KR20030008359A - A TiAlN origin multi-layer coated to cemented carbide tool - Google Patents

Abstract

PURPOSE: A covered hard alloy for cutting tools and wear resistance tools having cutting performance with superior wear resistance, impact resistance and heat resistance is provided. CONSTITUTION: In a TiAlN based multi-layered hard thin film coated on cutting tools or wear resistance tools using physical deposition method, the multi-layered hard thin film is formed by alternately laying up TiAlN covered hard layer and TiAlCrN covered hard layer on the tools in the order of TiAlN/TiAlCrN/TiAlN/TiAlCrN...., wherein the TiAlCrN covered hard layer comprises a composition of (TiaAlbCrc)N, wherein a+b+c=1, c= 5 to 12 at.%, the TiAlN covered hard layer comprises a composition of (TiaAlb)N, wherein a+b=1, a=50 to 60 at.%, and b=50 to 40 at.%, the multi-layered hard thin film is formed on the tools as a 100 to 1700 layer by alternately coating the thin film layer in the structure of TiAlN/TiAlCrN, and the TiaAlbCrcN covered hard layer has a preferential growing direction of <200> surface.

Description

TiAN origin multi-layer coated to cemented carbide tool coated on cemented carbide for tooling

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coated hard alloy for cutting tool / abrasion resistant tool having cutting performance excellent in wear resistance, impact resistance and heat resistance.

In order to improve abrasion resistance of cutting tools / abrasion resistant tools, it is common to deposit TiN, TiCN, TiAlN-coated hard alloys using physical vapor deposition. The thin film is a TiAlN coated hard alloy. However, as the machinery industry develops highly and as a result, machining conditions are increased, it is required to increase the life of cutting tools or wear resistant tools. Therefore, TiAlN coated hard alloy, known as Vickers hardness 2700 and oxidation start temperature of 800 ° C, is also hardened due to oxidation of TiAlN coated hard alloy due to heat generated at temperatures above 800 ° C under high-speed processing conditions. As the life is shortened, there is a need for a thin film having excellent oxidation resistance while maintaining high hardness even at high temperatures.

Recently, in order to improve the performance of cutting tools or wear-resistant tools, TiAlXN coated hard alloys containing silicon (Si), chromium (Cr), copper (Cu), etc., which are metal elements, have been developed. .

In the case of TiAlXN coated hard alloys, the hardness is Vickers hardness of 3000 or more, and the oxidation temperature is higher than 1000 ° C. .

However, TiAlXN coated hard alloys had high hardness and had good abrasion resistance, but impact resistance was relatively inferior to TiAlN coated hard alloys, resulting in breakage of the tool during interrupted cutting.

According to US Pat. No. 5,503,912, breakage can be reduced by stacking cross-coated hard alloys having different crystal growth directions in order to prevent breakage during interrupted cutting.

The present invention is to solve the conventional problems and problems as described above, the TiAlCrN coated hard alloy (200) first growth and the (111) preferred growth TiAlN coated hard alloy with the addition of Cr as a metal element to the TiAlN coated hard alloy It is the purpose to obtain a coating hard alloy capable of high-speed processing by maintaining the high temperature hardness and improving the oxidation start temperature by cross-coating to 100-1700 layers and the impact resistance.

The present invention to achieve the above object;

In the method of coating a multilayer hard thin film on a cemented carbide for tools,

Load the targets to be coated and coated into the furnace, evacuate the furnace pressure to 5.0 × 10 ^-5 Torr or less by using a pump, heat the furnace temperature to 400 ℃ with a heater, and add Ar gas and reaction gas. The bias voltage is applied at 130V, the sputter power of one target is fixed at 5KW, the sputter power of the other target is 1-5KW, and the physical speed is controlled by adjusting the number of revolutions of the jig mounted on the coated object to control the stacking number. Provided is a multilayer hard thin film coating method coated by vapor deposition. Here, the targets are preferably TiAl targets on one side, and TiAlCr targets on the other side, and the reaction gas is N ₂ . In addition, the thickness of the coated multi-layered thin film was deposited at 2 ℃ m, and also to change the sputter power of the other target to control the Cr content to be laminated, the coating method in the present invention is physical vapor deposition Coating is performed using unbalanced magnetron sputtering method (hereinafter referred to as "UMB method") of the coating method to create a separate magnetic field in the conventional magnetron sputtering method, the sputtered electrons and ions are bound to the magnetic field to reach the coating object To be able.

