CN113481408B - A kind of dental powder metallurgy Ti-Zr alloy and preparation method thereof - Google Patents

Abstract

The invention discloses a powder metallurgy Ti-Zr alloy for dental use and a preparation method thereof. The preparation method comprises the following steps: mixing titanium powder and zirconium powder according to a designed ratio to obtain a titanium-zirconium composite powder, and compounding the titanium-zirconium The powder is sintered to obtain a sintered body with an α' martensitic phase Widmandarin structure, and then the sintered body is thermally deformed at 600° C. to 1000° C. to obtain a Ti-Zr alloy plate or a Ti-Zr alloy rod. In the ‑Zr alloy sheet or the Ti‑Zr alloy bar, titanium: zirconium = 85-95: 5-15 by mass ratio; in the present invention, the α' martensitic phase Widmandarin microstructure is first prepared by a powder metallurgy preparation method The sintered body of the structure is then thermally deformed at a medium temperature, without destroying the α' martensitic structure, the Widmandarin structure is elongated and deformed, and finally a fibrous heterostructure is formed, thereby simultaneously improving the Ti- Strength and ductility of Zr alloys. The method has the advantages of simple procedure, short flow and stable product performance, and is beneficial to industrialized production and clinical application in dentistry.

Description

A kind of dental powder metallurgy Ti-Zr alloy and preparation method thereof

technical field

The invention belongs to the technical field of preparation of dental medical Ti-based materials, in particular to a dental powder metallurgy Ti-Zr alloy and a preparation method thereof.

Background technique

Biomaterials refer to structural materials that can be implanted into the human body, which are at the intersection of materials science and biomedicine, and are usually used in orthopaedic and dental implants and clinical applications. As a kind of medical biological hard material, dental materials are different from industrial materials in that they are characterized by small dosage, many specifications and strict requirements.

Compared with the early gold alloys, cobalt-chromium alloys and nickel-chromium alloys, pure titanium and titanium alloys are widely used in biomedical materials due to their excellent biological safety, good corrosion resistance and high mechanical properties. The field of dental implants. Originally, pure titanium was only used to make orthopaedic and dental restoration materials and parts with low load-bearing force, such as making crowns and bridges, but it was slightly insufficient for making dental implants. Pure titanium has good corrosion resistance, but poor stiffness, strength, and wear resistance, so it cannot be used for large parts of the load. For this reason, people join other elements in pure titanium to form titanium alloys in order to improve its mechanical properties. In the late 1970s, TC4 (Ti-6A1-4V) used in aerospace materials was widely used in surgical repair materials due to its high strength, plasticity and machinability. But then, it was found in clinical application that Al and V in Ti-6Al-4V are toxic to the human body and are not suitable for long-term implantation.

Institute Straumann AG，巴塞尔，瑞士)，其中Zr含量在13～17Zr(wt.％)。Medvedev将其用于齿科植入物，在这项工作中，Ti～15Zr(wt.％)的抗拉强度值为968MPa，比cp-Ti植入物的最低要求高约40％。但屈服强度低于800MPa，且均匀延伸率仅为6％。The element Zr belongs to the life group element that has no toxic and side effects on the human body. As a new type of dental medical Ti alloy, Ti-Zr alloy is not only non-toxic and non-allergenic, and has no toxic and side effects to the human body, but also has high strength, wear resistance and biocompatibility, and can be used as dental biomedical Material. Bernhard et al. prepared binary Ti-Zr alloys that can be used in clinical medicine (

Institute Straumann AG, Basel, Switzerland), wherein the Zr content is between 13 and 17 Zr (wt.%). Medvedev used it for dental implants, and in this work, the tensile strength value of Ti~15Zr (wt.%) was 968 MPa, which was about 40% higher than the minimum requirement for cp-Ti implants. But the yield strength is lower than 800MPa, and the uniform elongation is only 6%.

