TiN、TiCN和CrN涂层在海水环境下的摩擦学性能

为提高海洋机械系统关键摩擦零部件的摩擦学性能,分别用多弧离子镀制备的TiN、TiCN和CrN涂层进行其表面防护。通过扫描电子显微镜(SEM)、能谱仪(EDS)和X-射线衍射仪(XRD)表征涂层的结构,用纳米压痕和划痕仪测试其硬度和结合力,并用UMT-3往复式摩擦磨损试验机测试涂层的摩擦磨损性能。结果表明,在海水环境中CrN涂层具有最低的摩擦因数。TiN和TiCN涂层已被磨穿,而CrN涂层在海水中最大磨痕深度为1.5μm左右,表明CrN在海水环境中具有良好的耐磨性。CrN涂层在海水中涂层的磨损率小于在蒸馏水中,说明海水的腐蚀作用在磨损过程中不明显,而海水环境良好的润滑性能起了主导作用,导致磨损率较低,这表明CrN涂层在海水环境中主要的磨损机理为机械磨损。     

船用辅汽轮机转子汽封轴颈喷涂WC–12Co涂层的摩擦学性能

采用超音速火焰喷涂技术和电镀技术分别在45钢试件表面制备了WC-12Co涂层和硬铬镀层,测试了涂层、镀层的显微硬度和室温摩擦磨损性能,并观察分析了磨损表面形貌。结果表明:WC-12Co涂层的显微硬度是电镀硬铬层的1.5倍以上;在时间为1.5h,载荷为20N和100N的试验条件下,电镀硬铬层摩擦磨损失质量分别为WC-12Co涂层的3倍和4倍,表明WC-12Co涂层的耐磨性能明显优于电镀硬铬镀层;与硬铬镀层相比,WC-12Co涂层能缩短磨合时间,较快地进入稳定磨损阶段,该阶段因WC-12Co涂层摩擦因数低,波动范围小,更有利于摩擦状态下延长工件的使用寿命。将超音速火焰喷涂技术用于修复汽轮机转子汽封轴颈,可极大提高汽轮机转子的性能,降低维修频率,延长使用寿命。     

船用辅汽轮机转子汽封轴颈喷涂WC-12Co涂层的摩擦学性能

采用超音速火焰喷涂技术和电镀技术分别在45钢试件表面制备了WC-12Co涂层和硬铬镀层,测试了涂层、镀层的显微硬度和室温摩擦磨损性能,并观察分析了磨损表面形貌。结果表明:WC-12Co涂层的显微硬度是电镀硬铬层的1.5倍以上;在时间为1.5h,载荷为20N和100N的试验条件下,电镀硬铬层摩擦磨损失质量分别为WC-12Co涂层的3倍和4倍,表明WC-12Co涂层的耐磨性能明显优于电镀硬铬镀层;与硬铬镀层相比,WC-12Co涂层能缩短磨合时间,较快地进入稳定磨损阶段,该阶段因WC-12Co涂层摩擦因数低,波动范围小,更有利于摩擦状态下延长工件的使用寿命。将超音速火焰喷涂技术用于修复汽轮机转子汽封轴颈,可极大提高汽轮机转子的性能,降低维修频率,延长使用寿命。     

船用辅汽轮机转子汽封轴颈喷涂WC-12Co涂层的摩擦学性能研究

采用超音速火焰喷涂技术和电镀技术分别在45钢试件表面制备了WC-12Co涂层和硬铬镀层,测试了涂层/镀层显微硬度和室温摩擦磨损性能,并观察分析了磨损表面形貌。结果表明：WC-12Co涂层的显微硬度是电镀硬铬层的1.5倍以上,表明WC-12Co涂层的抗疲劳强度性能更优;在时间为1.5h,载荷为20N和100N的试验条件下,电镀硬铬层摩擦磨损失重量分别为WC-12Co涂层的3倍和4倍,表明WC-12Co涂层的耐磨性能明显优于电镀硬铬镀层;与硬铬镀层相比,WC-12Co涂层能缩短磨合时间,较快地进入稳定磨损阶段,该阶段因WC-12Co涂层摩擦因数低,波动范围小,更有利于摩擦状态下延长工件的使用寿命。将超音速火焰喷涂技术用于修复汽轮机转子汽封轴颈,可极大提高汽轮机转子的技战术性能,降低维修频率,延长使用寿命。     