The present invention is also a multilayer hard thin film coated by the multilayer hard thin film coating method as described above, wherein the multilayer hard thin film is (TiaAlbCrc) N-based, where a + b + c = 1, c = 5 atomic% to 12 atomic% The hard thin film layer provides a multilayer hard thin film that is coated with a 100-1700 layer by crossing in a TiAlN / TiAlCrN structure. Here, the TiAlCrN coating layer is preferably a growth orientation (200) plane.

In addition, the TiAlN coating hard layer used in the present invention is composed of (TiaAlb) N, wherein a + b = 1, a = 50 atomic% to 60 atomic% and b = 50 atomic% to 40 atomic%.

To determine the composition of the coated specimen, Auger electron spectroscopy analysis (hereinafter referred to as AES) was performed, and the diffraction peaks were examined by X-ray diffraction (XRD) method.

Example 1

First, the coated material was cemented carbide, coated with P30 grade ISO standard SPCN1203EDTR for milling cutting test, and then coated on a Z10 grade 4 mm end mill for end mill cutting test.

As described above, the coating method used the UBM method to fix the sputter power at 5KW, the TiAlCr target power at 3KW, and the bias voltage at 130V.

And coating was performed until the film thickness became 2 micrometer, changing the rotation speed of JIG to 1-10 rpm in order to adjust the lamination number.

Table 1 below shows the hardness values according to the number of stacked TiAlN-coated hard alloy and TiAlCrN-coated hard alloy prepared according to the present invention.

As shown in Table 1, when comparing TiAlN and TiAlCrN coated hard alloys manufactured in the prior art, it can be seen that the hardness of TiAlCrN coated hard alloys is relatively high.

The exact reason for the increase of the hardness value is not yet known, but it is assumed that the third element prevents the oxidation of Ti at high temperature and densifies the thin film.

In the case of the present invention, when the content of Cr is equal to 12at%, the hardness of TiAlN-coated hard alloy and TiAlCrN-coated hard alloy is compared to the hardness of up to 300 layers. It can be seen that the hardness value is higher than that of the prepared TiAlCrN-coated hard alloy. The hardness value started to increase dramatically when the number of laminated layers was 500 layers, and the highest hardness value was obtained when 1500 layers.

However, when the lamination number was 1700 layers, the hardness value was rather decreased, which resulted in a lower result than the TiAlCrN-coated hard alloy of the single layer, and when the lamination number was 2000 layers, the hardness value was lower.

division Thin film composition Stacked Number Hardness (Hv) Oxidation Temperature (℃) Prior art One (Ti _0.5 Al _0.5 ) N One 2700 800 2 (Ti _0.44 Al _0.44 Cr _0.12 ) N One 2950 1000 Invention 3 (Ti _0.44 Al _0.44 Cr _0.12 ) N 100 2970 1160 4 (Ti _0.44 Al _0.44 Cr _0.12 ) N 300 2980 1160 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 500 3060 1190 6 (Ti _0.44 Al _0.44 Cr _0.12 ) N 700 3100 1190 7 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1000 3120 1210 8 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1300 3140 1210 9 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1500 3180 1200 10 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1700 2900 1170 11 (Ti _0.44 Al _0.44 Cr _0.12 ) N 2000 2800 1170

Table 1

Example 2

Oxidation test was performed using the sample coated in Example 1. The oxidation-resistant test was performed under the conditions of Table 2 and the results are shown in Table 1.

As shown in Table 1, the oxidation temperature was 800 ° C. for sample No. 1, but the oxidation temperature was increased to 1000 ° C. for sample No. 2 containing 12 atomic percent Cr.

