CN111826652B

CN111826652B - Method for preparing low-friction-coefficient coating cutter by utilizing pre-cutting method and cutter

Info

Publication number: CN111826652B
Application number: CN202010675966.0A
Authority: CN
Inventors: 王兵; 刘战强; 梁晓亮; 任小平; 蔡玉奎; 马海峰; 宋清华; 陈龙
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2020-07-14
Filing date: 2020-07-14
Publication date: 2021-06-22
Anticipated expiration: 2040-07-14
Also published as: CN111826652A

Abstract

The invention discloses a method for preparing a low-friction coefficient coating cutter by utilizing a pre-cutting method and a cutter, and the technical scheme is as follows: and utilizing a cutter to perform successive pre-cutting on the pre-cut workpiece of at least two low-friction-coefficient coating materials, coating the low-friction-coefficient coating materials on the surface of the cutter, and forming a composite low-friction-coefficient coating on the surface of the cutter. The invention utilizes the cutter to pre-cut the coating material with low friction coefficient, thereby obtaining the coating cutter with low friction coefficient, and the invention has simple process, does not need complex equipment to support and has low cost.

Description

Method for preparing low-friction-coefficient coating cutter by utilizing pre-cutting method and cutter

Technical Field

The invention relates to the technical field of cutting tool coatings, in particular to a method for preparing a low-friction-coefficient coated tool by utilizing a pre-cutting method and a tool.

Background

With the continuous development of material science and high-end equipment manufacturing industry, new materials with excellent properties such as high strength, high hardness and the like or high brittleness continuously emerge and play an important role, and guarantee is provided for the service performance and the working reliability of equipment materials, parts and complete machines. However, the material performance and the machinability thereof often show a mutually exclusive contradictory relationship, that is, high-performance materials are often difficult to machine, so that difficult-to-machine materials and parts always face technical bottlenecks of low machining efficiency, poor machining quality and the like, and a severe challenge is provided for the field of machining. The advanced cutter technology is an effective technical means for realizing high-quality and high-efficiency cutting of difficult-to-machine materials.

The low friction coefficient coating can reduce the adhesion of the tool and the workpiece material, reduce the friction and wear, and reduce the cutting force and the cutting temperature. Although the technology of the superhard coating tool is relatively mature, the superhard coating tool is not suitable for processing due to diffusion between a processed material and the coating, such as high-strength aluminum alloy, titanium alloy or precious metal material used in the aerospace field, and the like, and the uncoated cemented carbide tool is still mainly used; in addition, for the high temperature alloy widely used in the aeroengine, the machining effect of the superhard coating cutter is not ideal due to the serious work hardening, and the development of the low friction coefficient coating cutter can better solve the machining problem of the material.

The low-friction-coefficient coating of the cutter has excellent tribological characteristics under cutting conditions, such as low friction coefficient, high bearing limit, good chemical stability at high temperature, small physical property change, wide working temperature range and wide friction pair movement speed range, and is suitable for being used under special environmental conditions of high temperature, high speed, large load and the like. Similar to the preparation technology of superhard coating cutters, the preparation technology of the low-friction-coefficient coated cutters mainly comprises a physical vapor deposition method and a chemical vapor deposition method, the requirements on required equipment and technical operation are high, the technological process is complex, the cost is high, and the subsequent part processing and manufacturing cost is high.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for preparing a low-friction-coefficient coating cutter by using a pre-cutting method and a cutter.

In order to achieve the purpose, the invention is realized by the following technical scheme:

in a first aspect, embodiments of the present invention provide a method for preparing a low-friction-coefficient coated cutting tool by a pre-cutting method, in which a cutting tool is used to perform successive pre-cutting on a pre-cut workpiece with at least two low-friction-coefficient coating materials, so that the low-friction-coefficient coating materials are coated on the surface of the cutting tool, and a composite low-friction-coefficient coating is formed on the surface of the cutting tool.

As a further implementation mode, silicon-aluminum alloy and nodular cast iron are selected as coating materials with low friction coefficient.

