JPH10219375A - Titanium alloy and hard tissular substitutive material using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new titanium alloy having strength particularly suitable for an organic hard tissular substitutive material for the such as bone, a part of the bone, prostheses for the bone, an artificial joint, a dental root, and an implant, and also having high elongation and low elastic modulus and also to provide a hard tissular substitutive material using this titanium alloy. SOLUTION: The titanium alloy has a composition consisting of, by weight, 20-60%, in total, of Nb and Ta and the balance Ti with inevitable impurities. It is desirable to regulate Nb content and Ta content to >15-50% and >6-20%, respectively. One or >=2 kinds among <=10% Mo, <=5% Zr, and <=5% Sn are further added to the above titanium alloy. The hard tissular substituting material is obtained by subjecting these titanium alloys to solution heat treatment or further to aging treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel titanium (T)
i) The present invention relates to an alloy, particularly a titanium alloy suitable for a hard tissue substitute such as an artificial bone of a living body or a part thereof, or an auxiliary material thereof, and a hard tissue substitute using the titanium alloy.

[0002]

2. Description of the Related Art In general, titanium alloys typified by Ti-6 wt% Al-4 wt% V are applied or studied to artificial dental roots and artificial aggregates for medical use. This is because titanium has higher adaptability in vivo than other metals. However, according to various studies, it has been pointed out that V (hanasidium) among the above titanium alloys has toxicity to living cells. Therefore, instead of V, Nb
Ti-6wt% Al-7wt% Nb and Ti-
A so-called α + β type titanium alloy such as 5 wt% Al-2.5 wt% Fe has been proposed. However, A in these alloys
It has also been pointed out that l (aluminum) causes some types of dementia.

[0003] Therefore, using a metal element that does not indicate the above-mentioned toxicity and allergenicity, it has higher elongation and better cold workability than α + β type titanium alloy, and has a low elastic modulus to reduce the hard tissue in vivo. Β-type titanium alloys have been proposed so as to be close to. This β-type titanium alloy includes, for example, Ti-13 wt% Nb-13 wt% Zr, Ti-16 wt% N
b-10wt% Hf, Ti-15wt% Mo, Ti-15wt% M
o-5wt% Zr-3wt% Al, Ti-12wt% Mo-6wt%
Zr-2wt% Fe, Ti-15wt% Mo-2.8wt% Nb-
It contains 0.2 wt% Si-0.26 wt% O and the like. However, among the above-mentioned β-type titanium alloys, what component composition is suitable for a hard tissue substitute such as an artificial aggregate has not been studied much, and it is still unclear. .

[0004]

SUMMARY OF THE INVENTION In view of the above prior art, the present invention is particularly suitable as a substitute for a hard tissue of a living body, is less toxic or allergic to the living body, has a suitable strength, a high elongation, and a low elasticity. Another object of the present invention is to provide a new titanium alloy which has excellent corrosion resistance and fits the activity of a living body, and a hard tissue substitute using the titanium alloy.

[0005]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on β-type titanium alloys. As a result, titanium (Nb) and Ta (tantalum) were added to titanium.
Is also obtained by focusing on adding a predetermined amount at a time. That is, the titanium alloy of the present invention
b and Ta in total from 20 wt% to 60 wt%, and the balance
and i and unavoidable impurities. By using an alloy having such a composition, the above-described problem can be solved. The upper limit of the sum of the above Nb and Ta is 50
It is desirably set to wt%. Of this titanium alloy, Nb
Is desirably in the range of more than 15 wt% to 50 wt% or less. When Nb is 15 wt% or less, an α phase precipitates in the metal structure. On the other hand, when Nb exceeds 50 wt%,
This is because elongation starts to be insufficient, and a more desirable upper limit of Nb is 45% by weight.

The content of Ta is more than 6 wt% to 2%.
Desirably, it is within the range of 0 wt% or less. Ta is 6wt
% Or less, the elongation starts to be insufficient, while Ta is 20 wt.
%, The melting point of the alloy itself is too high, and a more desirable upper limit of Ta is 15% by weight. Further, for each of the above titanium alloys, Mo (molybdenum) of 10 wt% or less, Zr (siliconium) of 5 wt% or less, or 5 w% or less.
Also includes those to which one or more of Sn (tin) of t% or less is added. By adding such elements, a titanium alloy having more stable characteristics can be obtained.

