CN111014531B - Cold forging lubricating method based on net-shaped storage structure - Google Patents
Cold forging lubricating method based on net-shaped storage structure Download PDFInfo
- Publication number
- CN111014531B CN111014531B CN201911227296.XA CN201911227296A CN111014531B CN 111014531 B CN111014531 B CN 111014531B CN 201911227296 A CN201911227296 A CN 201911227296A CN 111014531 B CN111014531 B CN 111014531B
- Authority
- CN
- China
- Prior art keywords
- storage structure
- blank
- layer
- net
- lubricating
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J3/00—Lubricating during forging or pressing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
- B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
- B21J5/02—Die forging; Trimming by making use of special dies ; Punching during forging
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
Abstract
A lubricating method in the field of cold forging of metal materials is a cold forging lubricating method based on a net-shaped storage structure, and the surface lubricating treatment is realized by preparing a multi-layer net-shaped storage structure, fully soaking the multi-layer net-shaped storage structure by a thermosetting lubricating medium, adhering the net-shaped storage structure soaked with the lubricating medium to a cold forging blank subjected to surface treatment, heating and curing the cold forging blank to form a composite lubricating layer. The invention can quickly realize the lubrication treatment of the blank, is used for the subsequent cold forging processing, greatly reduces the harm to the environment, and does not need to continuously add the lubricant in the subsequent use process.
Description
Technical Field
The invention relates to a technology in the field of cold forging processing, in particular to a cold forging lubricating method based on a net-shaped storage structure.
Background
In the cold forging process, the friction is generated between the die and the blank on a contact interface, the surface of the die is easily damaged under the condition of no lubrication, and the batch production cannot be realized. Therefore, the cold forging process must be well lubricated to improve the surface quality of the forging and the service life of the die. The phosphorization and saponification treatment is a classic lubrication treatment mode in cold forging processing, and a porous phosphate coating is formed on the surface of the treated metal and is used for storing saponified fat to play a role in lubrication. However, the process has many steps and long flow, and is accompanied with the problem of environmental pollution such as heavy metal ions, acid mist, wastewater and the like, and the application of the process is restricted by strict laws at present. Meanwhile, many products after cold forging processing need to be continuously added with lubricant to ensure normal use, and the subsequent operation is relatively complex. Therefore, it is urgently required to develop a new cold forging lubrication method which can solve the above-mentioned problems.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides the cold forging lubricating method based on the net-shaped storage structure, which can quickly realize the lubricating treatment of the blank, and does not need to supplement additional lubricant during the subsequent cold forging and use, thereby greatly reducing the harm to the environment and simplifying the lubricating treatment process.
The invention is realized by the following technical scheme:
the invention realizes the surface lubrication treatment by preparing a multi-layer reticular storage structure, fully impregnating the reticular storage structure with the thermosetting lubricating medium, adhering the reticular storage structure impregnated with the lubricating medium on the cold forging blank subjected to the surface treatment, heating and curing the reticular storage structure to form a composite lubricating layer.
The multilayer mesh storage structure is formed by stacking a plurality of single-layer mesh storage structures, warp-wise fiber bundles and weft-wise fiber bundles are staggered between adjacent single layers and are stacked, and the multiple layers are connected by using an orthogonal interlocking structure.
The multilayer mesh memory structure is preferably three layers.
The multilayer reticular storage structure is made of fiber materials, and the material parameters preferably meet the following requirements: elongation at break deltag>18% initial modulus Eg>20cN/dtex, fiber diameter
And surface expansion ratio eta when the blank is cold-forgeds>2 hour (eta)s＝SAfter forging/SBefore forging) Elongation at break deltag>41 percent; further preferred is polytetrafluoroethylene or polyacrylonitrile in a cylindrical shape.
