阅读说明：本技术 一种多孔铂骨架生物相容性钽金属涂层及其制备方法 (Porous platinum framework biocompatible tantalum metal coating and preparation method thereof ) 是由 冯晶 苏涛 汪俊 种晓宇 屈晨凯 邹若安 王建坤 于 2021-08-31 设计创作，主要内容包括：本发明公开了一种多孔铂骨架生物相容性钽金属涂层及其制备方法。本发明方案提供的钽金属涂层制备方法,依次对多孔铂骨架进行表面处理、清洗并干燥,将多孔铂置于装置中的沉积室,将钽金属粉末放于装置中的氧化室,并检查装置各反应室的气密性,抽真空后升温；反应室内温度稳定后分别向氧化室和沉积室中通入氯气和氢气,氧化室中氯气与金属钽粉末反应生成前驱体五氯化钽,五氯化钽流通到沉积室中与氢气发生还原反应后生成纯钽,沉积在多孔铂表面,制得到钽金属涂层；其致密超过95%,纯度则超过99.5%,材料既拥有了铂金属优异的力学性能、易加工的优势,还提高了材料的生物相容性、耐腐蚀和耐磨损性能。(The invention discloses a porous platinum framework biocompatible tantalum metal coating and a preparation method thereof. According to the preparation method of the tantalum metal coating provided by the scheme of the invention, the porous platinum framework is subjected to surface treatment, cleaning and drying in sequence, porous platinum is placed in a deposition chamber in the device, tantalum metal powder is placed in an oxidation chamber in the device, the air tightness of each reaction chamber of the device is checked, and the temperature is raised after vacuumizing; after the temperature in the reaction chamber is stable, chlorine and hydrogen are respectively introduced into the oxidation chamber and the deposition chamber, the chlorine in the oxidation chamber reacts with the metal tantalum powder to generate a precursor tantalum pentachloride, the tantalum pentachloride flows into the deposition chamber to generate a reduction reaction with the hydrogen to generate pure tantalum, and the pure tantalum is deposited on the surface of the porous platinum to obtain a tantalum metal coating; the compactness is over 95 percent, the purity is over 99.5 percent, the material has the advantages of excellent mechanical property and easy processing of the platinum metal, and the biocompatibility, corrosion resistance and wear resistance of the material are improved.)

1. A porous platinum framework biocompatible tantalum metal coating is characterized in that the coating raw material is metal tantalum powder.

2. The porous platinum framework biocompatible tantalum metal coating according to claim 1, characterized in that the purity of the metal tantalum powder is 99.99%, and the particle size is 48-150 μm.

3. The porous platinum framework biocompatible tantalum metal coating as claimed in claim 1 or 2, wherein said coating is a tantalum metal coating and has a uniform texture distribution, high strength and no cracks; the bending strength of the tantalum metal coating is 110-150 MPa, and the elastic modulus is 40-65 GPa.

4. A preparation method of a porous platinum framework biocompatible tantalum metal coating is characterized by comprising the following steps:

(1) sequentially carrying out surface treatment, cleaning and drying on a porous platinum framework, placing the porous platinum in a deposition chamber in a device, placing tantalum metal powder in an oxidation chamber in the device, checking the air tightness of each reaction chamber of the device, vacuumizing and heating;

(2) after the temperature in the reaction chamber is stable, introducing chlorine and hydrogen into the oxidation chamber and the deposition chamber respectively, wherein the chlorine in the oxidation chamber reacts with metal tantalum powder to generate a precursor tantalum pentachloride, the tantalum pentachloride flows into the deposition chamber to generate a reduction reaction with the hydrogen to generate pure tantalum, and the pure tantalum pentachloride is deposited on the surface of the porous platinum to obtain a tantalum metal coating;

(3) and after the reaction is finished, cooling, sampling, cleaning and polishing the tantalum metal coating, and treating tail gas generated in the experimental process by using a sodium hydroxide solution.

5. The preparation method of the biocompatible tantalum metal coating with the porous platinum framework is characterized in that the porosity of the porous platinum in the step (1) is 75% -85%, and the pore diameter is 100-500 mu m.

6. The method for preparing the biocompatible tantalum metal coating with the porous platinum framework as claimed in claim 4, wherein the step (1) of cleaning and drying specifically comprises the following steps: and ultrasonically cleaning the platinum by using alcohol for 10-30 min, wherein the drying temperature is 80-100 ℃, and the drying time is 2-5 h.

