the transport characteristics of the sparse-toothed micro-nano structure, the lubricant can spontaneously maintain a large oil pool on both sides of the track, and can resist the effects of inertial forces including centrifugal force.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Rolling Contact Bearings (AREA)
  • Laser Beam Processing (AREA)

Abstract

公开了一种轴承用三维梳齿状凹槽阵列表面及制备方法，先采用飞秒激光在轴承表面刻蚀出一定深度凹槽，再将PTFE薄膜压印贴合到轴承内圈表面，然后调节激光焦点位置，使焦点聚焦到PTFE薄膜下表面，对同一凹坑位置进行重复扫描，在激光烧蚀加热作用下，轴承内圈表面发生涟漪状特征条纹的同时薄膜瞬间气化，在机械联锁作用下气化后部分高分子材料吸附到凹坑内机械表面，在凹槽内部得到了超疏油的PTFE表面，能够在不连续供油条件下，使有限量润滑剂维持在轴承润滑轨道之间，轴承两侧的疏油涂层能够降低润滑剂的搅动摩擦阻力，减小轴承的摩擦力矩。

Description

一种轴承用三维梳齿状凹槽阵列表面及制备方法 技术领域：
本发明属于滚动轴承抗摩减磨技术领域，涉及一种实现润滑剂定向流动、增强润滑、降低轴承摩擦的表面及制备方法，特别是一种轴承用三维梳齿状凹槽阵列表面及制备方法，对轴承以三维梳齿状凹槽阵列(3d-CTG)表面作为虚拟挡边进行集油增强，利用梳齿几何形貌与化学涂层润湿性梯度的协同作用，达到集油增强的效果。
背景技术：
轴承素有机械关节之称，轴承中有效润滑油膜的维持能够减少摩擦降低磨损，但是在实际工作中，过量供给润滑剂会带来额外的轴承温升以及资源浪费；而降低供油量，润滑滚道中的润滑剂大部分被挤压分布在润滑滚道两侧，并没有形成有效的润滑供给，在高速运转中，还会因为离心力和惯性力等作用而甩出润滑轨道，无法有效的分离滚动或者滑动接触的两对偶摩擦副表面，在润滑剂有限量供给时，容易导致轴承热色变、滚子大端擦伤甚至整体锁死。因此需要在轴承中进行润滑剂回填的调控设计，来增强润滑油的回流和防止爬移，在限量供给润滑剂的工况下，增强轴承抵抗断油的能力。例如，在轴承内圈表面进行图案润湿性设计，不仅可以有效的提高润滑油的回填效果，并且可以对润滑剂的分布进行人为调控。
随着镀层、涂层等表面工程技术的进一步完善，液体润滑剂在自由表面的调控工艺越来越成熟，然而在轴承齿轮等微小接触间隙中，仍然缺少有效的方式进行润滑剂的调控。虽然通过机械加工挡边的方案可以有效的维持润滑剂的供给量，但高速条件下，润滑剂依然可以甩离轴承轨道。在无密封或间隙配合密封轴承中，润滑剂甩离后，需要不断注入新鲜润滑剂，额外的注油装置为工业设计和生产带来负担。
发明内容：
