微纳米多孔α-钛的制备与组织结构及性能研究

发布时间：2018-05-16 20:24

本文选题：纳米多孔金属 + 钛与钛合金　；参考：《东南大学》2017年硕士论文

【摘要】：多孔钛继承了钛良好的耐蚀性、生物相容性、高的比强度等性能,还具有密度低、比表面积大、渗透性好、耐冲击性和隔声等特点。但是国内外对于微纳米多孔钛的研究较少,因为微纳米多孔钛的制备难度很大。然而微纳米多孔钛由于其双连续开放性微纳米孔的存在具有很多优异的特性,在生物传感器件,生物催化器件,生物医药用超滤乃至纳滤介质,气体传感器,超级电容器的电极,气体吸附存储等领域具有巨大的潜在应用价值和广泛的应用前景。因此,对微纳米多孔钛的制备工艺,组织结构与性能及其在能源与生物领域的应用进行研究意义重大。本论文采用镁粉包覆的固态脱合金法,运用放电等离子烧结技术(SPS)成功地制备了三维微纳米多孔α-Ti。结果表明,Ti30Cu70母合金随着SPS烧结温度的提高与保温时间的延长而逐渐致密。当SPS烧结温度为1053 K,保温30 min,烧结压力为80 MPa时,母合金的致密度已达99.54%。Ti30Cu70母合金薄片中Cu原子的残余量随着烧结温度的提高与保温时间的延长而逐渐减少。镁粉包覆薄片在873 K氩气保护无压烧结下,仅需保温5 min,即可得到三维微纳米多孔α-Ti。此外,研究表明,烧结压力对孔隙率并没有明显得影响,但压力的存在降低了多孔钛的平均孔径、孔径分布及圆度值。对微纳米多孔α-Ti的脱合金过程及孔粗化动力学机理进行了研究。结果表明:Mg粉包覆着Ti30Cu70薄片烧结时,扩散过程中中间相的转变为:致密的Ti30Cu70相——多孔TiCu相——多孔α-Ti相,从而逐渐形成三维微纳米多孔结构。过渡层长大的激活能在104-128 KJ/mol之间,微纳米多孔α-Ti相结构的粗化是由界面反应扩散控制,其粗化的活化能远大于Ti原子表面自扩散的活化能。通过N2吸附及压汞测试分析可知,制备的微纳米多孔α-Ti满足第IV型吸附等温曲线,纳米孔的孔径范围主要集中在10 nm以下,微米孔径平均值为1.1μm,其比表面积在9.45-37.59m2/g之间。通过改变原始母合金的成分得到了孔隙率在66.33%-84.15%的微纳米多孔α-Ti,得出用脱合金法制备微纳米多孔α-Ti时,骨架金属Ti的最佳含量为20 at%-50 at%之间。由纳米压痕结果可知,当孔隙率由66.33%增加到84.15%时,硬度由628 MPa降至11.5 MPa,杨氏模量由7.649 GPa降至0.163 GPa。平均孔壁尺寸由523.4nm增加至649.8 nm时,多孔α-Ti的硬度由364.9 MPa降至209 MPa,杨氏模量由7.08 GPa降至4.07 GPa。通过电化学沉积的方法在三维微纳米多孔α-Ti上电镀ε-Mn02,当电流密度为60 A/m2时,制备的多孔Ti/MnO2电极镀层与基体的结合情况最好。通过C-V曲线计算,得到多孔Ti/MnO2电极的质量比电容比致密Ti/MnO2电极高了 56.25%,说明多孔Ti/MnO2电极是一种很具有潜力的超级电容器电极。此外,我们结合电镀和脱合金法成功地在纯钛上制备了表面三维微纳米多孔结构,可以通过改变前驱体Ti-Cu的热处理温度从而改变微纳米孔的形貌、孔径。并且通过浸泡人体模拟液分析知,多孔结构中Ti02纳米管的存在使材料具有良好的诱导磷灰石沉积的能力。因此,其在生物医学领域具有广阔的应用前景。
[Abstract]:Porous titanium has good corrosion resistance, biocompatibility, high specific strength and so on. It has the characteristics of low density, large surface area, good permeability, impact resistance and sound insulation. However, there are few studies on micro nano porous titanium at home and abroad, because the preparation of micro nano porous titanium is very difficult. However, micro nano porous titanium is due to its dual characteristics. The existence of continuous and open micropores has many excellent properties. It has great potential value and wide application prospects in the fields of biosensors, biocatalytic devices, ultrafiltration and nanofiltration, gas sensors, supercapacitor electrodes, gas adsorption storage and so on. The preparation process, the structure and properties and its application in the energy and biological fields are of great significance. In this paper, the solid state dealloying method of magnesium powder coating was used. The results of three-dimensional micronano porous alpha -Ti. were successfully prepared by the discharge plasma sintering (SPS). The results showed that the parent alloy of Ti30Cu70 was improved with the sintering temperature of SPS. When the temperature of the SPS is 1053 K, the heat preservation is 30 min and the sintering pressure is 80 MPa, the density of the mother alloy is reached to the increase of the Cu atom in the 99.54%.Ti30Cu70 mother alloy sheet gradually with the increase of the sintering temperature and the prolongation of the holding time. The magnesium powder coated sheet is under 873 K argon protection without pressure sintering. Under the condition of only 5 min heat