Each layer of the multi-layer mesh storage structure is woven by warp-wise and weft-wise fiber bundles to obtain weaving units, and the weaving units repeatedly extend in the warp direction and the weft direction to form the multi-layer mesh storage structure, wherein the warp-wise and weft-wise fiber bundles are respectively formed by ngAnd nwRoot cylindrical fibers and satisfies ng＝nwThe cross section of the weaving unit is in a fan blade shape, and the weaving unit is 80-120.
The weaving unit obtained by the weaving satisfies
Wherein:
every n warp yarns for a weft yarn are interwoven,
for one warp to interlace every n picks, αgTo weave corners, 0<αg≤90°。
The material of the thermosetting lubricating mediumThe material parameters preferably satisfy: curing temperature Ts80-130 ℃ and average particle diameter
The solution viscosity eta is 0.015 to 0.020Pa · s, the pH value is 9 to 10, and a PTFE concentrated solution or a nylon 6 fiber concentrated solution is further preferable.
The impregnation is as follows: putting the multi-layer net-shaped storage structure into a thermosetting lubricating medium for soaking for a time ts≥0.5h。
Preferably, the surface treatment is performed to satisfy Ra 5 to 7.5 μm, that is, the roughness Ra of the contact surface between the blank and the mesh-like storage structure is increased, and the surface treatment is performed by, but not limited to, sandblasting or the like.
The composite lubricating layer arranged on the surface of the blank is as follows: according to the surface area S of the composite lubricating layer contacted with the blanknCutting the mesh storage structure into areas S using laser cuttingc＝1.1～1.15SnAnd removing burrs of the composite lubricating layer after cutting is finished and flatly paving the burrs on the surface of the blank.
The heating temperature T in the heating and curinghThe corresponding relation is satisfied: when the solidification temperature of the lubricating medium meets TsWhen the temperature is 80-10 ℃, Th130-160 ℃; when T issT at 100-130 ℃h160-190 ℃. Holding time t for solidifying lubricanth＝1.5～2.5h。
The heating solidification is preferably carried out by clamping the net-shaped storage structure and the metal blank by using a clamping tool, and the clamping force F is further preferably selectedN＝200～400N。
The invention relates to a lubricating surface prepared by the method, wherein the shear friction factor m of the lubricating surface is 0.10-0.17. When the fibres are polyacrylonitrile, alphag90 degrees, using PTFE concentrated solution as lubricating medium, surface treating, Ra 7 μm, FN＝400N，Th＝190℃，thWhen m is 2.5h, m is 0.10-0.13, and eta follows the blanksThe friction factor is increased and floated; when the fibres are of polytetrafluoroethylene, alphag60 degrees, the concentrated solution of nylon 6 fiber is used as lubricating medium, and Ra is 5 mu after surface treatmentm，FN＝300N，Th＝150℃，thWhen 2h, m is 0.17 and remains stable.
Technical effects
Compared with the prior art, the invention integrally solves the technical problems that: the traditional phosphorization saponification lubricating method which has multiple working procedures and great harm to the environment in the field of cold forging processing is replaced, and a treatment mode of continuously lubricating cold forging blanks without adding a lubricating agent is provided. The unexpected technical effects that result from this include:
the invention adopts a mode of heating and solidifying a lubricating medium to finish the lubricating treatment of the blank. The net-shaped storage structure is formed by weaving single-layer or multi-layer fiber bundles, and is fully soaked in a lubricating medium and then is adhered to the blank subjected to surface treatment. And then the cold forging blank is lubricated by the net-shaped storage structure after being heated and solidified by the lubricating medium.
Drawings
FIG. 1 is a schematic view of a multi-layered web storage structure adhered to a surface of a blank;
in the figure: a is a three-layer mesh memory structure, b is a partial enlarged schematic diagram of a, and c is an enlarged schematic diagram of part I;
FIG. 2 is a flow chart of the construction of the composite lubricating layer;
in the figure: a is surface treatment, b is clamping and adding a composite lubricating layer, and c is heating and curing treatment.