7. The preparation method of the porous platinum framework biocompatible tantalum metal coating according to claim 4, wherein the purity of the tantalum metal powder in the step (1) is 99.99%, and the particle size of the tantalum metal powder is 48-150 μm.

8. The method for preparing the biocompatible tantalum metal coating with the porous platinum framework as claimed in claim 4, wherein the temperature rise rate in the step (1) is 5 ℃/min, and the deposition temperature is 800-1500 ℃.

9. The method for preparing the biocompatible tantalum metal coating with the porous platinum framework as claimed in claim 4, wherein the purity of the chlorine gas and the purity of the hydrogen gas in the step (2) are respectively more than 99.99%; the flow rate of the chlorine gas is 50-150 ml/min, and the flow rate of the hydrogen gas is 400-1000 ml/min.

10. The method for preparing the biocompatible tantalum metal coating with the porous platinum framework as claimed in claim 4, wherein the deposition time in the step (2) is 30-300 min;

the step (3) is specifically as follows: ultrasonically cleaning the prepared sample by using a methanol solution, and then cleaning the sample by using acetone and distilled water, wherein the prepared tantalum metal coating is uniformly distributed, and has high bonding strength and no crack gap;

the bending strength of the tantalum metal coating is 110-150 MPa, and the elastic modulus is 40-65 GPa.

Technical Field

The invention belongs to the technical field of medical materials, and particularly relates to a porous platinum framework biocompatible tantalum metal coating and a preparation method thereof.

Background

The medical metal platinum has excellent performances of high obdurability, fatigue resistance, easy processing and the like, is a biological material widely applied to clinical medicine, and is widely applied to various implanted medical instruments in important medical fields of orthopedics, dentistry, interventional therapy and the like. But its greater density (21.45 g/cm)³) It can generate a large load on the bone and muscle, limiting its application. The metal material is prepared into the porous material, and the density and Young modulus of the material matched with human skeleton can be obtained by regulating and controlling the porosity of the porous material. However, the medical metal material in clinical application at present generally has no bioactivity in organisms, and needs to be further surface modified so as to have certain bioactivity.

Aiming at the problems that the existing platinum metal has no bioactivity and needs to be subjected to surface modification, so that the platinum metal has certain bioactivity, and in addition, the density of the platinum metal is high, and needs to be reduced to be matched with the density of human skeleton, so that the design and development of a porous platinum skeleton biocompatible tantalum metal coating and a preparation method thereof are urgently needed.

Disclosure of Invention

The invention aims to provide a porous platinum framework biocompatible tantalum metal coating;

the invention also aims to provide a preparation method of the porous platinum framework biocompatible tantalum metal coating;

the first purpose of the invention is realized by that the raw material of the coating is metal tantalum powder.

Another object of the invention is achieved in that the method comprises the steps of:

(1) sequentially carrying out surface treatment, cleaning and drying on a porous platinum framework, placing the porous platinum in a deposition chamber in a device, placing tantalum metal powder in an oxidation chamber in the device, checking the air tightness of each reaction chamber of the device, vacuumizing and heating;

(2) after the temperature in the reaction chamber is stable, introducing chlorine and hydrogen into the oxidation chamber and the deposition chamber respectively, wherein the chlorine in the oxidation chamber reacts with metal tantalum powder to generate a precursor tantalum pentachloride, the tantalum pentachloride flows into the deposition chamber to generate a reduction reaction with the hydrogen to generate pure tantalum, and the pure tantalum pentachloride is deposited on the surface of the porous platinum to obtain a tantalum metal coating;

(3) and after the reaction is finished, cooling, sampling, cleaning and polishing the tantalum metal coating, and treating tail gas generated in the experimental process by using a sodium hydroxide solution.