本发明的目的在于克服现有技术存在的缺点，设计提供一种轴承用三维梳齿状凹槽阵列表面及制备方法，将梳齿状凹槽阵列形成的虚拟挡边作用于自集油增强轴承，克服滚动体与接触表面因为离心作用以及爬移作用等造成断油的缺陷，通过对轴承中润滑剂的分布进行调控，增强限量供油条件下轴承的润滑效率并防 止破坏表面，使得接触部件的摩擦副在限量供油的条件下能够有效的利用润滑滚道的集油能力，得到充足的润滑油来形成全膜润滑，最终得到最优的摩擦学性能，达到润滑过程可控，提高润滑剂使用效率的目的。
为了实现上述目的，本发明所述轴承用三维梳齿状凹槽阵列表面包括梳齿状凹槽阵列和疏油层，疏油层设置在梳齿状凹槽阵列表面，梳齿状凹槽阵列的每个凹槽均为梳齿状结构，凹槽的深度沿齿底到齿顶为0.2～2.5μm逐渐变化，梳齿尖端角度为30°，梳齿长为1mm，单个梳齿宽度为150μm，疏油层采用厚度为30μm的PTFE薄膜，PTFE薄膜的接触角达到140°。
本发明轴承用三维梳齿状凹槽阵列表面应用于轴承时，所述梳齿尖端指向轴承滚道中心，并沿轴承滚动中心均匀分布。
本发明制备三维梳齿状凹槽阵列表面通过飞秒加工系统制备，所述飞秒加工系统主体结构包括飞秒激光光源1、光阑2、反光镜3、半反半透镜4、物镜5、样品6、微动电机7和精密三维平移台8组成，样品6与微动电机7相连并置于精密三维平移台8，精密三维平移台8控制样品6在XYZ三个方向进行移动，物镜5置于样品6正上方，飞秒激光光源1、光阑2和反光镜3设置在同一水平面上，反光镜3设置在物镜5正上方，反光镜3和物镜5之间设有半反半透镜4，外接的CCD与半反半透镜4在同一水平面上，CCD分别与飞秒激光光源1和光阑2相连，飞秒激光光源1、光阑2、精密三维平移台8和CCD分别与外接的计算机相连。
本发明所述精密三维平移台8的移动精度为0.1mm。
本发明所述飞秒激光光源1的波长为1040nm，平均功率40W，激光能量为50μJ；所述飞秒激光光源1依次经过光阑2、反光镜3、半反半透镜4和物镜5到达样品6，到达样品6的光斑直径为10um。
本发明所述微动电机7每16秒转动5度，样品6为滚动轴承内圈，物镜5为八倍物镜。
本发明在滚动轴承内圈制备三维梳齿状凹槽阵列表面时，先采用飞秒激光在轴承表面刻蚀出一定深度凹槽，再将PTFE薄膜压印贴合到轴承内圈表面，然后调节激光焦点位置，使焦点聚焦到PTFE薄膜下表面，对同一凹坑位置进行重复扫描，在激光烧蚀加热作用下，轴承内圈表面发生涟漪状特征条纹的同时薄膜瞬 间气化，在机械联锁作用下气化后部分高分子材料吸附到凹坑内机械表面，在凹槽内部得到了超疏油的PTFE表面，具体过程为：
S1、轴承部件清洗：选择滚动轴承内圈作为样品6，对滚动轴承内圈表面依次放入石油醚、无水乙醇和去离子水中分别超声清洗10分钟，清洗完毕后将轴承内圈用高压氮气吹干备用；
S2、预刻蚀深度：将S1中清洗后的样品6与微动电机7装配后安装到精密三维平移台8上，同一位置激光刻蚀处理16s后主轴旋转5度，刻蚀深度根据选用的疏油材料不同选择0-5μm之间，制备过程中采用排气系统进行气化金属和有机材料的清除，避免产生物料沉积；
S3、薄膜转移准备：选择足够覆盖样品表面的PTFE薄膜，利用微量液体树脂粘合剂填充S2中轴承内圈刻蚀位置，并将S2中制备的轴承内圈与PTFE薄膜利用真空除气装置进行紧密贴合；
S4、薄膜转移制备：先将S3中的贴合薄膜的样品放入精密三维平移台8，移动激光的焦点使得薄膜下表面和刚表面清晰可见，此时重复S2步骤进行刻蚀处理，每次扫描后提高激光焦点位置10μm，总共扫描3次，使得滚动轴承内圈表面镀有均匀疏油的PTFE膜，其中单次扫描平均能量选取衰减后能量10μJ，该步骤激光能量根据薄膜材料厚度不同而改变(激光器能量为50μJ)。