化学刻蚀高硅铝合金缸套的摩擦磨损性能

采用对置往复式摩擦磨损试验机,选用铬基陶瓷复合镀活塞环(CKS环)为配副试样,研究机械珩磨+化学刻蚀法加工高硅铝合金缸套的摩擦磨损性能。通过测量摩擦因数、磨损量,用扫描电子显微镜(SEM)和激光共聚焦显微镜(LSM)观察分析摩擦副磨损前后表面形貌。结果表明:在20℃下,将机械珩磨的高硅铝合金缸套试样浸入浓度为5%的NaOH溶液中腐蚀2min,可制备出硅颗粒凸出高度约为1μm的工作表面;相对于单纯采用机械珩磨加工方法制备的高硅铝合金缸套,机械珩磨+化学刻蚀加工的高硅铝合金缸套摩擦副的摩擦因数可从0.141 41降至0.129 56,降幅约为8.38%,两者的磨损量相近。采用机械珩磨加工方法的高硅铝合金缸套磨损试验后表面有磨粒磨损带来的轻微划痕,而化学刻蚀后的缸套磨损表面没有发现划痕现象,与其对磨的活塞环的磨损状况也较轻微。     

CrN涂层对中碳轴承钢摩擦磨损性能的影响

为了改善钟形壳用中碳轴承钢的耐磨性能,采用磁控溅射技术在中碳轴承钢表面制备了CrN涂层。采用扫描电镜(SEM)、X射线衍射仪(XRD)、纳米压痕仪和摩擦磨损试验机等对比分析了有无涂层的中碳轴承钢的微观形貌、力学性能和摩擦磨损性能。结果表明:中碳轴承钢热处理后的组织为回火马氏体,硬度为589. 2 HV0. 5,表面沉积CrN涂层后,硬度达到了756. 9 HV0. 5。该涂层由CrN和Cr_2N相构成,结构致密,厚度约5. 891μm。在相同摩擦磨损条件下,涂层试样比无涂层试样的磨损量减少了约35. 6%。涂层试样的主要磨损机制为氧化黏着磨损,而无涂层试样则为氧化黏着磨损和磨粒磨损。     

超音速火焰喷涂涂层的摩擦磨损性能研究

采用划痕分析和干砂粒/橡胶轮磨损测试,主要研究了超音速火焰喷涂(High-Velocity-Air-Fuel,简称HVAF )WC涂层与Al-Ni-Cu合金的摩擦磨损性能,并且与电镀硬铬的性能进行了对比.结果表明,HVAF WC涂层和Al-Ni-Cu合金都发生微量磨损,而电镀铬层中发生明显的增重,同时导致Al-Ni-Cu合金大量磨损.在与Al-Ni-Cu合金对磨中,HVAF WC涂层的磨损机理为磨粒磨损,而电镀硬铬为粘着磨损.滚动接触疲劳磨损对涂层均有作用.     

多弧离子镀制备的大厚度Cr/Cr_2N/CrN多层涂层的结构和力学性能（英文）

采用多弧离子镀制备一种厚度为24.4μm的Cr/Cr2N/CrN多层结构涂层。采用场发射扫描电子显微镜(FESEM)、X射线光电子能谱(XPS)、能量散射谱(EDS)、X射线衍射(XRD)和透射电镜(TEM)对涂层进行表征,并用纳米压痕和划痕仪测试其硬度和结合力。用UMT-3MT往复式摩擦磨损试验机对涂层在大气和海水环境中的摩擦性能进行测试。结果表明,该涂层由3种相结构组成,分别是Cr相、Cr2N相和CrN相。相对于单层CrN涂层,多层涂层的结合力明显提高,该涂层的硬度为(21±2)GPa。多层结构涂层在人工海水中的耐蚀性能显著优于单层CrN涂层的耐蚀性能,且在大气和海水中多层结构涂层的摩擦因数均低于单层CrN涂层的摩擦因数。     