As a further implementation, the silicon-aluminum alloy is pre-cut with a cutter, and then the nodular cast iron is pre-cut.

As a further implementation mode, the time of each pre-cutting of the cutter is 2-3 s.

As a further implementation mode, the cutter adopts a dry cutting mode to process the coating material with the low friction coefficient.

As a further implementation, both low-friction coating materials are pre-cut using high-speed, low-feed, and large-cut-depth cutting doses.

As a further implementation mode, the adhesion and uniform distribution condition of the coating material in the contact area of the cutter and the pre-cut workpiece is tested by utilizing an X-ray energy dispersion spectrum or an X-ray photoelectron spectrum.

As a further implementation, a single low-coefficient of friction coated tool is formed by pre-cutting a low-coefficient of friction coated material with the tool.

In a second aspect, the embodiment of the present invention further provides a low-friction-coefficient coated cutting tool, which is manufactured by the method for manufacturing a low-friction-coefficient coated cutting tool by using the pre-cutting method.

As a further implementation, the coating comprises a substrate, and the surface of the substrate is coated with a low-friction coefficient coating.

The beneficial effects of the above-mentioned embodiment of the present invention are as follows:

(1) according to one or more embodiments of the invention, before cutting difficult-to-process materials such as high-temperature alloy and the like, a tool is used for cutting workpiece materials with low hardness, low friction coefficient and strong adhesion such as silicon-aluminum alloy and/or nodular cast iron in advance, and the pre-cut workpiece materials are adhered and deposited on the surface of the tool to form a low-friction-coefficient material coating, so that the efficient preparation of the low-friction-coefficient coating tool is realized;

(2) one or more embodiments of the invention can prepare single or composite low-friction-coefficient coatings of any soft material on the surface of the cutter, and the operation is flexible and convenient and the expansibility is extremely strong; the preparation process is simple, does not need complex equipment for support, has low preparation cost and is easy to popularize;

(3) when the one or more embodiments of the invention pre-cut workpiece materials, the cutting amount of high speed, small feed and large cutting depth is adopted, and firstly, the cutting force in the pre-cutting process is reduced, and the abrasion of a cutter is avoided; and secondly, a larger contact area is formed among the cutting edge, the front cutter face and the rear cutter face of the cutter and the pre-cutting material, and a larger-area coating is coated on the surface of the cutter so as to ensure that the processed low-friction coefficient coating cutter can play a better cutting performance when cutting difficult-to-machine materials.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and together with the description serve to explain the invention and not to limit the invention.

FIG. 1 is a process flow diagram according to one or more embodiments of the present invention;

FIG. 2 is a schematic view of a processing tool according to one or more embodiments of the present disclosure;

FIG. 3 is an enlarged view of region I of the pre-cut deformation zone of FIG. 2;

FIG. 4 is a schematic view of a low coefficient of friction coated cutting tool according to one or more embodiments of the present invention;

FIG. 5 is a schematic view of a composite coating profile according to one or more embodiments of the present invention;

wherein, 1, a machine tool main shaft; 2. a machine tool chuck; 3. a raw surface; 4. a machined surface; 5. a cutter; 6. a low coefficient of friction coated cutting tool; 7. coating with nodular cast iron; 8. a silicon-aluminum alloy coating; 9. a substrate.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an", and/or "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof;

the terms "mounted", "connected", "fixed", and the like in the present application should be understood broadly, and for example, the terms "mounted", "connected", and "fixed" may be fixedly connected, detachably connected, or integrated; the two components can be connected directly or indirectly through an intermediate medium, or the two components can be connected internally or in an interaction relationship, and the terms can be understood by those skilled in the art according to specific situations.