Zr solid solution can not only lead to solid solution strengthening and enhance the strength of Ti alloys, but its solid solution behavior also affects the microstructure of Ti alloys. Some studies have found that with the increase of Zr solute content, the grains of α-Ti alloys will also be refined. However, by the method of powder metallurgy, the Widmandarin structure will be formed during the α' martensite transformation during cooling, which will cause the segregation of Zr elements. Therefore, when the strength of Ti-Zr alloy reaches 900MPa, the elongation is less than 6%.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the first object of the present invention is to provide a preparation method of powder metallurgy Ti-Zr alloy for dental use, and the preparation method is simple and controllable.

The second object of the present invention is to provide a powder metallurgy Ti-Zr alloy for dental use with both high strength and high plasticity.

In order to achieve the above object, the technical scheme provided by the invention is:

The invention provides a preparation method of powder metallurgy Ti-Zr alloy for dental use, which comprises the following steps: mixing titanium powder and zirconium powder according to a designed ratio to obtain titanium-zirconium composite powder, and sintering the titanium-zirconium composite powder to obtain α' A sintered body with a Widmandarin structure in the intensified phase, and then the sintered body is thermally deformed at 600°C to 1000°C to obtain a Ti-Zr alloy sheet or a Ti-Zr alloy rod, the Ti-Zr alloy sheet or Ti-Zr In the alloy bar, in terms of mass ratio, titanium: zirconium = 85-95: 5-15.

The preparation method of the powder metallurgy Ti-Zr alloy provided by the present invention firstly prepares a sintered body with an α' martensite phase Widmandarin structure by a powder metallurgy method, and then through thermal deformation at a medium temperature, without destroying the α 'Under the premise of the martensitic structure, the Widmandarin structure is elongated and deformed, and finally a fibrous heterostructure is formed. The fibrous heterostructure hinders the grain growth during thermal deformation, and the Zr solid solution causes Solid solution strengthening and grain refinement strengthening can simultaneously improve the strength and plasticity of Ti-Zr alloy materials.

The present invention cleverly utilizes the structure considered harmful in the prior art and transforms it into a favorable structure, thereby achieving the effect of improving the mechanical properties of the Ti-Zr alloy material and overcoming the prejudice of the prior art.

In the present invention, on the one hand, the content of Zr needs to be effectively controlled. If the content of Zr is too small, the solid solution strengthening effect is not obvious enough, and if the content of Zr is too large, more oxygen will be introduced, and the desired performance effect cannot be obtained at the same time. On the one hand, it is necessary to control the thermal deformation to a medium temperature condition (600°C to 1000°C), otherwise the ideal microstructure cannot be obtained, resulting in unsatisfactory performance improvement.

In a preferred solution, the titanium powder is hydrogenated titanium powder, the purity of the titanium powder is >99.9%, and the particle size is ≤45 μm, preferably 25 μm to 45 μm

In a preferred solution, the shape of the titanium powder is an irregular shape. The inventors have found that the best formability is achieved with an irregular shape.

In a preferred solution, the zirconium powder is selected from hydrogenated dehydrogenated zirconium powder, the purity of the zirconium powder is >99.9%, and the particle size is less than or equal to 5 μm, preferably 40 μm to 75 μm.

In a preferred solution, the form of the zirconium source is an irregular shape.

The titanium powder and zirconium powder selected by the present invention do not contain other element components except titanium and zirconium, and only have inevitable trace oxygen elements.

In a preferred solution, the mixing is carried out on a V-type mixer, and the mixing time is 240 min to 480 min, preferably 360 min.

In the actual operation process, the ball mill jar with titanium powder and zirconium powder is placed in the transition chamber of the glove box, filled with argon gas, and the mixed powder is packaged. The whole process of packaging and mixing is protected by argon gas.

In a preferred solution, the sintering is selected from spark plasma sintering, hot pressing sintering, and vacuum sintering.

Further preferably, the conditions of the spark plasma sintering are as follows: the pressure is 10 MPa to 40 MPa, a heating rate of 60 to 100 ℃/min is used below 950 ℃, and a heating rate of 40 to 70 ℃/min is used above 950 ℃. The time is 1min～10min, the sintering temperature is 900℃～1400℃, and the vacuum degree is 1×10 ^-3 Pa. More preferably, the pressure is 30MPa, the sintering time is 5min-10min, the sintering temperature is 1200℃～1300℃, and the vacuum degree is 1× ^{10 −3 Pa} .

