JPH0576263A - Horseshoe - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a horseshoe that can be used under a heavy load, is lightweight, and has excellent corrosion resistance and wear resistance. The horseshoe main body is made of titanium or a titanium alloy, and at least the ground surface of the horseshoe body is covered with a melt diffusion hardening layer, and the melt diffusion hardening layer contains nickel and an element constituting titanium alloy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horseshoe attached to a hoof of a race horse or the like, and more particularly to an improvement for increasing wear resistance and weight reduction.

[0002]

2. Description of the Related Art As conventional horseshoes, those forged by using carbon steel for cattle and general horses, and those cast by casting aluminum alloy for competitive horses are mainly used.

[0003]

The horseshoe made of carbon steel is inexpensive, but the specific gravity of carbon steel is as large as about 7.6, so that the running speed is suppressed when used on a race horse. Further, carbon steel has a drawback that it is inferior in corrosion resistance because it reacts with water and rusts.

On the other hand, horseshoes made of aluminum alloy are light,
It is suitable for race horses, but the price per piece is high, and because it is relatively soft, it has poor wear resistance and wears the ground contact surface quickly.
Therefore, it is necessary to replace with a new one every one or several races, and there is a problem that the replacement work is complicated and costly.

Since the exchange of horseshoes inevitably damages the hoof, the frequency of exchanging the horseshoes is limited in accordance with the growth of the hoof.
Therefore, due to the wear resistance of the horseshoe, the number of times the race can participate is limited, and it is strongly desired to reduce the weight and improve the wear resistance.

To solve this problem, for example, Japanese Patent Laid-Open No. 54-80223 proposes to make a horseshoe with lightweight titanium or titanium alloy. However, although titanium or a titanium alloy is lightweight and excellent in corrosion resistance, it is not so high in wear resistance, and has a merit in view of an expensive cost as compared with an aluminum alloy.

On the other hand, as one of the surface hardening methods for titanium,
As is well known, the nitriding method is used in a wide range of applications, but the nitriding method can cure only a very surface layer of the titanium surface (for example, about several μm of the surface), and is not applicable to a horseshoe under a heavy load. Is the meaning.

A hardening method of depositing an alloy having high wear resistance on the surface of titanium has been partially carried out. However, due to the characteristics of titanium,
Welding of other alloys is difficult, and in the case of a horseshoe with a heavy load, the reliability is low, and the cost is too high to use this method.

Further, Japanese Patent Application Laid-Open No. 50-28443 discloses a method in which titanium or a titanium alloy is coated with another kind of metal or alloy and then cured. However, the thickness of the hardened layer obtained by this method is at most about several tens of μm, and the strength is insufficient for a horseshoe subjected to a large load.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a horseshoe that can be used under a large load, is lightweight, and is excellent in corrosion resistance and wear resistance.

[0011]

A horseshoe according to claim 1 of the present invention is made of titanium or a titanium alloy, and at least the ground surface thereof is covered with a melt diffusion hardening layer, and the melt diffusion hardening layer is titanium or a titanium alloy. It is characterized in that it contains nickel and the elements that make up.

The horseshoe of claim 2 is characterized in that the melt diffusion hardening layer contains at least one element selected from carbon, nitrogen, boron, zirconium, copper, tungsten, molybdenum and niobium. To do.

In any case, ceramic particles may be dispersed in the melt diffusion hardening layer.

[0014]

Since the horseshoe of the present invention is composed of titanium or a titanium alloy, it is lightweight and has excellent corrosion resistance.
Since at least the ground contact surface is covered with a hard melt diffusion hardening layer, the wear resistance of the ground contact surface is higher than that of titanium or titanium alloy itself. Therefore, the service life is longer than that of the conventional horseshoe, the frequency of horseshoe replacement is reduced, the cost is reduced, and the load on the hoof can be reduced.

[0015]

FIG. 1 is a plan view showing a horseshoe for a racing horse as an embodiment of the present invention. The horseshoe 1 comprises a horseshoe body 2 formed of titanium or a titanium alloy, and a melt diffusion hardening layer 3 formed on the ground plane of the horseshoe body 2. The melt diffusion hardening layer 3 may be formed not only on the ground plane but also on the entire surface of the horseshoe 1 or a part of another portion.

The horseshoe main body 2 is formed by casting a cast ingot of titanium or an alloy containing titanium as a main component, hot and cold, and then cutting, cutting and grinding the molded ingot into the shape shown in the drawing. The size and shape may be changed as needed.

The melt diffusion hardening layer 3 is an intermetallic compound of titanium and various metals, or a carbide or nitride of titanium,
It is a layer containing boride, and its thickness is 0.1
It is about 5.0 mm, more preferably about 0.5 to 2.0 mm. If it is less than 0.1 mm, the strength of the melt diffusion hardened layer 3 is lowered, and it cannot be used as a horseshoe. Also, 5.
Even if it is formed thicker than 0 mm, the strength is not further improved and it is difficult to form.

To form the melt diffusion hardening layer 3, an alloying material containing an element capable of reacting with titanium to form a compound such as an intermetallic compound, a carbide, a nitride or a boride is formed on the surface of the horseshoe body 2. And are heated in vacuum. As a result, both are diffused to cause a melt diffusion reaction (alloying, intermetallic compound formation, compound formation of metal and nonmetal),
The melt diffusion hardening layer 3 is formed.

As the material of the alloying material, nickel alloys, titanium alloys and the like are preferable, and several kinds of composition examples are listed below. However, it is not limited to these.

Nickel alloy Pure Ni Ni-7Cr-3B-4Si-3Fe alloy (Ni brazing material) Ni-15Cr-3B alloy (Ni brazing material) Ni-25Cr alloy Ni-0.5C-3Si-10Cr-2.5Fe -2B-0.1Co alloy (hard face material for PTA) (Colmonoy N
o4) Ni-0.65C-12Cr-4.2Fe-4.0Si-2.5B
Alloy (Hard Face Material for PTA) (Colmonoy N
o5) Ni-1.5C-27Cr-8W-1.6Fe-1.55B-0.5
Co alloy (hard face material for PTA) (Colmonoy N
o84) 50Ni-32Mo-15Cr-3Si alloy (trade name: Trivalloy 700) JIS standard BNi (Ni brazing material)

Titanium braze Ti-48Zr-4Be Ti-30V-4Be Ti-33Cr Ti-13V-11Cr-3Al

Ceramic particles may be dispersed in the melt diffusion hardening layer 3 to further increase its strength. To do this, mix the alloy powder with ceramic powder in advance,
This ceramic powder is dispersed in the melt diffusion hardening layer 3. Ceramic particles that can be used include TiC, W
C, B ₄ C, CBN, TiN, Si ₃ N ₄ , Sialon, Si
C etc. are mentioned. Also, whiskers may be used as the ceramic particles.

In order to bring the alloying material into contact with the horseshoe body, the following method is possible. (1) The alloying material is formed into a foil having a thickness of a fraction of a few mm to a few mm, and is joined to the surface of the horseshoe body 2 by spot welding or the like. (2) The alloying material is pulverized and mixed in a binder such as alcohol or a commercially available organic binder, and this binder is applied to the surface of the horseshoe main body 2. (3) The surface of the horseshoe body 2 is electrolessly or electrolytically plated to form a thin film of alloying material.

After the alloying material is fixed to the horseshoe body, the horseshoe body is placed in a vacuum heating furnace and held at a temperature of about 900 to 1100 ° C. for about 0.5 to 2.0 hours for alloying. More preferably, the heating temperature is set near the temperature of the eutectic point of the alloying material and the alloy main component contained in the horseshoe main body 2. Exceeding the above heating conditions causes a problem of excessive reaction and propagation to a portion where a hardened layer is not desired to be formed. If the heating conditions are lower than the above, unmelting problem occurs.

The reaction between the alloying material and the horseshoe body 2 progresses faster as the temperature rises, and as the reaction time increases, the thickness of the melt diffusion hardened layer 3 produced increases. As shown in FIG. 2, the alloyed material after the heat treatment is melted and diffused to form the melt diffusion hardened layer 3 integrated with the horseshoe body 2. The hardened layer 3 thus obtained reaches a thickness of several mm.

According to the horseshoe 1 having the above structure, since the horseshoe body 2 is made of titanium or a titanium alloy, the horseshoe body 2 is lightweight and has excellent corrosion resistance, and at least the ground plane is covered with the melt diffusion hardening layer 3 which is hard. Therefore, the wear resistance of the ground contact surface is higher than that of titanium or titanium alloy itself. Therefore, the service life is longer than that of the conventional horseshoe, the frequency of horseshoe replacement is reduced, the cost is reduced, and the load on the hoof can be reduced.

[0027]

[Experimental Example] Next, the effect of the present invention will be demonstrated with reference to an experimental example. Instead of the horseshoe main body, various alloying materials were fixed on the base metal, the melt diffusion hardening layer was formed while various heat treatment conditions were changed, and the Vickers hardness thereof was measured. As the base metal, Ti and Ti-6Al-4
V was used. The hardness of each of these is 20
0 Hv and 270 Hv. Table 1 shows the types of alloying materials used, heat treatment conditions, and Vickers hardness measurement results.
It shows in Table 4.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

[Table 3]

[0031]

[Table 4]

As is clear from these tables, the melt diffusion hardening layer exhibited extremely high hardness as compared with the hardness of the base metal itself, whichever alloying material was used.

[0033]

As described above, the horseshoe according to the present invention is lightweight and excellent in corrosion resistance because the main body is made of titanium or titanium alloy, and at least the grounding surface is hard and has a relatively thick melting point. Since it is coated with the diffusion hardened layer, the wear resistance of the ground contact surface is higher than that of titanium or titanium alloy itself. Therefore, the service life is longer than that of the conventional horseshoe, the frequency of horseshoe replacement is reduced, the cost is reduced, and the load on the hoof can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a horseshoe according to the present invention.

FIG. 2 is an enlarged cross-sectional view of the horseshoe of FIG. 1 taken along line II-II.

[Explanation of symbols]

 1 Horseshoes 2 Horseshoes body 3 Melt diffusion hardening layer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Kano 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Materials Corporation Product Development Center

Claims (3)

[Claims] 1. A horseshoe comprising titanium or a titanium alloy, at least the ground surface of which is covered with a melt diffusion hardening layer, and the melt diffusion hardening layer contains nickel and an element constituting a titanium alloy and nickel. . 2. Titanium or a titanium alloy, at least the ground plane of which is coated with a melt diffusion hardened layer, the melt diffusion hardened layer comprising carbon, nitrogen, boron, zirconium,
A horseshoe comprising a titanium alloy containing at least one element selected from copper, tungsten, molybdenum and niobium. 3. The horseshoe according to claim 1, wherein ceramic particles are dispersed in the melt diffusion hardened layer.