The first embodiment is as follows:

the present embodiment provides a method for preparing a low-friction-coefficient coated cutting tool by using a pre-cutting method, as shown in fig. 1, a cutting tool is used to perform successive pre-cutting on a pre-cut workpiece with at least two low-friction-coefficient coating materials, so that the low-friction-coefficient coating materials are coated on the surface of the cutting tool, and a composite low-friction-coefficient coating is formed on the surface of the cutting tool. Alternatively, only one low coefficient of friction coating workpiece material is cut to form a single low coefficient of friction coating on the tool surface.

Specifically, a solid carbide or high speed steel tool, such as a turning insert, a milling insert, a solid milling cutter, or a drill, is first selected as the object to be coated. The silicon-aluminum alloy and the nodular cast iron are selected as low-friction-coefficient coating materials, the silicon-aluminum alloy and the nodular cast iron are subjected to successive pre-cutting, and the two materials are respectively bonded and coated on the surface of a cutter to form the silicon-aluminum alloy and nodular cast iron composite low-friction-coefficient coating.

By the same method, a single low-friction coefficient coated tool or a multi-layer composite low-friction coefficient coated tool can be prepared if only one kind of coated workpiece material or more kinds of coated workpiece materials are cut.

In the embodiment, the preparation of the tool with the composite coating of silicon-aluminum alloy and nodular cast iron is taken as an example for detailed description, and the following steps are included:

the silicon-aluminum alloy Al-8% Si and the ductile nodular cast iron QT400 are suitable for preparing low-friction coefficient coatings of cutters. The silicon-aluminum alloy Al-8% Si has the characteristics of low melting point, low friction coefficient, excellent ductility, good chemical compatibility with a hard alloy cutter matrix and the like. The nodular cast iron QT400 has excellent impact resistance and ductility, and the graphite flakes inside it have outstanding lubricating properties.

The hardness of the two materials is low, the two materials belong to easily-processed materials, the hardness of the nodular cast iron QT400 is about HB 130, and the hardness of Al-8% Si of the silicon-aluminum alloy is less than HB 100. During the pre-cutting process, a large amount of cutting heat is formed between the cutter and the workpiece material due to the friction effect and the plastic deformation of the workpiece material, so that the temperature of a cutting area is increased, and the high-temperature effect is favorable for the adhesion and the flowability of the silicon-aluminum alloy and the nodular cast iron on the surface of the cutter.

The silicon-aluminum alloy Al-8% Si is cut by using an uncoated cutter such as hard alloy or high-speed steel. In order to prevent unnecessary abrasion of the cutter caused by too long precutting time, the cutting time is controlled to be 2 s; and the cutting force in the machining process is reduced by adopting a high-speed dry cutting mode.

The cutting parameters are shown in table 1 below,

TABLE 1

Wherein the cutting speed is 500m/min, the feeding speed is 0.05mm/r, and the cutting depth is 1-5 mm. After the pre-cutting, a layer of evenly distributed aluminum-silicon alloy coating material can be formed on the contact surface of the cutting edge, the front tool face and the chip of the cutter, the contact surface of the rear tool face and the processing surface of the cutter and the like.

And testing the adhesion and uniform distribution of the coating material in the contact area of the cutter and the material of the pre-cut workpiece by using X-ray Energy Dispersion Spectroscopy (EDS) or X-ray photoelectron spectroscopy (XPS). Multiple experiments prove that under the cutting parameters, a silicon-aluminum alloy coating film with the thickness of 40 microns +/-5 microns can be formed in the contact area of the cutting edge, the front cutter face and the rear cutter face of the cutter and the pre-cutting material. The macroscopic geometry and the tool angle of the tool are not significantly affected by the thin thickness of the coating material.

Further, the nodular cast iron QT400 was cut using the above-described cutter coated with the silicon-aluminum alloy coating. The cutting parameters are shown in table 1. Wherein the cutting speed is 300m/min, the feeding speed is 0.05mm/r, the cutting depth is 1-5 mm, the cutting time is 2s, and the cutting mode is dry cutting.