Further preferably, the hot pressing sintering conditions are as follows: the pressure is 10MPa～40MPa, the sintering temperature is 900℃～1400℃, the sintering time is 30min～120min, and the vacuum degree is 1×10 ^-3Pa . More preferably, the pressure is 30MPa, the sintering temperature is 1200℃～1300℃, the sintering time is 40min～60min, and the vacuum degree is 1×10 ^-3 Pa.

Further preferably, before the vacuum sintering, cold isostatic pressing is used to press the titanium-zirconium composite powder into a green body. More preferably: the pressure is 180MPa～200MPa, the pressure holding time is 2min～5min; the conditions of the vacuum sintering are: the sintering temperature is 1200℃～1500℃, the sintering time is 240min ^～ 720min, and the vacuum degree is 10- ³ Pa. More preferably, the sintering temperature is 1300℃～1400℃, the sintering time is 480min, and the vacuum degree is 10 ^-3 Pa.

In the present invention, the above three sintering methods are adopted, and under the above conditions, the material can be made dense quickly, and Zr can be fully diffused at high temperature. Using the segregation of Zr during α' martensitic transformation, streaks with Zr-rich regions are formed during the transformation into Widmandelsteiner structure.

Under the preferred pressure conditions, the density of the sintered body can be increased, which is beneficial to improve the success rate of subsequent hot working deformation and ensure the density of the material. Under the optimal sintering temperature and time conditions, the bonding ability between powders can be improved, the occurrence of pores and other defects can be reduced, and a uniform sintered body can be formed at the same time.

In a preferred solution, when preparing a Ti-Zr alloy sheet, the thermal deformation is medium temperature rolling, and the conditions of the medium temperature rolling are: the temperature is 600°C to 800°C, the holding time is 10min to 50min, and the deformation amount of each pass is It is 5% to 10%, the tempering temperature between passes is 500 ° C to 800 ° C, the tempering time between passes is 1 min to 10 min, and the total rolling deformation is 30% to 80%.

The more preferred medium temperature rolling conditions are: the temperature is 700-750°C, the holding time is 20min-30min, the pass deformation is 5%, the tempering temperature between passes is 650°C-750°C, and the tempering between passes is 5%. The time is 3min to 5min, and the total deformation of rolling is 75%.

In a preferred solution, when preparing Ti-Zr alloy bars, the thermal deformation is medium temperature extrusion and/or medium temperature swaging, and the conditions for the medium temperature extrusion are: the temperature is 800°C to 1000°C, and the holding time is 60min ～180min, the extrusion ratio is 3～10:1; the more preferable conditions for medium temperature extrusion are: the temperature is 900℃～950℃, the holding time is 90min～120min, and the extrusion ratio is 6:1.

The conditions of the medium temperature swaging are as follows: the temperature is controlled to be 800° C. to 1000° C., the holding time is 60 min to 180 min, and the total deformation of the rotary forging is 50% to 90%. The more preferable conditions for medium-temperature swaging are as follows: the temperature is 900° C. to 950° C., the holding time is 90 min to 120 min, and the total deformation of the rotary forging is 80%.

In the present invention, by adopting the medium-temperature thermal deformation, the structure can be elongated and deformed without destroying the α' martensite structure, and finally a fibrous heterostructure can be formed. At the same time, the Zr solid solution can cause solid solution strengthening and fine-grain strengthening, and the fibrous heterostructure can also hinder the grain growth during thermal deformation and improve the strength and plasticity of the material. If the heat deformation temperature is too low, it may lead to the cracking of the matrix and the generation of defects, and the ideal fibrous heterostructure cannot be obtained, while the heat deformation temperature is too high. Coarse, thereby affecting the ability of thermal deformation to control the refinement of the tissue.

