沉积温度对多孔钛表面仿生制备羟基磷灰石的影响

为研究沉积温度对羟基磷灰石涂层生长的影响,制备了不同温度条件下成分恒定的仿生沉积液,并采用纯钛和不同孔径的多孔钛做基体,在其表面仿生沉积羟基磷灰石涂层,再将得到的涂层试样浸泡在标准模拟体液中检测其生物活性.通过X射线衍射仪(XRD)分析涂层物相结构,用金相显微镜、环境扫描电子显微镜(ESEM)表征涂层形貌,利用能谱分析仪(EDS)计算钙磷比.研究表明:基体孔径增大,有利于沉积液进入到孔隙且表面粗糙度相对增大,从而使得HA涂层变得均匀致密;沉积温度由30℃升高至37℃,会加快HA涂层致密均匀的生长,但温度升高到44℃时,HA晶粒变粗大,涂层变得疏松化;模拟体液浸泡后,Ti/HA涂层试样表面有新的HA生成,且Ca/P比接近标准的1.67,表明该Ti/HA涂层试样具有良好的生物活性.适当增大钛基体孔径,提高沉积液温度,可以得到均匀致密的HA生物活性涂层.     

淬冷速率对聚氨酯多孔膜形态结构的影响

采用热致相分离（TIPS）技术制备了聚氨酯（PU）多孔膜，研究了成膜平台温度对多孔膜表面形态，孔度大小，孔隙率和透湿率的影响，在不同成膜温度下制备的PU多孔膜的共同特征是底面（与成膜平台的接触面）光滑平整，孔洞的尺度小于相应的表面（与空气的接触面），断面结构显示，PU多孔膜的内部疏松而多孔，孔之间相互连通，且存在较为规则的梯形条纹状（Ladder-like)结构，以寻热性较差的玻璃代替不锈钢成膜平台，在相同的条件下所得多孔膜的孔度，了忆隙率和透湿率明显增大，通过控制成膜温度，成膜平台材质等制备条件，可对PU多孔膜的形态结构，孔度大小，孔隙率和透湿率等性能进行剪裁。     

Porous Titanium Coatings Through Electrophoretic Deposition of TiH2 Suspensions

In the biomedical field, modification of titanium surfaces to improve the osteoinductive and antibacterial behavior is widely investigated. This functionalization can be further ameliorated by providing a porous coating with high loading capacity for bioactive materials and drug delivery carriers at the implant surface. In this work, a new powder metallurgical processing route used to deposit such porous pure titanium coatings on Ti based substrates is presented. The coatings were prepared by electrophoretic deposition (EPD) of TiH₂ powder suspensions followed by dehydrogenation and sintering in vacuum. The use of hydrides allowed to lower the sintering temperature below that of the α–β transition of the Ti6Al4V substrate. Measurement of the tensile bond strength confirmed a strong adhesion of the porous coating. Deposition of powders with different grain sizes resulted in porous titanium coatings with varying thickness, pore morphology, and surface roughness. The possibility to extend this coating technique to complex shaped implants is highlighted.     

双步微弧氧化技术制备纯钛梯度膜层的研究

采用微弧氧化技术,以β-甘油磷酸钠和乙酸钙混合溶液为电解液,对样品进行预微弧氧化-微弧氧化复合工艺制备出含有羟基磷灰石与梯度结构的生物活性功能膜层。采用XRD、SEM、EDS等对膜层的相组成、形貌以及成分结构进行了分析,结果表明,预微弧氧化形成较小孔径结构的致密阻挡层,可以阻止基体金属离子向体内释放;进一步采用微弧氧化技术在预处理的样品表面制备出含羟基磷灰石的多孔生物活性功能膜层,使整个膜层沿垂直基体方向从致密结构的底层向多孔结构的表面层逐渐变化,膜层的成分从生物稳定性的底层向生物活性的表面层梯度变化;膜层表面成分主要由金红石型TiO2、锐钛矿型TiO2和低结晶程度的羟基磷灰石等相构成,具有梯度结构特征的膜层既保持了膜层的生物活性,又保证了膜层与基体具有高的结合强度。     

多孔玻璃粉的制备及其在玻璃基板上的粘接

利用硼硅酸盐玻璃的分相和酸侵蚀制备了孔径可控的多孔玻璃粉,采用SEM、BET等测试手段对玻璃的表面形貌和孔径分布进行了表征。并以Na2O-Al2O3-B2O3体系低熔点玻璃作为粘接剂将多孔玻璃粉烧结在普通玻璃板上,研制出一种表面孔径约50nm且均匀分布的多孔玻璃基板,并分析了烧结温度、烧结时间、颗粒大小等对粘接的影响。     