Detailed Description
Example 1
The embodiment relates to a cold forging lubricating method based on a net-shaped storage structure, wherein a PTFE concentrated solution is used for soaking a three-layer net-shaped storage structure, sand blasting is carried out on a metal blank, a clamping tool is used for clamping the net-shaped storage structure on the surface of the blank, and then the blank is placed into a high-temperature box for heating and curing, so that the lubricating treatment is completed.
This example uses a martensitic precipitation hardening stainless steel 05Cr17Ni4Cu4Nb to produce a metal blank in the form of a flanged ring having an outer diameter
The flange has a thickness ofhb2mm, the outer diameter of the metal ring is
An inner diameter of
The first step is to prepare a three-layer mesh storage structure: due to the target etas>2, so delta is selectedg＝46％，Eg＝30.8cN/dtex，
The acrylic fiber (polyacrylonitrile) is formed by respectively combining a warp-wise fiber bundle and a weft-wise fiber bundleg＝nw100 cylindrical acrylic fibers are polymerized, and the section of the acrylic fiber is in a fan blade shape.
The single-layer storage structure is woven in a mode of three-layer, one-layer, two-layer, twill and four-layer satin, and the warp parameters and the weft parameters of each layer are respectively
αg90 degrees, and the fiber parameters meet the following conditions:
the warp and weft fiber bundles are staggered and stacked between two single layers, and the multiple layers are connected by an orthogonal interlocking structure.
Step two, lubricating treatment: and selecting a PTFE concentrated solution as a thermosetting lubricating medium for impregnating the three-layer mesh storage structure. Curing temperature T of PTFE concentrates130 ℃ C, average particle diameter of
The viscosity eta of the colloidal solution is 0.019 Pa.s, and the pH value is 9.8. When the three-layer net-shaped storage structure is soaked by using the PTFE concentrated solution, the soaking time ts＝1h。
Step three, blank surface treatment: as shown in fig. 1, the blank is surface-treated by sandblasting, and then a mesh-like storage structure is attached, specifically: setting a target surfaceThe upper and lower end faces of the ring and the diameter of the sand grains
Water content less than 2%, hard particles with edges and corners, and air pressure P of air machinea＝6.0～6.5X105Pa, air pressure amplitude Delta P is 0.5-1.0X 105Pa, the distance L between the nozzle and the metal surface is 100-300 mm, and the included angle alpha between the sand blasting direction and the surface normal lines15 ~ 30 degrees, the cyclic annular removes the shower nozzle and slowly sandblasts 3 ~ 7 circles, shields the protection to the non-sandblast position before the sandblast. In this embodiment, the values of the parameters are
Pa＝6.5X105Pa，L＝200mm，αs22.5. The surface roughness Ra of the sand blasted was 7 μm.
The reticular storage structure adhered to the blank surface is obtained by laser cutting, and the surface area S is obtained after cuttingc＝1.15Sn，SnIs the surface area of the web-like storage structure in contact with the web. After cutting, the burrs are removed and laid flat on the target surface of the blank.
Step four, heating and curing: as shown in FIG. 2, a clamping tool is used, as FNA clamping force of 400N clamps the web storage structure to the blank and the whole is placed in a high temperature oven for heat curing. Heating temperature Th190 deg.C, holding time th＝2.5h。
The lubrication method was evaluated after all the lubrication treatment steps were completed: the lubrication conditions were evaluated using ring upsetting with a deformation speed v of 20 mm/s. The result shows that the shearing friction factor m in the embodiment is 0.10-0.13, and the eta along with the blanksIncreasing, the friction factor floats. Until the height variation of the ring reaches 54.5%, the surface expansion ratio of the blank reaches etasWhen 2.26, the net-like storage structure may not completely cover the blank.
Example 2
The cold-forged blank of this example was the same as example 1.
First step, preparationThree-layer mesh memory structure: different from example 1, due to the target ηs<1.5, therefore, delta is selectedg＝19％，Eg＝106.3cN/dtex，
The warp and weft fiber bundles are respectively composed of ng＝nw116 cylindrical teflon fibers are polymerized, and the section of the fiber is in a fan blade shape.