本发明采用梳齿状凹槽阵列表面作为滚动轴承内圈的虚拟挡边来增强对润滑剂的流动控制，梳齿状凹槽阵列表面将梳齿状凹槽阵列结构分布在轴承滚道两侧，同时赋予该梳齿区域疏油特性，当润滑剂由于离心作用或者爬移发生时，该疏油部位可以有效地进行润滑剂的调控，防止润滑剂的流失。
本发明利用飞秒激光在内圈轨道两侧进行沟槽阵列加工，接着利用PTFE薄膜进行烧蚀处理，使凹槽表面吸附一层超疏油的PTFE涂层，接触角达到140°，在未刻蚀形成了依然保持内圈原来表面特性的亲油区，亲油区接触角小于10°，能够锁住润滑油，使润滑油在制备的虚拟挡边中间形成均匀的润滑油膜；疏齿状的凹槽阵列增加了液体润滑剂扩展的势能垒，梳齿状织构也增加了润滑剂的回填能力，PTFE薄膜烧蚀后表面呈现凹凸不平的团簇状微纳米结构，在锁住润滑油的同时能够起到疏油效果。
本发明对制备的三维梳齿状凹槽阵列表面采用全轴承扭矩测量仪在不同转 速下进行轴承扭矩测量，同时采用玻璃块试样在光弹流实验机上进行润滑成膜实验，测试带有虚拟挡边的试样与普通试样的成膜性能，成膜实验采用往复运动模块，行程为10mm，润滑油为PAO4，用量为0.5μL，载荷为30N，速度范围1-4Hz；在成膜实验和扭矩测量实验中，摩擦副之间存在有限的润滑油，润滑剂均匀分布在亲油区域，当摩擦副相对运动时，张力驱动两侧的润滑剂向润滑轨道中央区迁移，而制备的三维梳齿状凹槽阵列表面内圈除增强润滑剂向润滑轨道中央迁移外，同时由于两侧涂层对润滑剂的驱动力作用，润滑剂在轴承润滑轨道两侧具有抵抗离心力的作用。
本发明与现有技术相比，具有如下优点及有益技术效果：
(1)本发明能够发挥微纳米凹槽阵列对润滑油的输运导引作用，能够改善接触零件的摩擦副上的润滑油的约束分布，同时也能够发挥疏油涂层的界面梯度力作用，主动调控润滑剂的流失；
(2)在所制备的带有虚拟挡边的轴承中，能够有效解决轴承中出现的乏油，润滑剂回流难的问题，在采用本发明制备的带有虚拟挡边的轴承后，润滑材料的成膜性增加，并且轴承扭矩显著降低；
(3)本发明制备的带有三维梳齿状凹槽阵列表面的轴承能够使润滑剂向润滑轨道中央迁移，在限量供油条件下，轴承扭矩能够维持较低的水平，大大提高了轴承的使用寿命和运转性能；
(4)本发明制备的带有三维梳齿状凹槽阵列表面的轴承能够在不连续供油条件下，使有限量润滑剂维持在轴承润滑轨道之间，同时，轴承两侧的疏油涂层能够降低润滑剂的搅动摩擦阻力，减小轴承的摩擦力矩。
附图说明：
图1为本发明涉及的飞秒激光加工系统结构原理示意图。
图2为本发明涉及的带有三维梳齿状凹槽阵列表面轴承的扭矩测量结果。
图3为本发明涉及的不同表面的接触角测量结果图，其中(a)为普通钢表面接触角，(b)为带有PTFE钢表面接触角。
图4为本发明涉及的在载荷30N的条件下2μL润滑油PAO4在不同表面膜厚对比图，其中(a)为光干涉结果图，左侧为三维梳齿状凹槽阵列表面膜厚光干涉结果，右侧为普通表面膜厚光干涉结果；(b)为膜厚轮廓图。
图5为本发明涉及的轴承钢表面PTFE镀层的电镜照片图，其中(a)为钢刻蚀表面，(b)为PTFE疏油涂层表面。
图6为本发明涉及的轴承在内圈表面的集油实验结果，其中(a)为轴承内圈油滴初始位置(左：具有三维梳齿状凹槽阵列表面；右：普通轴承)，(b)为轴承内圈旋转后油滴分布(左：具有三维梳齿状凹槽阵列表面；右：普通轴承)。