According to the biocompatible tantalum metal coating with the porous platinum framework, provided by the scheme of the invention, the coating raw material is metal tantalum powder, the porous platinum framework is subjected to surface treatment, cleaning and drying sequentially through a preparation method of a corresponding coating, the porous platinum is placed in a deposition chamber in a device, the tantalum metal powder is placed in an oxidation chamber in the device, the air tightness of each reaction chamber of the device is checked, and the temperature is raised after vacuumizing; after the temperature in the reaction chamber is stable, chlorine and hydrogen are respectively introduced into the oxidation chamber and the deposition chamber, and the chlorine and the metal tantalum powder in the oxidation chamberReacting to generate a precursor tantalum pentachloride, wherein the tantalum pentachloride flows into the deposition chamber to perform a reduction reaction with hydrogen to generate pure tantalum, and depositing the pure tantalum pentachloride on the surface of the porous platinum to obtain a tantalum metal coating; after the reaction is finished, cooling, sampling, cleaning and polishing the tantalum metal coating, and treating tail gas generated in the experimental process by using a sodium hydroxide solution, wherein the finally prepared porous platinum framework biocompatible tantalum metal coating is compact and more than 95%, has the purity of more than 99.5% and has enough thickness, so that the material has the advantages of excellent mechanical property, low cost and easiness in processing, and the biocompatibility, corrosion resistance and wear resistance of the material are improved; and has a low density of 4.2 to 5.6g/cm³The high-porosity factor is 75-85%, the high bending strength is 110-150 MPa, the elastic modulus is 40-65 GPa which is closer to that of human skeleton, and the high-porosity factor can be implanted into human body to repair bone wound and bone defect.

In addition, the thickness of the metal tantalum coating deposited on the porous platinum framework by adopting the scheme reaches 90-120 mu m, and the metal tantalum coating is uniform, so that the material not only retains the excellent performance of porous platinum, but also has excellent biocompatibility of tantalum metal, and meets the use requirement of the biological material; and the porous tantalum coating material has high porosity, all the holes are communicated, and the porous tantalum coating material has no closed hole, is similar to human cancellous bone, and can promote the repair of bone. Meanwhile, the bone substitute material has good processability, can be processed into various complex shapes without damaging pores, and is a good bone substitute material.

The method can control the thickness of the tantalum metal coating by controlling parameters such as the concentration of reaction gas, the deposition temperature, the reaction time and the like in the chemical vapor deposition process. The metal tantalum coating is deposited on the traditional material by using a coating preparation technology, not only is the excellent biological performance of the metal tantalum utilized, but also the cost is reduced, and the scheme has a very high application prospect in the aspect of cost control.

Drawings

FIG. 1 is a schematic diagram of a device for chemical vapor deposition of tantalum for preparing a biocompatible tantalum metal coating with a porous platinum framework according to the present invention;

FIG. 2 is a schematic diagram showing the relationship between the ammonia gas flow rate change and the coating deposition rate in example 2 of the method for preparing a biocompatible tantalum metal coating with a porous platinum framework according to the present invention;

FIG. 3 is a schematic diagram showing the relationship between the chlorine flow rate change and the coating deposition rate in example 3 of the method for preparing a biocompatible tantalum metal coating with a porous platinum framework according to the present invention;

in the figure: 1-an oxidation chamber; 2-tantalum; 3-a sample; 4-a deposition chamber; 5-trans-gene; 6, vacuum exhausting; 7-sodium hydroxide solution; 8-a chlorine inlet; 9-hydrogen inlet.

Detailed Description

The invention will be further described with reference to the drawings and examples, but the invention is not limited thereto in any way, and any modification or improvement based on the teaching of the invention is within the scope of the invention.

As shown in fig. 1 to 3, the present invention provides a biocompatible tantalum metal coating with a porous platinum skeleton, wherein the coating is made of metal tantalum powder.

The purity of the metal tantalum powder is 99.99%, and the particle size is 48-150 mu m.

The coating is specifically a tantalum metal coating, and has uniform texture distribution, high strength and no crack gaps; the bending strength of the tantalum metal coating is 110-150 MPa, and the elastic modulus is 40-65 GPa.

The invention also provides a preparation method of the porous platinum framework biocompatible tantalum metal coating, which comprises the following steps:

(1) sequentially carrying out surface treatment, cleaning and drying on a porous platinum framework, placing the porous platinum in a deposition chamber in a device, placing tantalum metal powder in an oxidation chamber in the device, checking the air tightness of each reaction chamber of the device, vacuumizing and heating;

(2) after the temperature in the reaction chamber is stable, introducing chlorine and hydrogen into the oxidation chamber and the deposition chamber respectively, wherein the chlorine in the oxidation chamber reacts with metal tantalum powder to generate a precursor tantalum pentachloride, the tantalum pentachloride flows into the deposition chamber to generate a reduction reaction with the hydrogen to generate pure tantalum, and the pure tantalum pentachloride is deposited on the surface of the porous platinum to obtain a tantalum metal coating;

(3) and after the reaction is finished, cooling, sampling, cleaning and polishing the tantalum metal coating, and treating tail gas generated in the experimental process by using a sodium hydroxide solution.

