JP3719847B2 - Sliding material and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slidable material that can be used without lubrication and hardly causes damage or seizure of a counterpart material, and a method for manufacturing the same.
[0002]
[Prior art]
In general, a titanium nitride (TiN) film is widely used as a hard wear-resistant film in dies, cutting tools, and the like, and in recent years, it is also applied to sliding parts. Normally, when the TiN film is rubbed against the metal material itself or the counterpart material in an unlubricated state, the friction coefficient does not necessarily decrease because the counterpart material adheres to the film surface. However, according to the study of the present inventor, it has become clear from a series of continuous research results that the friction coefficient between the TiN film formed by the plasma CVD method and the metal material is relatively low. The reason for this is not clear, but chlorine derived from undecomposition of titanium chloride, which is a raw material during film formation when applying the plasma CVD method, particularly chlorine that remains undecomposed when the temperature during film formation is low. It is presumed to be mixed into the entire surface of the TiN film. However, the chlorine mixed in the entire surface of the TiN film has a serious problem that it oxidizes and erodes the material by coming into contact with the metal material, and cannot be put into practical use as it is.
[0003]
[Problems to be solved by the invention]
In view of the present situation, an object of the present invention is to provide a slidable material that can be used without lubrication and hardly cause damage or seizure of the mating material, and a method for manufacturing the same. Under such a problem, the present inventors pay attention to the effect of improving the wear resistance by containing chlorine in the plasma CVD method, and do not contain chlorine on the entire surface of the TiN film, and form a chlorine injection layer only on the surface. The present invention has been conceived in combination with a TiN film forming method that does not cause chlorine contamination during film formation.
[0004]
[Means for solving problems]
That is, the present invention is a slidable material having a self-lubricating property for molds or sliding parts, and is formed on a surface portion of a base material made of a hard metal by a physical vapor deposition method or a powder metallurgy method. A TiN coating layer is formed, and chlorine concentration from the surface of the TiN coating layer is a concentration of 1 × 10 ¹⁶ ions / cm ² or more, preferably 1 × 10 ¹⁶ ions / cm ² to 1 × 10 ¹⁷ ions / cm ^2. And a slidable material characterized in that chlorine ions are not present in the vicinity of the interface of the TiN coating layer with the base material, and self for molds or sliding parts A method for producing a slidable material having lubricity, wherein a TiN coating layer formed by physical vapor deposition or powder metallurgy is formed on a surface portion of a base material made of hard metal, and the surface of this TiN coating layer the surface concentration of chlorine from the 1 × 10 ¹⁶ ions / cm ² or more concentration, preferably 1 × 10 ¹⁶ ions / cm ² to 1 10 ¹⁷ ions / cm implanted at ² concentrations, and the production method of a sliding material which is in the vicinity of the interface between the base material of the TiN coating layer, characterized in that the ion implantation such that there is chloride ion Thus, the above-mentioned problem has been achieved.
[0005]
BEST MODE FOR CARRYING OUT THE INVENTION
According to the present invention, the surface chlorine concentration on the surface of the TiN coating layer formed on the metal material surface by physical vapor deposition or powder metallurgy is 1 × 10 ¹⁶ ions / cm ² or more, preferably 1 ×. Since the ions are implanted at a concentration of 10 ¹⁶ ions / cm ² to 1 × 10 ¹⁷ ions / cm ² , this chlorine implanted layer has a self-lubricating property and low friction even when the counterpart material is a soft metal material. Due to the series number, it is possible to prevent adhesion of the mating material, and it is difficult to wear while maintaining the characteristics of the hard TiN layer. In addition to the low friction coefficient and excellent wear resistance, the TiN layer near the metal material layer on which the TiN layer is formed does not contain chlorine, so the problem of corrosion of the material is also eliminated.
