阅读说明：本技术 一种梯度结构钛钽层状复合材料及其制备方法 (Titanium-tantalum layered composite material with gradient structure and preparation method thereof ) 是由 陈畅 刘蕊 王珊 侯旭升 夏雪 钟志宏 张真 于 2020-06-04 设计创作，主要内容包括：本发明公开一种梯度结构钛钽层状复合材料及其制备方法,包括多个依次层叠的重复单元,每个重复单元包括依次设置的钛层和钽层；所述钛层和所述钽层均由轧制态的金属箔片制成,所述钛层和所述钽层在界面处有钛钽固溶体生成；本发明为包括多个依次层叠的重复单元,每个重复单元包括依次设置的钛层,钽层的梯度结构钛/钽层状复合材料,其具有优异的强度和韧性,力学性能好,该医用钛/钽层状复合材料对医用钛钽合金具有重要的实用意义。(The invention discloses a titanium-tantalum layered composite material with a gradient structure and a preparation method thereof, wherein the titanium-tantalum layered composite material comprises a plurality of sequentially laminated repeating units, and each repeating unit comprises a titanium layer and a tantalum layer which are sequentially arranged; the titanium layer and the tantalum layer are both made of rolled metal foil, and titanium-tantalum solid solution is generated at the interface of the titanium layer and the tantalum layer; the medical titanium/tantalum laminar composite material has excellent strength and toughness and good mechanical property, and has important practical significance for medical titanium-tantalum alloy.)

1. The titanium-tantalum layered composite material with the gradient structure is characterized by comprising a plurality of sequentially laminated repeating units, wherein each repeating unit comprises a titanium layer and a tantalum layer which are sequentially arranged; the titanium layer and the tantalum layer are both made of rolled metal foil, and titanium-tantalum solid solution is generated at the interface of the titanium layer and the tantalum layer.

2. The gradient structure titanium tantalum layered composite material of claim 1, wherein the repeating unit is eleven.

3. The gradient structure titanium tantalum layered composite material as claimed in claim 1, wherein the thickness of the titanium layer is 30 μm to 150 μm.

4. The gradient structure titanium-tantalum layered composite material of claim 1, wherein the tantalum layer has a thickness of 30 μm to 150 μm.

5. The gradient structure titanium tantalum layered composite material of claim 1, wherein said titanium layer is 100 μm thick and said tantalum layer is 100 μm thick.

6. A method for preparing a gradient structure titanium-tantalum laminated composite material according to any one of claims 1 to 5, which comprises the following steps:

s1, surface treatment; carrying out surface treatment on the titanium foil and the tantalum foil;

s2, filling the mold; sequentially laminating the titanium foil and the tantalum foil subjected to surface treatment in a graphite mold to obtain a to-be-sintered body;

s3, sintering; performing discharge plasma sintering on the to-be-sintered body in a vacuum state;

and S4, demolding.

7. The method according to claim 6, wherein in step S1, the titanium foil and the tantalum foil are polished with SiC sand paper to remove surface oxides, and then the titanium foil and the tantalum foil are ultrasonically cleaned in absolute ethanol for 20min to remove surface-attached impurities, and then vacuum-dried and hermetically stored.

8. The method of claim 6, wherein the discharge plasma sintering process in the step S3 includes:

s31, temperature and pressure raising stage: firstly, raising the temperature from room temperature to a target temperature, wherein the target temperature is set to be 1000-1400 ℃, the temperature raising speed is 50 ℃/min, meanwhile, the pressure is raised at a constant rate, the pressure is set to be 5KN at the room temperature, and when the temperature reaches the target temperature, the pressure reaches 20-22 KN;

s32, heat preservation stage: preserving heat and pressure for 5-15 min;

s33, cooling and depressurizing; cooling from the target temperature to room temperature, furnace vacuum cooling while reducing the pressure at a constant rate, when the temperature is reduced to 300 ℃, reducing the pressure to 2KN, and then maintaining the pressure.

Technical Field

The invention relates to the technical field of biomedical materials, in particular to a titanium-tantalum layered composite material with a gradient structure and a preparation method thereof.

Background

Medical titanium alloys are one of the best biocompatible metals known today. In the middle of the 70's of the 20 th century, titanium and titanium alloys began to gain wide medical applications, becoming one of the most promising medical materials.

The density of titanium and titanium alloy is close to that of human hard tissue, and the biocompatibility, corrosion resistance and fatigue resistance of the titanium and titanium alloy are superior to those of stainless steel and cobalt alloy, so that the titanium and titanium alloy is the best metal medical material at present. The titanium and the titanium alloy have affinity with human body, show certain biological activity and osseointegration capability, and are particularly suitable for intraosseous implantation. The disadvantages of titanium and titanium alloys are low hardness, poor wear resistance and too high elastic modulus.