The single-layer storage structure is woven in a mode of three-layer, one-layer, two-layer, twill and four-layer satin, and the warp parameters and the weft parameters of each layer are respectively
αg60 degrees, and the fiber parameters meet the following conditions:
the warp and weft fiber bundles are staggered and stacked between two single layers, and the multiple layers are connected by an orthogonal interlocking structure.
Step two, lubricating treatment: unlike example 1, a nylon 6 fiber concentrate was chosen as the thermosetting lubricating medium for impregnating the three-layer reticulated storage structure. Curing temperature T of nylon 6 fiber concentrated solutions90 ℃ and an average particle diameter of
The viscosity eta of the colloidal solution is 0.015 Pa.s, and the pH value is 9.2; when the three-layer net-shaped storage structure is soaked by using the nylon 6 fiber concentrated solution, the soaking time ts＝0.5h。
Step three, blank surface treatment: the method comprises the following steps of carrying out surface treatment on a blank by using a sand blasting method, and then pasting a net-shaped storage structure, wherein the method specifically comprises the following steps: setting the target surface as the upper and lower end surfaces of a circular ring and the diameter of sand grains
Water content less than 2%, hard particles with edges and corners, and air pressure P of air machinea＝6.0～6.5×105Pa, air pressure amplitude Delta P is 0.5-1.0 x105Pa, the distance L between the nozzle and the metal surface is 100-300 mm, and the included angle alpha between the sand blasting direction and the surface normal lines15 ~ 30 degrees, the cyclic annular removes the shower nozzle and slowly sandblasts 3 ~ 7 circles, shields the protection to the non-sandblast position before the sandblast. Different from the embodiment 1, the values of the parameters are
Pa＝6.0×105Pa，L＝200mm，αs27.5 °; the surface roughness Ra of the sand blasted was 5 μm.
The reticular storage structure adhered to the blank surface is obtained by laser cutting, and the surface area S is obtained after cuttingc＝1.15Sn，SnIs the surface area of the web-like storage structure in contact with the web. After cutting, the burrs are removed and laid flat on the target surface of the blank.
Step four, heating and curing: using a clamping tool with FNThe web storage structure is clamped to the blank with a clamping force of 300N and the whole is placed in a high temperature oven for heat curing. Heating temperature ThKeeping the temperature at 150 ℃ for th＝2h。
The lubrication method was evaluated after completion of all steps of the lubrication treatment: the lubrication conditions were evaluated using ring upsetting with a deformation speed v of 20 mm/s. The results show that the shear friction factor in this example is stably maintained at m-0.17 until the ring height variation reaches 28.5%, and the surface expansion ratio of the billet reaches ηsWhen the thickness is 1.441, the net-shaped storage structure cannot completely cover the blank.
The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims (7)
1. A lubrication method in the field of metal material cold forging processing is characterized in that a multi-layer net-shaped storage structure is prepared and fully impregnated by a thermosetting lubrication medium, then the net-shaped storage structure impregnated with the lubrication medium is adhered to a cold forging blank subjected to surface treatment and is heated and cured to form a composite lubrication layer, and surface lubrication treatment is realized;
the multilayer mesh storage structure is formed by stacking a plurality of single-layer mesh storage structures, warp-wise fiber bundles and weft-wise fiber bundles are staggered between every two adjacent single layers and the multiple layers are connected by using an orthogonal interlocking structure;
the multilayer reticular storage structure is made of fiber materials, and the material parameters of the multilayer reticular storage structure meet the following requirements: elongation at break deltag>18% of surface expansion ratio eta when cold forging a billets>Elongation at break delta at 2g>41％，ηs＝SAfter forging/SBefore forgingInitial modulus Eg>20cN/dtex, fiber diameter
SAfter forging、SBefore forgingThe area of the surface of the blank where the mesh-shaped storage structure is located after forging and the area of the surface of the blank where the mesh-shaped storage structure is pasted before forging are respectively set;
each layer of the multi-layer mesh storage structure is woven by warp-wise and weft-wise fiber bundles to obtain weaving units, and the weaving units repeatedly extend in the warp direction and the weft direction to form the multi-layer mesh storage structure, wherein the warp-wise and weft-wise fiber bundles are respectively formed by ngAnd nwRoot cylindrical fibers and satisfies ng＝nwThe cross section of the weaving unit is in a fan blade shape, and the weaving unit is 80-120 parts;
the weaving obtains weaving units
Wherein:
meaning that one weft yarn is interwoven every n warp yarns,
refers to a warp yarnInterweaving every n weft yarns, agTo weave corners, 0<αg≤90°；
The material parameters of the thermosetting lubricating medium meet the following requirements: curing temperature Ts80-130 ℃ and average particle diameter
The solution viscosity eta is 0.015-0.020 Pa · s, and the pH value is 9-10.
