AZ31镁合金表面含纳米羟基磷灰石微弧氧化涂层的制备及性能研究

目的改善AZ31镁合金的耐腐蚀性能及生物活性。方法使用微弧氧化技术,分别在以六偏磷酸钠为主盐的电解液和以六偏磷酸钠为主盐、以纳米羟基磷灰石(HA)为添加剂的电解液中,在AZ31镁合金表面制备了微弧氧化涂层。通过扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)表征了涂层的微观形貌、元素特征和相组成。通过电化学方法和浸泡实验考察了涂层的耐蚀性。通过细胞实验评价了两种涂层的细胞相容性。结果电解液中的HA可以进入到微弧氧化涂层中,含HA的微弧氧化涂层较不含HA的更致密,且有封孔现象。电化学方法及浸泡实验结果表明,含HA的微弧氧化涂层的耐腐蚀性能更好。细胞表面粘附实验和细胞增殖实验也表明,经表面纳米HA微弧氧化处理后的AZ31镁合金生物相容性更好,且对MC3T3-E1细胞的增殖有促进作用。结论六偏磷酸钠电解液中添加纳米HA,可以在AZ31镁合金表面制备出含HA的微弧氧化涂层,且其耐腐蚀性能和生物活性均优于不含HA的微弧氧化膜。     

钛合金表面等离子喷涂热障涂层性能的研究

用等离子喷涂法在钛合金（Ti6Al4V）表面制备NiCrAlY＋（ZrO2＋Y2O3）陶瓷热障涂层。用XRD、SEM检测了涂层的金相组织、结构及形貌。对喷涂前后的试样在600℃进行了高温氧化实验,给出了氧化动力学曲线。结果表明．钛合金经等离子喷涂处理后表面形成陶瓷热障涂层且与基体结合紧密,涂层的厚度约为210um。所形成的热障涂层显著地提高了钛合金的高温抗氧化性能．降低了氧化速率,致密的氧化膜对继续氧化有阻碍作用。     

钛及钛合金表面涂层制备方法研究现状

随着钛合金应用范围不断扩大,对其性能也提出了更高的要求,钛合金的表面改性成为研究热点。综述了激光熔覆、微弧氧化和喷涂技术在钛合金表面改性中的应用,分析了各种方法的研究进展、影响涂层质量和性能的因素,并对其存在的问题和发展趋势进行了总结。激光熔覆技术在钛合金涂层的应用,主要采用自生制备陶瓷涂层,该方法增强相与基体结合界面干净,结合力较大,不容易脱落;钛合金微弧氧化较为热门的为激光复合微弧氧化技术,但其应用还存在氧化膜的膜基结合和膜层多孔问题,影响基材的耐蚀性;冷喷涂技术在钛合金表面制备喷涂涂层具备制备温度低、涂层沉积率较高、孔隙率低等特点,对冷喷涂钛合金涂层调控手段主要在喷涂参数、粉末状态、基体状态和喷嘴等方面,未来的研究趋势是冷喷涂技术与其他技术如激光熔覆、搅拌摩擦焊等的融合。     

等离子喷涂层与微弧氧化膜层的摩擦磨损性能比较

采用等离子喷涂法在钛合金基体上制备了纳米氧化锆陶瓷涂层,采用微弧氧化法在锆合金基体上制备了氧化锆陶瓷膜层。通过摩擦磨损试验研究了纳米陶瓷涂层和微弧氧化膜层的摩擦磨损性能。结果表明:在往复滑动磨损条件下和两种载荷水平下,两种涂层均呈现相同的耐磨性规律;在较大载荷下,微弧氧化膜层的磨痕深度较大,即纳米ZrO2陶瓷涂层的耐磨性优于微弧氧化陶瓷膜层。     

微弧氧化法制备钛基HA/CS涂层及其生物学特性

采用微弧氧化法在医用钛表面制备羟基磷灰石（HA）/壳聚糖（CS）涂层。通过扫描电镜（SEM）、X射线衍射（XRD）仪、红外光谱（FTIR）仪分析涂层的形貌和物相,评价HA/CS涂层对成骨细胞的毒性及其在动物体内的生物活性,分析微弧氧化法制备钛基HA/CS涂层的特征及其在骨修复中应用的可能性。结果表明：微弧氧化法可在钛表面生成HA/CS涂层,厚度40±2 mm、粗糙度3.3±0.1 mm、孔隙率(30±2)%,孔隙近圆形、直径几微米到20 mm,结合强度20.5±1.1 MPa;涂层中HA与CS之间没有形成化学键,晶体HA占10%,平均粒径37 nm,非晶体HA占90%;钛基HA/CS涂层材料对成骨细胞增殖具有促进作用,无细胞毒性,在动物体内能够诱导骨小梁形成,具有高的生物活性。微弧氧化法制备的高生物活性钛基HA/CS涂层材料,在骨修复方面具有良好的应用前景     