In the step (1), the porosity of the porous platinum is 75% -85%, and the pore diameter is 100-500 mu m.

The washing and drying specifically comprises: and ultrasonically cleaning the platinum by using alcohol for 10-30 min, wherein the drying temperature is 80-100 ℃, and the drying time is 2-5 h. The purity of the tantalum metal powder is 99.99%, and the particle size is 48-150 mu m. The heating rate is 5 ℃/min, and the deposition temperature is 800-1500 ℃.

The purities of the chlorine and the hydrogen in the step (2) are respectively more than 99.99 percent; the flow rate of the chlorine gas is 50-150 ml/min, and the flow rate of the hydrogen gas is 400-1000 ml/min. The deposition time in the step (2) is 30-300 min;

the step (3) is specifically as follows: ultrasonically cleaning the prepared sample by using a methanol solution, and then cleaning the sample by using acetone and distilled water, wherein the prepared tantalum metal coating is uniformly distributed, and has high bonding strength and no crack gap; the bending strength of the tantalum metal coating is 110-150 MPa, and the elastic modulus is 40-65 GPa.

That is to say, the scheme of the invention provides a porous platinum framework biocompatible tantalum metal coating and a preparation method thereof, and the preparation method comprises the following steps:

the method comprises the following steps: carrying out surface treatment, cleaning and drying on the porous platinum framework, placing platinum in a deposition chamber, placing tantalum metal powder in an oxidation chamber, checking the air tightness of the device, vacuumizing and heating;

step two: and after the temperature is stable, introducing chlorine and hydrogen into the oxidation chamber and the deposition chamber respectively, reacting the chlorine in the oxidation chamber with the metal tantalum powder to generate a precursor tantalum pentachloride, and under the action of pressure, allowing the tantalum pentachloride to flow into the deposition chamber to perform a reduction reaction with the hydrogen to generate pure tantalum to be deposited on the surface of the porous platinum to obtain the tantalum metal coating. After the reaction is finished, cooling, sampling, cleaning and polishing, and treating tail gas generated in the experimental process by using a sodium hydroxide solution.

In the first step, the porosity of porous platinum is 75% -85%, and the pore diameter is 100-500 mu m; . After surface treatment, the platinum is cleaned by alcohol ultrasonic for 10-30 min, the drying temperature is 80-100 ℃, and the drying time is 2-5 h.

In the first step, the purity of the tantalum metal powder is 99.99%, and the particle size is 48-150 mu m.

In the first step, the heating rate is 5 ℃/min, and the deposition temperature is set to be 800-1500 ℃.

And in the second step, the purity of the chlorine and the purity of the hydrogen are more than 99.99%, wherein the flow rate of the chlorine is 50-150 ml/min, and the flow rate of the hydrogen is 400-1000 ml/min.

In the second step, the oxidation reaction is carried out in the oxidation chamber to generate a prefabricated body TaCl5, and the prefabricated body TaCl5 and hydrogen gas are subjected to a reduction reaction in the deposition chamber to generate metal tantalum, wherein the related chemical reaction formula is as follows:

and in the second step, the deposition time is 30-300 min, the prepared sample is firstly ultrasonically cleaned by using a methanol solution and then cleaned by using acetone and distilled water, the obtained tantalum metal coating is uniformly distributed, the bonding strength is high, no crack gap exists, the bending strength of the porous platinum framework tantalum metal coating is 110-150 MPa, and the elastic modulus is 40-65 GPa.

The chemical formula of the tail gas treatment in the second step in the step is as follows:

in the embodiment of the invention, tantalum (Ta) is an inert metal, has good mechanical strength, biocompatibility, excellent corrosion resistance and osseointegration, can be fused with bone tissues, and is the most widely used orthopedic biomaterial in clinical application at present. Tantalum is very difficult to electrochemically corrode and produce metal ion stimulation, even at different implant sites, implant area texture types, and implant morphologies. The ideal bone-promoting characteristics (osteoinduction and osteoconductivity) are the key points for the good repairing effect of the implant material, the osteoconductivity refers to the characteristic of the material which is beneficial to the adhesion and proliferation of the osteoblast-related cells on the surface of the implant material, and the osteoinduction refers to the capability of the material to promote the osteogenic differentiation of the adhered cells.