Because the hardness of the nodular cast iron QT400 is higher than that of the silicon-aluminum alloy Al-8% Si, the cutting speed value adopted in the pre-cutting process is slightly lower. After the pre-cutting, a layer of uniformly distributed ductile cast iron coating material can be continuously formed on the silicon-aluminum alloy coating at the positions of a cutting edge of a cutter, a contact surface between a front cutter surface of the cutter and chips, a contact surface between a rear cutter surface of the cutter and a processing surface and the like.

Also, the coating material adhesion and uniform distribution in the contact area of the tool with the pre-cut workpiece material were verified by EDS or XPS. Through multiple experiments, the contact area of the cutting edge, the front cutter face and the rear cutter face of the cutter and the pre-cutting material can form a layer of nodular cast iron coating film with the thickness of 25 mu m +/-3 mu m under the cutting parameters.

In this example, the two pre-cut materials were processed in the order of silicon aluminum alloy before ductile iron. Therefore, the composite low-friction coefficient coated cutter with the silicon-aluminum alloy coating below and the nodular cast iron coating above can be formed on the surface of the cutter. The graphite layer in the nodular cast iron has excellent lubricating property, and is arranged on the outermost layer of the composite coating, so that the lubricating advantage between a cutter and a workpiece material can be fully exerted in the process of cutting a difficult-to-machine material.

When two workpiece materials are pre-cut, the cutting consumption of high speed, small feed and large cutting depth is adopted, and firstly, the cutting force in the pre-cutting process is reduced, and the abrasion of a cutter is avoided; and secondly, a larger contact area is formed among the cutting edge, the front cutter face and the rear cutter face of the cutter and the pre-cutting material, and a larger-area coating is coated on the surface of the cutter so as to ensure that the processed low-friction coefficient coating cutter can play a better cutting performance when cutting difficult-to-machine materials.

Example two:

this example provides a low coefficient of friction coated cutting tool made by the method described in the first example. As shown in fig. 4 and 5, the low-friction-coefficient coated tool 6 includes a base 9, and a ductile iron coating 7 and a silicon-aluminum alloy coating 8 coated on the surface of the base 9, wherein the ductile iron coating 7 is located on the upper side of the silicon-aluminum alloy coating 8.

The low-friction-coefficient coated tool 6 uses a machining apparatus as shown in fig. 2, a pre-cut workpiece is connected to a machine tool spindle 1 through a machine tool chuck 2, and a tool 5 is machined from one end of the pre-cut workpiece to the other end thereof, so that the pre-cut workpiece forms a machined surface 4 and an unmachined surface 3.

As shown in fig. 3, first, the uncoated solid cemented carbide or high-speed steel tool 5 is used as a target to be processed, and in the present embodiment, a silicon-aluminum alloy Al-8% Si having a diameter of 100mm and a length of 150mm is used as a material of the precut workpiece.

And (3) carrying out pre-cutting processing in the first step by adopting the cutting parameters of the silicon-aluminum alloy in the table 1, and stopping cutting after the cutting time reaches 2 s. And then, performing EDS or XPS test on the cutter 5 after the pre-cutting is finished, and ensuring that the contact area of the cutting edge, the front cutter face and the chip of the cutter 5 and the contact area of the rear cutter face and the processed surface 4 are uniformly coated with the silicon-aluminum alloy coating 8.

Then, by the same procedure, the blade coated with the silicon-aluminum alloy coating is used as the object to be processed, and the nodular cast iron QT400 with a diameter of 100mm and a length of 150mm is used as the material of the pre-cut workpiece. And (3) carrying out the second pre-cutting processing by adopting the cutting parameters of the nodular cast iron in the table 1, and stopping cutting after the cutting time reaches 2 s.

Then, the EDS or XPS test is carried out again on the cutter after the pre-cutting is finished, and the contact area of the cutter and the cut material is ensured to be uniformly coated with the ball-milling cast iron coating 7. Finally, the prepared low-friction coefficient coating cutter 6 is used for processing target difficult-to-process materials such as high-temperature alloy and the like.