图7为本发明涉及的带有三维梳齿状凹槽阵列表面结构图。
具体实施方式：
下面结合附图并通过实施例对本发明作进一步详细说明。
实施例1：
本实施例所述轴承用三维梳齿状凹槽阵列表面包括梳齿状凹槽阵列和疏油层，疏油层设置在梳齿状凹槽阵列表面，梳齿状凹槽阵列的每个凹槽均为梳齿状结构，凹槽的深度沿齿底到齿顶为0.2～2.5μm逐渐变化，梳齿尖端角度为30°，梳齿长为1mm，单个梳齿宽度为150μm，疏油层采用厚度为30μm的PTFE薄膜，PTFE薄膜的接触角达到140°。
本实施例轴承用三维梳齿状凹槽阵列表面应用于轴承时，所述梳齿尖端指向轴承滚道中心，并沿轴承滚动中心均匀分布。
本实施例制备三维梳齿状凹槽阵列表面通过飞秒激光加工系统制备，所述飞秒激光加工系统主体结构包括飞秒激光光源1、光阑2、反光镜3、半反半透镜4、物镜5、样品6、微动电机7和精密三维平移台8组成，样品6与微动电机7相连并置于精密三维平移台8，精密三维平移台8控制样品6在XYZ三个方向进行移动，物镜5置于样品6正上方，飞秒激光光源1、光阑2和反光镜3设置在同一水平面上，反光镜3设置在物镜5正上方，反光镜3和物镜5之间设有半反半透镜4，外接的CCD与半反半透镜4在同一水平面上，CCD分别与飞秒激光光源1和光阑2相连，飞秒激光光源1、光阑2、精密三维平移台8和CCD分别与外接的计算机相连。
本实施例所述精密三维平移台8的移动精度为0.1mm。
本实施例所述飞秒激光光源1的波长为1040nm，平均功率40W，激光能量为50μJ；所述飞秒激光光源1依次经过光阑2、反光镜3、半反半透镜4和物镜5到达样品6，到达样品6的光斑直径为10μm。
本实施例所述微动电机7每16秒转动5度，样品6为滚动轴承内圈，物镜5为八倍物镜。
本实施例在制备自集油轴承(即在滚动轴承内圈制备三维梳齿状凹槽阵列表面)时，按照如下步骤进行：
S1、轴承部件清洗：选择滚动轴承内圈作为样品6，对滚动轴承内圈表面依次放入石油醚、无水乙醇和去离子水中分别超声清洗10分钟，清洗完毕后将轴承内圈用高压氮气吹干备用；
S2、预刻蚀深度：将S1中清洗后的样品6与微动电机7装配后安装到精密三维平移台8上，同一位置激光刻蚀处理16s后主轴旋转5度，刻蚀深度根据选用的疏油材料不同选择0-5μm之间，制备过程中采用排气系统进行气化金属和有机材料的清除，避免产生物料沉积；
S3、薄膜转移准备：选择足够覆盖样品表面的PTFE薄膜，利用微量液体树脂粘合剂填充S2中轴承内圈刻蚀位置，并将S2中制备的轴承内圈与PTFE薄膜利用真空除气装置进行紧密贴合；
S4、薄膜转移制备：先将S3中的贴合薄膜的样品放入精密三维平移台8，移动激光的焦点使得薄膜下表面和刚表面清晰可见，此时重复S2步骤进行刻蚀处理，每次扫描后提高激光焦点位置10μm，总共扫描3次，使得滚动轴承内圈表面镀有均匀疏油的PTFE膜，其中单次扫描平均能量选取10μJ，该步骤激光能量根据薄膜材料厚度不同而改变(激光器能量为40μJ)；并取出试样进行性能测试；
S5、疏油表征(采用相同材料的圆盘轴承钢)：用接触角测量仪分别测试未镀膜的试样和S4中镀膜后的试样的接触角，测量相同体积润滑油滴在圆盘试样表面的静态接触角，所述润滑油用量为5μL，润滑油选用PAO4基础油，用以验证试样在镀层后的疏油效果，其结果如图3所示；