The method takes porous platinum as a framework material as a substrate, adopts a chemical vapor deposition method to deposit a layer of metal tantalum on the surface of the porous platinum, and obtains a tantalum metal coating with the compactness of more than 95 percent, the purity of more than 99.5 percent and enough thickness, so that the material has the advantages of excellent mechanical property, low cost and easy processing of the platinum metal, and the biocompatibility, corrosion resistance and wear resistance of the material are improved.

The specific embodiment is as follows:

example 1

The novel medical porous tantalum metal coating material and the preparation method thereof provided by the embodiment specifically comprise the following steps:

(1) ultrasonically cleaning a porous platinum framework by using alcohol for 30min, drying the porous platinum framework in a 90 ℃ oven for 3h, and fixing the porous platinum framework in a deposition chamber, wherein the porosity of the porous platinum framework is 80%, the pore diameter is 50-200 mu m, the bending strength is 120MPa, and the elastic modulus is 46 GPa; and placing metal tantalum powder with the purity of 99.99% and the particle size of 48-150 mu m in an oxidation chamber. Checking the tightness of the instrument, vacuumizing, and setting the deposition temperature to 1050 ℃.

(2) When the temperature rises to 1050 ℃, introducing chlorine (the flow rate is 100 ml/min) and hydrogen (the flow rate is 500 ml/min) into the oxidation chamber and the deposition chamber respectively, reacting for 30min, so that the metal tantalum coating is uniformly deposited on the porous platinum framework, taking out the sample after the furnace is cooled, polishing, ultrasonically cleaning the sample by using a methanol solution, cleaning the sample by using acetone and distilled water, and drying the sample in a 90 ℃ oven for 3h to obtain the medical porous tantalum metal coating with the thickness of 41 mu m. After the reaction is finished, cooling, sampling and cleaning are carried out, and high-concentration sodium hydroxide solution is used for treating tail gas generated in the experimental process.

The compactness and the porosity of the tantalum coating are detected according to the methods described in the national standard ISO-21714 and the national standard GB/T21650.1-2008 respectively, the compactness of the obtained tantalum coating is 95.7%, and the porosity of the porous platinum-based tantalum coating material is 75.1%.

Example 2

(1) Ultrasonically cleaning a porous platinum framework by using alcohol for 30min, drying the porous platinum framework in a 90 ℃ oven for 3h, and fixing the porous platinum framework in a deposition chamber, wherein the porosity of the porous platinum framework is 88%, the pore diameter is 50-200 mu m, the bending strength is 132MPa, and the elastic modulus is 35 GPa; and placing metal tantalum powder with the purity of 99.99% and the particle size of 48-150 mu m in an oxidation chamber. Checking the tightness of the instrument, vacuumizing, and setting the deposition temperature to 1050 ℃.

(2) And when the temperature rises to 1050 ℃, introducing chlorine (with the flow rate of 50 ml/min) and hydrogen (with the flow rate of 400-900 ml/min) into the oxidation chamber and the deposition chamber respectively, reacting for 60min to ensure that the metal tantalum coating is uniformly deposited on the porous platinum framework, taking out a sample after the furnace is cooled, polishing, ultrasonically cleaning the sample by using a methanol solution, cleaning the sample by using acetone and distilled water, and drying the sample in a 90 ℃ oven for 3h to obtain a relation graph of the hydrogen flow rate and the deposition rate. After the reaction is finished, cooling, sampling and cleaning are carried out, and high-concentration sodium hydroxide solution is used for treating tail gas generated in the experimental process. The obtained tantalum coating has high density and good uniformity. As can be seen from fig. 2, the deposition rate increases with an increase in the hydrogen flow rate.

