不锈钢基体预处理对合成类金刚石碳膜的影响

本文研究了在射频等离子体增强化学气相沉积工艺中不同的预处理方法对不锈钢基底上类金刚石碳膜生长的影响。所沉积的碳膜的结构和形貌分别用激光Raman光谱和扫描电子显微镜进行了分析，薄膜与基底的结合力通过划痕实验进行了表征。实验结果表明，通过采用合适的过渡层能显著提高类金刚石碳膜与基底的结合力，而通过化学腐蚀的方法对提高结合力的帮助不大。     

脉冲真空电弧离子镀在不锈钢上沉积类金刚石薄膜的研究

利用脉冲真空电弧离子镀技术在3Cr13不锈钢上制备了类金刚石(DLC)薄膜,通过Raman光谱分析了膜的结构特征,采用摩擦磨损试验机测试了薄膜在不同载荷下的摩擦系数,运用划痕仪研究了膜基的结合强度.结果表明:所镀制的薄膜具有典型类金刚石结构特征,膜中ID/IG为1.33;摩擦系数随着载荷的增大而减小,载荷为5 N,转速120 r/min时的摩擦系数为0.12;Ti过渡层的引入显著地提高了膜基结合力.     

Zr-Ti-Nb porous alloys for biomedical application

Recent studies linked to the production of implants focus on the development of porous materials, as they provide good biological fixation to the surrounding tissue through bone tissue ingrowth into the porous network.Research on the biological behavior of metals has shown that the composition of implant biomaterials must be carefully selected to avoid adverse reactions. Ti, Zr and Nb are non-toxic metals with a good compatibility.In the present study, Zr-Ti-Nb foams of two compositions (Zr-34.4%Ti-1.6%Nb and Zr-34.5%Ti-5.5%Nb) were fabricated starting from hydride-dehydride powdered metal using space-holding fillers. Both foams displayed an interconnected porous structure with a porosity of 70%. The average pore size was around 260 μm. The Young's modulus and the compressive plateau stress were observed to vary with the Nb content in the range of 0.3-1.4 GPa and 11-32 MPa, respectively. All alloys tested - in porous and solid forms - showed excellent biocompatibility in subcutaneous as well as in bone tissues. The alloy with more Nb content showed pronounced osteoinductive properties.     

粉末冶金法制备钛基生物医学材料的研究进展

综述了国内外用粉末冶金方法制备钛基生物材料的研究进展以及应用情况,介绍了目前粉末冶金新技术如注射成型、放电等离子烧结法制备Ti生物材料,综述了常规烧结法、燃烧合成法、纤维烧结法等制备多孔Ti生物材料的进展,论述了粉末冶金方法制备Ti合金-陶瓷复合材料的研究动态。指出将材料科学与生物科学结合起来是今后的发展方向。     

不锈软磁合金研究

探讨了不锈软磁合金的产生、发展和应用。提出了开发不锈软磁合金、提高磁性能和耐蚀性的设计理念和方法。推荐了磁感应强度B25,电阻率ρ与合金成分关系的经验方程式。     

Bulk and porous metastable beta Ti-Nb-Zr(Ta) alloys for biomedical applications

In this work, metastable beta Ti-Nb-Zr(Ta) ingots were manufactured by vacuum arc melting. The ingots thus obtained were divided into two batches: the first subjected to cold rolling (CR) from 30 to 85% of thickness reduction and subsequent annealing in the 450 to 900 °C temperature region, and the second atomized to produce 100 μm size powders. This powder was used to manufacture open-cell porous material. Regardless of the CR intensity, Ti-(18…20)Nb-(5…6)Zr (at.%) samples subjected to 600 °C (1 h) annealing showed a significant material softening due to the stress-induced martensitic transformation. The Young's modulus of these alloys varied between 45 and 55 GPa, and the yield stress, between 300 and 500 MPa. The obtained Young's moduli, which are comparable to 55-66 GPa of concurrent beta-titanium alloys and 45-50 GPa of superelastic Ti-Ni alloys, come close to those of cortical bones. Compression testing of the porous material as a function of porosity (from ~ 45 to 66%) and interconnected cell size (d₅₀ from 300 to 760 μm) showed the following properties: Young's modulus from 7.5 to 3.7 GPa, which comes close to that of trabecular bones, and ultimate compression strength, of from 225 to 70 MPa.     