The variety of medical metal materials needs to be further expanded in the future, and the use cost needs to be further reduced. Therefore, it is important to develop an alloy having high strength, high toughness, high corrosion resistance, high wear resistance, and an appropriate elastic modulus. Tantalum has excellent chemical stability and resistance to physical corrosion, tantalum oxides are not substantially absorbed and do not exhibit toxic reactions, and tantalum can be used in combination with other metals without damaging the oxide film on its surface. Clinically, tantalum also exhibits good biocompatibility. Tantalum is also used in biomedicine as a bone plate, an implant root, a denture, a cardiovascular stent, an artificial heart and the like, and therefore titanium-tantalum composite materials are developed to meet more medical applications.

However, the titanium-tantalum composite material manufactured by the existing process technology has very low mechanical property, very poor yield capacity and low degree of combination with a human body, is easy to cause the falling of tissues and implanted materials to cause operation failure, and greatly improves the medical cost.

In view of the above-mentioned drawbacks, the inventors of the present invention have finally obtained the present invention through a long period of research and practice.

Disclosure of Invention

In order to solve the technical defects, the technical scheme adopted by the invention is to provide a titanium-tantalum layered composite material with a gradient structure, which comprises a plurality of sequentially laminated repeating units, wherein each repeating unit comprises a titanium layer and a tantalum layer which are sequentially arranged; the titanium layer and the tantalum layer are both made of rolled metal foil, and titanium-tantalum solid solution is generated at the interface of the titanium layer and the tantalum layer.

Preferably, the number of the repeating units is eleven.

Preferably, the thickness of the titanium layer is 30 μm to 150 μm.

Preferably, the thickness of the tantalum layer is 30-150 μm.

Preferably, the thickness of the titanium layer is 100 μm, and the thickness of the tantalum layer is 100 μm.

Preferably, a preparation method of the titanium-tantalum layered composite material with the gradient structure comprises the following steps:

s1, surface treatment; carrying out surface treatment on the titanium foil and the tantalum foil;

s2, filling the mold; sequentially laminating the titanium foil and the tantalum foil subjected to surface treatment in a graphite mold to obtain a to-be-sintered body;

s3, sintering; performing discharge plasma sintering on the to-be-sintered body in a vacuum state;

and S4, demolding.

Preferably, in step S1, the titanium foil and the tantalum foil are polished by SiC sand paper to remove surface oxides, and then the titanium foil and the tantalum foil are placed in absolute ethanol for ultrasonic cleaning for 20min to remove impurities attached to the surfaces, and are vacuum-dried and then sealed for storage.

Preferably, the spark plasma sintering process in step S3 includes:

s31, temperature and pressure raising stage: firstly, raising the temperature from room temperature to a target temperature, wherein the target temperature is set to be 1000-1400 ℃, the temperature raising speed is 50 ℃/min, meanwhile, the pressure is raised at a constant rate, the pressure is set to be 5KN at the room temperature, and when the temperature reaches the target temperature, the pressure reaches 20-22 KN;

s32, heat preservation stage: preserving heat and pressure for 5-15 min;

s33, cooling and depressurizing; cooling from the target temperature to room temperature, furnace vacuum cooling while reducing the pressure at a constant rate, when the temperature is reduced to 300 ℃, reducing the pressure to 2KN, and then maintaining the pressure.

Compared with the prior art, the invention has the beneficial effects that: the medical titanium/tantalum laminar composite material has excellent strength and toughness and good mechanical property, and has important practical significance for medical titanium-tantalum alloy.

Drawings

FIG. 1 is a drawing graph of the titanium-tantalum layered composite material with the gradient structure in the first embodiment;

FIG. 2 is a line scan EDS plot of the gradient structure titanium tantalum layered composite of example one;

FIG. 3 is a tensile fracture morphology of the titanium-tantalum layered composite material with the gradient structure of the first embodiment;

FIG. 4 is a drawing graph of the titanium tantalum layered composite material with the gradient structure of the second embodiment;

FIG. 5 is a line scan EDS plot of the gradient structure titanium tantalum layered composite of example two;

FIG. 6 is a tensile fracture morphology of the titanium tantalum layered composite material with the gradient structure of the second embodiment;

FIG. 7 is a graph of the tensile elongation of the titanium tantalum layered composite material with the gradient structure of example III;

FIG. 8 is a line scan EDS plot of the gradient structure titanium tantalum layered composite of example three;

FIG. 9 is a tensile fracture morphology of the gradient titanium tantalum layered composite of example three;

FIG. 10 is a graph of the tensile elongation of the titanium tantalum layered composite material of the gradient structure of example four;

FIG. 11 is a line scan EDS plot of the gradient structure titanium tantalum layered composite of example four;

FIG. 12 is a tensile fracture morphology of the gradient titanium tantalum layered composite of example four;

FIG. 13 is a graph of the tensile elongation of the gradient titanium tantalum layered composite of example five;

FIG. 14 is a line scan EDS plot of the gradient structure titanium tantalum layered composite of example five;

FIG. 15 is a tensile fracture morphology of the gradient titanium tantalum layered composite of example five.