Example three:

in this embodiment, a turning insert of the type SNMG120412 made of cemented tungsten carbide is used as an example, and the composite low-friction coefficient coated tool of silicon-aluminum alloy and ductile iron is prepared by the method described in the first embodiment.

Firstly, the cutting parameters in the table 1 are adopted, the workpiece materials of the silicon-aluminum alloy Al-8% Si and the nodular cast iron QT400 with the diameter of 100mm and the length of 150mm are turned successively, the turning time is 2s respectively, and the turning mode is dry cutting. After the silicon-aluminum alloy Al-8% Si and the nodular cast iron QT400 are turned, the distribution condition of the coating material in the contact area of the cutter and the workpiece material is respectively tested by using EDS. And finishing the preparation work of the silicon-aluminum alloy and nodular cast iron composite low-friction coefficient coating cutter after the pre-cutting is finished.

The prepared composite coating cutter is used for cutting a typical difficult-to-machine material nickel-based high-temperature alloy GH4169 and is compared with an uncoated hard alloy cutter. The nickel-based superalloy serving as the processed material is a rod-shaped workpiece with the diameter of 50mm and the length of 120 mm. The cutting parameters are as follows: the cutting speed is 150m/min, the feeding speed is 0.05mm/r, the cutting depth is 0.5mm, and the cutting mode is dry cutting.

And comparing the processing effects of the prepared composite coating cutter and the uncoated cutter by taking the maximum wear zone width of the rear cutter surface of the cutter as 0.3mm as the cutter dull-grinding standard, wherein the processing effects comprise the parameters of cutter service life, processing surface roughness, processing surface hardening degree and the like.

The result shows that the cutting performance and the service life of the composite low-friction coefficient coated tool of the silicon-aluminum alloy and the nodular cast iron prepared by the pre-cutting method are obviously improved compared with the uncoated tool, wherein the service life of the tool is improved by nearly 8 times, and the surface roughness R is processed_aThe reduction is 45 percent, and the degree of hardening of the processing surface is reduced by 60 percent.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. The method for preparing the low-friction-coefficient coating cutter by the pre-cutting method is characterized in that the cutter is used for sequentially pre-cutting pre-cut workpieces of at least two low-friction-coefficient coating materials, so that the low-friction-coefficient coating materials are coated on the surface of the cutter, a composite low-friction-coefficient coating is formed on the surface of the cutter, and the coating materials adopt silicon-aluminum alloy and nodular cast iron as the low-friction-coefficient coating materials.

2. The method for preparing the low-friction coefficient coated cutter by the pre-cutting method according to claim 1, wherein the silicon-aluminum alloy is pre-cut by the cutter, and then the nodular cast iron is pre-cut.

3. The method for preparing the low-friction coefficient coated cutter by the pre-cutting method according to claim 1, wherein the pre-cutting time of the cutter is 2-3 s.

4. A method for preparing a low-friction coated cutting tool using a precutting process as claimed in claim 1 or 3, wherein the cutting tool is used for processing the low-friction coating material by dry cutting.

5. The method for preparing the low-friction-coefficient coating cutter by the pre-cutting method according to claim 1, wherein the cutting dosage of high speed, small feed and large cutting depth is adopted when the two low-friction-coefficient coating materials are pre-cut.

6. The method for preparing the low-friction coefficient coated cutter by the pre-cutting method according to claim 1, wherein the adhesion and uniform distribution of the coating material in the contact area of the cutter and the pre-cut workpiece are tested by X-ray energy dispersion spectroscopy or X-ray photoelectron spectroscopy.

7. The method for preparing the low-friction coefficient coated cutter by the pre-cutting method according to claim 5, wherein the cutting speed is 300m/min, the feeding speed is 0.05mm/r, and the cutting depth is 1-5 mm.

8. A low-friction coated cutting tool, characterized in that it is manufactured by a method for manufacturing a low-friction coated cutting tool by a pre-cutting method according to any of claims 1-7.

9. The low coefficient of friction coated cutting tool of claim 8 comprising a substrate having a surface coated with a low coefficient of friction coating.