The effect of microstructure on the mechanical properties of two-phase titanium alloys

This article presents the results of investigations of microstructure and mechanical properties of two-phase +β titanium alloys with different volume fraction of the β-phase. Microstructure of the specimens was examined using an optical microscope. Fracture surfaces were observed by SEM technique. The influence of the microstructure and phase composition on the mechanical properties of the alloys was studied. Static tensile tests, hardness tests and fatigue investigations were performed. It was noticed that the volume fraction and chemical composition of the β-phase has a significant effect on mechanical properties and cracking process during fatigue.     

Ti掺杂及Ti应力缓和层对类金刚石薄膜附着力的影响

研究了Ti掺杂对磁控溅射类金刚石(DLC)薄膜附着力及硬度的影响,同时在Ti掺杂类金刚石(Ti-DLC)薄膜的基础上,通过引入Ti应力缓和层制备了Ti/Ti-DLC/Ti/Ti-DLC……软硬交替多层薄膜,研究了Ti应力缓和层对进一步提高薄膜附着力特性的作用.采用纳米划痕仪和显微硬度计分析测试了薄膜的附着力和硬度.研究表明,金属Ti的掺杂有利于DLC薄膜附着力特性的改善,但对硬度有一定的影响.Ti应力缓和层的导入进一步改善了Ti-DLC薄膜的附着力特性,使其达到或超过了TiN薄膜的水平,对于附着力的改善Ti应力缓和层存在最佳的厚度值.采用特殊的变周期多层结构设计即在应力集中的膜基界面附近采用较小的调制周期,薄膜项层附近采用较大的调制周期不但可以保持足够的附着力,还可维持Ti-DLC薄膜原有的硬度.     

De-alloying and fatigue of high temperature alloys used for gas turbine blades

The laws governing high temperature oxidation and de-alloying of high temperature nickel toasted alloys with aluminium content of up to 2% and their effect on the fatigue resistance at high temperatures are investigated. An experimental and calculation procedure to predict the elements distribution curves in the surface layer of blades, implemented by means of an algorithm and a program for solution of direct and inverse diffusion problems under the arbitrary law of temperature changing, with mobile boundary and selected limiting conditions has been developed.

With the availability of sufficient data for a given alloy that characterize the diffusion and the influence of de-alloying on the longevity, the procedure allows a prediction of the remaining service life of the gas turbine blades.     

Deposition of boron doped DLC films on TiNb and characterization of their mechanical properties and blood compatibility

Abstract

Diamond-like carbon (DLC) material is used in blood contacting devices as the surface coating material because of the antithrombogenicity behavior which helps to inhibit platelet adhesion and activation. In this study, DLC films were doped with boron during pulsed plasma chemical vapor deposition (CVD) to improve the blood compatibility. The ratio of boron to carbon (B/C) was varied from 0 to 0.4 in the film by adjusting the flow rate of trimethylboron and acetylene. Tribological tests indicated that boron doping with a low B/C ratio of 0.03 is beneficial for reducing friction (μ = 0.1), lowering hardness and slightly increasing wear rate compared to undoped DLC films. The B/C ratio in the film of 0.03 and 0.4 exhibited highly hydrophilic surface owing to their high wettability and high surface energy. An in vitro platelet adhesion experiment was conducted to compare the blood compatibility of TiNb substrates before and after coating with undoped and boron doped DLC. Films with highly hydrophilic surface enhanced the blood compatibility of TiNb, and the best results were obtained for DLC with the B/C ratio of 0.03. Boron doped DLC films are promising surface coatings for blood contacting devices.     

Si过渡层对梯度影响类金刚石薄膜结合力的影响研究

实验利用双放电腔微波-ECR等离子体源设备,采用复合PVD（physical vapor deposition）和PECVD（plasma enhanced chemical vapor deposition）的方法, 先后在NiTi基体上沉积Si和Si/α-C∶H过渡层,然后制备类金刚石薄膜.Raman光谱和透射电镜表明制备的梯度薄膜是典型的类金刚石薄膜,划痕的测试结果表明, Si过渡层沉积时间影响着梯度类金刚石薄膜与NiTi合金基体之间的结合强度,当沉积时间在60min左右时可获得具有最好结合强度的梯度薄膜,而超过或低于这个时间值会导致膜基结合强度降低.     