[0006]
FIG. 1 is an explanatory view of the present invention, where (a) shows only the base material 1, (b) shows a state where a TiN layer 2 is formed on one side of the base material, and (c) shows chlorine on the surface of the TiN layer. The states in which the injected chlorine injection layer 3 is formed are respectively shown. The base material 1 can be made of normal high speed tool steel, alloy tool steel, bearing steel, stainless steel, heat resistant steel, aluminum and its alloys, titanium and its alloys, carbide, various ceramics, etc., and the TiN layer 2 is formed. Prior to this, one surface of the film to be deposited is mirror-finished by polishing. The TiN layer 2 is formed by physical vapor deposition, so-called PVD method, specifically, ion plating method, vacuum vapor deposition method, sputtering method, ion beam mixing method or the like, or powder metallurgy method. To do. In the present invention, the TiN layer 2 is formed by such a method. In the chemical vapor deposition method, the thermal CVD method uses titanium chloride as a raw material in the same manner as the plasma CVD method. Is extremely high, so that undecomposed chlorine does not remain in the TiN layer 2 and is applicable. In short, the present invention may be applied by any method as long as it does not contain chlorine on the entire surface of the film. The thickness of the TiN layer 2 is preferably in the range of 0.2 to 10 μm, which is applied as a normal hard wear-resistant film, although it depends on the formation method. If the thickness is less than 0.2 μm, there is a greater possibility that chlorine ions will reach the vicinity of the base material interface when chlorine is injected in the next step. On the other hand, even if it is thicker than 10 μm, the improvement in wear resistance cannot be expected so much though the deposition time and cost increase.
[0007]
On the TiN layer 2, chlorine is injected to form a chlorine injection layer 3. Ion implantation is a technique widely used in semiconductor technology, and the present invention can use an ion implantation apparatus used at the time of manufacturing a semiconductor as it is. These injection apparatuses usually have an acceleration energy of about 100 keV, and chlorine injection can be performed at an appropriate concentration to an appropriate depth by performing chlorine injection with such an acceleration energy. Of course, if the acceleration energy is set to a higher level, it is natural that chlorine reaches deeper from the surface. In the present invention, the concentration of the chlorine implantation layer 3 on the surface of the TiN layer 2 is 1 × 10 ¹⁶ ions / cm. It is important that ions are implanted at a concentration of ² to 1 × 10 ¹⁷ ions / cm ² and that there is no chlorine in the TiN layer 2 in the vicinity of the interface between the base material 1 and the TiN layer 2. It is preferable to use an injection device for semiconductor manufacturing equipment or the like as it is. If the chlorine concentration of the chlorine injection layer 3 is less than 1 × 10 ¹⁶ ions / cm ² on the surface of the TiN layer 2, the effect of improving wear resistance in a non-lubricated state or a low friction coefficient will not be obtained, and the desired problem cannot be achieved. . The chlorine injection layer 3 on the surface of the TiN layer 2 gradually decreases in concentration as it becomes deeper in the film thickness direction of the TiN layer 2, and becomes almost zero at about 1/10 to 8/10 of the film thickness. Examples of the present invention are shown below, but the present invention is not limited to these Examples.
[0008]
【Example】
Commercial powder high speed tool steel was used as the substrate. By machining, the diameter was adjusted to 25 mm and the thickness was about 4 mm. After quenching and tempering, one surface was mirror-polished with diamond abrasive grains. A TiN film having a thickness of about 2 μm was formed on the entire surface of the substrate using a hollow cathode discharge industrial ion plating apparatus, and used as a test piece. During film formation, the substrate was heated with a heater set at a temperature of 723K.
[0009]
Chlorine ion implantation uses a semiconductor manufacturing device. After vaporizing 99.99% purity aluminum trichloride with a solid evaporation source loaded in the ion source, ionization and mass separation select only monovalent chlorine ions. did. The acceleration energy was 100 keV, and the ion implantation amount was in the range of 1 × 10 ¹⁶ ions / cm ² to 1 × 10 ¹⁷ ions / cm ² . The average ion beam current density during ion implantation was about 4 μA / cm ² . In addition, temperature control during processing was not performed.
[0010]
For evaluation of sliding characteristics, a ball-on-disk type friction and wear tester was used, and SUS304 and carbide (WC) balls were selected as counterpart materials. The test conditions were a load of 2 or 5 N, a sliding speed of 10 or 100 mm / s, and the change in the friction coefficient was recorded. Further, the wear scar on the sample surface was observed with a scanning electron microscope (SEM), and further elemental analysis was performed with an energy dispersive X-ray spectrometer (EDS).