纯钛材微弧氧化电参数对陶瓷层组织结构的影响

以往就纯钛材表面微弧氧化陶瓷层表面积对提供羟基磷灰石生长条件的研究不多,为此,在Na2HPO4电解液中,采用微弧氧化法在纯钛材表面制得多孔结构的二氧化钛陶瓷层.研究了正向电压、频率对微弧氧化陶瓷层组织结构的影响.结果表明,随正向电压升高,膜厚增加,孔径增大,表面变得粗糙;随频率的增加,膜层表面变得光滑,孔径减小,膜厚减...     

表面多孔NiTi-羟基磷灰石/NiTi生物复合材料的制备与性能

利用放电等离子烧结技术制备了表面多孔NiTi-羟基磷灰石(HA)/NiTi生物复合材料,研究了烧结温度对复合材料宏观形貌、微观结构、表面孔隙特征、力学性能及体外生物活性的影响。结果表明:随着烧结温度从800℃提高到950℃,NiTi-HA/NiTi复合材料由复杂的Ti、Ni、Ti_2Ni、Ni_3Ti、HA混合相逐渐转变为单一的NiTi+HA相,内外层界面形成稳定的冶金结合且表面孔隙率与平均孔径呈缓慢减小趋势;同时抗压强度显著提高而弹性模量变化不明显。与传统NiTi、多孔NiTi及多孔NiTi-HA材料相比,950℃温度下制备的NiTi-HA/NiTi复合材料不仅具有良好的界面结合和表面孔隙特征(孔隙率45.6%、平均孔径393μm)、较高的抗压强度(1 301MPa)、较低的弹性模量(10.2GPa)以及优异的超弹性行为(超弹性恢复应变4%)的最佳匹配,而且还具有良好的体外生物活性。     

温度对铁基预合金粉腐蚀泡沫化人造金刚石微粉的影响

采用铁基预合金粉对粒径为40~50μm的人造金刚石微粉进行腐蚀泡沫化处理。研究了不同温度对金刚石微粉表面形貌、颗粒直径、比表面积和孔容积的影响,并对腐蚀图案的各向异性和泡沫化机理进行分析。结果表明:当金刚石和预合金粉质量比为1∶2时,800℃处理的金刚石表面出现明显的腐蚀坑。随着处理温度升高,金刚石泡沫化程度先增大后减小,当处理温度为1 000℃时,金刚石泡沫化效果最好;此时,金刚石的比表面积和孔容积最大,分别为7.322m2/g和0.012mL/g。在腐蚀泡沫化过程中,金刚石发生了石墨化。     

叔丁醇基凝胶注模工艺制备轻质、高强莫来石多孔陶瓷

以叔丁醇为成型溶剂, 莫来石粉为起始原料, 采用凝胶注模成型方法制备出轻质、高强莫来石多孔陶瓷. 莫来石多孔陶瓷中的孔隙形成于干燥过程中叔丁醇的快速挥发, 孔隙分布均匀且相互连通. 随烧结温度升高, 气孔率、开气孔率和比表面积分别由77.8%、76.0%和10.39m²/g下降到67.6%、65.5%和4.26m²/g, 而抗压强度则由3.29MPa显著提高到32.36MPa, 材料孔径大小受烧结温度影响较小, 孔径尺寸呈单峰分布, 且几乎所有的气孔都为开口气孔, 透气度与孔径尺寸具有一致的变化关系. 莫来石多孔陶瓷在高气孔率条件下仍然保持高强度的主要原因是材料中均匀的孔隙结构、孔径尺寸小且相对集中、以及因烧结颈的形成在空间上所表现出的一种颗粒搭接骨架结构.     