铜基引线框架材料的研究与发展

引线框架材料是半导体元器件和集成电路封装的主要材料之一，其主要功能为电路连接、散热、机械支撑等。随着IC向高密度、小型化、大功率、低成本方向发展，集成电路I/O数目增多、引脚间距减小，对引线框架材料提出了高强度、高导电、高导热等多方面性能上的要求。由于拥有良好的导电导热性能，铜合金已成为主要的引线框架材料。本文对电子封装铜合金引线框架材料的性能要求、国内外研究与发展等进行了综述。     

304奥氏体不锈钢粉末渗硅层的结构和性能

为了提高高镍铬含量不锈钢的抗渗碳性,探索了奥氏体不锈钢表面的渗硅效果.通过扩散处理,在304奥氏体不锈钢表面获得了结构致密的渗硅层.应用SEM电镜和EDS能谱分析、显微硬度测定等方法观察了渗硅层的微观结构及其性能.结果表明,渗硅层厚度达50μm以上,为典型的柱状晶结构;渗层晶粒中由里到外的硅浓度分布区间为12.24%～20.93%;相应的微观组织的细密程度由表及里呈梯度分布,与基体结合处呈纳米晶结构;显微硬度由里到外在406～477 HV1N.缺口断裂法试验结果表明,渗硅层与钢基体结合十分良好.     

钛/不锈钢复合板界面分析及性能研究

研究了厚复层TA1/304复合板沿着爆轰波传播方向、距离起爆端不同位置处的焊接界面变化情况,通过金相分析及性能检测将复合界面的变化情况进行了整体分析,系统研究了在爆轰波传播过程中,界面的动态变化过程。结果表明：沿着爆轰波传播方向,焊接界面形态经历了无波,成波,波幅、波长增大,稳定至消失的动态变化过程。伴随着界面形态的改变,剪切强度先增加随后稳定,最终在起爆对边位置强度明显降低,剪切强度最低为230 MPa。在距起爆边300~400 mm处,界面波形态稳定,波幅比为0.22,剪切强度约为450 MPa。     

钛合金精密铸造陶瓷型壳性能的研究

获得高质量精密铸造钛合金铸件的关键是制备出高质量的陶瓷型壳 .本文对Y/Y、ZY/ZY和TJ/ZC等三种面层材料的性能进行了研究 ,主要包括TG/DTA测试、型壳强度测试以及热膨胀性能测试 .实验表明 ,TJ/ZC材料是钛合金精密铸造理想的面层材料 .     

Wear behaviour and rolling contact fatigue life of Ti/TiN/DLC multilayer films fabricated on bearing steel by PIIID

In order to improve the friction and wear behaviours and rolling contact fatigue (RCF) life of bearing steel materials, Ti/TiN/DLC (diamond-like carbon) multilayer hard films were fabricated onto AISI52100 bearing steel surface by plasma immersion ion implantation and deposition (PIIID) technique. The micro-Raman spectroscopy analysis confirms that the surface film layer possess the characteristic of diamond-like carbon, and it is composed of a mixture of amorphous and crystalline phases, with a variable ratio of sp²/sp³ carbon bonds. Atomic force microscope (AFM) reveals that the multilayer films have extremely smooth area, excellent adhesion, high uniformity and efficiency of space filling over large areas. The nanohardness (H) and elastic modulus (E) measurement indicates that the H and E of DLC multilayer films is about 32 GPa and 410 GPa, increases by 190.9% and 86.4%. The friction and wear behaviours and RCF life of DLC multilayer films specimen have also been investigated by ball-on-disc and three-ball-rod fatigue testers. Results show that the friction coefficient against AISI52100 steel ball decreases from 0.92 to 0.25, the longest wear life increases nearly by 22 times. In addition, wear tracks of the PIIID samples as well as wear tracks of the sliding steel ball were analyzed with the help of optical microscopy and scanning electron microscopy (SEM). The L₁₀, L₅₀, L_a and mean RCF life L of treated bearing samples, in 90% confidence level, increases by 10.1, 4.2, 3.5 and 3.4 times, respectively. Compared with the bearing steel substrate, the RCF life scatter extent of Ti/TiN/DLC multilayer films sample is improved obviously.     

Effects of molybdenum content on the structure and mechanical properties of as-cast Ti-10Zr-based alloys for biomedical applications