preservation, three-dimensional micronano porous alpha -Ti. can be obtained. The study shows that the sintering pressure has no obvious effect on the porosity, but the existence of pressure reduces the average pore size, pore size distribution and roundness value of porous titanium. The dealloying process and the kinetic mechanism of pore coarsening of microporous and porous alpha -Ti have been studied. It is shown that when the Mg powder is coated with Ti30Cu70 sheet, the transition of the mesophase in the diffusion process is as follows: dense Ti30Cu70 phase - porous TiCu phase - porous alpha -Ti phase, which gradually forms a three-dimensional microporous structure. The activation energy of the transition layer is between 104-128 KJ/mol and the microstructure of micronanometers of the porous alpha -Ti phase structure is expanded by interfacial reaction The activation energy of roughening is far greater than the activation energy of self diffusion on the surface of Ti atoms. Through N2 adsorption and mercury pressure analysis, it is found that the prepared microporous alpha -Ti satisfies the IV adsorption isotherm curve, the pore size of nanoscale is mainly below 10 nm, and the mean value of micron Kong Jingping is 1.1 u m, and its specific surface area is in 9.45-37.59m2/g. By changing the composition of the original mother alloy, the microporous and porous alpha -Ti of the porosity in 66.33%-84.15% is obtained. The optimum content of the skeleton metal Ti is 20 at%-50 at% when the micronano porous alpha -Ti is prepared by dealloy method. It is known by the nano indentation results that when the porosity is increased from 66.33% to 84.15%, the hardness is reduced from 628 MPa to 11.5 MPa. When the young's modulus is reduced from 7.649 GPa to 0.163 GPa., the average pore wall size is increased from 523.4nm to 649.8 nm, the hardness of the porous alpha -Ti is reduced from 364.9 MPa to 209 MPa, and the young's modulus is reduced from 7.08 GPa to 4.07 GPa. by electrodeposition to electroplating epsilon -Mn02 on the three-dimensional micronano porous alpha -Ti, when the current density is 60 A/m2, the porous materials prepared by the current density are 60 A/m2. The combination of the O2 electrode coating and the matrix is the best. Through the calculation of the C-V curve, the mass of the porous Ti/MnO2 electrode is 56.25% higher than that of the compact Ti/MnO2 electrode, indicating that the porous Ti/MnO2 electrode is a very potential super capacitor electrode. In addition, we have successfully prepared the surface three on the pure titanium with the electroplating and dealloy method. The microporous nanoporous structure can change the morphology and pore size of the micropores by changing the heat treatment temperature of the precursor Ti-Cu, and it is known that the presence of Ti02 nanotubes in the porous structure makes the material have a good ability to induce apatite deposition in the porous structure. Therefore, it has a wide range of Biomedical fields. Application prospects.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG146.23;TB383

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