2. The method of claim 1, wherein the multi-layered network storage structure is made of cylindrical polytetrafluoroethylene or polyacrylonitrile.
3. The method of claim 1, wherein the thermosetting lubricating medium is a PTFE concentrate or a nylon 6 fiber concentrate.
4. The method of claim 1, wherein said impregnating comprises: putting the multi-layer net-shaped storage structure into a thermosetting lubricating medium for soaking for a time ts≥0.5h。
5. The method of claim 1, wherein the web-like storage structure is disposed on the surface of the blank by: according to the surface area S of the net-like storage structure in contact with the blanknCutting the mesh storage structure into areas S using laser cuttingc＝1.1～1.15SnAnd removing burrs of the mesh storage structure after cutting is finished and flatly paving the burrs on the surface of the blank.
6. The method as set forth in claim 1, wherein the heating temperature T in said heat curinghThe corresponding relation is satisfied: when the solidification temperature of the lubricating medium meets TsWhen the temperature is 80-100 ℃, Th130-160 ℃; when T issT at 100-130 ℃h160-190 ℃, and the heat preservation time t of the solidification of the lubricating mediumh＝1.5～2.5h。
7. A lubricated surface prepared according to any one of claims 1 to 6, wherein the shear friction factor m is 0.10 to 0.17, α is α when the fiber is polyacrylonitrilegThe PTFE concentrated solution is used as a lubricating medium, Ra is 7 mu m after the surface treatment of the blank, a clamping tool is used for clamping the reticular storage structure and the blank, and the clamping force F isN＝400N，Th＝190℃，thWhen m is 2.5h, m is 0.10-0.13, and eta follows the blanksThe friction factor is increased and floated; when the fibres are of polytetrafluoroethylene, alphag60 degrees, using nylon 6 fiber concentrated solution as lubricating medium, surface treating blank, Ra 5 μm, FN＝300N，Th＝150℃，thWhen 2h, m is 0.17 and remains stable.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911227296.XA CN111014531B (en) | 2019-12-04 | 2019-12-04 | Cold forging lubricating method based on net-shaped storage structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911227296.XA CN111014531B (en) | 2019-12-04 | 2019-12-04 | Cold forging lubricating method based on net-shaped storage structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111014531A CN111014531A (en) | 2020-04-17 |
| CN111014531B true CN111014531B (en) | 2021-08-27 |
Family
ID=70207839
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911227296.XA Active CN111014531B (en) | 2019-12-04 | 2019-12-04 | Cold forging lubricating method based on net-shaped storage structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111014531B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112935161A (en) * | 2021-01-29 | 2021-06-11 | 中国第二重型机械集团德阳万航模锻有限责任公司 | Method for forming large flat die forging |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1259599A (en) * | 1999-12-24 | 2000-07-12 | 中国科学院兰州化学物理研究所 | Self lubricating fabric thin layer composite material and its prepn. method |
| GB2420160A (en) * | 2004-11-12 | 2006-05-17 | Minebea Co Ltd | Lined bearings |
| CN101319464B (en) * | 2008-05-30 | 2011-02-16 | 广州市晶邦液压密封技术有限公司 | Technique for producing helicoidal surface underlayer of transmission nut by self-lubricating materials |
| US10207312B2 (en) * | 2010-06-14 | 2019-02-19 | Ati Properties Llc | Lubrication processes for enhanced forgeability |
| CN102145556A (en) * | 2010-11-29 | 2011-08-10 | 复旦大学 | Composite material of high-temperature resistant metal-fabric/resin self-lubricating bearing and preparation method of composite material |