不同粉末粒度的粉末轧制多孔钛板的孔隙性能研究

为满足湿法冶金、氯碱、水处理、制药等行业对多孔钛板过滤元件的需求,以粉末轧制法制备多孔钛板为出发点,开展了满足轧制工艺要求的多孔钛板粉末轧制、烧结、性能测试等研究。通过对不同性能的钛粉进行粉末轧制、真空烧结,制得了宽度为420 mm、厚度不同、组织均匀的多孔钛板,研究了不同粉末性能对其孔隙度、最大孔径和透气度的影响。结果表明:随着粉末粒度的减小,多孔钛板的密度有所增大,孔隙度、最大孔径和透气度逐渐减小。其中,多孔钛板最大孔径和透气度的变化规律与模压多孔材料的相同。在追求孔隙度最大化时,以最小的轧制压力轧制成型多孔钛板,粉末粒度越大,其厚度越大。当粉末粒度相同时,多孔钛板厚度越大,其内部孔道路径越长,孔结构越复杂,气体在透过多孔结构通道时所消耗的能量也越多,透气度则越低。     

粉料形貌对多孔Al2O3支撑体的影响

采用球形和非球形Al2O3粉料，探讨扩出成型中粉料颗粒形貌对多孔支撑体的性能的影响，用压汞仪，扫描电子显微镜（SEM）等于手段分析了1450和1500℃下4h烧成的试样，结果表明，规则球表Al2O3粉料可以按球形密堆积的形成支撑体，使气孔率变小，不利于制备高气孔率的支撑体，并且球表Al2O3粉料颗粒自身的多孔性使制得的试样出现孔径的双峰分布，要在较高烧成温度下可以消除，但该双峰分布结构对透气度没有影响，球形颗粒间的接触面积减少，不利不烧结和支撑体强度，但是，球形粉料形成的孔的形状规则，易于使支撑体整体均匀化。     

过氧化氢处理胶粉对橡胶-沥青黏弹性的影响

为了研究废胎胶粉经过氧化氢（H₂O₂）溶液处理后其孔结构和表观形貌的变化及对所制备橡胶-沥青高温性能的影响,采用三种不同比例的H₂O₂溶液对废胎胶粉进行表面改性处理,并制备橡胶-沥青。通过胶粉气体吸附试验、扫描电镜试验、沥青旋转黏度试验和动态剪切流变试验分析了不同比例的H₂O₂溶液对胶粉的孔隙结构、微观形貌和所制备橡胶-沥青的黏度、黏弹性等宏观力学性能的影响规律。结果表明:胶粉经H₂O₂溶液处理后,平均孔径明显变小,孔体积和孔面积的变化呈现一定的规律;随H₂O₂溶液比例的增加,胶粉颗粒间接触面增加,表面絮状物和孔隙增多,加强了胶粉与沥青的界面结合度。这使得胶粉中的橡胶烃在沥青中的溶解度增加,炭黑颗粒释放增多,胶粉颗粒的强度、弹性和耐磨性等力学性能下降,导致橡胶-沥青的弹性、黏度和高温抗车辙能力降低。      

Large photocurrent-response observed at Pt/InP Schottky interface formed on anodic porous structure

A photoelectric-conversion device—based on an InP porous structure utilizing the large surface area inside pores and the low reflectance on the porous surface—is proposed. The InP walls inside the pores are covered with thin platinum films that form a Schottky barrier yielding an electric field that separates photo carriers generated under illumination. The coverage of the platinum film and its optical reflectance depended largely on the surface morphology of the porous structure. Removal of the irregular top layer formed at the initial stage of the pore formation effectively improved the coverage of the platinum film, which showed a very low optical reflectance (i.e., below 3.2%). According to current-voltage measurements under illumination, the platinum/porous InP showed larger photocurrents and higher responsivity than those of a reference planar sample.     

Effect of Ti on Morphology and Growth of Zn–Fe Intermetallic Phases

The effect of Ti in Fe substrate on the morphology and growth of Zn–Fe alloy phases in (Zn–0.2 wt.%Al)/Fe diffusion couples was investigated using optical and scanning electron microscopy. It is shown that ζ phase layer does not exist in (Zn–0.2 wt.%Al)/Fe couple, but it can be clearly observed in (Zn–0.2 wt.%Al)/(Fe–Ti) diffusion couples. Increasing of dissolved Ti in Fe substrate delays the disappearance of the ζ phase and promotes the formation of δ_k phase. The δ_p phase grows toward the ζ phase layer in the form of arborescence. The growth of total intermetallic phase layers in all diffusion couples is controlled by diffusion of Zn and Fe atoms within the layers at 380 °C. The thickness of total intermetallic layer increases with increasing of dissolved Ti in Fe substrate and reaches the maximum when Ti content is 0.4 wt.%.     