S6、轴承扭矩测量：将S4制备的轴承内圈与轴承外圈、钢球和保持架进行组合，将组合后的轴承进行轴承扭矩测量，并与普通轴承测量结果进行对比，其结果如图2所示。
本实施例通过CCD观测到样品5表面上出现烧蚀光斑时，PTFE烧蚀表面疏油效果最佳。
本实施例制备出的自集油轴承的结构为在轴承内圈表面刻蚀出一层具有一定粗糙度梯度和一定几何形貌的梳齿状微纳米结构，同时将疏油性能优越的PTFE疏油层烧蚀到样品表面，使得接触角能够具有疏油性能，并且疏油层的接触角达到140°，在刻蚀掉的位置涂覆微量树脂粘合剂，有利于PTFE的黏附，利用飞秒激光再次刻蚀同一位置，PTFE薄膜气话同时黏附到凹槽阵列位置，而制备超疏油和滑移的PTFE涂层，所述的PTFE涂层微观结构如图5所示，剩余轨道位置为普通钢表面的亲油区，所述亲油区能够锁住润滑油，使润滑油在制备的亲油轨道内连续分布，而两侧疏油涂层可以很好的限制润滑油往两侧的扩展；所述梳齿状微纳结构齿尖端朝向轴承轨道中心，由齿尖向齿根粗糙度逐渐增加，疏油涂层结合能力更好，梳齿状微纳结构对分布其上的润滑剂起到往轨道中心输运的效果。
实施例2：
本实施例对实施例1中制备的自集油轴承采用轴承扭矩实验机以及光弹流油膜测量试验机分别进行轴承扭矩实验和润滑成膜测试实验，将自集油轴承和未处理轴承的测试结果进行对比，成膜实验润滑油为PAO4，用量为0.5μL，载荷为30N，速度范围0-80mm/s，测试样品为带有相同织构和PTFE涂层的玻璃块；在轴承扭矩试验台上进行轴承扭矩测量实验，采用的载荷为280N，速度范围为500-2500rpm，润滑油为PAO4，用量为5μL。采用扫描电镜对制备的轴承钢样品5表面的显微结构进行观察，如图5所示，从图5中能够看出原本光滑的PTFE表面在刻蚀后呈现出微小的团簇状结构，显微结构变化明显，出现了纳米级的层状分布结构，这是典型的疏水疏油结构；并对轴承内圈的集油效果进行实验，将0.5μLPAO4润滑油滴加到涂层边界处，以1000rpm的转速进行离心测试，实验前后的油滴在轴承内圈表面的分布如图6所示，显示了制备的虚拟挡边(即三维梳齿状凹槽阵列表面)的集油性能，亲油区与疏油区边界处疏油区的纳米结构对亲油区润滑油流动起到抑制作用，能够有效的防止润滑油爬移；在成膜实验和摩擦磨损实验中，摩擦副之间存在有限的润滑油，润滑剂均匀分布在亲油区域，当摩擦副相对运动时，张力驱动两侧的润滑剂向润滑轨道中央区迁移，而制备的自集油轴承中的虚拟挡边除增强润滑剂向润滑轨道中央迁移外，同时由于疏齿状微纳米结构的输运特性，润滑剂在轨道两侧能够自发的维持较大的油池，能够抵抗 包括离心力在内的惯性力的作用。
本实施例轴承扭矩测试结果如图2所示，在相同供油量和相同载荷条件下，自集油轴承其内圈表面的虚拟挡边能够使膜厚维持一定的厚度，但普通润滑轨道表面在现有速度条件下，轴承扭矩较大，从图4的膜厚轮廓图也可以看出，带有梳齿状沟槽的表面较普通表面可以维持较高的膜厚；从图2中还能够看出，在500rpm的低速段，两类轴承扭矩差别较大，有0.011N·m，随着速度增加，两者差别较小，但在2000-2500rpm时，两者差距逐渐稳定，达到0.005N·m；图4的膜厚实验结果显示，普通轨道的油池分布较小，表明图案润湿性轨道的润滑效果要比普通轨道的好，改进后的润滑轨道的集油效果明显加强，即使用少量的润滑剂也能达到很好的供油效果，对于工业应用中粘度较小的PAO4基础润滑油，在80mm/s速度下，接触区中心膜厚差别能够达到22nm。