65Mn钢基体CrTiAlN微纳米复合膜的制备与抗高温磨损性能研究

采用多弧离子镀在活塞环65Mn钢基体表面制备CrTiAlN微纳米复合膜,研究了CrNx过渡缓冲层与工作负偏压对CrTiAlN微纳米复合膜性能的影响规律,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、划痕仪、纳米硬度仪和发动机台架试验装置,系统分析了薄膜相结构、表面形貌、纳米硬度和抗高温摩擦磨损性能。结果表明:当N2含量为45%时,CrNx薄膜中主要以CrN(220)相为主,此时复合膜结合强度相对较高;复合膜厚度随负偏压增大而减小,纳米硬度随负偏压增大而增大,当偏压为–200V时,CrTiAlN微纳米复合膜的晶粒较为细小。采用优化工艺沉积的CrTiAlN复合膜具有优异的抗高温粘着磨损性能,优于CrN膜和电镀Cr,最后对3种活塞环涂层的抗高温磨损机理进行了分析讨论。     

离子渗氮对多弧离子镀CrN涂层摩擦学性能的影响

目的 采用离子渗氮技术强化40Cr钢基体,以提高大载荷条件下基体表面CrN涂层的耐磨性能。方法 首先采用离子渗氮技术强化40Cr钢基体,再采用多弧离子镀在强化后的基体表面上沉积硬质CrN涂层。采用金相显微镜和扫描电镜观察分析基体和涂层的微观形貌,采用划痕试验测试涂层与基体的结合力,采用维氏硬度表征涂层及基体不同深度的硬度,通过大载荷摩擦磨损试验研究基体强化对涂层耐磨性的影响。结果 经离子渗氮后,40Cr钢基体的表面硬度由380HV提高至879HV,渗层深度达到0.30 mm;多弧离子镀CrN涂层的表面硬度为2 380HV,厚度为33 μm,涂层的结合力达到37.79 N。摩擦磨损试验结果表明,40Cr钢基体的平均摩擦因数为0.92,磨损量为43.1 mg,磨痕宽度和深度分别为1 805、224 μm;经离子渗氮后40Cr钢基体的平均摩擦因数为0.68,磨损量为28.4 mg,磨痕的宽度和深度分别为1 260、156 μm;未强化基体表面CrN涂层的平均摩擦因数为0.55,磨损量为19.4 mg,磨痕的宽度和深度分别为884、89 μm,在摩擦磨损试验中出现了涂层剥落失效现象;经强化后基体表面CrN涂层的平均摩擦因数为0.42,磨损量为2.6 mg,磨痕的宽度和深度分别为328、16 μm,未出现涂层剥落现象。结论 采用离子渗氮强化基体的方法,使基体、渗氮层、CrN涂层形成了硬度梯度,提高了多弧离子镀CrN涂层的耐磨性能,避免在大载荷条件下出现因基体变形引起的涂层脱落失效。     

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.     

Rheology Feature of Simple Metal Melt

The rheology feature of Sb, Bi melt and alloys was studied using coaxial cylinder high-temperature viscometer. The results showed that the curve of torsion-rotational speed for Sb melt presents a linear relation in all measured temperature ranges, whereas for the Bi melt, the curve presents obvious non-Newtonian feature within the low temperature range and at relative high shear stress. The rheology feature of Sb80Bi20 and Sb20Bi80 alloy melts was well correlated with that of Sb and Bi, respectively. It is considered that the rheology behavior of Sb melt plays a crucial role in Sb80Bi20 alloy and that of Bi melt plays a crucial role in Sb20Bi80 alloy.