JPS58197265A - Surface-coated sintered hard alloy member for cutting tool - Google Patents

Abstract

PURPOSE:To obtain an alloy member with high toughness, superior wear and oxidation resistances, by coating the surface of a sintered hard alloy substrate contg. the carbide or the like of a IVa, Va or VIa group metal in the periodic table as a hard dispersed phase and an iron group metal as a binding phase with the composite nitride or the like of Si and Al in the form of a layer having a specified thickness. CONSTITUTION:The hard dispersed phase of a sintered hard alloy substrate is composed essentially of >=1 kind of compound selected from the carbides, nitrides and carbonitrides of the IVa, Va and VIa group metals in the periodic table, and the binding phase is composed essentially of >=1 kind of iron group metal or >=1 kind of iron group metal and >=1 kind of metal selected from the Cr group metals and Al. The surface of the alloy substrate is coated with a single layer of the composite nitride or carbonitride of Si and Al, a double layer of the composite nitride and carbonitride, or a layer of a mixture of them to obtain a sintered hard alloy member for a cutting tool. The thickness of the layer is 0.5-20.0mum.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a surface-coated superhard alloy for cutting tools that exhibits excellent cutting performance when cutting steel and cast iron, especially when cutting under severe conditions such as high-speed cutting and high-feed cutting. It is related to members.

Generally, the hard dispersed phase is mainly 4a and 5 of the periodic table of elements.
a, and carbides and nitrides of group 6a metals.

and carbonitrides, while the binder phase is mainly one or two of iron group metals.
or more than one species, or one or two of the iron group metals,
The same (4a, 5a
, and carbides, nitrides, and oxides of group 6a metals,
and one of the group consisting of two or more of these solid solutions
BACKGROUND ART A surface-coated superhard alloy member formed by forming a coating layer consisting of a single layer of seeds or a multilayer of two or more types by a chemical vapor deposition method or the like is used as a cutting tool.

However, these conventional surface-coated cemented carbide members have an excellent cutting life when used for cutting steel, but only a short cutting life when cutting cast iron.
On the other hand, cutting cast iron shows a long cutting life, but cutting steel has a short cutting life.There is no material that shows a satisfactory cutting life when cutting either steel or cast iron, especially these corrugated materials. Currently, cutting performance is not satisfactory under harsh conditions such as high-speed cutting and high-feed cutting.

Therefore, from the above-mentioned viewpoint, the present inventors have developed a cutting machine that can not only be used for cutting both steel and cast iron, but also capable of high-speed cutting and high-feed cutting of both of these corrugated materials. As a result of research to develop the tool, it was found that carbides, nitrides, and oxides of metals from groups 4a, 5a, and 6a of the periodic table were added to the surface of the cemented carbide substrate in the conventional surface-coated cemented carbide member. , and instead of a coating layer consisting of a solid solution of two or more of these, a composite nitride of S] and A9 (hereinafter referred to as 5i-AQ-N) and a composite carbonitride (hereinafter referred to as 5i-AQ-C-N) are used. A coating layer consisting of a single layer, a multilayer, or a mixed layer of two types of
The surface-coated superhard alloy member formed with a layer thickness of 5 to 20.071 m has the above-mentioned 5i-AA-N and 5i-AA
-High room temperature and high temperature hardness of the C-N coating layer.

High toughness and excellent wear and oxidation resistance.

Furthermore, due to its chemical stability at high temperatures, when used as a cutting tool for cutting steel and cast iron, it has an excellent cutting life when cutting any rigid material, especially when cutting these corrugated materials at high speeds. They obtained the knowledge that it exhibits extremely excellent cutting performance even in cutting and high-feed cutting.

This invention was made based on the above knowledge, and the reason why the thickness of the coating layer is set to 05 to 20.0 μm is that if the layer thickness is less than 0.5 μm, the desired excellent cutting performance cannot be achieved. 20.0μ
This is because if the layer thickness exceeds m, the coating treatment time becomes long, the crystals become coarse, the toughness decreases, and the surface becomes rough and uneven.

Next, the surface-coated cemented carbide member of the present invention will be specifically explained with reference to Examples.

Example 1 A cutting tip of ISO standard P20 grade (tungsten carbide-Co-based superhard alloy) was charged into a heat-resistant alloy reaction vessel, and 5 ict: 1. , Section 5, AlCl2
: 2.0 section, NH3: 3.0 section, H2: 93.5%
The reaction mixture gas having a composition consisting of (the above volume ratio)
By applying chemical vapor deposition treatment at a temperature of 1000° C. for 3 hours under a reduced pressure of 70 torr while flowing at a flow rate of O)-/min, the composition formula: Sio+5 was applied to the surface.
A covering layer of an amorphous solid phase was formed having oAlo, zzNo, 4'7 + layer thickness: 6 μm. The cutting tip obtained as a result is referred to as the coated cutting tip 1 of the present invention.

Example 2 The reaction mixture gas composition was CH3.5iCA3: 1.5.

A elephant CL3: 2.0%, NH3: 3.0%, H,:
Example 1 above, except that the ratio is 93.5 (capacity%)
By performing chemical vapor deposition treatment under the conditions of 42, the composition formula: 5io3oAl! o, zoc 0.2
3N0.271 A coated cutting tip 2 of the present invention having a layer thickness of 6 μm and a coating layer made of an amorphous solid phase was manufactured.

Example 3 5-8ict: 1.5%, AACt3:
2.0 ratio, NH3: 3.0%.

A reaction mixture gas having a composition (volume %) of H2: 93.5%, CH3・5iCt3: 1.5%, AεCL3:
2.0%.

NH3: 3. 10% of the reaction mixture gas with a composition (capacity: □%) of O and H2: 93.5%.
H2 gas: to
J! The chemical vapor deposition process was carried out under the same conditions as in Example 1, except that this was carried out for 2 hours, with an intervening residual gas cleaning process consisting of 3 minutes of flow at a flow rate of , /m=. By composition formula:
Sio, 5oAAo, zzNo4fu and the same Sio, 5o
Layer thickness: 4μ with a mixed structure in which the two phases of AAo, zoCo, 2sNo, and zy are intermittent layers (volume ratio of both phases is 1:l)
A coated cutting tip 3 of the present invention whose surface was coated with a coating layer of m was produced.

Then, the resulting coated chips 1 to 3 of the present invention were prepared. For the purpose of comparison, a conventionally coated cutting tip consisting of a commercially available P20 grade substrate surface coated with titanium carbide with a layer thickness of 6 μm was examined. Work material: SNCM-8 (Hardness:
HB270), cutting speed: 180 m/rrm, feed: 0.25 mz/rev, depth of cut.

6- Steel high-speed cutting test under conditions of 1.5 m, rigid material SN
CM-8 (hardness HB270), cutting speed: ], 20
m/rmn.

Feed: 0.5 mm1rev, , Depth of cut: ]-,
] Steel high-speed cutting test under the condition of 5 mm, workpiece abrasion: F
C-25 (hardness, HB200), cutting speed: 160
Cast iron high-speed cutting test under the conditions of m/min, feed 1): 0.25 mm/r6■, depth of cut: ], 5 m, and work material: FC-25 (hardness: HB200).

Cutting speed: 120m1m1n, feed: 0.5mm1
A cast iron high-feed cutting test was conducted under the conditions of rev, depth of cut: 1.5 mm, and the flank wear depth was measured after continuous cutting for 30 minutes. These results are shown in Table 1.

From the results shown in Table 1, the present invention coated cutting tip 1-
3. In high-speed and high-feed cutting of steel and cast iron,
It is clear that the cutting tip exhibits a much better cutting life than conventionally coated cutting tips.

As described above, the surface-coated superhard alloy 1 of the present invention: The coating layer of the member has high room temperature and high temperature hardness, and high toughness, and further has wear resistance and oxidation resistance.

and 5i-AQ-Table 1 N and 5i-A+ with excellent chemical stability at high temperatures! -Since it is composed of C-N,
When used for cutting steel and cast iron, it exhibits a long cutting life in both cases, and also exhibits excellent cutting performance during high-speed cutting and high-feed cutting of these rigid materials, making it an excellent cutting tool. It has useful properties.

Applicant: Mitsubishi Metals Corporation Agent Tomi 1) Kazuo

Claims (1)

[Claims] The hard dispersed phase is mainly composed of elements 4a and 5a of the periodic table. and carbides, nitrides, and carbonitrides of group 6a metals, while the binder phase is mainly composed of one or more of iron group metals, or iron group metals. A composite nitride of Sl and AQ and a composite carbonitride are applied to the surface of a super hard alloy substrate composed of one or more of these and one or more of a chromium group metal and AC. A surface-coated super-hard alloy member for a cutting tool, comprising a coating layer having a thickness of 05 to 20.0 μm and consisting of one type of single layer, or two types of multilayer or mixed layer.