JPS63290237A - Ni based cast alloy for dentistry - Google Patents

Abstract

PURPOSE:To provide excellent wear resistance, corrosion resistance and toughness to the titled alloy and to improve the castability thereof by incorporating specific amounts of C, Si, Mn, Cr, Mo, Hf and B into the Ni based alloy. CONSTITUTION:The compsn. of the Ni based cast alloy for dentistry consists of, by weight, 0.01-0.6% C, 0.1-5% Si, 0.1-3% Mn, 20-37% Cr, 1-20% Mo, 0.005-6% Hf, 0.0001-0.5% B and the balance Ni with inevitable impurities. 0.1-10% W and one or more kinds among 0.1-12% Ti, Nb and Ta are furthermore incorporated into the alloy at need. The alloy is prepd. by using a conventional high-frequency melting furnace and is cast by using a sand mold, etc. Since said cast alloy has high strength, high hardness and high toughness equal to or above the conventional Ni-Cr based alloy and has excellent castability, the cast having a complicated shape can soundly be produced with a fine cast case.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides dental N, which has the properties required for dental parts such as dental beds and crowns, and which has excellent castability.
This relates to i-base casting alloys.

[Conventional technology]

In general, the above-mentioned dental components have the strength to not be deformed by the pressure of occlusion when actually installed in the oral cavity, the corrosion resistance to not corrode by intraoral secretions, etc., and are ground after being cast. Because properties such as toughness are required while maintaining a certain degree of hardness, manufacturing of these parts requires
Ni-Cr based casting alloys having these properties are used.

[Problem that the invention seeks to solve]

However, this conventional dental N1-Cr-based nN alloy has an extremely high melting point and poor flowability, so when casting, combined with the complicated shape of the casting, it is necessary to control the molten metal temperature. It must be cast at a high height, and as a result, it is easy to seize with the mold, making it difficult to produce castings with a clean surface, and finishing grinding requires considerable effort and time. Met.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors focused on the above-mentioned Ni-Cr1 casting alloy, which has the characteristics required for dental components, and found that it has excellent castability, that is, a relatively low molten metal temperature. It also shows excellent lagooning properties when cast with a mold, allowing complex-shaped castings to have a clean and healthy casting surface! As a result of conducting research to develop an alloy that can be made into a single alloy, it was found that the weight M% (hereinafter % indicates weight%) and C: 0.01 to 0.6%.

3i: 0.1-5%.

Mn: 0.1-3%.

Cr: 20-37%.

Mo: 1-20%.

Tolf: 0.005-6%.

3: 0.0001-0.5%.

Contains, and if necessary, W: 0.1 to 10%.

One or more of Ti, Nb, and Ta: 0.1 to 12%.

A Ni1l casting alloy containing either or both of the above, with the remainder consisting of Ni and unavoidable impurities, has the strength, corrosion resistance, toughness, and hardness required for dental components, and has the properties of They discovered that because it has good flowability and excellent castability, it is possible to manufacture complex-shaped dental parts with a clean casting surface.

This invention was made based on the above knowledge, and the reason why the component composition was limited as described above will be explained below.

(a) CC The C component is solid-dissolved in the base material to strengthen it, and
Cr, Mo, and further combine with W, Ti, Nb, Ta, etc. to form M7 Ca, MC, and M2
3. Forming carbides such as Ca has the effect of not only improving the hardness of the alloy but also improving the castability, but if the content of C is less than 0.01%, the desired effect is not achieved by 1ri. 0. If the content exceeds G%, not only will the formation of carbides increase, but the grain size will also become coarser, reducing toughness, making it difficult to manufacture components with delicate and complex shapes. Its content is 0.0
It was set at 1% to 0.6%.

(b) In addition to having a deoxidizing effect, the Si 3i component also has the effect of lowering the melting point of the alloy, improving its upflow properties, and thereby improving its castability, but if its content is less than 0.1%, The desired effect cannot be obtained in the above action, and on the other hand, if the content exceeds 5%, C
Since the toughness of the alloy decreases in relation to the r content, the content was determined to be 0.1 to 5%.

(C) Mn The M component has a deoxidizing effect like the Si component, and
It dissolves in solid solution in the base material and has the effect of stabilizing the A-stenite in the base material, but if its content is less than 0.1%, the desired effect cannot be obtained; on the other hand, if it is contained in excess of 3%, However, the content is determined to be 0.1 to 3% because not only the effect of further improvement cannot be obtained due to the above-mentioned action, but also the corrosion resistance tends to deteriorate.

(d) Cr A part of the Cr component dissolves in the base material, strengthening it and significantly improving corrosion resistance, and the remaining part forms carbide to improve hardness. However, if the content is less than 20%, the desired effect will not be achieved by 1q, while if the content exceeds 37%, the toughness will tend to decrease.
It was set at 37%.

(e)M.

Like the Cr component, the MOC component also has the effect of forming a solid solution in the base material, strengthening it, and forming carbides to improve hardness, but if the content is less than 1%, the desired strength and hardness cannot be achieved. However, if the content exceeds 20%, the toughness of the alloy decreases, so the content was set at 1 to 20%.