Further, the present invention provides a hard tissue substitute material characterized by using the above-mentioned titanium alloys, subjecting them to a solution treatment, and recrystallizing the crystal grains thereof. Further, a hard tissue substitute which has been subjected to aging treatment is also included. By performing the solution treatment and / or the aging treatment, the crystal grains in the β phase are refined, the strength can be appropriately increased, and the elongation and the elastic modulus can be optimized.
According to such a hard tissue substitute, by using as a bone or a tooth root, or as a component such as a denture, a prosthesis, or a prosthesis, it is possible to obtain characteristics and effects adapted to the activity of a living body, It is possible to contribute to improvement.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below together with embodiments. Based on Ti, combined with Nb and Ta with high adaptability to living body with Ti
Titanium alloys having various component compositions to which o, Zr, or Sn were added incidentally were melted. These alloys were cast into molds to obtain ingots of a certain size. Next, after performing a predetermined cold working on each of the ingots, a required number of thin plates were cut out from each of the processed materials. Next, each of these thin plates was subjected to a predetermined solution treatment and / or aging treatment (see FIG. 1), and thereafter, a test piece having a required shape was finished and subjected to a tensile test and the like. As a comparative example, the α + β-type and β-type titanium alloys shown in the above-mentioned prior art were subjected to the same process from melting to heat treatment as in FIG. 1 to form test pieces, and the same tensile tests were performed on these test pieces. went.

[0009]

EXAMPLES Hereinafter, specific examples will be described together with comparative examples. Various combinations of Nb and Ta highly adaptable to living bodies were added to Ti, and further, Mo, Zr, or Sn was added thereto, and titanium alloys having the respective component compositions shown in Table 1 were dissolved. On the other hand, as a comparative example, Ti-6wt% A shown in Table 1 was used.
l-4wt% V etc. (α + β type) and Ti-13wt% Nb-13w
t% Zr and the like (β type) were dissolved.

[0010]

[Table 1]

Next, each of these titanium alloys was cast in a predetermined mold to obtain a button ingot of 45 g for each. Cold rolling (rolling reduction 75%) was performed on each of the button ingots to obtain a plate in which crystal grains in each alloy structure were refined. Next, from each of the titanium alloy plates, ten thin plates were cut out for each alloy. Further, each thin plate was subjected to a solution treatment (ST) under the conditions shown in Table 1, and 10 to 5
It is recrystallized to a crystal grain size of about 0 μm.
(STA) (see FIG. 1).

The reason why the aging treatment time (Aging) in Table 1 is set to 3 hours or more is that as shown in the graph of FIG. 2, the hardness is less than 3 hours, whereas the hardness is unstable. If it exceeds this, the hardness becomes stable. Each of the above thin plates is finished into a tensile test piece 1 shown in FIG. By performing a tensile test on each of these test pieces in accordance with JIS; Z2241, the tensile strength (σ _B / MP
a), 0.2% proof stress (σ _0.2 / MPa), elongation (%), and
The elastic modulus (GPa) was measured. Those measurement results
(Average value) is shown in Table 2.

[0013]

[Table 2]

In order to make the results in Table 2 easy to understand, Examples Nos. 4, 5, 18, 18, 19, 22, and 23 and Comparative Examples Nos. 1 to 6
Fig. 4 shows the tensile strength, elongation and elastic modulus of
6 to FIG. The graph of 0.2% proof stress had the same tendency as the tensile strength in FIG.
Omitted. From these results, the ST materials (4, 18, 22) subjected to only the solution treatment of each example have an elongation of 30% or more, which is higher than each comparative example (see FIG. 5). , Tensile strength and modulus of elasticity were lower than those of the comparative example (FIGS. 4 and 6).
reference). When the tensile strength and the elastic modulus are high as in the comparative example, the surface of a bone or the like in contact with a site where the material is applied to a living body may be worn and easily damaged. In particular, since the elastic modulus of bone is about 30 GPa, the closer to this, the higher the adaptability to a living body. From these results, the ST material of the titanium alloy of each example has excellent elongation characteristics, and the strength and the elastic modulus are lower than those of the comparative example and approximates to the hard tissue of a living body. When inserted into the tissue, it changes to follow the deformation together,
It becomes a part of the bone and can be used for a long time.