Temperature range Room temperature-1300 ℃ Temperature increase rate 10 ℃ / min atmosphere Dry air, 1atm Air flow Air flow rate: 150 cm3 / min

TABLE 2

It can be seen from the sample No. 3 having the number of laminated layers of the present invention that the oxidation resistance increased dramatically. However, as the number of laminations increased to 11 samples, the oxidation initiation temperature was slightly different. The results showed almost the same results. From the sample No. 10 having 1700 layers, the oxidation start temperature was lowered. Therefore, when the content of Cr is the same, the number of TiAlN / TiAlCrN laminated number from 100 layers to 1500 layers showed the same effect of improving the oxidation resistance according to the laminated number.

Example 3

Milling performance test was performed using the ISO standard SPCN1203EDTR coated in Example 1. The cutting performance test was performed by the continuous cutting test and the intermittent cutting test. The evaluation conditions are shown in Table 3.

The continuous abrasion resistance test processed 150mm wide and 265mm long beams, and the intermittent cutting test was processed three layers of 25mm wide and 265mm long by 3mm apart.

The evaluation of the continuous wear test measured the amount of wear on the surface after 10 pass machining. The intermittent cutting test was carried out once under the following conditions.

Continuous wear test Intermittent Cutting Test Workpiece SCM440 (H _B 250) SCM440 (H _B 250) Cutting speed (m / min) 271 125 Feed per day (mm / 刃) 0.167 0.24-0.6 Depth of cut (mm) 2.0 2.0 Coolant radish radish Pass time 10 Until breakage

TABLE 3

The results of the evaluation are shown in Table 4, and when the samples of No. 1 and No. 2 manufactured according to the prior art were compared, the No. 2 containing 12 atomic percent Cr was excellent in abrasion resistance but inferior in the interrupted cutting test.

In the case of the present invention, the sample No. 3 with 100 layers of lamination showed the same cutting performance as the sample No. 2 with single layer, but from the sample No. 4 with 300 layers of lamination, the continuous wear resistance and intermittent cutting performance began to improve. The burned samples showed excellent performance in the continuous wear test and the interrupted cutting test, which showed the effect of improving the performance of the continuous and interrupted cutting properties due to the lamination.

However, sample 10 was inferior to the improvement of intermittent machinability, and sample 11 showed no improvement in continuous wear resistance and intermittent cutting performance.

division Thin film composition Stacked Number Continuous wear resistance margin wear (mm) Intermittent cutting test Max feed rate (mm / 刃) One (Ti _0.5 Al _0.5 ) N One 0.28 0.48 2 (Ti _0.44 Al _0.44 Cr _0.12 ) N One 0.19 0.24 3 (Ti _0.44 Al _0.44 Cr _0.12 ) N 100 0.20 0.30 4 (Ti _0.44 Al _0.44 Cr _0.12 ) N 300 0.17 0.36 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 500 0.161 0.54 6 (Ti _0.44 Al _0.44 Cr _0.12 ) N 700 0.15 0.54 7 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1000 0.156 0.54 8 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1300 0.158 0.54 9 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1500 0.152 0.54 10 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1700 0.18 0.3 11 (Ti _0.44 Al _0.44 Cr _0.12 ) N 2000 0.195 0.24

Table 4

Example 4

Cutting performance test was carried out using a four-day end mill with a diameter of 8mm coated in Example 1 and the evaluation conditions are shown in Table 5.

In the end mill cutting performance test, 20 passes were processed for 265mm length of the bar, and the average wear was measured in Table 6 after measuring the edge wear of each blade.

When the wear amount was measured even if one day out of four days, the average amount of wear is indicated as breakage.

Continuous wear test Workpiece SKD61 (HRC52) Cutting speed (m / min) 60 Feed rate (mm / tooth) 0.023 Depth of cut (mm) Axial direction: 1.2 Radial direction: 0.8 Coolant radish Pass time 20

Table 5

The evaluation results are shown in Table 6, and the first sample prepared according to the prior art had two blade breakages in four days.

