JPS62211365A - Surface treatment - Google Patents

Abstract

PURPOSE:To easily form a metallic nitride film by shielding an N2 plasma flame from the atm. by other gaseous N2 at the time of blowing the plasma jet of N2 to the surface of Ti, etc., and forming the nitride film of TiN, etc. CONSTITUTION:The surface of a metallic material 1 such as Ti, Al, Si or Zr as the work for a surface treatment is shielded from the atm. by maintaining the same in an N2 gaseous atmosphere 2. Gaseous N2, 5 is then introduced into a water-cooled Cu nozzle 3 of a plasma generator provided with an electrode 4 and a DC voltage is impressed between the electrode 4 and the Cu nozzle 3 to ionize the gaseous N2, 5 and to eject the plasma jet 6. The plasma jet 6 of a high temp. contg. such N2 ions is blown to the surface of the metallic material 1, by which a ceramic layer 7 of TiN, AlN, Si3N4, ZrN, etc., having high toughness and excellent resistance to corrosion, wear and heat is easily formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for nitriding the surface of a substrate such as T1. More specifically, the present invention relates to a surface treatment method in which a workpiece and a plasma processing device are placed in N2 gas, and nitrogen gas plasma is sprayed onto the surface of the workpiece to form a thin film of metal nitride such as TIN.

[Conventional technology and its problems]

Conventionally, a sputtering method (PVD or SP) has been used to form a TiN film by combining with nitrogen such as Tl.
, a method using chemical vapor deposition (CVD), and a method using plasma spraying.

In the sputtering method, a cathode is placed in a low-pressure container containing N2 gas, and a workpiece (a substance that combines with nitrogen, such as Ti) is placed at a certain distance from the cathode, and the workpiece is heated and the When a potential difference is applied between the cathode and the liquid workpiece, a glow discharge occurs, and the electrons ejected from the cathode collide with the residual N2 gas and ionize this nitrogen gas, and these ions and the workpiece (T1) There is a method (DC bipolar sputtering method) in which TiN is bonded to form a thin film of TiN.

CVD method is N! A workpiece is placed in bagasse, a laser is introduced near the workpiece, and N! These methods separate bagasse ions and react with the workpiece to form a TiN layer, but both have the drawback of slow vapor deposition speed.

Further, the plasma spraying method is a method in which TIN powder is plasma sprayed, but it is difficult to spray because metal nitrides such as TiN easily sublime.

Furthermore, when TIN is sprayed in the atmosphere, there is a problem in that the quality of the formed layer changes due to reaction with oxygen in the atmosphere.

[Means for solving problems]

In the surface treatment method according to the present invention, Pg s Tl # AA e S shielded by N gas
If the workpiece is made of a metal material such as i or Zr, other N
.

The surface of the workpiece was nitrided by spraying gas plasma.

[Effect]

In this invention, N! Since the nitrogen plasma flame is irradiated under a gas-shielded state, a thin film of, for example, TIN is formed on the surface of the workpiece without being oxidized.

〔Example〕

FIG. 1 is an explanatory diagram of a surface treatment method showing an embodiment of the present invention. In the figure, 1 is the workpiece, 2 is the N2 gas that shields the workpiece 1 from the air, 6 is a water-cooled steel nozzle installed above the workpiece 1 to blow out a nitrogen plasma jet, - 4 is an electrode provided in this water-cooled steel nozzle 3, 5 is nitrogen gas introduced between this electrode 4 and the water-cooled copper nozzle 3, and 6 is a nitrogen gas 5 decomposed into ions by glow discharge. The ejected plasma jet 7 is a TiN layer formed on the surface of the workpiece 1.

Next, this operation will be explained. First, the workpiece 1 is
Shield with 2 gases. For example, a water-cooled steel nozzle of a plasma generator is placed in a container (not shown) together with a workpiece 1, and N2 gas 2 is introduced into the shield.

The pressure of the N2 gas 2 varies depending on the purpose of use of the workpiece, but is controlled at approximately 1 to 200 Torr.Next, another N2 gas is injected between the water-cooled steel nozzle 3 and the electrode 4. If you apply DC voltage (30 to 50v) while guiding, N2
The gas 5 is decomposed into ions and a plasma jet 6 is ejected. Since this plasma jet 6 has a high temperature and contains a large amount of N ions, the surface Kf of the workpiece 1 is
i to form a nitride 7 (eg TIN) of the workpiece. TiN and AtN thus formed.

SIN, ZrN, etc. are generally called ceramics, and although they are thin films, they are strong, and have corrosion resistance, wear resistance,
It has excellent properties such as heat resistance.

The table below shows plasma output of 600AK80V.

The components of Plasma Jet B are nitrogen ions and electrons, the shield is N2 gas 2, and a Ti base material processed under conditions of 200 Torr is shown for comparison with the conventional technology.

Each test method in this table was as follows.

The oxidation test method was to leave the product in the air at 90°C for 5 hours.

(B) Corrosion test method: immersion in 80'C, 15% HCL.

(C) Abrasion test method: Pin-on-disk method was used to determine the amount of wear when running 5 km on a rotating disk.

The above data can prove the superiority of the present invention.

〔Effect of the invention〕

This invention is an extremely simple method, as described above, in which the workpiece is shielded by N2 gas while a plasma jet of another N2 gas is directly sprayed onto the surface of the workpiece (for example, TI). However, it is effective in obtaining a ceramic layer that is strong and has excellent wear resistance, corrosion resistance, and heat resistance.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a surface treatment method showing an embodiment of the present invention. In the figure, 1 is the workpiece and 2 is N! 6 is a water-cooled steel nozzle, 4 is an electrode, 5 is N2 gas, 6 is a plasma jet, and 7 is a TiN layer.

Claims (1)

[Claims] Fe, Ti, Al, shielded by N_2 gas
A surface treatment method characterized in that a plasma of another N_2 gas is sprayed onto a workpiece whose base material is a metal material such as Si or Zr, and the surface of the workpiece is nitrided.