外科植入物用钛合金的表面改性

钛合金作为外科植入物用材料在临床上得到了越来越多的应用。综述了钛合金作为外科植入物的优良性能及国内外在钛合金表面改性方面的发展和研究现状。阐述了表面改性对改善钛合金的耐磨性，耐蚀性和生物学性能方面的重要作用。分析表明：开发新型钛合金和寻求理想的表面改性工艺来获得高质量的涂层或将生物活性相添加到钛合金基体中制备成复合材料是提高钛合金生物学性能的有效途径。     

Fatigue Life of Cast Titanium Alloys Under Simulated Denture Framework Displacements

The objective of the study was to evaluate the hypothesis that the mechanical properties and fatigue behavior of removable partial dentures (RPD) made from cast titanium alloys can be improved by alloying with low-cost, low-melting elements such as Cu, Al, and Fe using commercially pure Ti (CP-Ti) and Ti-6Al-4V as controls. RPD specimens in the form of rest-shaped, clasp, rectangular-shaped specimens and round-bar tensile specimens were cast using an experimental Ti-5Al-5Cu alloy, Ti-5Al-1Fe, and Ti-1Fe in an Al₂O₃-based investment with a centrifugal-casting machine. The mechanical properties of the alloys were determined by performing tensile tests under a controlled displacement rate. The fatigue life of the RPD specimens was tested by the three-point bending in an MTS testing machine under a cyclic displacement of 0.5 mm. Fatigue tests were performed at 10 Hz at ambient temperature until the specimens failed into two pieces. The tensile data were statistically analyzed using one-way ANOVA (α = 0.05) and the fatigue life data were analyzed using the Kaplan-Meier survival analysis (α = 0.05). The experimental Ti-5Al-5Cu alloy showed a significantly higher average fatigue life than that of either CP-Ti or Ti-5Al-1Fe alloy (p < 0.05). SEM fractography showed that the fatigue cracks initiated from surface grains, surface pores, or hard particles in surface grains instead of the internal casting pores. Among the alloys tested, the Ti-5Al-5Cu alloy exhibited favorable results in fabricating dental appliances with an excellent fatigue behavior compared with other commercial alloys.     

Influence of Specimen Layout on 17-4PH (AISI 630) Alloys Fabricated by Low-Cost Additive Manufacturing

This work examined the effects of specimen layout on physical, microstructural, and mechanical properties of 17-4PH (AISI 630) fabricated by metal-fused deposition modeling process. Tensile specimens were 3D-printed with the different layouts using 100 pct infill. The as-printed and as-sintered specimens with the flat layout had the best appearance, green, relative sintered density, and sintered tensile properties with good repeatability, while the specimens with the vertical layout were the worst. The as-sintered tensile properties of specimens with the side layout were slightly lower than those with the flat layout but significantly higher than those with the vertical layout. Moreover, the tensile properties of specimens with the flat and side layouts met the Metal Powder Industry Federation standard 35 for metal injection molding. The tensile properties and corresponding fracture surfaces can be explained in terms of the combined effect of load-bearing and stress concentration due to the pre-existence of voids at perimeters. The fracture surfaces of specimens with the vertical layout showed large defects induced during printing and voids between perimeter walls generating high stress concentration and layer delamination. The difference between tensile properties of specimens with the side and flat layouts is mainly due to the characteristic of the printing—voids in the side layout are larger and more detrimental to the mechanical properties—which was confirmed by the evidence of cracking in the fracture surface.

     

牙科用Ti-Mo合金的研制及组织性能特点

对不同Mo含量（5％、10％、15％和20％，质量分数）的二元Ti-Mo合金的显微组织和机械性能进行了研究。结果表明：当Mo含量为5％时，合金由单一的等轴α相组成；Mo含量为10％时，等轴α晶粒内部有针状析出物；当Mo含量为15％、20％时，合金由单一的等轴声β组成。Mo含量为10％，合金的综合性能最好：硬度为4510MPa，压缩强度为1636MPa，压缩率为22．5％，弹性模量为29．8GPa。Mo含量的增加有利于合金组织的细化，塑性的提高。Ti-Mo合金是一种有发展前景的口腔修复用钛合金。     

Grain Refinement of Alloys in Fusion-Based Additive Manufacturing Processes

Metallurgical and Materials Transactions A - One of the less desirable aspects of fusion-based additive manufacturing is the propensity for coarse columnar grain structures crossing build layers to...     

Use of Alloying to Effect an Equiaxed Microstructure in Additive Manufacturing and Subsequent Heat Treatment of High-Strength Titanium Alloys

This paper addresses the use of alloying additions to titanium alloys for additive manufacturing (AM) with the specific objective of producing equiaxed microstructures. The additions are among those that increase freezing ranges such that significant solutal undercooling results when combined with the rapid cooling rates associated with AM, and so be effective in inducing a columnar-to-equiaxed transition (CET). Firstly, computational thermodynamics has been used to provide a simple graphical means of predicting these additions; this method has been used to explore additions of Ni and Fe to the alloy Ti–6Al–4V (Ti64). Secondly, an experimental means of determining the minimum concentration of these alloying elements required to effect the CET has been developed involving gradient builds. Thirdly, it has been found that additions of Fe to Ti64 cause the alloy to change from an α/β Ti alloy to being a metastable β-Ti alloy, whereas additions of Ni do not produce the same result. This change in type of Ti alloy results in a marked difference in the development of microstructures of these compositionally modified alloys using heat treatments. Finally, hardness measurements have been used to provide a preliminary assessment of the mechanical response of these modified alloys.