Claims (7)

  1. 一种轴承用三维梳齿状凹槽阵列表面，其特征在于，包括梳齿状凹槽阵列和疏油层，疏油层设置在梳齿状凹槽阵列表面，梳齿状凹槽阵列的每个凹槽均为梳齿状结构，凹槽的深度沿齿底到齿顶为0.2～2.5μm逐渐变化，梳齿尖端角度为30°，梳齿长为1mm，单个梳齿宽度为150μm，疏油层采用厚度为30μm的PTFE薄膜，PTFE薄膜的接触角达到140°。
  2. 根据权利要求1所述轴承用三维梳齿状凹槽阵列表面，其特征在于，应用于轴承时，所述梳齿尖端指向轴承滚道中心，并沿轴承滚道中心均匀分布。
  3. 根据权利要求1所述轴承用三维梳齿状凹槽阵列表面，其特征在于，所述三维梳齿状凹槽阵列表面通过飞秒加工系统制备，所述飞秒加工系统主体结构包括飞秒激光光源、光阑、反光镜、半反半透镜、物镜、样品、微动电机和精密三维平移台组成，样品与微动电机相连并置于精密三维平移台，精密三维平移台控制样品在XYZ三个方向进行移动，物镜置于样品正上方，飞秒激光光源、光阑和反光镜设置在同一水平面上，反光镜设置在物镜正上方，反光镜和物镜之间设有半反半透镜，外接的CCD与半反半透镜在同一水平面上，CCD分别与飞秒激光光源和光阑相连，飞秒激光光源、光阑、精密三维平移台和CCD分别与外接的计算机相连。
  4. 根据权利要求3所述轴承用三维梳齿状凹槽阵列表面，其特征在于，所述精密三维平移台的移动精度为0.1mm。
  5. 根据权利要求3所述轴承用三维梳齿状凹槽阵列表面，其特征在于，所述所述飞秒激光光源的波长为1040nm，平均功率40W，激光能量为50μJ；飞秒激光光源依次经过光阑、反光镜、半反半透镜和物镜到达样品，到达样品的光斑直径为10μm。
  6. 根据权利要求3所述轴承用三维梳齿状凹槽阵列表面，其特征在于，所述所述微动电机每16秒转动5度，样品为滚动轴承内圈，物镜为八倍物镜。
  7. 一种如权利要求3所述轴承用三维梳齿状凹槽阵列表面的制备方法，其特征在于，具体制备过程为：
    S1、轴承部件清洗：选择滚动轴承内圈作为样品，对滚动轴承内圈表面依次放入石油醚、无水乙醇和去离子水中分别超声清洗10分钟，清洗完毕后将轴承内圈用高压氮气吹干备用；
    S2、预刻蚀深度：将S1中清洗后的样品与微动电机装配后安装到精密三维平移台上，同一位置激光刻蚀处理16s后主轴旋转5度，刻蚀深度根据选用的疏油材料不同选择0-5μm之间，制备过程中采用排气系统进行气化金属和有机材料的清除，避免产生物料沉积；
    S3、薄膜转移准备：选择足够覆盖样品表面的PTFE薄膜，利用微量液体树脂粘合剂填充S2中轴承内圈刻蚀位置，并将S2中制备的轴承内圈与PTFE薄膜利用真空除气装置进行紧密贴合；
    S4、薄膜转移制备：先将S3中的贴合薄膜的样品放入精密三维平移台，移动激光的焦点使得薄膜下表面和刚表面清晰可见，此时重复S2步骤进行刻蚀处理，每次扫描后提高激光焦点位置10μm，总共扫描3次，使得滚动轴承内圈表面镀有均匀疏油的PTFE膜，其中单次扫描平均能量选取衰减后能量10μJ。
PCT/CN2022/093605 2021-12-01 2022-05-18 一种轴承用三维梳齿状凹槽阵列表面及制备方法 WO2023097987A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111450909.3A CN114198406A (zh) 2021-12-01 2021-12-01 一种轴承用三维梳齿状凹槽阵列表面及制备方法
CN202111450909.3 2021-12-01