FIG. 16 is a tensile graph of the gradient titanium tantalum layered composite of example six;

FIG. 17 is a tensile graph of the gradient titanium tantalum layered composite of example seven;

FIG. 18 is a tensile graph of the gradient titanium tantalum layered composite of example eight;

FIG. 19 is a tensile graph of the gradient titanium tantalum layered composite of example nine.

Detailed Description

The above and further features and advantages of the present invention are described in more detail below with reference to the accompanying drawings.

The titanium-tantalum laminated composite material with the gradient structure comprises a plurality of sequentially laminated repeating units, wherein each repeating unit comprises a titanium layer and a tantalum layer which are sequentially arranged; the titanium layer and the tantalum layer are both made of rolled metal foil.

In the invention, the titanium layer and the tantalum layer are bonded by the repeating unit through a discharge plasma sintering process, and a titanium-tantalum solid solution is formed at the composite material interface between the titanium layer and the tantalum layer, so that a metallurgical bonding with a gradient structure and strong bonding force is formed between the titanium layer and the tantalum layer, the problems of poor interface bonding force and poor mechanical property caused by a heterogeneous interface are solved, the mechanical property of the titanium/tantalum layered composite material is obviously improved, and the yield stage of a tensile stress-strain curve of the titanium/tantalum layered composite material is represented as a smooth yield platform.

Typically, the repeating unit is eleven, the titanium layer has a thickness of 30 μm to 150 μm, and the tantalum layer has a thickness of 30 μm to 150 μm.

Most preferably, the thickness of the titanium layer is 100 μm, and the thickness of the tantalum layer is 100 μm.

It should be noted that, in the specific embodiment, the thicknesses of the titanium foil and the tantalum foil can be adjusted within the range of 30 μm to 150 μm as required, the number of the repeating units is not limited to eleven, and the specific number can be set according to the actual situation.

The preparation method of the titanium-tantalum layered composite material with the gradient structure comprises the following steps:

s1, surface treatment: because the titanium foil and the tantalum foil have good plasticity at room temperature, the titanium foil and the tantalum foil are manually cut into round sheets with the diameter of 30mm respectively. Polishing the titanium foil and the tantalum foil through SiC sand paper to remove oxides on the surfaces, then placing the titanium foil and the tantalum foil in absolute ethyl alcohol for ultrasonic cleaning for 20min to remove impurities such as dust and the like attached to the surfaces, and sealing and storing after vacuum drying;

s2, die filling: sequentially laminating the titanium foil and the tantalum foil after surface treatment in a graphite mold to obtain a body to be sintered, wherein the size of a mold cavity of the graphite mold isThe wall thickness is 15 mm.

S3, sintering: performing discharge plasma sintering on the to-be-sintered body in a vacuum state;

and S4, demolding.

The discharge plasma sintering process in step S3 specifically includes three stages:

s31, temperature and pressure raising stage: raising the temperature from room temperature to 1000-1400 ℃, wherein the temperature raising speed is 50 ℃/min, meanwhile, raising the pressure at a constant rate, the set pressure is 5KN at room temperature, and when the temperature reaches the target temperature, the pressure reaches 20-22 KN;

s32, heat preservation stage: preserving heat and pressure for 5-15 min;

s33, cooling and depressurizing; the temperature is reduced from the target temperature to room temperature, the furnace is cooled in vacuum, and the pressure is reduced at a constant rate, when the temperature is reduced to 300 ℃, the pressure is reduced to 2KN, and then the pressure is maintained.

The sintering temperature set by the invention is lower than the melting point temperature of titanium, and the diffusion coefficient of tantalum is very low at the temperature, so that titanium element and tantalum element cannot be completely alloyed, therefore, a gradient structure consisting of areas rich in titanium and tantalum can be formed, and the mechanical property of the titanium/tantalum laminar composite material can be adjusted by changing the interface structure between the titanium layer and the tantalum layer, thereby contributing to the development of medical materials. The titanium layer and the tantalum layer are bonded by adopting a discharge plasma sintering process, and a titanium-tantalum solid solution is formed at the interface, so that metallurgical bonding with a gradient structure and strong bonding force is formed between the titanium layer and the tantalum layer, and the problems of poor interface bonding force and poor mechanical property caused by a heterogeneous interface are solved.

The titanium-tantalum layered composite material with the gradient structure has excellent mechanical property, the toughness of the whole medical titanium/tantalum layered composite material is obviously improved by the beneficial combination of the tantalum layer and the titanium layer, the mechanical property of the titanium/tantalum layered composite material is obviously improved, and the yield stage of a tensile stress-strain curve of the titanium/tantalum layered composite material is represented as a smooth yield platform, so that the stress shielding phenomenon is effectively solved, and the stability of the medical titanium/tantalum layered composite material in a human body is improved.

The preparation method can adjust the strength and toughness of the material by adjusting the thickness of the titanium layer and the tantalum layer and the thickness of the titanium-tantalum solid solution layer according to the clinical requirements on the implant material, thereby meeting the requirements of medical implant materials and reducing the medical cost.

Specifically, the following examples are specifically discussed.