JPH11106852A - Titanium alloy - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide Ti-Mn-Ag and Ti-Mn-Ag-Co-Si alloys as low m.p. alloys for joining titanium and titanium alloys. SOLUTION: The titanium alloys are ones having a compsn. contg., by weight, 3 to 15% Mn and 5 to 30% Ag, contg. 1 to 5% Co and 0.1 to 1.5% Si according to necessary, in which the content of Co+Si is also limited to <=5.1%, and the balance substantially Ti. In the former Ti-Mn-Ag, Mn is added in a range in which its hardening caused by Mn is allowable to reduce its m.p., and Ag imparts fitness to the base metal as a joining material. Moreover, the latter Ti-Mn-Ag-Co-Si is the alloy furthermore reducing its m.p., flowing into a narrow joined part and obtaining high strength by a small cross-sectional area. Co and Si have effect of reducing the m.p., but they raise its hardness, therefore, the compsn. is the one suppressing the hardnesss in relation to both elements. Moreover, the elements to be added for alloying are the ones through the consideration of biological safety, and, furthermore, they are joinable without eroding the base metal in titanium and titanium alloys in artificial joints and dental materials. Moreover, defects in casting are hard to occur therein as alloys for casting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The alloy of the present invention has a lower melting point than titanium and a melt near the melting point is well compatible with titanium materials, and is suitable for artificial joints used in surgical treatment and artificial roots used in dental treatment. The present invention relates to a titanium alloy which is particularly effective when used for repairing a joint or attaching members when titanium and titanium alloys are used, among metal implants to be implanted in a living body.

[0002]

2. Description of the Related Art When metals or alloys used for implants are eluted into a body fluid of a living body, depending on the elements, it is feared that they cause or induce some kind of disease. Much research has been done. On the other hand, from the viewpoint of the material, those having a small ion elution amount in relation to time in a simulated body fluid were first selected, and the safety was examined by animal experiments and the like. As a result, titanium and some titanium alloys have been selected and applied to implant materials. However, titanium has difficulties in processing into implant materials, especially when making dental prostheses and bridges by centrifugal casting or pressure casting, since titanium has poor castability,
It was necessary to overcome the low yield rate by easily casting defects in the detailed structure and repeat the trial production until the desired product was obtained. In addition, as part of the method of increasing the effect of fixing the bone to part of the artificial joint, a peg may be provided instead of screwing or supplementing the screw. Due to restrictions, it is difficult to provide a peg having a sufficient shape, and other fixing auxiliary means such as bone cement for bonding the artificial joint itself to living bone have been required.

[0003] In these productions, if it can be joined metallically, it is extremely effective in terms of shape design. However, in the development of joining alloys, there are restrictions on the elements that can be used due to its harmfulness to the living body. Often forms an intermetallic compound with the elements of the alloy, which hinders the flow of molten metal as a brazing material,
A titanium alloy for brazing that can be applied to a biological implant aimed at by the present invention has not yet been developed. If titanium and titanium alloys of the same quality as the base material are to be welded as filler metal as is performed in general industrial materials, the base material is a small material in the biomaterial intended for the present invention. Even if a concentrated heat source such as a plasma or a laser is used, the base metal is inevitably burned off, so no welding is currently performed. In addition, alloys such as gold, silver, and palladium are used as bonding materials in dental metal materials such as Co alloys and Ni alloys other than titanium or titanium alloys. Conversion to a titanium alloy is being pursued, and development of an alloy containing titanium as a main component for a joining alloy has been desired.

[0004]

In a metallic member for a living body, a portion to which bonding is to be applied is thin or thick and has a complicated shape. Therefore, the heat input during bonding must be kept low. This may cause burn-through or deformation of the shape. For this reason, it is necessary that the joining alloy has a melting point lower than that of the base material, has good compatibility with the titanium-based base material, and has a liquid property that can easily flow into a narrow gap particularly when used in a brazing method. Many of the alloying elements Ni, Zn, Cd that are inserted into a living body for a long period of time and may cause cancer when they are eluted in trace amounts are considered.
And Pb are elements to be avoided. In addition, even when an element whose melting point is not much lower than that of titanium is selected as an alloying addition element to titanium, the eutectic point of the element is not so low in many cases. Are often insufficient to spread the liquid at the surface. Even in this case, chromium and vanadium are highly allergic and are the elements to be avoided at present. As described above, the selection of alloying elements added to titanium that can be applied to the present purpose has extremely narrow restrictions.