Example 3

(1) Ultrasonically cleaning a porous platinum framework by using alcohol for 30min, drying the porous platinum framework in a 90 ℃ oven for 3h, and fixing the porous platinum framework in a deposition chamber, wherein the porosity of the porous platinum framework is 82%, the pore diameter is 50-200 mu m, the bending strength is 128MPa, and the elastic modulus is 41 GPa; and placing metal tantalum powder with the purity of 99.99% and the particle size of 48-150 mu m in an oxidation chamber. Checking the tightness of the instrument, vacuumizing, and setting the deposition temperature to 1050 ℃.

(2) And when the temperature rises to 1050 ℃, introducing chlorine (with the flow rate of 50-150 ml/min) and hydrogen (with the flow rate of 600 ml/min) into the oxidation chamber and the deposition chamber respectively, reacting for 60min to ensure that the metal tantalum coating is uniformly deposited on the porous platinum framework, taking out a sample after the furnace is cooled, polishing, ultrasonically cleaning the sample by using a methanol solution, cleaning the sample by using acetone and distilled water, and drying the sample in a 90 ℃ oven for 3h to obtain a relation graph of the chlorine flow rate and the deposition rate. After the reaction is finished, cooling, sampling and cleaning are carried out, and high-concentration sodium hydroxide solution is used for treating tail gas generated in the experimental process. The obtained tantalum coating has high density and good uniformity. As can be seen from fig. 3, the deposition rate increases with increasing chlorine flow.

Example 4

The novel medical porous tantalum metal coating material and the preparation method thereof provided by the embodiment specifically comprise the following steps:

(1) ultrasonically cleaning a porous platinum framework by using alcohol for 30min, drying the porous platinum framework in a 90 ℃ oven for 3h, and fixing the porous platinum framework in a deposition chamber, wherein the porosity of the porous platinum framework is 83%, the pore diameter is 50-200 mu m, the bending strength is 127MPa, and the elastic modulus is 48 GPa; and placing metal tantalum powder with the purity of 99.99% and the particle size of 48-150 mu m in an oxidation chamber. Checking the tightness of the instrument, vacuumizing, and setting the deposition temperature to 1050 ℃.

(2) And when the temperature rises to 1050 ℃, introducing chlorine (with the flow rate of 50 ml/min) and hydrogen (with the flow rate of 400 ml/min) into the oxidation chamber and the deposition chamber respectively, reacting for 80min, so that the metal tantalum coating is uniformly deposited on the porous platinum framework, taking out the sample after the furnace is cooled, polishing, ultrasonically cleaning the sample by using a methanol solution, cleaning the sample by using acetone and distilled water, and drying the sample in a 90 ℃ oven for 3h to obtain the medical porous tantalum metal coating with the thickness of 71 mu m. After the reaction is finished, cooling, sampling and cleaning are carried out, and high-concentration sodium hydroxide solution is used for treating tail gas generated in the experimental process.

The corrosion resistance of the tantalum metal coating was tested by electrochemical tests and the corrosion parameters in simulated body fluids are shown in table 1 below. The result shows that the protective efficiency of the tantalum coating on the platinum substrate is 74.8%, so that the tantalum coating has better corrosion resistance.

Table 1:

wherein: ecoor-self-corrosion potential, mV; Icor-Corrosion Current Density, μ A ∙ cm^-2；β_aTafel slope of anodic polarization curve, mV ∙ cm^-2；β_cTafel slope of cathodic polarization curve, mV ∙ cm^-2；R_pPolarization resistance, Ω; p_i-protection efficiency,%.

Example 5

The difference from the example 1 is that the process parameters in the preparation process are different, and the specific difference is shown in the table 2.

Table 2:

as the porosity is increased, the density, the bending strength and the Young modulus of the platinum-based tantalum metal coating are reduced along with the increase of the porosity and are closer to the density and the Young modulus of human bones.

Example 6

The difference from the example 1 is that the process parameters in the preparation process are different, and the specific difference is shown in the table 3.

Table 3:

as the pore diameter increases, the density, the bending strength and the Young modulus of the platinum-based tantalum metal coating are reduced along with the increase of the porosity, and the density, the bending strength and the Young modulus are closer to those of human bones.

Example 7

The difference from the example 1 is that the process parameters in the preparation process are different, and the specific difference is shown in the table 4.

Table 4:

it can be seen from the table that the density, bending strength and young's modulus of the platinum-based tantalum metal coating layer do not change much with the increase of the grain size of the metallic tantalum, indicating that the grain size of the metallic tantalum has no influence on the density, bending strength and young's modulus.