RU123356U1 - CUTTING PLATE FOR TREATMENT OF TITANIUM ALLOYS - Google Patents

Abstract

A cutting insert for processing titanium alloys containing a hard alloy base and a coating applied to it, including layers of titanium carbide, titanium carbonitride, a metal layer located between the outer layer of nanostructured nitride of hard refractory metal and a layer of titanium carbonitride, while the outer layer is made from nanostructured niobium and molybdenum nitrides, and the metal layer is from molybdenum.

Description

The solution relates to the field of mechanical engineering, in particular, to metalworking, and in particular to a metal-cutting tool, including a cutting plate of sintered hard alloy with a wear-resistant coating.

Known cutting inserts with multilayer coatings of refractory compounds (Vereshchak A.S. Serviceability of the tool with a wear-resistant coating. M .: Mechanical Engineering, 1993. - 336 s), in particular, a two-layer coating TiC + Ti (CN), i.e. from titanium carbide and titanium carbonitrides. The coating allows you to increase the efficiency of the cutting plate up to 2 ... 3 times when machining structural steels, cast irons. Such coatings are applied by vapor deposition with a thickness of 5 ... 6 microns.

A known insert, where the deposition of the coating is carried out both by gas-phase method (CVD) and physical method (PVD), in particular by condensation with ion bombardment by particles of refractory metals (CIB method). A soft layer of chromium is deposited by the CIB method with grains of the order of 30 nanometers, i.e. is nanostructured (see O.V. Volkhonsky, N.V. Blinov et al. Effect of a nanostructured TiN finish layer in combined PVD / CVD / PVD coatings on the properties of a cutting tool / Proceedings of the International Scientific and Technical Conference <Functional Materials Nanotechnology> C. Petersburg, 2010). This cutting insert coated with Cr-NiC-Ti (CN) -TiN allows you to increase the wear resistance by 1.5 ... 2 times compared with a cutting insert coated with TiC-Ti (CN).

The disadvantage of this type of cutting insert is the low increase in wear resistance. This is due to the fact that, as our study has shown, the destruction of the coating occurs by cracking it, begins with the upper layers and cracks grow into the substrate. In this case, a network of microcracks is formed, and the detachment of coating particles occurs due to adhesion with the metal being treated. Upon separation of the coating particles, a base (substrate) of hard alloy is exposed. Therefore, it is necessary to increase both the adhesion strength of the lower coating layer with the carbide base and the crack resistance of the upper coating layers of the cutting insert, which crack from the very beginning of cutting. Therefore, a soft layer of metal should be placed in front of the top layer of the coating. In addition, the disadvantage of this type of plates is the low wear resistance in the processing of stainless and corrosion-resistant steels and alloys. The fact is that when they are cut, higher temperatures are observed than when machining structural steels. The top layer of titanium nitrides does not provide such requirements.

The prototype of the present invention is a patent of the Russian Federation for utility model No. 112657, B23B 27/14, C23C 14/00, publ. 01/20/2012.

In a cutting plate containing a base of hard alloy and a coating deposited on it, including layers: titanium carbide, titanium carbonitride, a layer of metal and an outer layer of nanostructured hard refractory metal nitride, the outer layer is made of nanostructured zirconium nitride, and the layer of metal is made of zirconium and is located between the upper layer of nanostructured zirconium nitride and a layer of titanium carbonitride.

However, the disadvantage of this plate is the low efficiency of the cutting tool when cutting titanium alloys containing zirconium in their structure. This causes increased adhesion of titanium alloys to the upper layers of the coating. As a result, tool performance is reduced.

This disadvantage is eliminated by the proposed solution.

The problem to be solved is improving the structure of the coating of cutting inserts during processing of titanium alloys containing zirconium in their structure.

EFFECT: increased wear resistance of cutting inserts during processing of titanium alloys containing zirconium.

This technical result is achieved in that in a cutting plate for processing titanium alloys containing a base of hard alloy and a coating deposited on it, including layers: titanium carbide and titanium carbonitride, a metal layer located between the outer layer of nanostructured solid refractory metal nitride and the layer made of titanium carbonitride, the outer layer is made of nanostructured niobium and molybdenum nitrides, and the metal layer is made of molybdenum.

The technical result is achieved by the deposition of a two-element refractory compound in the outer coating layer and the use of a metal layer (soft layer) from more heat-resistant refractory compounds.

The deposition of a metal layer (soft layer) from pure molybdenum and the upper soybean coating of nanostructured zirconium and molybdenum nitrides increases the heat resistance and crack resistance of the coating, and hence the wear resistance of the cutting insert as a whole by reducing the separation of coating particles. This effect is especially significant when cutting titanium alloys containing zirconium in their structure.

The proposed cutting insert is shown in the drawing. It contains a base 1 of hard alloy and a coating deposited on it, including layers: layer 2 — titanium carbide, layer 3 — titanium carbonitride, layer 4 (soft layer) of molybdenum, and outer layer 5 — of nanostructured niobium and molybdenum nitrides.

Cutting inserts are made as follows. The base layer 1 of a hard alloy, for example, TT10K8B, is deposited by the lower layers of the coating by both CVD (gas phase deposition) and PVD (ion-plasma or magnetron sputtering), layer 2 of titanium carbide and layer 3 of titanium carbonitride with a thickness of 2.5 microns. Then, a metal layer 4 (soft layer) of molybdenum 1 μm thick is deposited by the CIB method (for example, in the NNV installation) and two cathodes are evaporated: from niobium and molybdenum in a nitrogen medium, forming niobium nitride and molybdenum (NbMo) N 1-1 thick, 5 microns with a grain size of the order of 30 ... 50 nanometers.

The titanium alloy VT20 was turned. Cutting mode: cutting speed V = 40 m / min, cutting depth t = 2 mm, feed S = 0.21 mm / rev. T was determined - the cutting time when the wear of the cutting insert on the rear surface h3 = 0.4 mm was achieved. Tests were subjected to the proposed tetrahedral cutting inserts and cutting inserts of the prototype. The test results are shown in the table.

According to the test results of the cutting inserts it is seen that the proposed insert provides an increase in wear resistance over 2 times in comparison with the prototype.

The advantage of the proposed plate is provided by the fact that the cracking process of the outer nanostructured coating layer and the separation of coating particles from the carbide base are reduced. This helps to increase the wear resistance of the insert.

Table

Type of plates Suggested Cutting Insert TT10K8B- (TiC) -Ti (CN9-Mo- (NbMo) N Prototype (TT10C8E-TiC-Ti (CN) -Zr- (ZrN) Cutting time to wear h3 = 0.4 mm, in min 17 8

Claims (1)

A cutting plate for processing titanium alloys containing a base of hard alloy and a coating deposited on it, including layers of titanium carbide, titanium carbonitride, a metal layer located between the outer layer of nanostructured solid refractory metal nitride and a layer of titanium carbonitride, while the outer layer is made from nanostructured nitrides of niobium and molybdenum, and the metal layer is from molybdenum.