In the case of the present invention, sample 3 showed a similar amount of wear to sample 2, and sample 4 of which the number of laminated layers was 300 began to improve wear resistance, and sample 8 of the 1300 layers had the best cutting performance.

division Thin film composition Stacked Number Abrasion resistance test average wear (mm) One (Ti _0.5 Al _0.5 ) N One damage 2 (Ti _0.44 Al _0.44 Cr _0.12 ) N One 0.157 3 (Ti _0.44 Al _0.44 Cr _0.12 ) N 100 0.152 4 (Ti _0.44 Al _0.44 Cr _0.12 ) N 300 0.142 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 500 0.130 6 (Ti _0.44 Al _0.44 Cr _0.12 ) N 700 0.124 7 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1000 0.110 8 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1300 0.107 9 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1500 0.112 10 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1700 0.142 11 (Ti _0.44 Al _0.44 Cr _0.12 ) N 2000 damage

Table 6

Example 5

The cutting sample was coated in the same manner as in <Example 1>.

As described in <Example 1>, the coating method uses the UBM method in order to fix the sputter power at 5 KW and control the Cr content in the TiAl target by varying the power of the TiAlCr target to 0.5-5 KW and the bias voltage. Fixed at 130V. And the rotation speed of the JIG was fixed at 6rpm was coated until the film thickness is 2㎛.

Table 7 below shows the multi-layered thin film of TiAlN-coated hard alloy and TiAlCrN-coated hard alloy according to the amount of Cr prepared by the present invention.

As shown in Table 7, in the present invention, when the number of laminated layers is the same as 1500 layers, sample 1 having 3 atomic percent Cr has no effect of improving the hardness, but rather has a lower hardness than the TiAlCrN-coated hard alloy of single layer. Indicated.

However, from sample No. 2 with 5 atomic percent Cr, hardness increased, and sample No. 5 with 12 atomic percent showed the highest hardness. However, when more than 12 atomic% is added, the hardness value begins to decrease, and when the Cr content is more than 12 atomic%, it can be seen that there is no effect of improving the hardness.

division Thin film composition Stacked Number Hardness (Hv) Oxidation Temperature (℃) Invention One (Ti _0.485 Al _0.485 Cr _0.03 ) N 1500 2820 1000 2 (Ti _0.475 Al _0.475 Cr _0.05 ) N 1500 3070 1050 3 (Ti _0.465 Al _0.465 Cr _0.07 ) N 1500 3120 1140 4 (Ti _0.455 Al _0.455 Cr _0.09 ) N 1500 3150 1180 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 1500 3180 1200 6 (Ti _0.425 Al _0.425 Cr _0.15 ) N 1500 3100 1090 7 (Ti _0.41 Al _0.41 Cr _0.18 ) N 1500 2980 1020 8 (Ti _0.4 Al _0.4 Cr _0.2 ) N 1500 2890 970

TABLE 7

Example 6

Oxidation resistance test was performed using the sample coated in Example 5. In the case of the oxidation-resistant experiment was carried out under the same conditions as Table 2 and the results are shown in Table 7.

In the case of the present invention, as shown in Table 7, sample 1 showed an oxidation start temperature of 1000 ° C., but from sample 2, the oxidation start temperature started to increase and from sample 3 added with 7 atomic percent Cr, The 5th sample added with 12 atomic percent Cr showed the highest oxidation start temperature.

However, from the sixth sample in which Cr was added to 15 atomic%, the oxidation initiation temperature began to decrease rapidly.

Example 7

Milling cutting performance test was performed using the ISO standard SPCN1203EDTR coated in Example 5. The cutting performance test was performed by the continuous cutting test and the intermittent cutting test. The evaluation conditions are shown in Table 3, and the evaluation of the abrasion resistance test was evaluated in the same manner as in Example 3.