CuCo2Be表面热喷涂制备Cr3C2-NiCr涂层的微观结构及高温摩擦磨损行为

选用等离子喷涂技术在CuCo2Be合金表面制备了Cr3C2-NiCr/NiAl复合涂层。以Al2O3陶瓷球为对偶材料运用UMT-2摩擦磨损试验机对基体和复合涂层进行高温摩擦磨损试验,并选用共聚焦激光扫描显微镜、扫描电镜、能谱仪、XRD等分析测试手段,详细研究了CuCo2Be合金表面等离子喷涂涂层物相组成、微观形貌及涂层和基体的高温滑动摩擦磨损行为,结果表明:CuCo2Be合金表面等离子喷涂获得的复合涂层致密,涂层为层状结构,物相组成呈现非晶态。通过高温摩擦磨损研究,结果表明:500℃摩擦磨损磨损过程中,涂层及CuCo2Be合金基体的磨损机制为:疲劳磨损和粘着磨损及少量氧化磨损的共同作用,从磨损的体积形貌来看涂层磨损量明显小于未喷涂之前的基体材料,等离子喷涂工艺制备的Cr3C2-NiCr/NiAl涂层质量优异,提高了材料的高温耐磨性。     

等离子喷涂制备MoSi_2-CoNiCrAlY复合涂层的高温氧化行为

以高能球磨法制备的纳米MoSi_2-CoNiCrAlY复合粉末为喷涂材料,利用等离子喷涂技术在GH4169合金表面沉积了MoSi_2-CoNiCrAlY复合涂层,并研究了GH4169基材和复合涂层合金试样在900℃静态大气环境下的循环氧化行为。结果表明:复合涂层表现出较好的抗高温氧化性能,其氧化速率仅为1.23×10~(-7)mg~2·cm~(-4)·s~(-1),这归因于MoSi_2在氧化早期形成了SiO_2相,可以自封氧化膜。氧化后期SiO_2的脱落,Mo_5Si_3相的再次氧化生成MoO_3和MoO_2气相,以及MoSi_2的内氧化直接气化,会降低涂层的抗氧化性能。     

微束等离子喷涂羟基磷灰石涂层的体外生物活性研究

采用微束等离子喷涂(MPS)方法在Ti6A14V基体上制备羟基磷灰石(HA)涂层.利用扫描电镜(SEM)和x射线衍射(XRD)分析技术对HA涂层的表面形貌、相组成和结晶度进行表征,并通过模拟体液进行体外生物活性试验.结果表明,微束等离子喷涂制备的HA涂层具有一定粗糙度,存在气孔以及微裂纹.涂层存在热分解现象,涂层中含有HA、α-TCP、β-TCP和非晶相,不含CaO等杂质相.模拟体液试验表明,微束等离子喷涂工艺制备的HA涂层具有较好的生物活性和稳定性.涂层表面均有较大比例的CaP沉积层,且涂层整体保持完整,没有出现明显的剥离.     

钛合金表面等离子喷涂涂层材料的研究进展

介绍了钛及钛合金表面等离子喷涂涂层材料的研究进展,主要从钛合金表面等离子喷涂陶瓷材料耐磨涂层、固体润滑减摩涂层、生物活性涂层、功能涂层等几方面进行了简要的介绍。并对钛及钛合金表面等离子喷涂涂层材料的发展趋势进行了展望。     

钛合金阳极氧化法制备自组装纳米多孔结构薄膜

钛及钛合金在含有F-离子的电解液中阳极氧化,可自组装制备出有序TiO2纳米多孔或纳米管阵列薄膜,这类纳米阵列膜材料具有极大的内比表面积和优异的电子传输性能,可以用作纳米结构制备模板、高灵敏度传感器、染料敏化太阳能电池等。以TLM钛合金为阳极氧化的基片,通过改变阳极氧化电压、钛合金相结构,找到了制备纳米多孔阵列的参数,通过条件试验发现,在恒电压小于30V时,经时效处理的TLM钛合金表面可以制备得到合金元素掺杂的TiO2纳米多孔结构薄膜。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.