[0005]

According to the present invention, as a titanium alloy for bonding a living body insert comprising titanium and a titanium alloy, the present invention contains 3 to 15% of Mn and 5 to 30% of Ag by weight, and the balance is substantially Ti. It is a titanium alloy characterized by comprising. In another embodiment, Mn is 3 to 15% by weight,
g, 5 to 30%, Co 1 to 5%, Si 0.1
チ タ ン 1.5%, Co + Si is limited to 5.1 or less, and the balance is substantially titanium. Because these alloys are based on titanium,
If a melting furnace made of ordinary refractory material is used, elements of the furnace material will be mixed.Use a calcia crucible under a vacuum or inert gas atmosphere, or use a water-cooled copper container in these atmospheres. It can be made by dissolution or the like.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

The titanium-based alloy of the present invention has a melting point of 1900K or less in consideration of the flow of molten metal and the spread of the melt on the base material of titanium and titanium alloy under an inert gas atmosphere, and has a hardness as a joining alloy. For, the HV was set to 300 or less as one standard in alloy design. The resulting invention chose Mn and Ag as the alloying elements in claim 1. Each of these alloys has a composition region having a β phase region up to a relatively low temperature in an alloy with Ti, and can avoid embrittlement. Mn hardens as its amount increases, but the degree of hardening is small at 15% or less, which is the upper limit of the present invention. Further, Mn can lower the melting point even when added in a small amount, and is effective at 3% or more in the present alloy. Ag does not tend to harden depending on the amount even in the presence of other elements in the alloy system of the present invention, but rather improves the adaptation of the melt to the base material.
% Is effective. In terms of melting point, Ag
Represents a slight decrease in melting point. Therefore,
The upper limit of the amount of Ag is 30%, which is the upper limit of the claims of the present invention.
Although it is possible to make the above, the upper limit value is set to 30% because the oxidation color of the surface generated during the practical joining operation is different from that of the base material.

A second aspect of the present invention is to add Co and Si in specific amounts in addition to the first aspect. By adding these elements, the hardening is large in any case, and the quantitative tendency changes in the hardening tendency with respect to the Co added amount according to the stage of the Si amount. When the amount of Si is low, the degree of hardening with an increase in the amount of Co is small. For this reason, the upper limit of the amount of Si is limited to 1.5%.
By setting the amount of i to 5.1% or less, excessive addition of Co is not performed in the higher Si amount. Co and Si
Has a tendency to harden, but is an extremely effective element for lowering the melting point.
With the additions up to, the melting point still tended to decrease as the amount increased. It was also found that the melting point of Si decreased to about 8%. The effect of lowering the melting point was found to be 1% or more for Co and 0.1% or more for Si. However, since the curing is large, the upper limits are 5% and 1 respectively.
5%, and within that range, the amount of Co + Si is 5.1.
% Or less.

[0008]

EXAMPLE An ingot was repeatedly arc-melted using a water-cooled copper container under an argon gas atmosphere. After measuring the hardness of each of these samples, the melting completion temperature was determined at a constant heating rate by a thermal analyzer. Table 1 shows these results. In addition, 5 × 5 × 5 mm of each sample
Was cut out, placed on a mirror-polished Ti flat plate, and placed in an argon atmosphere using a tube furnace under an atmosphere of 1900.
The alloy of the present invention, in which the welded shape of each alloy was observed after holding at K for 3.6 ks and the conformity with the base material Ti, the smoothness of the surface and the form of the shrinkage were observed, were all good spread. The surface was determined to be glossy and smooth with no shrinkage holes and hardly solidified, indicating that these alloys were suitable as joining materials.

[0009] The Ti-Mn-Ag alloy included in the present invention has the following characteristics: For Nos. 2 and 6, casting and rolling were used to form rods having a diameter of about 3 mm. Using these as filler metals, titanium round rods having a diameter of 6 mm and a length of 60 mm were used in a glove box in an argon gas atmosphere in a Tig arc. Welding was performed. After removing the excess portion so that the welded portion was the same as the surface of the base material, any of the tensile tests resulted in breakage of the base material. In addition, N of the Ti—Mn—Ag—Co—Si alloy
o. 10 and 13 were processed into a tape shape. A cross section of two titanium round bars having a diameter of 6 mm and a length of 60 mm was abutted, and this portion was covered with the alloy tape.
After vacuum-heating at K and brazing, the joints were all removed from the base material as a result of a tensile test after removing the excess of the joint.

[0010]

[Table 1]

[0011]

Industrial Applicability Since titanium and titanium alloys are light and have excellent in vivo safety and corrosion resistance, they have begun to be used in artificial joints and various dental materials instead of stainless steel and cobalt chrome alloys. However, titanium-based metals have difficulties in casting compared to conventionally used stainless steels and cobalt-chromium alloys, and casting defects occur and the success rate is low, so that repeated casting must be attempted. In order to repair this or to form a welded structure by welding, it has been attempted to use a base metal and a common metal as joining materials, but the joining operation itself required much skill. All welding failures are erosion of the base metal, and in order to prevent this, the present invention has provided an alloy having a lower melting point than the base metal, and enabled welding and brazing. Furthermore, the effect as a biomaterial was obtained by not using alloying elements that had been considered to cause cancer. This has the effect of expanding the degree of freedom in the shape design of artificial joints and dental materials, as well as expanding the use of dental cast titanium alloys with few casting defects.

Claims (2)

[Claims] 1. An amount of Mn of 3 to 15% and Ag of 5 to 3 by weight.
A titanium alloy containing 0%, with the balance being substantially Ti. 2. An amount of Mn of 3 to 15% and Ag of 5 to 3% by weight.
0%, Co1-5%, Si0.1-1.5%
And Co + Si is limited to 5.1% or less, and the balance substantially consists of Ti.