Alloy wire suitable for oral implants and preparation method thereof

Abstract

The present invention discloses an alloy wire suitable for oral implants and a preparation method thereof. The preparation method comprises: preparing an alloy ingot; forging the alloy ingot into a rod; performing a solid solution treatment on the rod; performing a hot rolling deformation treatment on the rod after the solid solution treatment; performing a recrystallization annealing treatment on the rod after the hot rolling deformation treatment; and performing a cold rolling treatment on the rod after the recrystallization annealing treatment to obtain an alloy wire of a desired specification. Based on Ti‑15Zr, the present invention successfully prepares a low-modulus high-strength titanium-zirconium alloy wire with excellent comprehensive mechanical properties by controlling and adjusting the content of Nb, Ta and O elements and combining specific process treatment, so that it can be used for long-term use in dental narrow-diameter implants and complex oral environments.

Description

Technical Field

[0001] The present invention generally relates to a titanium-zirconium alloy wire, and in particular to the preparation of an alloy wire suitable for oral implants. Background Art

[0002] In recent decades, many dental biomaterials with multifunctional properties have been developed. With the growing demand for implants, various types of implants with high biocompatibility and high strength have emerged. At present, most dental implants use pure titanium as the basic material, which has good mechanical properties and biocompatibility, but is prone to breakage when used in narrow-necked implants (diameter ≤ 3.3 mm).

[0003] Powder metallurgy and 3D printing are a new type of manufacturing process, but due to the poor uniformity of thermal cycles during the molding process, their mechanical properties are greatly affected. Therefore, only by combining smelting and heat treatment can a titanium alloy with excellent comprehensive mechanical properties be prepared. Among them, CN 101215655B discloses a metastable B-type Ti-Nb-Ta-Zr-0 alloy and a preparation method thereof. Although it has obtained a high tensile strength, its fracture toughness is poor, and it is easy to break during use, and it is not suitable for long-term implantation in the human body. CN 117205375A discloses a titanium-zirconium alloy wire for oral implants, and its comprehensive mechanical properties also need to be further improved, especially when used for narrow-necked implants. CN 116590551 A discloses a high-strength, low-elastic modulus Ti-Nb-Zr biomedical titanium alloy and a preparation method thereof, which has high tensile properties and low elastic modulus, but due to its large deformation, it has greater brittleness.

[0004] In summary, there is an urgent need to study a titanium-zirconium alloy material with excellent comprehensive mechanical properties for narrow-diameter implants, and to effectively improve the mechanical properties of the titanium-zirconium alloy material based on a specific heat treatment process. It is of great research value to develop a high-strength and low-modulus biomedical alloy material. Summary of the invention

[0005] The object of the present invention is to provide a titanium-zirconium alloy wire having mechanical properties suitable for oral implants, especially for dental narrow-necked implants.

[0006] According to one aspect of the present invention, there is provided a method for preparing an alloy wire suitable for oral implants, comprising:

[0007] An alloy ingot containing Zr, Nb, Ta, Ti and oxygen is prepared, wherein the mass content of each element is: Zr 14-16%; Nb 0.7%-1.2%; Ta 0.4%-1.0%; O 0.1%-0.3%; the balance is Ti;

[0008] The alloy ingot is forged into bars, wherein the forging temperature is 835-860°C;

[0009] The rod is subjected to solution treatment, wherein the annealing temperature is 750-830°C, the time is 0.5-2 hours, and the cooling method is water cooling;

[0010] The bars after solution treatment are subjected to multiple hot rolling deformation treatments, wherein the hot rolling temperature is 650-750°C, the total deformation is 75-90%, and the single deformation is 3%-5%;

[0011] Performing recrystallization annealing on the hot-rolled deformed bar, wherein the annealing temperature is 650-750°C, the time is 0.5-2 hours, and the cooling method is furnace cooling; and

[0012] The bars after recrystallization annealing are subjected to multiple cold rolling treatments to obtain alloy wires of required specifications, wherein the total deformation is 45% to 55% and the single deformation is less than 5%.

[0013] According to the preparation method of the present invention, the preparation of the alloy ingot preferably includes: vacuum melting Zr particles, Ti40Nb master alloy, Ta particles, titanium dioxide powder and titanium sponge and then molding them into the alloy ingot.