Publications (1)

Publication Number Publication Date
WO2023097987A1 true WO2023097987A1 (zh) 2023-06-08

Family

ID=80649998

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/093605 WO2023097987A1 (zh) 2021-12-01 2022-05-18 一种轴承用三维梳齿状凹槽阵列表面及制备方法

Country Status (2)

Country Link
CN (1) CN114198406A (zh)
WO (1) WO2023097987A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114198406A (zh) * 2021-12-01 2022-03-18 青岛理工大学 一种轴承用三维梳齿状凹槽阵列表面及制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009002529A1 (de) * 2009-04-21 2010-10-28 Robert Bosch Gmbh Einspritzpumpe für eine Verbrennungskraftmaschine
CN102226459A (zh) * 2011-06-03 2011-10-26 江苏大学 一种轴承的激光微造型自润滑处理方法
CN106925894A (zh) * 2017-03-15 2017-07-07 江苏理工学院 一种激光微造型制备轴承耐腐蚀表面的方法
CN107100940A (zh) * 2017-05-19 2017-08-29 温岭市九洲电机制造有限公司 一种电机的润滑结构
CN112230318A (zh) * 2020-11-06 2021-01-15 山东交通学院 一种利用飞秒激光直写技术制备平面光栅的装置和方法
CN112303125A (zh) * 2020-11-02 2021-02-02 江苏科技大学 一种在表面加工有微造型的滑动轴承及其制备方法
CN114198406A (zh) * 2021-12-01 2022-03-18 青岛理工大学 一种轴承用三维梳齿状凹槽阵列表面及制备方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009002529A1 (de) * 2009-04-21 2010-10-28 Robert Bosch Gmbh Einspritzpumpe für eine Verbrennungskraftmaschine
CN102226459A (zh) * 2011-06-03 2011-10-26 江苏大学 一种轴承的激光微造型自润滑处理方法
CN106925894A (zh) * 2017-03-15 2017-07-07 江苏理工学院 一种激光微造型制备轴承耐腐蚀表面的方法
CN107100940A (zh) * 2017-05-19 2017-08-29 温岭市九洲电机制造有限公司 一种电机的润滑结构
CN112303125A (zh) * 2020-11-02 2021-02-02 江苏科技大学 一种在表面加工有微造型的滑动轴承及其制备方法
CN112230318A (zh) * 2020-11-06 2021-01-15 山东交通学院 一种利用飞秒激光直写技术制备平面光栅的装置和方法
CN114198406A (zh) * 2021-12-01 2022-03-18 青岛理工大学 一种轴承用三维梳齿状凹槽阵列表面及制备方法

Also Published As

Publication number Publication date
CN114198406A (zh) 2022-03-18

Similar Documents

Publication Publication Date Title
ES2393559T3 (es) Pieza de rozamiento en medio lubrificado que trabaja a presiones de contacto superiores a 200 MPa
WO2023097987A1 (zh) 一种轴承用三维梳齿状凹槽阵列表面及制备方法
WO2022057414A1 (zh) 一种径向滑动轴承轴瓦内表面织构复合加工方法和装置
Li et al. Tailoring friction interface with surface texture for high-performance ultrasonic motor friction materials
Xie et al. An experimental investigation of tribological performance of triangular textures in water lubrication regime
Liu et al. Laser pattern-induced unidirectional lubricant flow for lubrication track replenishment
Chen et al. Effect of geometric micro-groove texture patterns on tribological performance of stainless steel
Zou et al. Efficiency of surface texturing in the reducing of wear for tests starting with initial point contact
JP6095090B2 (ja) 摺動方法、摺動構造の製造方法、摺動構造およびデバイス
Syed et al. Influence of positive texturing on friction and wear properties of piston ring-cylinder liner tribo pair under lubricated conditions
Yang et al. Study on tribological properties of surface concave convex micro-texture on the mold steel
Wang et al. Evaluation of tribological performance for laser textured surfaces with diverse wettabilities under water/oil lubrication environments
Miyanaga et al. Experimental investigation of load carrying capacity and frictional torque of dimpled parallel thrust bearings
Gimeno et al. Effect of different laser texturing patterns on rolling contact surface and its tribological & fatigue life behavior on 100Cr6 bearing steel
Liu et al. Wedge-shaped lyophilic pattern on superlyophobic surface for unidirectional liquid guidance and lubrication enhancement
Xu et al. Optimization of Bionic Texture Parameters by Box–Behnken Method and Study on Tribological Performance of 42CrMo Self-Lubricating Composites in Solid–Liquid Composite Lubrication System
CN114034606B (zh) 一种提高油膜承载力的表面间隔润湿性结构
CN110645264B (zh) 一种滚动轴承内圈滚道及滚动轴承
CN116181803B (zh) 一种提高压裂泵滑动轴承润滑能力的轴瓦梯度表面织构
Etsion Laser surface texturing and applications
Allan The Influence of Low Friction TMD coatings on The Tribological Performance of Surface Textured Steels
Sasaki Surface Texturing for Friction Control: A Review on Existing Technology and Prospects
Demircan et al. Laser Surface Texturing and Techniques to Improve the Tribological Properties of Materials
Singh et al. Experimental studies for accessing the influence of micro-dimple area density on tribological performance of mating contacts
Xie et al. Friction and Wear Behavior of G20CrMo with Cylindrical Texture Filled with Sn-Ag-Cu under Different Conditions

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22899807

Country of ref document: EP

Kind code of ref document: A1