Effects of particle size of reactant on characteristics of combustion synthesis of TiC-Fe cermet

Four Ti-C-Fe powder mixtures, with a same molar ratio but a different particle size, were used for a combustion synthesis of TiC-Fe cermet to investigate effects of the particle size on the characteristics of the combustion synthesis. The results showed that the mixture with the finer Ti powder gave out a higher combustion temperature, a higher reaction velocity, a higher product density, a layer-shaped pore, and a greater size of TiC particles whether the Fe powder was finer or coarser. While in the case of the coarser Ti powder used, a small amount of residual phase remained in the product, and what is more interesting that the mixture with the finer Fe powder gave out a lower reaction velocity than that by the mixture with the coarser Fe powder. These effects were successfully explained with the previously proposed mechanisms of the combustion synthesis of TiC-Fe, and the mechanisms were proved to be valid thereby.     

Oxidation behavior of sputter-deposited Ti–Ni thin films at elevated temperatures

The isothermal oxidation kinetics of sputter-deposited equiatomic Ti–Ni thin films in pure oxygen from 823 to 923 K is studied using thermo-gravimetric analysis. The structure, composition-depth distribution and surface morphology of oxidized Ti–Ni thin films are investigated by X-ray diffraction (XRD), Auger electron spectroscopy (AES) and atomic force microscope (AFM), respectively. The results show that the oxidation kinetics of Ti–Ni thin films obeys a near-parabolic law. TiO₂, TiNi₃ and parent B2 phase are the compositions of oxidized Ti–Ni thin films. A double-layered scale including the outermost layer and the Ni-rich layer is formed outside the B2 matrix of oxidized Ti–Ni thin films. Moreover, thermal oxidation induces a surface smoothening of Ti–Ni thin films and surface roughness of oxidized Ti–Ni films decreases with the increasing oxidation temperature.     

Zinc phthalocyanine — Influence of substrate temperature, film thickness, and kind of substrate on the morphology

Zinc phthalocyanine (ZnPc), C₃₂H₁₆N₈Zn, is a planar organic molecule having numerous optical and electrical applications in organic electronics. This work investigates the influence of various deposition parameters on the morphology of vapour thermal evaporated ZnPc films. For this purpose, ZnPc is deposited at different substrate temperatures up to 90 °C and film thickness up to 50 nm onto various substrates. The morphology of this ZnPc layers is characterised by X-ray diffraction (XRD), X-ray reflectivity (XRR) and atomic force microscopy (AFM) methods. XRD measurements show that all ZnPc films are crystalline in a triclinic (α-ZnPc) or monoclinic (γ-ZnPc) phase, independent from the kind of substrate, layer thickness, or substrate temperature. The ZnPc powder, the starting product for the thermally evaporated ZnPc films, is present in the stable monoclinic β-phase. Thus, the stacking of the ZnPc molecules changes completely during deposition. The crystallite size perpendicular to the substrate determined by XRD microstructure analysis is in the range of the layer thickness while the lateral size, obtained by AFM, is increasing with substrate temperature and film thickness. AFM and XRR show an increase of the layer roughness for thicker ZnPc layers and higher substrate temperatures during film deposition. The strain in the ZnPc films decreases for higher substrate temperatures due to enhanced thermal relaxation and for thicker ZnPc films due to lower surface tension.     

梯度结构羟基磷灰石生物活性涂层的性能

采用等离子喷涂系统在Ti6Al4V钛合金基体表面制备出真有梯度结构的羟基磷灰石生物活性梯度涂层，利用纳米硬度计等手段分析了生物活性涂层的梯度结构．结果表明：金属基体与陶瓷界面区域的弹性模量和硬度呈梯度变化；生物活性功能涂层的表面具有典型的多孔结构特征，整个涂层沿垂直基体方向从底层致密结构向表面层多孔结构过渡；涂层的成分从生物稳定性的底层至生物活性的表面层呈梯度变化，涂层表面成分为具有生物活性的羟基磷灰石．涂层的这种结构特征保持了涂层的生物活性，提高涂层与基体的结合强度（48．6MPa）。     

多孔NiTi形状记忆合金的制备及性能

采用球磨后的NiTi合金粉末为原料,添加尿素作为造孔剂,利用粉末烧结法制备多孔NiTi形状记忆合金.研究烧结温度、保温时间和预成型压力等条件对制备的多孔NiTi合金组织结构和力学性能的影响.结果表明:相对于传统的Ni粉和Ti粉近等原子比混合烧结方法,此方法制备的多孔NiTi合金的相组成更加纯净.且随烧结温度升高,多孔N...