Of course, other conditions also need to be effectively controlled, such as the amount of deformation. If the amount of rolling deformation is too large, it will easily lead to the formation of internal defects in the material and accelerate the failure of the material; while too small amount of rolling deformation will make the porosity of the material not completely eliminated. , there are still defects, and they will not be able to make full use of the Widmandarin structure to form stripes with Zr-rich regions to obtain an ideal fibrous heterostructure. In addition, if the holding time is not well controlled, it will also affect the plasticity of the material. In a word, under the synergy of various parameters and conditions of hot deformation of the present invention, a Ti-Zr alloy sheet or Ti-Zr alloy rod with the lowest impurity content and the most ideal structure can be obtained, and finally the structure of the material is the most ideal, thereby A powder metallurgy Ti-Zr alloy with both high strength and high plasticity is obtained.

The present invention also provides the dental powder metallurgy Ti-Zr alloy prepared by the above preparation method.

Principles and Advantages

The key to the technical solution of the present invention is that a special microstructure is obtained under the synergistic effect of powder metallurgy and subsequent thermal deformation methods. Using powder metallurgy methods, specifically spark plasma sintering, hot pressing sintering or cold isostatic pressing plus subsequent vacuum sintering, can make the material quickly dense and Zr can be fully diffused at high temperature. Using the segregation of Zr during α' martensitic transformation, streaks with Zr-rich regions are formed during the transformation into Widmandelsteiner structure. Afterwards, through medium-temperature thermal deformation, the structure is elongated and deformed without destroying the α' martensite structure, and finally a fibrous heterostructure is formed. At the same time, the Zr solid solution can cause solid solution strengthening and fine-grain strengthening, and the fibrous heterostructure can also hinder the grain growth during thermal deformation and improve the strength and plasticity of the material.

Therefore, the technical solution of the present invention is based on the high-strength and high-plastic dental Ti-Zr alloy prepared by the powder metallurgy method. In the preferred solution, the ultimate tensile strength at room temperature is 733.4MPa～1129.7MPa, and the yield strength is 712.2 MPa～1086.9MPa, total elongation is 14.9%～26.7%. Compared with the similar preparation process in the prior art, it has the following obvious advantages:

(1) The process steps are relatively simple, the energy consumption is low, and the utilization rate of raw materials is high.

(2) The powder metallurgy method is used for sintering. Compared with the traditional process method, the sintering temperature and pressing pressure of the material can be more accurately controlled to achieve rapid densification and homogenization of the material.

(3) The α' martensite phase Widmandarin structure formed by the powder metallurgy method can cause the segregation of Zr element, which is the reason for the formation of the heterostructure. The special structure obtained by powder metallurgy can form a fibrous heterostructure after thermal deformation, which improves the strength and plasticity of the material.

Description of drawings

1 is the XRD patterns of the prepared Ti-Zr alloys of Examples 1, 2 and 3 of the present invention.

2 is a SEM image of the prepared Ti-Zr alloys of Examples 1, 2 and 3 of the present invention.

3 is a graph of room temperature tensile curves of the prepared Ti-Zr alloys of Examples 1, 2 and 3 of the present invention.

Detailed ways

In order to facilitate understanding of the present invention, the content of the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings and preferred embodiments of the specification, but the protection scope of the present invention is not limited to the following specific embodiments.

Unless otherwise defined, all technical terms used hereinafter have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments, and are not intended to limit the protection scope of the present invention.

Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or can be prepared by existing methods.

Example 1:

The invention provides a powder metallurgy preparation method of high-strength and high-plastic dental Ti-Zr alloy, comprising the following steps:

(1) Using high-purity hydrogenated titanium powder (≤45μm) and hydrogenated zirconium powder (≤75μm) as raw materials, the alloy element powder does not contain other impurities except a small amount of unavoidable impurity oxygen element, and the raw material does not contain any other impurities. Other elements except titanium and zirconium; weigh titanium powder and zirconium powder in a mass ratio of 95:5, and mix the weighed raw material powder with a V-type mixer. The mixing time is 360min. The whole process is protected by argon gas.

(2) Spark plasma sintering is performed on the powder fully mixed in step (1), the pressure during the sintering treatment is controlled to be 30 MPa, and a two-stage heating method is used in the heating process. /min, the sintering temperature is controlled to be 1200° C., the holding time is controlled to be 10 minutes, and the vacuum degree is 1×10 ^-3 Pa to obtain a sintered green body.

