KR20180065117A - High-strength cutting tool coated with carbon fiber - Google Patents

Abstract

The present invention relates to a cemented carbide alloy useful for milling alloy steel and tool steel at a high cutting speed, and milling hardening steel. The cutting tool performs surface-coating carbon fiber on conventional alloy steel or W-alloy steel, or WC-Co cemented carbide alloy to exhibit high strength and high corrosion resistant properties.

Description

High-strength cutting tool coated with carbon fiber {omitted}

The present invention relates to a cemented carbide cutting tool useful for milling alloy steels and tool steels at high cutting speeds and milling hardened steels. The cutting tool is characterized in that carbon fiber is coated on a surface of a conventional alloy steel, W-alloy steel or WC-Co cemented carbide to have high strength and high corrosion resistance.

During machining of steel, stainless steel and cast iron using coated cemented carbide tools, the cutting edges wear due to different wear mechanisms such as chemical wear, grinding wear and adhesive wear. During high speed cutting, the amount of heat generated in the cutting area is significant and plastic deformation may occur at the cutting edge, which may promote the progress of wear due to other mechanisms. When the alloy steel is milled, adhesion wear is often remarkable, and edge chipping frequently occurs as a result of peeling or cracking of the protective film.

The cutting performance for a particular type of wear can be improved by a single insert, but very often will have a negative impact on other wear characteristics. Thus, the preferred tool composite should be carefully designed to optimize numerous properties. For milling of alloy and tool steels, often milling in the cured state, one important consideration is the balance between the plastic deformation resistance of the cutting edge and the edge chipping resistance. A simple way to increase resistance to plastic deformation, and also to increase resistance to abrasive wear, is to lower the binder phase content. However, this will reduce the toughness of the cutting insert, and the presence of vibration, casting or forging epidermis can substantially reduce the aerodynamic lifetime in applications requiring such properties. An alternative way to increase strain resistance is to add cubic carbides such as TiC, TaC and / or NbC. But. This addition has a negative effect on the edge chipping behavior, so-called comb crack formation. The composition of the wear resistant surface coatings applied is an important factor in the tool's properties. In general, a thicker, stronger antiwear coating is applied by chemical vapor deposition (CVD). In addition, these coatings improve the resistance of the plastic deformation, but can greatly damage the edge toughness. Coatings produced by thinner physical vapor deposition (PVD) on the whole are not well protected against thermal and plastic deformation, but show very good edge integrity and are well protected against edge chipping. However, a high-strength cutting tool through a coating method capable of improving strength together with an increase in corrosion resistance other than PVD, CVD and the like has not been developed yet. It is a reality.

US 6,062,776 US 6,177,178 US 6,250,855

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The present invention provides a cutting tool coated with carbon fiber, which is useful for milling alloy steels and tool steels at high cutting speeds with improved properties for the various types of wear described above and for milling hardened steels.

According to an aspect of the present invention, there is provided a high-strength cutting tool comprising: a carbon fiber composite material having a base of a cemented carbide, an alloy steel, or a tool steel; .

Since the high strength cutting tool according to the present invention has a non-rigidity characteristic that is 9 times or more higher than that of a conventional carbide tool by coating a high strength carbon fiber on the outside of a metal material, the fundamental frequency is 3 times or more, Therefore, excellent cutting stability can be secured due to a very high damping characteristic.

Fig. 1 Photograph of inner coating layer of the invention material

According to the present invention, the cutting tool comprises a cemented carbide or alloy steel base having a relatively small amount of cubic carbide, medium to high W-alloy binder phase and fine to medium WC grain size. The base is provided with a coating comprising an outer layer coated with carbon fibers. According to the present invention, prepreg sheets impregnated with ultrahigh stiffness carbon fibers having a Young's modulus of 600 GPa are laminated on a thermosetting resin in a plurality of layers, Lt; / RTI > The carbon fiber can be attached without using any adhesive, and the resin is cured while being vacuum-pressed, and the resin itself acts as an adhesive to be coated on the outside. The carbon fiber used herein may be pitch or carbon fiber derived from coke, and more preferably, a prepreg state in which a reinforcing fiber is impregnated into a resin may be laminated and simultaneously cured.

The outer coating is coated with carbon fiber and has a surface hardness of at least 9 times higher than that of conventional SCM435 alloy steel and a coating thickness of preferably from 1 to 50 um and more preferably from 15 to 30 um through a carbon fiber prepreg Coating is preferable. The coating does not use an adhesive, and can be deposited through a coating method which is preferably compressed using a carbon fiber prepreg. The present invention also relates to a method for milling a hardened steel at a cutting speed of 50 to 350 m / min with an average chip thickness value of 0.03 to 0.18 mm by dry-milling alloy steel and tool steel with high-speed cutting according to cutting speed and insert shape, To a cutting tool coating method and a cutting tool according to the present invention.

Claims (4)

A cutting tool comprising a cemented carbide body and a coating useful for milling alloy steel and tool steel by high speed cutting and milling hardened steel, wherein the composition of the hardened body is 7.9-8.6 wt% Co, preferably 8.0-8.5 wt% Co ; Cubic carbides of metals Ta and Nb in a total amount of 0.5-2.1 wt%, preferably 0.7-1.8 wt%; And a WC residual amount having an average intercept length in the range of 0.4-0.9 mu m, preferably 0.5-0.8 mu m, and a prepreg in which carbon fibers are contained in a thermosetting resin produced from pitch or coke in an outer coating layer is pressed Manufacturing method of a cutting tool having a thickness of 1-50um Wherein the thermosetting resin is a prepreg obtained by impregnating a thermosetting resin impregnated with a carbon fiber in at least one of phenol, amino, epoxy, polypropylene, polystyrene and polyvinyl chloride Wherein the carbon fibers are laminated in a prepreg state in which the reinforcing fibers are impregnated and are co-cured bonded. In the above 1, a cutting tool coating method in which a carbon prepreg is coated on a base through a press without using an adhesive

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