[0015] On the other hand, the STA which has also been subjected to the aging treatment of each embodiment.
The material (5, 19, 23) has a higher tensile strength than the ST material having the same composition, but is equal to or slightly lower than each comparative example (see FIG. 4). Further, the elongation percentage is lower than that of the ST material having the same composition except for Example 5, but the elongation is equal to or higher than the comparative example (more than 10%) (see FIG. 5). Furthermore, the elastic modulus shows a lower value than the comparative example except for Example 19 (see FIG. 6). From these results, it is considered that the STA material of the titanium alloy of each example has high adaptability to a relatively hard hard structure different from the ST material. From these results, each of the titanium alloys of the present invention is subjected to a solution treatment and / or an aging treatment,
It is understood that various characteristics that are easily compatible with various hard tissues in a living body can be obtained. In addition, the solution treatment is
In order to obtain fine recrystallized grains, it is desirable to heat to 800 to 1000 ° C. and hold for about 30 to 60 minutes. Also,
The aging treatment is performed in a range of 400 to 5 to obtain the above strength and hardness.
It is desirable to heat to 00 ° C. and hold for at least 2 hours, including up to 24 hours.

The titanium alloy and the hard tissue substitute of the present invention can be used as substitutes for various hard tissues, such as implant materials, artificial joints, and orthodontic materials, or as auxiliary materials for some of them, in addition to those described above. Can also be used. In addition, the titanium alloy of the present invention is not limited to the above-mentioned biological applications, and is characterized by its excellent elongation and moderate strength, low elastic modulus, and excellent corrosion resistance, so that it can be used in various fields other than medical applications, for example, mechanical instruments It can be applied to materials, welfare equipment materials, consumer goods materials, and the like.

[0017]

According to the titanium alloy of the present invention described above, a suitable strength, a high elongation and a low elastic modulus can be obtained. In addition, the hard tissue substitute using the titanium alloy has excellent characteristics adapted to the hard tissue of a living body, and can provide a material which is less toxic and allergic and can be adapted to the living body for a long time. Become.

[Brief description of the drawings]

FIG. 1 is a schematic flow chart showing a process for obtaining a hard tissue substitute of the present invention.

FIG. 2 is a graph showing the relationship between hardness and treatment time in the aging treatment of the titanium alloy of the present invention.

FIGS. 3A and 3B are a front view and a side view of a tensile test piece using a titanium alloy or the like of the present invention.

FIG. 4 is a graph showing tensile strengths of Examples and Comparative Examples.

FIG. 5 is a graph showing elongation percentages of an example and a comparative example.

FIG. 6 is a graph showing the elastic modulus of an example and a comparative example.

[Table 1]

[Table 2]

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Claims (6)

[Claims] 1. A total of 20 wt% to 60 wt% of Nb and Ta.
A titanium alloy including, and the balance being Ti and unavoidable impurities. 2. The method according to claim 1, wherein the content of Nb is more than 15 wt% to 50 wt%.
The titanium alloy according to claim 1, wherein: 3. The titanium alloy according to claim 1, wherein the content of Ta is more than 6 wt% to 20 wt% or less. 4. The titanium alloy according to claim 1, further comprising M
4. The titanium alloy according to claim 1, wherein one or two or more of Zr of 5 wt% or less and Sn of 5 wt% or less are added. 5. The hard tissue substitute according to claim 1, wherein the titanium alloy is subjected to a solution treatment, and crystal grains of the titanium alloy are recrystallized. 6. The hard tissue substitute according to claim 5, wherein after the solution treatment, the titanium alloy is subjected to an aging treatment.