(3) The sintered body obtained in step (2) is subjected to medium-temperature hot rolling, the temperature of hot rolling is controlled to be 750° C., the holding time is 30 minutes, the amount of deformation in each pass is 5%, and the tempering between passes is carried out. The temperature is 750°C, the tempering time between passes is 2min, and the total rolling deformation is 75% to obtain a powder metallurgy Ti-5Zr alloy medium-temperature rolled sheet.

(4) The product of this example is tested by the microstructure observation method. The XRD pattern and SEM photograph of the powder metallurgy Ti-Zr alloy prepared in this example are shown in Figure 1 and Figure 2(a) respectively, and the phase is hcp single phase , the tissue is the deformed Widmandelweiss tissue.

(5) The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of this material was 733.4MPa, the yield strength was 712.2MPa, the elongation was 26.7%, and the elastic modulus was 110.0GPa. The tensile curve is as follows shown in Figure 3.

Example 2:

A method for preparing a titanium-zirconium-based composite material bar, other conditions are the same as in Example 1, except that titanium powder and zirconium powder are weighed and mixed in a mass ratio of 90:10, and finally a Ti-10Zr alloy is obtained.

The product of this example is tested by the microstructure observation method. The XRD pattern and SEM photograph of the powder metallurgy Ti-Zr alloy prepared in this example are shown in Figure 1 and Figure 2(b) respectively. The phase is hcp single phase, and the microstructure is The deformed Widman's tissue.

The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of this material was 853.1MPa, the yield strength was 810.2MPa, the elongation was 25.2%, and the elastic modulus was 104.0GPa. The tensile curve is shown in Figure 3. Show.

Example 3:

A method for preparing a titanium-zirconium-based composite material bar, other conditions are the same as in Example 1, except that titanium powder and zirconium powder are weighed and mixed at a mass ratio of 85:15 to finally obtain a Ti-15Zr alloy.

The product of this example is tested by the microstructure observation method. The XRD pattern and SEM photograph of the powder metallurgy Ti-Zr alloy prepared in this example are shown in Figure 1 and Figure 2(b) respectively. The phase is hcp single phase, and the microstructure is The deformed Widman's tissue.

The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of this material was 947.7MPa, the yield strength was 927.8MPa, the elongation was 23.9%, and the elastic modulus was 99.9GPa. The tensile curve is shown in Figure 3. Show.

Comparative Example 1:

A method for preparing a titanium-zirconium-based composite material bar, other conditions are the same as in Example 1, except that titanium powder and zirconium powder are weighed and mixed at a mass ratio of 70:30, and finally a Ti-30Zr alloy is obtained.

But in the room temperature tensile test, the final brittle fracture, the tensile strength is 612MPa, and the elongation is 2.9%. The reason is that the oxygen content of Zr powder is high, resulting in a high overall oxygen content, which exceeds the ductile-brittle transition point of α-Ti alloy, and brittle fracture occurs.

Example 4:

The invention provides a powder metallurgy preparation method of high-strength and high-plastic dental Ti-Zr alloy, comprising the following steps:

(1) Using high-purity hydrogenated titanium powder (≤45μm) and hydrogenated zirconium powder (≤75μm) as raw materials, the alloy element powder does not contain other impurities except a small amount of unavoidable impurity oxygen element, and the raw material does not contain any other impurities. Other elements except titanium and zirconium; Weigh the titanium powder and zirconium powder in a mass ratio of 85:15, and mix the weighed raw material powder with a V-type mixer. The mixing time is 360min. The whole process is protected by argon gas.

(2) hot-press sintering the powder fully mixed in step (1), the pressure during the sintering treatment is controlled to be 30MPa, the sintering temperature is controlled to be 1200°C, the holding time is controlled to be 60min, and the vacuum degree is controlled to be 1×10 ^-3 Pa, A sintered body is obtained.

(3) The sintered body obtained in step (2) is subjected to medium-temperature hot rolling, the temperature of hot rolling is controlled to be 750° C., the holding time is 30 minutes, the amount of deformation in each pass is 5%, and the tempering between passes is carried out. The temperature is 750°C, the tempering time between passes is 2min, and the total rolling deformation is 75% to obtain a powder metallurgy Ti-15Zr alloy medium-temperature rolled sheet.