[0014] According to another aspect of the present invention, there is also provided an alloy wire, which is prepared according to the above method, wherein the alloy wire has a tensile strength of 1120-1180 MPa, a yield strength of not less than 970 MPa, an elongation after break of 21%-26%, and an elastic modulus between 82 and 85 GPa.

[0015] The present invention is based on Ti-15Zr, and by controlling and adjusting the content of Nb, Ta and O elements and combining specific process treatment, a low-modulus and high-strength titanium-zirconium alloy wire with excellent comprehensive mechanical properties is successfully prepared, so that it can be used for dental narrow-diameter implants and long-term use in complex oral environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 : is a metallographic image of the alloy wire prepared according to Example 1 of the present invention.

[0017] Figure 2 : is a metallographic image of the alloy wire prepared according to Example 2 of the present invention.

[0018] Figure 3 This is a metallographic image of the alloy wire prepared according to Example 3 of the present invention.

[0019] Figure 4 : is the metallographic image of the alloy wire prepared according to Comparative Example 1.

[0020] Figure 5This is a metallographic image of the alloy wire prepared according to Comparative Example 2. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to specific embodiments and accompanying drawings.

[0022] Example 1

[0023] Preparation of titanium-zirconium alloy wire:

[0024] (1) Weigh the raw materials of each alloy element according to the weight percentage composition of the alloy: Zr: 15.19%, Nb: 0.78%, Ta: 0.44%, O: 0.11%, and the balance is Ti, where the raw materials of each element come from: Zr is zirconium particles, Nb is Ti40Nb master alloy, Ta is tantalum particles, oxygen and Ti are sponge titanium and titanium dioxide powder respectively. Use a vacuum consumable arc melting furnace to perform three smeltings to obtain an alloy ingot with uniform composition;

[0025] (2) grinding the alloy ingot obtained in step (1), and transforming it into a large-size (diameter 55 mm) bar by high-temperature forging, wherein the temperature of the forging is 850° C.;

[0026] (3) subjecting the bar material after high temperature hot forging in step (2) to solid solution treatment, wherein the solid solution annealing temperature is 770° C., the solid solution annealing time is 1 hour, and the cooling method is water cooling;

[0027] (4) subjecting the bar after the solution treatment in step (3) to multiple hot rolling treatments, with the hot rolling temperature being 750° C., the total deformation being 85%, and the single deformation being controlled at 4%;

[0028] (5) performing recrystallization annealing on the bar (diameter 10 mm) after hot rolling deformation in step (4), the recrystallization temperature is 710° C., the recrystallization annealing time is 1 hour, and the cooling method is furnace cooling;

[0029] (6) The sample after recrystallization annealing in step (5) is subjected to multiple (roller pulling) cold rolling, the total cold rolling deformation is 50%, and the single cold rolling deformation is controlled to be 4%, to obtain a titanium-zirconium alloy wire with the required wire diameter (diameter 5 mm);

[0030] The metallographic diagram of the obtained titanium-zirconium alloy wire is shown in Figure 1 The structure is fine and uniform, mainly composed of needle-shaped α phase.

[0031] Example 2

[0032] The rest is the same as in Example 1, except that:

[0033] In step (1), the raw materials of the alloy elements are weighed according to the alloy weight percentage composition: Zr: 14.96%, Nb: 0.86%, Ta: 0.92%, O: 0.21%, and the balance is Ti;

[0034] In step (4), the hot rolling temperature is 700°C;

[0035] The metallographic diagram of the obtained titanium-zirconium alloy wire is shown in Figure 2 The structure is also fine and uniform, mainly composed of needle-shaped α phase.

[0036] Example 3

[0037] The rest is the same as in Example 1, except that:

[0038] In step (1), the raw materials of the alloy elements are weighed according to the alloy weight percentage composition: Zr: 15.82%, Nb: 1.1%, Ta: 0.76%, O: 0.29%, and the balance is Ti;

[0039] In step (4), the hot rolling temperature is 650°C;

[0040] The metallographic diagram of the obtained titanium-zirconium alloy wire is shown in Figure 3 Due to the decrease in hot rolling temperature, the structure becomes finer and more uniform, and the metallographic phase is still dominated by needle-shaped α phase.