1-If The Hf component is solid-solved in the austenite base formed mainly by Ni and Cr components, improving toughness and strength, lowering the melting point of the alloy and improving field flow properties, thereby improving 81 i7x properties. In addition to having the effect of improving hardness, it also combines with the C component to form MC type carbide, which has the effect of improving hardness, but the content is 0.005%.
If the content is less than 6%, the desired effect cannot be obtained, and on the other hand, if the content exceeds 6%, no further improvement effect will be obtained.
It was set at 6%.

((+) B A part of the B component dissolves in the base material to improve strength, and also forms borides to improve hardness, contributing to rough flowability and improving castability. However, if the content is less than 0.0001%, the desired effect will not be achieved, while if the content exceeds 0.5%, there will be a tendency for the toughness to decrease. From becoming,
Its content was determined to be 0.0001 to 0.5%.

(HLW The W component, like Cr and MOC components, has the effect of forming a solid solution in the base material, strengthening it, and forming carbonization forces to improve hardness, so these properties are particularly required. It is included as necessary when the content is 0.
If the content is less than 1%, the desired effect of improving the above action cannot be obtained, while if the content exceeds 10%, the toughness will decrease, so the content was set at 0.1 to 10%.

(+) Ti, Nb, and Ta These components have the effect of significantly suppressing the growth of crystal grains in the base material, rather refining the crystal grains, and forming MC type carbides to improve hardness. , is contained as necessary when these properties are required, but if the content is less than 0.1%, the desired effect of improving the above function cannot be obtained, while if it is contained in excess of 12%, Since the toughness of the alloy decreases, the content of 1 is reduced to 0.1 to 12%.
It was determined that

In addition, Zr acid component may be contained as an unavoidable impurity, but if its content exceeds 0.3%, it will have a negative effect on toughness and castability.
must not exceed 0.3%. Further, Fe1CO may be contained depending on the melted raw material used, but there is no problem if the content is up to 3%.

〔Example〕

Next, the N of this shot +11J! The Wvin alloy will be specifically explained using examples.

The Ni-based cast alloys 1 to 1 of the present invention, each having the composition shown in Table 1, were cast in the atmosphere using a normal high-frequency melting furnace.
Molten metals of No. 28 and a conventional Ni blast casting alloy were prepared, and then VF cast into sand molds to produce a test piece for hardness measurement, a test piece for tensile strength measurement, and a material for dry flow measurement, respectively.

Next, using these test pieces, we measured Vickers hardness at room temperature to evaluate wear resistance, and measured tensile strength, 0.2% proof stress, and elongation to evaluate strength and toughness. Furthermore, for the purpose of evaluating the moldability, the above-mentioned material was heated and melted at a relatively low temperature of 1450°C, where no reaction with the mold would occur, and as soon as this temperature was reached,
Diameter formed in a mold made of phosphate material: 0.5#
Casting was carried out in an argon atmosphere using a small high-frequency centrifugal casting machine in a mold having dimensions of lIφ×length near 0trrtrr, and the flow length was measured for each. The results of these measurements are shown in Table 2. In addition, the evaluation of castability is as follows:
If the length of the lagoon flow is less than 30m, mark it with an X, and the length of the lagoon is 30 to 50m.
The case where the distance was less than 50m+ was evaluated as O, and the case where it was 50m+ or more was evaluated as ◎.

〔Effect of the invention〕

From the results shown in Table 2, the present invention Ni! Casting alloy 1~
All of No. 28 have high hardness, high strength, and high toughness that are equal to or higher than conventional Ni-based casting alloys, and have even better castability than the conventional Ni-based casting alloys. it is obvious.

As described above, the Ni-based casting alloy of the present invention not only has the excellent wear resistance, corrosion resistance, and toughness required for dental parts, but also has even better castability, which is essential for the production thereof. .

Claims (4)

[Claims] (1) C: 0.01-0.6%, Si: 0.1-5%, Mn: 0.1-3%, Cr: 20-37%, Mo: 1-20%, Hf: 0. 005 to 6%, B: 0.0001 to 0.5%, and the remainder is Ni and unavoidable impurities (weight %). (2) C: 0.01-0.6%, Si: 0.1-5%, Mn: 0.1-3%, Cr: 20-37%, Mo: 1-20%, Hf: 0. 005-6%, B: 0.0001-0.5%, further contains W: 0.1-10%, and the remainder is Ni and unavoidable impurities (wt%) A dental Ni-based casting alloy characterized by having: (3) C: 0.01-0.6%, Si: 0.1-5%, Mn: 0.1-3%, Cr: 20-37%, Mo: 1-20%. Contains Hf: 0.005 to 6%, B: 00001 to 0.5%, and further contains one or more of Ti, Nb, and Ta: 0.1 to 12%. , the remainder being Ni and unavoidable impurities (weight %). (4) C: 0.01-0.6%, Si: 0.1-5%, Mn: 0.1-3%, Cr: 20-37%, Mo: 1-20%, Hf: 0. 005 to 6%, B: 0.0001 to 0.5%, furthermore, W: 0.1 to 10%, and one or more of Ti, Nb, and Ta: 0. 1 to 12%, and the remainder consists of Ni and unavoidable impurities (weight %).