(4) The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of the material was 925.7MPa, the yield strength was 904.3MPa, the elongation was 22.5%, and the elastic modulus was 98.7GPa.

Example 5:

The invention provides a powder metallurgy preparation method of high-strength and high-plastic dental Ti-Zr alloy, comprising the following steps:

(1) Using high-purity hydrogenated titanium powder (≤45μm) and hydrogenated zirconium powder (≤75μm) as raw materials, the alloy element powder does not contain other impurities except a small amount of unavoidable impurity oxygen element, and the raw material does not contain any other impurities. Other elements except titanium and zirconium; Weigh the titanium powder and zirconium powder in a mass ratio of 85:15, and mix the weighed raw material powder with a V-type mixer. The mixing time is 360min. The whole process is protected by argon gas.

(2) Cold isostatic pressing is performed on the fully mixed powder in step (1), the pressure is 180 MPa, and the pressing time is 2 min.

(3) vacuum sintering the compact obtained in step (2) in a vacuum sintering furnace, the sintering temperature is 1300° C., the holding time is 480 min, and the vacuum degree is 1×10 ⁻³ Pa to obtain a sintered green body.

(4) The sintered body obtained in step (3) is subjected to medium-temperature hot rolling, and the temperature of hot rolling is controlled to be 750° C., the holding time is 30 minutes, the amount of deformation in each pass is 5%, and the tempering between passes is carried out. The temperature is 750°C, the tempering time between passes is 2min, and the total rolling deformation is 75% to obtain a powder metallurgy Ti-15Zr alloy medium-temperature rolled sheet.

(4) The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of the material was 951.2MPa, the yield strength was 932.7MPa, the elongation was 20.8%, and the elastic modulus was 102.8GPa.

Example 6:

The invention provides a powder metallurgy preparation method of high-strength and high-plastic dental Ti-Zr alloy, comprising the following steps:

(1) Using high-purity hydrogenated titanium powder (≤45μm) and hydrogenated zirconium powder (≤75μm) as raw materials, the alloy element powder does not contain other impurities except a small amount of unavoidable impurity oxygen element, and the raw material does not contain any other impurities. Other elements except titanium and zirconium; Weigh the titanium powder and zirconium powder in a mass ratio of 85:15, and mix the weighed raw material powder with a V-type mixer. The mixing time is 360min. The whole process is protected by argon gas.

(2) Spark plasma sintering is performed on the powder fully mixed in step (1), the pressure during the sintering treatment is controlled to be 30 MPa, and a two-stage heating method is used in the heating process. /min, the sintering temperature is controlled to be 1200° C., the holding time is controlled to be 10 minutes, and the vacuum degree is 1×10 ^-3 Pa to obtain a sintered green body.

(3) subjecting the sintered body obtained in step (2) to medium-temperature hot extrusion processing, the extrusion temperature is 950° C., the holding time is 120 min, and the extrusion ratio is 6:1 to obtain a powder metallurgy Ti-15Zr alloy at medium temperature Extruded bar.

(4) The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of the material was 932.6MPa, the yield strength was 914.5MPa, the elongation was 23.6%, and the elastic modulus was 102.1GPa.

Example 7:

The invention provides a powder metallurgy preparation method of high-strength and high-plastic dental Ti-Zr alloy, comprising the following steps:

(1) Using high-purity hydrogenated titanium powder (≤45μm) and hydrogenated zirconium powder (≤75μm) as raw materials, the alloy element powder does not contain other impurities except a small amount of unavoidable impurity oxygen element, and the raw material does not contain any other impurities. Other elements except titanium and zirconium; Weigh the titanium powder and zirconium powder in a mass ratio of 85:15, and mix the weighed raw material powder with a V-type mixer. The mixing time is 360min. The whole process is protected by argon gas.

(2) Spark plasma sintering is performed on the powder fully mixed in step (1), the pressure during the sintering treatment is controlled to 30MPa, and the heating process adopts a two-stage heating method. /min, the sintering temperature was controlled to be 1200° C., the holding time was controlled to be 10 minutes, and the vacuum degree was 1×10 ^-3 Pa to obtain a sintered green body.