[0041] Comparative Example 1

[0042] The rest is the same as in Example 1, except that:

[0043] In step (1), the raw materials of the alloy elements are weighed according to the alloy weight percentage composition: Zr: 9.98%, Nb: 0.84%, Ta: 0.81%, O: 0.17%, and the balance is Ti;

[0044] The metallographic diagram of the obtained titanium-zirconium alloy wire is shown in Figure 4 Compared with the examples, when the Zr content is 10 wt.%, larger α grains and greater tensile strength are obtained, but the appearance of large α grains significantly reduces the elongation of the material, as shown in Table 1.

[0045] Comparative Example 2

[0046] The rest is the same as in Example 1, except that:

[0047] In step (1), the raw materials of the alloy elements are weighed according to the alloy weight percentage composition: Zr: 25.01%, Nb: 0.93%, Ta: 1.05%, O: 0.25%, and the balance is Ti;

[0048] The metallographic diagram of the obtained titanium-zirconium alloy wire is shown in Figure 5 Compared with the examples, the increase in Zr content allows a small amount of β phase to be retained at room temperature, which greatly reduces the elastic modulus of the material, but its tensile strength decreases to some extent, as shown in Table 1.

[0049] Related performance tests

[0050] Comparative Example 1 is a medical TiZr alloy with a low content of Zr, and Comparative Example 2 is a medical TiZr alloy with a high content of Zr. The alloy wire samples of Examples 1 to 3 and Comparative Examples 1 to 2 were tested for room temperature tensile properties. The mechanical properties obtained from the test include tensile strength Rm, yield strength Rp 0.2 , elongation after fracture A and elastic modulus E, as shown in Table 1;

[0051] .

[0052] As shown in Table 1, the tensile strength of Comparative Examples 1 to 2 exceeds 990 MPa, and the elongation after fracture is about 16% to 22%, while the tensile strength of Examples 1 to 3 is between 1120 MPa and 1180 MPa, the elongation after fracture can reach between 21% and 26%, and the elastic modulus is 82 to 85 GPa. In addition, the mechanical properties of the alloy wires of each embodiment of the present invention are higher than those of conventional pure titanium and TC4 titanium alloy, and due to the lower elastic modulus, stress shielding phenomenon will not occur.

[0053] In summary, the present invention provides a method for preparing a low-modulus, high-strength titanium-zirconium alloy suitable for medical devices, especially dental narrow-diameter implants: through high-temperature forging, solution water cooling treatment, hot rolling, recrystallization annealing and cold drawing, the alloy wire material finally obtained has fine and uniform grains, and while achieving a lower elastic modulus, it ensures that strength and plasticity are well matched, so that it is particularly suitable for narrow-necked implants. In addition, the present invention refines the grains, improves the comprehensive mechanical properties of the titanium alloy material, improves the corrosion resistance, and also improves the cell adhesion, proliferation and bone differentiation ability by controlling the added Zr / Nb / Ta / O element ratio.

Claims

1. An alloy wire suitable for oral implants, the preparation method of which comprises: An alloy ingot containing Zr, Nb, Ta, Ti and oxygen is prepared, wherein the mass contents of the elements in the alloy ingot are: Zr 14-16%; Nb 0.7%-1.2%; Ta 0.4%-1.0%; O 0.1%-0.3%; the balance is Ti; The alloy ingot is forged into bars, wherein the forging temperature is 835-860°C; The rod is subjected to solution treatment, wherein the annealing temperature is 750-830°C, the time is 0.5-2 hours, and the cooling method is water cooling; The bars after solution treatment are subjected to multiple hot rolling deformation treatments, wherein the hot rolling temperature is 650-750°C, the total deformation is 75-90%, and the single deformation is 3%-5%; The bars after hot rolling deformation treatment are subjected to recrystallization annealing treatment, wherein the annealing temperature is 650-750°C, the time is 0.5-2 hours, and the cooling method is furnace cooling; The bars after recrystallization annealing are subjected to multiple cold rolling treatments to obtain alloy wires of the required specifications, wherein the total deformation is 45% to 55% and the single deformation is less than 5%. The preparation of the alloy ingot includes: vacuum melting Zr particles, Ti40Nb master alloy, Ta particles, titanium dioxide powder and sponge titanium and then molding them into alloy ingots, wherein the tensile strength of the alloy wire is 1120-1180MPa, the yield strength is not less than 970MPa, the elongation after fracture is 21%-26%, and the elastic modulus is between 82-85GPa.

Images