The effects of molybdenum on the structure and mechanical properties of a Ti-10Zr-based system were studied with an emphasis on improving the strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti-10Zr and a series of Ti-10Zr-xMo (x = 1, 3, 5, 7.5, 10, 12.5, 15, 17.5 and 20 wt.%) alloys prepared using a commercial arc-melting vacuum pressure casting system were investigated. X-ray diffraction (XRD) for phase analysis was conducted with a diffractometer. Three-point bending tests were performed to evaluate the mechanical properties of all specimens. The experimental results indicated that these alloys had different structures and mechanical properties when various amounts of Mo were added. The as-cast Ti-10Zr has a hexagonal α′ phase, and when 1 wt.% Mo was introduced into the Ti-10Zr alloy, the structure remained essentially unchanged. However, with 3 or 5 wt.%, the martensitic α″ structure was found. When increased to 7.5 wt.% or greater, retention of the metastable β phase began. The ω phase was observed only in the Ti-10Zr-7.5Mo alloy. Among all Ti-10Zr-xMo alloys, the α″-phase Ti-10Zr-5Mo alloy had the lowest elastic modulus. It is noteworthy that all the Ti-10Zr and Ti-10Zr-xMo alloys had good ductility. In addition, the Ti-10Zr-5Mo and Ti-10Zr-12.5Mo alloys exhibited higher bending strength/modulus ratios at 20.1 and 20.4, respectively. Furthermore, the elastically recoverable angles of these two alloys (26.4° and 24.6°, respectively) were much greater than those of c.p. Ti (2.7°). Given the importance of these properties for implant materials, the low modulus, excellent elastic recovery capability and high strength/modulus ratio of α″ phase Ti-10Zr-5Mo and β phase Ti-10Zr-12.5Mo alloys appear to make them promising candidates.     

羟基磷灰石/钛合金骨替代材料体外培养成骨细胞的实验研究

实验选用小鼠头盖骨成骨细胞,采用体外细胞培养技术对具有羟基磷灰石涂层的钛合金(HA/Ti)与未经过表面改性的钛合金两种骨替代材料进行细胞相容性评价,动态观察两种骨替代材料对成骨细胞生长、附着的影响。结果表明两种骨替代材料对成骨细胞生长无抑制作用,未发生细胞毒性反应,细胞在两种材料表面均能正常粘附、生长、增殖,均具有良好的细胞附着形态和细胞增殖率,而HA/钛合金材料具有更好的成骨性,是一种骨细胞相容性良好的骨替代材料。     

The Effect of Hydrogen on Fatigue Properties of Metals used for Fuel Cell System

The effect of hydrogen on the fatigue properties of alloys which are used in fuel cell (FC) systems has been investigated. In a typical FC system, various alloys are used in hydrogen environments and are subjected to cyclic loading due to pressurization, mechanical vibrations, etc. The materials investigated were three austenitic stainless steels (SUS304, SUS316 and SUS316L), one ferritic stainless steel (SUS405), one martensitic stainless steel (0.7C-13Cr), a Cr-Mo martensitic steel (SCM435) and two annealed medium-carbon steels (0.47 and 0.45%C). In order to simulate the pick-up of hydrogen in service, the specimens were charged with hydrogen. The fatigue crack growth behaviour of charged specimens of SUS304, SUS316, SUS316L and SUS405 was compared with that of specimens which had not been hydrogen-charged. The comparison showed that there was a degradation in fatigue crack growth resistance due to hydrogen in the case of SUS304 and SUS316 austenitic stainless steels. However, SUS316L and SUS405 showed little degradation due to hydrogen. A marked increase in the amount of martensitic transformation occurred in the hydrogen-charged SUS304 specimens compared to specimens without hydrogen charge. In case of SUS316L, little martensitic transformation occurred in either specimens with and without hydrogen charge. The results of S-N testing showed that in the case of the 0.7C–13Cr stainless steel and the Cr–Mo steel a marked decrease in fatigue resistance due to hydrogen occurred. In the case of the medium carbon steels hydrogen did not cause a reduction in fatigue behaviour. Examination of the slip band characteristics of a number of the alloys showed that slip was more localized in the case of hydrogen-charged specimens. Thus, it is presumed that a synergetic effect of hydrogen and martensitic structure enhances degradation of fatigue crack resistance.     

Impact of ruthenium on microstructure and corrosion behavior of β-type Ti–Nb–Ru alloys for biomedical applications

Corrosion behavior and microstructure of as-cast metastable β-type Ti–20Nb–xRu (x = 0, 0.5, 1.0, 1.5 at.%) have been investigated using linear polarization and transmission electron microscopy (TEM), respectively.Ruthenium (Ru) was confirmed to be a β-phase stabilizer as a titanium (Ti) alloying element which served to suppress both ω precipitation and elemental segregation; the prominence and degree of elemental segregation between the Nb-rich primary dendrites and the interdendritic areas rapidly decreased with minor Ru addition, yielding a more homogenous microstructure overall. Additionally, even minimal Ru additions significantly altered the corrosion potential (E_corr), yielding a 0.3 V shift in the noble direction over the Ru-free controls, along with a comparable shift in the potential at which the initial passive region begins to fail (E_inc). The present result suggests Ru addition can confer a greater resistance to corrosion in β-Ti alloys.