(3) subjecting the sintered body obtained in step (2) to medium-temperature hot extrusion processing, the extrusion temperature is 950° C., the holding time is 120 min, and the extrusion ratio is 6:1 to obtain a powder metallurgy Ti-15Zr alloy at medium temperature Extruded bar.

(4) The medium-temperature extruded bar obtained in step (3) is subjected to medium-temperature hot swaging processing, the swaging temperature is 950° C., the holding time is 90 min, and the total deformation of the swaging is 80%.

(5) The room temperature tensile test was carried out under the condition of using an extensometer. After testing, the tensile strength of this material was 1129.7MPa, the yield strength was 1086.9MPa, the elongation was 14.9%, and the elastic modulus was 104.1GPa.

Claims (9)

1. A preparation method of powder metallurgy Ti-Zr alloy for dentistry is characterized in that: the method comprises the following steps: mixing titanium powder and zirconium powder according to a designed proportion to obtain titanium-zirconium composite powder, sintering the titanium-zirconium composite powder to obtain a sintered body with an alpha' martensite phase Widmannstatten structure, thermally deforming the sintered body at 600-1000 ℃ to obtain a Ti-Zr alloy plate or a Ti-Zr alloy bar, wherein in the Ti-Zr alloy plate or the Ti-Zr alloy bar, the mass ratio of titanium: zirconium = 85-95: 5-15;

the titanium powder is hydrogenated and dehydrogenated titanium powder, the purity of the titanium powder is more than 99.9%, the particle size of the titanium powder is less than or equal to 45 mu m, the zirconium powder is selected from hydrogenated and dehydrogenated zirconium powder, the purity of the zirconium powder is more than 99.9%, and the particle size of the zirconium powder is less than or equal to 75 mu m.

2. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 1, wherein: and the mixing is carried out on a V-shaped mixer, and the mixing time is 240-480 min.

3. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 1, wherein: the sintering is selected from one of spark plasma sintering, hot-pressing sintering and vacuum sintering.

4. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 3, wherein: the discharge plasma sintering conditions are as follows: the pressure is 10 MPa-40 MPa, the sintering time is 1 min-10 min, the sintering temperature is 900-1400 ℃, and the vacuum degree is 1 multiplied by 10^-3Pa。

5. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 3, wherein: the hot-pressing sintering conditions are as follows: the pressure is 10MPa to 40MPa, the sintering temperature is 900 ℃ to 1400 ℃, the sintering time is 30min to 120min, and the vacuum degree is 1 multiplied by 10^-3Pa。

6. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 3, wherein: before the vacuum sintering, pressing the titanium-zirconium composite powder into a green body by adopting cold isostatic pressing, wherein the conditions of the cold isostatic pressing are as follows: the pressure is 150 MPa-250 MPa, and the pressure maintaining time is 1 min-10 min; the vacuum sintering conditions are as follows: the sintering temperature is 1200-1500 ℃, the sintering time is 240-720 min, and the vacuum degree is 10^-3Pa。

7. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 1, wherein: when the Ti-Zr alloy plate is prepared, the thermal deformation is medium temperature rolling, and the medium temperature rolling conditions are as follows: the temperature is 600-800 ℃, the heat preservation time is 10-50 min, the pass deformation is 5-10%, the inter-pass tempering temperature is 500-800 ℃, the inter-pass tempering time is 1-10 min, and the total rolling deformation is 30-80%.

8. The method for preparing a dental powder metallurgy Ti-Zr alloy according to claim 1, wherein: when the Ti-Zr alloy bar is prepared, the thermal deformation is medium-temperature extrusion and/or medium-temperature rotary swaging, and the medium-temperature extrusion conditions are as follows: the temperature is 800-1000 ℃, the heat preservation time is 60-180 min, and the extrusion ratio is 3-10: 1; the medium-temperature rotary swaging conditions are as follows: the temperature is 800-1000 ℃, the heat preservation time is 60-180 min, and the total deformation amount of rotary swaging is 50-90%.

9. The powder metallurgy Ti-Zr alloy for dentistry produced by the production method according to any one of claims 1 to 8.

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