The evaluation results are shown in Table 8. In the case of the present invention, the continuous and interrupted cutting performance was improved from sample No. 2 containing 5 atomic percent Cr, and the result was improved to sample no. 5 but containing more than 12 atomic percent Cr. Interrupted cutting performance was good for samples 6 and 7, but continuous wear resistance was inferior to sample 5.

division Thin film composition Continuous wear resistance margin wear (mm) Intermittent cutting test Max feed rate (mm / 刃) One (Ti _0.485 Al _0.485 Cr _0.03 ) N 0.20 0.24 2 (Ti _0.475 Al _0.475 Cr _0.05 ) N 0.17 0.54 3 (Ti _0.465 Al _0.465 Cr _0.07 ) N 0.151 0.54 4 (Ti _0.455 Al _0.455 Cr _0.09 ) N 0.15 0.54 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 0.152 0.54 6 (Ti _0.425 Al _0.425 Cr _0.15 ) N 0.168 0.54 7 (Ti _0.41 Al _0.41 Cr _0.18 ) N 0.181 0.54 8 (Ti _0.4 Al _0.4 Cr _0.2 ) N 0.23 0.3

Table 8

Example 8

Cutting performance test was carried out using a four-day end mill coated with a diameter of 8mm in Example 5 and the evaluation conditions are shown in Table 5 and the evaluation of the cutting performance of the end mill was evaluated in the same manner as in Example 4. Shown in

In the case of the present invention, as the Cr content was increased, the wear resistance was improved, and the fourth sample containing 9 atomic% Cr showed the best performance, and the wear amount was similar to the sixth sample containing 15 atomic% Cr.

However, from the 7th sample with 18 atomic% Cr content, the amount of wear began to increase, indicating no improvement in cutting performance.

division Thin film composition Abrasion resistance test average wear (mm) One (Ti _0.485 Al _0.485 Cr _0.03 ) N 0.172 2 (Ti _0.475 Al _0.475 Cr _0.05 ) N 0.131 3 (Ti _0.465 Al _0.465 Cr _0.07 ) N 0.119 4 (Ti _0.455 Al _0.455 Cr _0.09 ) N 0.107 5 (Ti _0.44 Al _0.44 Cr _0.12 ) N 0.110 6 (Ti _0.425 Al _0.425 Cr _0.15 ) N 0.111 7 (Ti _0.41 Al _0.41 Cr _0.18 ) N 0.125 8 (Ti _0.4 Al _0.4 Cr _0.2 ) N 0.151

Table 9

As mentioned above, according to the present invention, the TiAlN-coated hard layer and the TiAlN-coated hard layer, which are (111) preferential growth, are added to the surface of the cutting tool or the wear resistant tool, and the metal element Cr is added to the (200) preferred growth (TiaAlbCrc). When N (where a + b + c = 1, c = 5 atomic% -12 atomic%) is laminated with 100-1700 layers of coated hard alloy having the chemical formula, the surface coating is excellent in wear resistance, oxidation resistance and interrupted cutting. A hard alloy is obtained.

When the present invention is applied to a cutting tool or a wear resistant tool, high speed dry processing is possible, and in particular, the breakage of the tool can be reduced even at high speed during intermittent cutting operations.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated.

Claims (5)

TiAlN-coated hard layer and TiAlCrN-coated hard layer are laminated by TiAlN / TiAlCrN / TiAlN / TiAlCrN ... Multilayer hard thin film. The multilayer hard film of claim 1, wherein the TiAlCrN coated hard layer is composed of (TiaAlbCrc) N, wherein a + b + c = 1 and c = 5 atomic% -12 atomic%. The method of claim 1, wherein the TiAlN coating hard layer is composed of (TiaAlb) N, wherein a + b = 1, a = 50 atomic% -60 atomic% and b = 50 atomic% -40 atomic% pellicle The multilayer hard film of claim 1, wherein the thin film layer is coated with a TiAlN / TiAlCrN structure and coated with a 100-1700 layer. 4. The multilayer hard thin film according to claim 3, wherein the TiaAlbCrcN coated hard layer has a growth direction of (200) plane.