[0011]
As a result, the change of the friction coefficient is shown in FIGS. From these figures, the amount of chlorine injected into the TiN layer surface is 1 × 10 ¹⁶ ions / cm ² , which shows a low coefficient of friction immediately after the start of the test, and the effect is about 1 × 10 ¹⁷ ions / cm ² . It can be seen that this is sufficient. Further, when the wear scar on the sample surface after the test was observed with a scanning electron microscope (SEM), a coherent partner material was found on the sample surface where chlorine injection was not performed. A large amount of oxygen was detected in the wear scars where adhesion was observed, indicating that oxidation occurred simultaneously. On the other hand, in the examples according to the present invention, no adhesion of the counterpart material was observed from the results of observation of wear marks by SEM and elemental analysis, and the presence of oxygen could not be confirmed. From these results, it is clear that the wear-resistant film of the present invention has self-lubricating performance and can be applied to sliding parts as various hard films that can be used in a non-lubricated state. became. Note that when the amount of chlorine implanted in the above embodiment is about 1 × 10 ¹⁶ ions / cm ^{2 on the} surface of the TiN layer, it is assumed that the normal thickness of the TiN layer is 2 μm and the chlorine is 1/10 or deeper than the surface. Ions are not substantially contained and are not present at all in the TiN layer near the base material.
[0012]
【The invention's effect】
According to the present invention as described above, it is possible to eliminate the need for a lubricant while maintaining wear resistance even in a mold that conventionally requires a lubricant. In addition, the lubricant can be eliminated from the sliding parts, and the energy loss can be reduced by reducing the friction coefficient. As described above, when the hard material according to the present invention is applied, resource saving and waste reduction effects can be expected. The scope of application includes the following.
(1) Bending and drawing: Improving tool life, preventing material adhesion, and improving processing accuracy
(2) Cutting: Improvement of tool life, prevention of material adhesion, improvement of machining accuracy
(3) Automobile parts: improved wear resistance, low friction coefficient, improved energy efficiency, reduced exhaust gas [Brief description of drawings]
FIG. 1 is an explanatory view showing a manufacturing process according to the present invention.
FIG. 2 is a relationship diagram between a sliding distance and a friction coefficient when a load of 2N is used with the counterpart material SUS304 in the embodiment.
FIG. 3 is a diagram showing the relationship between the sliding distance and the friction coefficient when the counter member WC has a load of 5 N in the embodiment.
[Explanation of symbols]
1 Base material 2 TiN layer 3 Chlorine injection layer

Claims (4)

A slidable material having a self-lubricating property for molds or sliding parts,
A TiN coating layer formed by physical vapor deposition or powder metallurgy is formed on the surface of the base material made of hard metal ,
In this TiN coating layer, chlorine is ion-implanted from the surface at a surface concentration of 1 × 10 ¹⁶ ions / cm ² or more, and chlorine ions are present in the vicinity of the interface with the base material of the TiN coating layer. A slidable material characterized by the absence of ^2. The slidable material according to claim 1, wherein chlorine is ion-implanted from the surface of the TiN coating layer at a surface concentration of 1 × 10 ¹⁶ ions / cm ² to 1 × 10 ¹⁷ ions / cm ² . A method for producing a slidable material having self-lubricity for a mold or a sliding part,
A TiN coating layer is formed by physical vapor deposition or powder metallurgy on the surface of a base material made of hard metal ,
Into this TiN coating layer, chlorine is ion-implanted from the surface at a surface concentration of 1 × 10 ¹⁶ ions / cm ² or more, and there is no chlorine ion in the vicinity of the interface of the TiN coating layer with the base material. A method for producing a slidable material , characterized by ion implantation. The slidable material according to claim 3, wherein chlorine is ion-implanted from the surface of the TiN coating layer so as to have a surface concentration of 1 × 10 ¹⁶ ions / cm ² to 1 × 10 ¹⁷ ions / cm ² . Production method.

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