JP2697553B2 - Titanium carbonitride cermet cutting tool with excellent toughness - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent toughness and excellent wear resistance, so that it can be used not only in continuous cutting of steel but also in intermittent cutting. The present invention relates to a titanium cermet (hereinafter, referred to as TiCN) cermet-based cutting tool that exhibits excellent cutting performance over a long period of time without occurrence of chipping or chipping (micro chipping).

[0002]

2. Description of the Related Art Conventionally, generally, as described in various technical papers and, for example, Japanese Patent Application Laid-Open No. 50-86512,
By volume% (hereinafter, simply “%” means volume%), a metal binding phase containing Co and / or Ni as a main component: 5 to 30
%, A hard dispersed phase composed of TiCN having a single phase structure,
And also having a single phase structure, and Ti, Ta, N
a hard dispersed phase composed of a complex carbonitride solid solution with one or more of b, Zr, W, and Mo [hereinafter, referred to as (Ti, M) CN]: TiCN substantially having the composition of
A cutting tool composed of a system cermet is known, and it is also known that the cutting tool is used for continuous cutting of, for example, steel.

[0003]

On the other hand, in recent years, the use of FA in cutting has been remarkable, and there has been a strong demand for labor saving. Accordingly, a cutting tool which can be used for both continuous cutting and interrupted cutting is desired. In the conventional TiCN-based cermet cutting tools described above, although continuous cutting shows excellent wear resistance, intermittent cutting tends to cause chipping or chipping due to insufficient toughness, resulting in short cutting. At present, the service life is reached in hours.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
From the above-mentioned viewpoint, focusing on the above-mentioned conventional TiCN-based cermet cutting tool, and without impairing the excellent wear resistance of the cutting tool, a study was conducted to impart excellent toughness to the cutting tool. Of the conventional TiCN-based cermet cutting tools, each of which has a cored double-phase structure and / or a cored triple-phase structure, and whose core is made of TiCN or (Ti, M) CN. When the hard disperse phase is contained at a ratio of 5 to 40%, the resulting cutting tool composed of the TiCN-based cermet becomes
Research results have shown that the steel has excellent toughness and exhibits excellent wear resistance not only in continuous cutting but also in interrupted cutting.

The present invention has been made based on the results of the above-mentioned research, and has a metal binding phase containing Co and / or Ni as a main component: 5 to 30%, each having a cored double phase structure and / or Alternatively, a hard dispersed phase having a cored triple phase structure and having a core portion of TiCN or (Ti, M) CN:
5 to 40%, each having a single phase structure (Ti, M)
Hard dispersed phase composed of CN and TiCN: This is characterized by a cutting tool made of a TiCN-based cermet having substantially the remaining composition and excellent in toughness and abrasion resistance composed of a TiCN-based cermet having the following composition.

In the cutting tool of the present invention, the ratio of the metal binder phase of the TiCN-based cermet constituting the cutting tool is set to 5 to 30%. If the ratio is less than 5%, desired strength is secured. Is not possible, while the ratio is 30%
Is exceeded, the abrasion resistance rapidly decreases, and the ratio of the hard dispersed phase having a cored double phase structure and / or a cored triple phase structure is 5 to 40 in all cases. The percentage is defined as being less than 5%,
Even in intermittent cutting, it is not possible to secure the desired excellent toughness with no chipping or chipping on the cutting edge. On the other hand, if the ratio exceeds 40%, the wear resistance rapidly decreases. It is based on.

[0007]

Next, the cutting tool of the present invention will be described in detail with reference to examples. As raw material powder, all 0.5 ~
It has a predetermined average particle size in the range of 2 μm (Ti, T
a) CN [TiCN / TaC = 70/30] powder, (T
i, Nb) CN [TiCN / NbC = 70/30] powder, (Ti, Zr) CN [TiCN / ZrC = 80/2
0] powder, (Ti, W, Ta) CN [TiCN / WC /
TaC = 60/20/20] powder, (Ti, Ta, N
b) CN [TiCN / TaC / NbC = 60/20/2
0] powder, (W, Mo) C _{[WC / Mo 2 C = 50/} 5
0] powder, (W, Mo, Ta, Nb, Zr) CN [WC
/ Mo ₂ C / TaCN / NbCN / ZrCN = 20/2
0/20/20/20] powder, further TiCN powder, N
bCN powder, WC powder, NbC powder, Mo ₂ C powder, C
O powder and Ni powder were prepared, and these raw material powders were blended in the composition shown in Table 1, wet-mixed in a ball mill for 72 hours, dried, and then compacted at a pressure of 1.5 ton / cm ^2. Then, the green compact was subjected to (1) a process of raising the temperature from room temperature to 1100 ° C. for 0.05 hour.
~ 0.1 torr nitrogen atmosphere, from 1100 ° C to 142
The process of raising the temperature to a predetermined sintering temperature in the range of 0 to 1600 ° C., the process of maintaining the sintering temperature for 1 hour, and the process of cooling from the end of the sintering temperature maintenance to the normal temperature are performed in a nitrogen atmosphere of 40 to 300 torr. (Hereinafter referred to as nitrogen sintering conditions), (2) in a vacuum of 0.05 to 0.1 torr,
After holding at a predetermined temperature in the range of 500 ° C. for 1 hour and then cooling under the conditions of cooling (hereinafter, referred to as vacuum sintering conditions), and sintering under the above conditions (1) or (2), all of them are SNMG.
Cutting tools made of TiCN-based cermet of the present invention (hereinafter, referred to as cutting tools of the present invention) 1 to 5 and conventional cutting tools of TiCN-based cermet (hereinafter, referred to as conventional cutting tools) 1 having a throw-away insert shape conforming to the standard of 432 , 2 were produced.

Next, with respect to various cutting tools obtained as a result, an arbitrary portion of the cutting tools was observed with a transmission electron microscope, and the Ti content in the total metal component at the center of each hard dispersed phase appeared in the image. And the ratio of the binder phase and the hard dispersed phase, and also the ratio of the individual constituent phases in the hard dispersed phase, were measured using an image analyzer together. , 3. Further, the above-mentioned various cutting tools, work material: SNCM439 (Hardness: H _B 270) round bar, Cutting speed: 200m / min. , Cut: 2.5 mm, Feed:. 0.3 mm / rev, Cutting time: continuous cutting test of steel in 5 minutes, conditions as well as work material: SNCM439 (Hardness: H _B 270) the length of the Round bar with 3 longitudinal grooves at equal intervals in the direction, Cutting speed: 180m / min. An intermittent cutting test of steel was performed under the following conditions: cutting depth: 2 mm, feed: 0.3 mm / rev., Cutting time: 20 minutes. In each test, the flank wear width of the cutting edge was measured. Table 4 shows the results of these measurements.

[0009]

[Table 1]

[0010]

[Table 2]

[0011]

[Table 3]

[0012]

[Table 4]

[0013]

From the results shown in Tables 2 to 4, all of the cutting tools 1 to 5 of the present invention have a cored double phase structure and / or a cored triple phase contained in the TiCN-based cermet constituting the cutting tools. It has a structure and the core is TiCN or (Ti,
M) The hard dispersed phase composed of CN provides excellent toughness without deterioration of wear resistance, and exhibits excellent cutting performance in both continuous cutting and interrupted cutting. Conventional cutting tool 1 containing only TiCN and (Ti, M) CN having a single phase structure as
In No. 2, it is apparent that chipping occurs in the cutting edge due to insufficient toughness in intermittent cutting, but shows a long service life in intermittent cutting, although excellent wear resistance is exhibited in continuous cutting. As described above, the TiCN-based cermet cutting tool of the present invention exhibits excellent cutting performance not only in continuous cutting but also in intermittent cutting in which high toughness is required for a remarkably long period of time. Therefore, it is possible to satisfactorily cope with energy saving and labor saving.

 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-64-28340 (JP, A) JP-A-1-116050 (JP, A)

Claims (2)

(57) [Claims] 1. A metal binding phase mainly composed of Co and / or Ni: 5% by volume
~ 30%, having a cored double phase structure and / or a cored triple phase structure,
Hard dispersed phase whose core is made of titanium carbonitride: 5 to 40
%, Having a single phase structure, and Ti, Ta, Nb, Zr,
A hard dispersed phase composed of a complex carbonitride solid solution with one or more of W and Mo; and a hard dispersed phase composed of titanium carbonitride, also having a single-phase structure: a carbon having substantially the following composition: A cutting tool made of titanium carbonitride cermet with excellent toughness, characterized by being composed of titanium nitride cermet. 2. A metal binding phase comprising Co and / or Ni as a main component: 5% by volume.
~ 30%, having a cored double phase structure and / or a cored triple phase structure,
And the core is made of Ti, Ta, Nb, Zr, W, and M
a hard dispersed phase composed of a composite carbonitride solid solution with at least one of the following: o, having a single-phase structure, and having Ti, Ta, Nb, Zr,
A hard dispersed phase composed of a complex carbonitride solid solution with one or more of W and Mo; and a hard dispersed phase composed of titanium carbonitride, also having a single-phase structure: a carbon having substantially the following composition: A cutting tool made of titanium carbonitride cermet with excellent toughness, characterized by being composed of titanium nitride cermet.