| CN102350476B (en) * | 2011-08-04 | 2014-03-26 | 攀钢集团江油长城特殊钢有限公司 | Method for manufacturing large cake forgings of high-carbon and high-chromium cold working die steel |
| CN102535167A (en) * | 2012-01-04 | 2012-07-04 | 江苏中天航空配件有限公司 | Self-lubricating composite gasket for bearing and preparing method for gasket |
| US9539636B2 (en) * | 2013-03-15 | 2017-01-10 | Ati Properties Llc | Articles, systems, and methods for forging alloys |
| FR3023880B1 (en) * | 2014-07-16 | 2017-05-26 | Hydromecanique & Frottement | AUTOLUBRICATING FRICTION COMPOSITE PIECE |
| CN108115066B (en) * | 2017-12-15 | 2019-12-17 | 中国第二重型机械集团德阳万航模锻有限责任公司 | forging cloth with heat preservation and lubrication functions and application method thereof |
-
2019
- 2019-12-04 CN CN201911227296.XA patent/CN111014531B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN111014531A (en) | 2020-04-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8486249B2 (en) | Cold spray and anodization repair process for restoring worn aluminum parts | |
| US4907765A (en) | Wall with a drag reducing surface and method for making such a wall | |
| US10900465B2 (en) | Noise reduction to the trailing edge of fluid dynamic bodies | |
| CN111014531B (en) | Cold forging lubricating method based on net-shaped storage structure | |
| WO2013160198A1 (en) | Method for manufacturing a component having an overhang by layer-wise buildup | |
| CN109112459A (en) | A kind of aircraft universal shaft remanufactures renovation technique | |
| CN111139465A (en) | Manufacturing method for manufacturing composite steel pipe by laser | |
| CN110145588B (en) | Cylindrical gear with textured side surface and preparation method thereof | |
| DE4041103A1 (en) | METHOD FOR TREATMENT OF COMPONENTS | |
| JP2008208447A (en) | Phosphate coated stainless steel wire for cold heading and self-drilling screw using the stainless steel wire | |
| US11453147B2 (en) | Method for producing a composite component formed with a fibre-reinforced plastic component on which at least one surface with a coating is formed | |
| Yuan et al. | On the processing and morphological aspects of metal fibers based on low-speed multi-tooth dry cutting | |
| US20230173769A1 (en) | Method of Designing and Producing Carbon Fiber Composite Wrist Pins | |
| CN1115497C (en) | Connecting rod with tight friction-bearing layer | |
| CN108168352A (en) | A kind of external spiral curve finned tube and its manufacturing method | |
| JP2013539503A (en) | Use of recycled carbon fiber | |
| Puoza et al. | Laser processing parameter optimization and tribological characteristics of different surface treatment | |
| Sagbas | Surface texture properties and tribological behavior of additive manufactured parts | |
| CN108411160B (en) | Self-lubricating bearing with self-adaptive characteristic and preparation method thereof | |
| CN108195218B (en) | A kind of external curve finned tube and its manufacturing method | |
| CN114060404A (en) | PTFE fabric liner and dry film combined friction pair, application and self-lubricating joint bearing | |
| CN112458274A (en) | Preparation method of fretting wear resistant coating on surface of titanium alloy workpiece | |
| CN114274557A (en) | Connection design and forming method of composite material cylindrical shell and metal component | |
| CN113025947A (en) | Preparation method of graphene-based hard alloy composite self-lubricating coating | |
| US10322436B2 (en) | Method of coating interior surfaces with riblets |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |