JP2861113B2 - Surface-coated carbide members for cutting and wear-resistant tools - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface-coated carbide member for a cutting / wear-resistant tool having a coating layer provided on the surface of a cutting tool or a wear-resistant tool and having improved wear resistance. .

[Conventional technology]

Conventionally, the materials of cutting tools and wear-resistant tools are cemented carbide such as tungsten carbide (WC), various cermets such as titanium carbide (TiC), steel and hard alloys such as high-speed tool steel, silicon carbide and silicon nitride. And the like were seeds.

In addition, in order to improve the wear resistance of cutting tools and wear-resistant tools, physical vapor deposition (PVD) or chemical vapor deposition (CVD) is applied on the entire surface or the surface of the cutting edge. A surface-coated hard member formed of a single layer or multiple layers of carbide, nitride or carbonitride of titanium, titanium (Ti), hafnium (Hf), zirconium (Zr), or aluminum (Al) has been developed. Recently, it has been widely used in practical use.
In particular, cutting tools and wear-resistant tools having a coating layer formed by the PVD method can improve the wear resistance without deteriorating the base material strength, and therefore require the strength of drills, end mills, throw-away chips for milling and the like. Suitable for cutting applications.

However, although the PVD method is superior to the CVD method in that a coating layer can be formed without deterioration of the base material strength, it is difficult to stably coat Al oxide on the base material by the PVD method. As a result, the coating layer of Al oxide has not yet been put into practical use.
Many of the coating layers of carbides, nitrides, carbonitrides and the like of Ti, Hf and Zr which can be formed by the PVD method have a short service life especially at high speed cutting, so that many of them have a short life.

[Problems to be solved by the invention]

In view of the conventional circumstances, the present invention maintains the base material strength of cutting tools and wear-resistant tools, and at the same time, by providing a coating layer having excellent wear resistance, the wear resistance is improved more than before, especially in high-speed cutting. It is an object of the present invention to provide a surface-coated cemented carbide member for cutting and wear-resistant tools.

[Means for solving the problem]

In order to achieve the above object, in the surface-coated carbide member for a cutting and wear-resistant tool of the present invention, TiN and AlN having a layer thickness of 0.04 to 0.2 μm are alternately formed on the surface of a base material made of a cutting tool or a wear-resistant tool. A coating layer having a total thickness of 0.5 to 8 μm is provided by laminating more than one layer.

The coating layer may be provided on the entire surface of the cutting tool or the wear-resistant tool, or may be provided only on the surface of the cutting edge. As a method for forming the coating layer, a conventionally known method can be used, but a PVD method such as a sputtering method or an ion plating method is preferable because the base material strength can be easily maintained.

[Action]

The surface-coated cemented carbide member of the present invention is used as a cutting tool or a wear-resistant tool, and has abrasion resistance not only in low-speed cutting but also in high-speed cutting.
It has excellent welding and fracture resistance and shows excellent cutting performance over a long period of time.

The reason is that by alternately laminating a thin TiN layer and an AlN layer on the base material surface, TiN increases the hardness of the coating layer and improves the adhesion to the base material, while AlN improves the fracture resistance of the coating layer. Each T, such as improving TiN and making TiN crystal grains fine
It is considered that the synergistic action of the iN layer and the AlN layer results in a coating layer having excellent wear resistance, welding resistance and chipping resistance as a whole.

The thickness of the TiN layer and the AlN layer that are alternately laminated is preferably as thin as possible, but it is difficult to form the layer with a thickness smaller than 0.04 μm by a normal method. Due to the above-described interaction, it is difficult to form a coating layer having excellent wear resistance, welding resistance, and chipping resistance as a whole, so that the thickness is in the range of 0.04 to 0.2 μm. Further, even if the number of laminations of the TiN layer and the AlN layer is less than 10, a coating layer having excellent wear resistance, welding resistance and chipping resistance as a whole due to the above interaction cannot be obtained.

The thickness of the entire coating layer of 0.5 to 8 μm is 0.5 μm
If it is less than 8 μm, no improvement in wear resistance due to the coating layer is observed, and if it is more than 8 μm, the residual stress in the coating layer will increase and the adhesion strength to the base material will decrease.

〔Example〕

As base material, the composition is JIS standard P30 (specifically WC-20wt
% TiC-10wt% Co) and a cutting chip made of cemented carbide with the same shape as SNG432, and the coating layer shown in Table 2 below was applied to the surface by ion plating using vacuum arc discharge as shown below. It was formed into a coated cutting chip sample of the present invention.

That is, a Ti target and an Al-target are arranged in the film forming apparatus so as to face each other, and two points on a diameter passing through the center of a ring-shaped base material holding jig that rotates around an intermediate point between the two targets. Each of the above-mentioned cutting tips as base materials was mounted. In this state, while rotating the cutting chip at 20 rpm, the inside of the film forming apparatus was maintained in an Ar gas atmosphere at a degree of vacuum of 1 × 10 ^-2 torr, and a voltage of -2000 V was applied to both cutting chips to perform cleaning. After the heating, the Ar gas was exhausted. Thereafter, N ₂ gas was introduced into the film forming apparatus at a rate of 300 cc / min while rotating the cutting chip, and Ti was removed by vacuum arc discharge.
By evaporating and ionizing both the target and the Al target, TiN is formed on the cutting chip when the cutting chip passes near the Ti target, and AlN is formed on the cutting chip when the cutting chip passes near the Al target. Then, TiN layers and AlN layers were alternately laminated. In addition, each laminated
The thickness of the TiN layer and AlN layer is controlled by adjusting the amount of arc current.
The thickness of the entire coating layer was controlled by the deposition time.

For comparison, TiC, TiN, TiCN were deposited on the surface of a cutting chip having the same composition and shape by the ion plating method using vacuum arc discharge using a normal film forming apparatus.
To form a multi-layer coating layer, and a coated cutting chip sample of a conventional example shown in Table 2 above was manufactured. In addition, normal
A coated cutting chip sample in which a coating layer such as TiC or Al ₂ O ₃ shown in Table 2 below was formed on the surface of the cutting chip having the same composition and shape by the CVD method was also prepared.

With respect to each coated chip sample having the obtained coated layer, a continuous cutting test and an intermittent cutting test were performed under the conditions shown in Table 1 below, and the flank wear width of the cutting edge was measured.
It is also shown in the table.

From the above results, the coated cutting chip sample of the present invention example,
It can be seen that both continuous cutting and intermittent cutting have excellent wear resistance and chipping resistance, and exhibit cutting performance superior to that of the conventional example.

[Effects of the Invention] According to the present invention, a surface coating for cutting and wear-resistant tools that has both excellent wear resistance and chipping resistance even in high-speed cutting as well as low-speed cutting, and can maintain excellent cutting performance over a long period of time. A super hard member can be provided.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masaaki Tobioka 1-1-1, Kunyokita, Itami-shi, Hyogo Sumitomo Electric Industries, Ltd. Itami Works (56) References JP-A-60-258462 (JP, A JP-A-2-167692 (JP, A) JP-A-62-56565 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C23C 14/00-14/58 B26D 7 / 00-7/34 B23P 15/28

Claims (1)

(57) [Claims] 1. A coating layer having a total thickness of 0.5 to 8 μm by alternately laminating 10 or more layers of 0.04 to 0.2 μm TiN layers and AlN layers on the surface of a base material made of a cutting tool or a wear-resistant tool. A surface-coated superhard member for a cutting and wear-resistant tool, characterized by comprising: