JPS6339653B2 - - Google Patents

Description

[Detailed description of the invention]

In the present invention, for example, the magnetic flux density B ₁₀₀ when a magnetic field of 100G is applied is made of a low melting point alloy of 1350℃ or less.
This relates to a low melting point magnetic alloy for dental use that has a resistance of 2000G or more and is highly corrosion resistant. There are many uses for magnetic alloys, and magnetic alloys have been developed for each use. Magnetic alloys generally have high melting temperatures;
For example, the melting temperature of silicon steel, which is well known as a high magnetic permeability alloy, is about 1500°C, and the melting temperature of permalloy alloy is about 1450°C. Therefore, when melting and casting these alloys, a high frequency melting furnace or an arc melting furnace is used. However, for some uses of magnetic alloys, it is an important requirement that they can be melted and cast extremely easily. That is, for example, when using it for experiments in a university laboratory, a small amount of magnetic alloy is created in a very simple melting furnace or the like using easily available city gas or a gas with oxygen added to city gas. Furthermore, when dentists or dental technicians manufacture alloys for use in dental prostheses, they are required to be able to melt and cast them using their usual melting equipment. High-performance small melting furnaces capable of high-frequency melting are capable of melting alloys with melting temperatures of 1400°C or higher. However, although it varies depending on the structure of the melting furnace, the melting point of metals that can be melted in a gas melting furnace made by adding oxygen to city gas is approximately 1300°C or lower.
Furthermore, since melting is normally performed in the atmosphere, casting can be facilitated if a small amount of sample can be melted in as short a time as possible. For this reason, at least
If the work can be done at temperatures below 1350°C, this goal can be easily achieved. Therefore, it has been strongly desired to develop a magnetic alloy having a melting temperature of desirably 1300° C. or less. On the other hand, in order to be commonly used as a magnetic alloy, the saturation magnetic flux density must be at least
A resistance of 2000G or more is required, and excellent corrosion resistance is also required for dental applications. Also,
For special applications, good porcelain baking properties are also required. Although such alloys have been desired for use in alloys that can be easily melted and cast, there have been no suitable ones to date. An object of the present invention is to provide a low melting point magnetic alloy having a melting temperature of 1300° C. or less, excellent corrosion resistance, and suitable for dental use. In order to achieve the above object, the present invention provides a method for achieving the above object by weight ratio of 3.2 to 21.0% of one or more of the group consisting of Cr, Pt, and Au, and 26.3 to 37.0% of Ni.
It is characterized by being a low melting point magnetic alloy suitable for dental use, consisting of 7.0 to 28.4% Co, and the balance Pd. In the present invention, 4.2 to 9.4% by weight of one or both of Cu and Al is added to the above composition.
By including it, the hardness can be improved and a low melting point magnetic alloy more suitable for dental use can be obtained. In the present invention, Pd, Ni, and Co are basic components, and by forming an alloy with these, a magnetic alloy with a low melting point can be obtained. In the present invention, Ni and Co are necessary to provide magnetism, and in order to obtain desired magnetic properties, it is necessary to contain 7.0 to 28.4% by weight of Co. Further, the reason why the Ni content is set to 26.3 to 37.0% by weight is to keep the melting temperature at 1300°C or lower.
In the present invention, Ni and Co in the above composition range are used.
By forming an alloy with Pd and Pd, a low melting point magnetic alloy can be obtained. In the present invention, Cr, Pt, and Au have the effect of improving corrosion resistance, and it is preferable that these components be contained alone or in combination in a total amount of 3.2 to 21.0% by weight. However, although Cr has the effect of increasing hardness, if it exceeds 15% by weight, it significantly reduces magnetic flux density and castability, so it is desirable to limit it to 15% by weight or less. Pt is preferably contained in an amount of 20% or less in order to improve hardness and corrosion resistance. In addition, Au is highly effective in improving corrosion resistance and can be contained at 21.0% by weight, but 10% by weight can be contained.
If it exceeds 10% by weight, the second phase tends to precipitate, resulting in brittleness, so it is more preferably 10% by weight or less. In the present invention, as described above, the hardness can be improved by further containing 4.2 to 9.4% by weight of one or both of Cu and Al. However, as the content of Cu and Al increases, the magnetic flux density decreases significantly, so Cu and Al
The content of Al is preferably 9.4% by weight or less. In the present invention, Fe may be contained mainly to improve magnetic flux density. In addition, to improve castability, Ag, Sn, Zn, or
Although Cd may be included, it is desirable to contain 3% by weight or less of each component, as the inclusion of these components will reduce the mechanical properties.
B ₁₀₀ decreases and castability also deteriorates. In the present invention, Mn, Nb, Ti, V, Ta, or Hf may be added in an amount of 5% or less to further increase the hardness or as a deoxidizing agent. Hereinafter, a more detailed explanation will be given based on examples. Example 1 Weight ratio: 38.2%Pd-30.2%Ni-28.4%Co-
A plastic alloy containing 3.2% Cr was melted and cast using city gas. The melting temperature TM was 1180°C, and the magnetic and mechanical properties of the cast body were as follows: magnetic flux density B ₁₀₀ =8800G and Hc =3.3Oe when an external magnetic field of 1000e was applied. In addition, no discoloration was observed even when the sample was kept in a 1% by weight Na ₂ S aqueous solution for 24 hours. The results are shown in Table 1 as sample No. 1. Table 1 below summarizes the properties of each alloy when the alloy composition was varied in similar experiments. As a result of the corrosion resistance test, the above 1% by weight
The fact that there was almost no discoloration in the Na ₂ S aqueous solution was the same for each alloy.

【table】

[Table] As is clear from the above examples, it is clear that according to the present invention, a magnetic alloy having a melting temperature of 1300° C. or less and excellent corrosion resistance can be obtained. Also,
The products of this example did not contain a large amount of Al, and all of them were able to be baked into porcelain. As described above, the alloy according to the present invention is a low-melting-point magnetic alloy that is particularly useful for dental applications because it can be easily melted and cast using ordinary city gas.

Claims (1)

[Claims] 1. 3.2 to 21.0% of one or more of the group consisting of Cr, Pt, and Au, and 26.3 to 21.0% by weight;
A dental low melting point magnetic alloy characterized by comprising 37.0% Ni, 7.0 to 28.4% Co, and the balance Pd. 2. In weight ratio, 3.2 to 21.0% of one or more of the group consisting of Cr, Pt, and Au, and 4.2 to 9.4% of one or two of Cu and Al;
26.3~37.0% Ni, 7.0~28.4% Co, balance
A dental low melting point magnetic alloy characterized by consisting of Pd.