     

圆坯连铸GCr15SiMn的成分偏析和接触疲劳寿命研究

利用金属原位分析技术和钻孔化学分析方法对高淬透性轴承钢GCr15SiMn的Φ450 mm连铸圆坯和Φ130 mm圆钢的C、Si、Mn、Cr元素横截面的分布情况进行分析。采用推力片式接触疲劳试验机进行了材料的接触疲劳寿命测试。结果表明：GCr15SiMn连铸圆坯C元素的偏析倾向较大,易产生中心正偏析,而Cr、Si、Mn元素的偏析倾向较小。通过采取稳定低过热度浇铸、三段强电磁搅拌等措施,铸坯的中心碳偏析得以改善。采用(1240±20)℃×5 h高温扩散、初轧首道次变形量≥90 mm大变形轧制的Φ130 mm圆钢的碳偏析可以得到进一步的改善,试验钢在5.3GPa高应力负载下的接触疲劳额定寿命L₁₀达到3.58×10⁶次,接近电渣重熔钢的水平。     

Microstructures and Mechanical Properties of Dental Co-Cr-Mo-W Alloys Fabricated by Selective Laser Melting at Different Subsequent Heat Treatment Temperatures

Metallurgical and Materials Transactions A - To apply the dental Co-Cr-Mo-W alloy restorations fabricated by selective laser melting to clinical use cases, it is necessary to perform a subsequent...     

钛合金超高周弯曲振动疲劳性能试验

在三点弯曲超高周疲劳试验的基础上,开发了悬臂梁式弯曲振动超高周疲劳试验系统,并介绍了疲劳试验试片的设计方法.利用超高周弯曲疲劳试验系统(20 kHz)测定了钛合金TC17的S-N曲线,结果表明,当应力比R=-1时TC17钛合金的S-N曲线是一条连续下降型曲线,在107周次以后,试样仍未发生疲劳破坏,不存在传统意义上的疲...     

航空用钛合金阻燃技术

综述了航空用钛合金的阻燃技术和阻燃机理,介绍了国内外阻燃技术的研究和应用状况。     

漫谈钛合金在舰船上的应用

钛合金优良的耐海水腐蚀性能、高的比强度、无磁性等特点,使其在船用领域大有潜力可为,我国的船用钛合金经过近40年的研究开发,基本能满足舰艇不同强度级别的需求,在舰船上应用具有明显的社会效益和经济效益,值得进一步应用推广。本文介绍了国内外舰船用钛合金的开发及应用情况。对钛合金在鱼雷发射水缸、高压气瓶、一回路危急冷却器、声扫雷具、二回路泵、阀及管系、声纳导流罩、螺旋桨等方面的应用作了重点介绍。     

漫谈钛合金在舰船上的应用

钛合金优良的耐海水腐蚀性能、高的比强度、无磁性等特点，使其在船用领域大有潜力可为，我国的船用钛合金经过近40年的研究开发，基本能满足舰艇不同强度级别的需求，在舰船上应用具有明显的社会效益和经济效益，值得进一步应用推广。本文介绍了国内外舰船用钛合金的开发及应用情况。对钛合金在鱼雷发射水缸、高压气瓶、一回路危急冷却器、声扫雷具、二回路泵、阀及管系、声纳导流罩、螺旋桨等方面的应用作了重点介绍。     

Geometric Characteristics of Scaffolds Made by Additive Manufacturing

Powder Metallurgy and Metal Ceramics - Additive manufacturing (AM) allows producing objects with functional internal structures; one of their applications is the production of medical implants...     

熔盐电解制备钛及钛合金研究进展

熔盐直接电解钛氧化物制备金属钛及其合金的机理至今仍是研究热点,目前主要存在两种解释：一是阴极氧化物得到电子,氧离子化后进入溶液,进而在阳极以气体的形态放出,而钛留在阴极;另外,熔盐中的Ca^2＋在阴极得到电子后生成金属钙,金属钙进一步还原钛氧化物得到金属钛。本文主要就近年来围绕两种机理展开的研究进行归纳总结,并在文献和实验的基础上通过能斯特方程计算推导钒钛磁铁矿直接熔盐电解制备钛合金的可行性,为实现经济、简洁的钛合金生产提供借鉴。     

多向锻造法细化钛及钛合金晶粒的研究现状

多向锻造技术是一种制备超细晶结构材料的重要方法,能够有效改善材料的各项性能,因此近年来越来越受到人们的广泛关注。综述了多向锻造技术细化钛合金晶粒的研究现状,介绍了多向锻造技术的工艺过程和晶粒细化机制,分析了当前研究中存在的主要问题,并展望了多向锻造技术在钛合金加工中的应用前景。     

西北有色院创新研制的船用钛合金

钛及钛合金以其优异的综合性能已成为一种理想的船用金属材料。主要介绍了西北有色金属研究院设计研制的具有我国自主知识产权的Ti75，Ti-B19，Ti31和Ti91 4种不同强度级别的性能优异的船用钛合金。其中Ti75和Ti31已工业化生产，并得到成功应用，Ti-B19和Ti91也具有良好的应用前景。在此基础上，初步建立了我国船用钛合金的体系。     

钛合金植入物材料的表面改性研究进展

简介了钛合金植入物材料的开发及表面改性技术。     

钛合金植入物材料的表面改性研究进展

简介了钛合金植入物材料的开发及表面改性技术。