强束流脉冲金属离子束表面改性技术及其应用

介绍了强束流脉冲金属离子束技术的基本原理和主要优点,并用由金属蒸汽真空弧离子源(MEWA)引出的强束流脉冲Ti、Mo、W、Ta、C离子对Cr12、H21、H13钢进行了离子注入材料改性试验。注入剂量为3×1017～5×1017cm-2,引出电压为25～48kV,平均束流为25～50μA/cm2。用卢瑟福背散射谱(RBS)测量了注入样品表面的成分,借助X射线行射仪(XRD))和X射线光电子能谱仪(XPS)考察了注入样品的耐磨机理。     

N^＋注入W18Cr4V钢磨损性能的研究

W18Cr4V高速钢是一种广泛应用的刀具钢,为进一步提高其使用寿命,应用CG-60型离子注入机对W18Cr4V高速钢进行了氮离子注入,得到一系列剂量的氮离子注入层,对注氮层的磨损性能进行研究。XRD分析表明,氮离子注入W18Cr4V钢在部分基体表层形成了CrN、ε-FeN和(Cr,Fe)2N1-x等相;表层显微硬度也有较大提高;磨损试验表明,氮离子的注入显著提高了高速钢基体的耐磨性。还对耐磨性提高的机理进行了讨论。     

N~+注入W18Cr4V钢磨损性能的研究

W18Cr4V高速钢是一种广泛应用的刀具钢,为进一步提高其使用寿命,应用CG－60 型离子注入机对W18Cr4V高速钢进行了氮离子注入,得到一系列剂量的氮离子注入层,对注 氮层的磨损性能进行研究。XRD分析表明,氮离子注入W18Cr4V钢在部分基体表层形成了CrN 、ε–FeN和（Cr,Fe）2N1-x等相;表层显微硬度也有较大提高;磨损试验表明,氮离子的 注入显著提高了高速钢基体的耐磨性。还对耐磨性提高的机理进行了讨论。     

离子注入对LaFe11.6Si1.4合金的缓蚀及其机理研究

目的通过表面Cr离子注入在LaFe_(11.6)Si_(1.4)合金表面生成一层具有耐蚀作用的保护层,从而提高合金的耐腐蚀性能。方法采用表面离子注入法,分别在注入电压为20、30、40 k V,注入计量为5×10~(16)、10×10~(16)、50×10~(16) ions/cm~2的条件下注入Cr离子。利用扫描电子显微镜及X-射线衍仪对合金的表面形貌、组织结构及成分进行了分析,通过电化学方法对合金表面离子注入后的耐腐蚀性进行了研究。结果当Cr离子的注入电压为40 k V,注入剂量为5×10~(16)、1×10~(17)、5×10~(17) ions/cm~2时,合金的开路电位分别是-0.585、-0.584、-0.57V(vs.SCE)。当Cr离子的注入剂量为5×10~(17) ions/cm2,注入电压为20、30、40 k V时,合金的开路电位分别是-0.63、-0.61、-0.57 V(vs.SCE)。可以看到,随着Cr离子注入计量和注入电压的增加,合金表面的腐蚀电位正向移动,耐腐蚀性提高。结论 Cr离子注入能够显著提高合金的耐腐蚀性,分析认为主要是由于合金表面生成了一层具有耐腐蚀性能的Cr_2O_3钝化层。此外,由于注入离子的轰击导致表面La(Fe,Si)13相分解生成α-Fe,也提高了合金的电极电位,增强了耐腐蚀性。     

离子注入法对冷作模具钢65Nb耐磨性的影响

一前言许多研究已经证明,离子注入工艺作为一种新型表面处理技术用于金属材料的表面处理,可以提高表面硬度、耐磨性、耐疲劳和耐腐蚀性。我们将65Cr4W3Mo2VNb 冷模具钢(以下简称65Nb)经不同的离子注入方法处理后,进行耐磨性试验,并初步探讨了离子注入能改善钢表面耐磨性的原因。注入离子的种类及注入的方法多种多样,其效果不一,开展这方面的研究探讨无疑是有益的,     

铁、钛背散射谱的分离和应用

采用由金属蒸汽真空弧(Metal Vapor Vacuum Arc 简称MEVVA)离子源引出的强束流脉冲钛离子对铁进行了离子注入表面改性研究。注入剂量为3×1017 cm-2,引出电压为48 kV,平均束流密度为47 A穋m-2。根据试验测得的离子注入层的卢瑟福背散射谱(Rutherford backscattering spectrum ),充分利用铁钛表面谱的能量间隔来计算可分离部分的铁、钛浓度深度分布,进而在一定的近似下,推出背散射谱不可直接分离部分的Ti、Fe的谱高度,最后采用迭代法把背散射谱转换成钛的浓度深度分布曲线,结果表明此转换方法是合理的且能说明钛离子注入的一些改性机理。此方法亦适用于样品中任意两种质量数相近的元素的卢瑟福背散射谱的分离以及浓度深度分布的转换。     

铜离子注入不锈钢中的剂量与抗菌性

Cu离子由MEVVA离子注入机引出注入 0Cr18Ni9不锈钢 ,采用 6 0～ 10 0keV的能量、(0 2～ 2 0 )× 10 1 7cm- 2 剂量。计算了不同能量下Cu离子的饱和注入量、Cu注入不锈钢中浓度分布和注入层表面的Cu离子浓度。分析了注入能量、注入剂量与抗菌性能的关系 ,注入后表面的Cu离子浓度与抗菌性能的关系。计算表明 ,在不同注入能量下 ,饱和注入量是不同的。当注入量接近饱和注入量时 ,试样具有最佳的抗菌性能 ,抗菌效果与注入层表面的铜含量密切相关。     

强束流钽、碳离子双注入H13钢的研究

选用强碳化物形成元素钽作为金属蒸汽真空弧离子源(metal vapor vacuum arc，简称MEWA)的阴极，对H13钢进行了钽离子注入表面改性研究。对比了Ta、C离子单注入和Ta、C离子双注入的效果，测量了离子注入表面的成分，考察了注入表面的相结构。在相同的摩擦磨损试验条件下，测量了摩擦因数和磨损量，研究表明，和未注入Ta、C单离子注入相比，Ta、C离子双注入提高了H13钢的耐磨性并大幅度降低了其表面的摩擦因数。双注入区出现的弥散TaC相是耐磨性提高、摩擦因数降低的主要原因。在试验条件下，对H13钢单注入Ta时未发现TaC的形成。     

Cr离子注入镍钛合金的表面组织结构

针对镍钛合金(NiTi)进行3种不同浓度Cr离子注入,采用扫描电子显微镜、三维白光形貌干涉仪、小角度掠射X射线衍射仪、X射线光电子能谱仪分析了离子注入前后镍钛合金表面形貌、粗糙度、组织结构及化合态。结果表明,随着注入Cr离子浓度的增大,镍钛合金表面更加平整,粗糙度变小。所有注入试样表面形成了近60nm厚的注入膜层,主要成分为三氧化二铬和铬碳化合物,并且随Cr离子注入剂量的增加,三氧化二铬和铬碳化合物的含量增加。     

碳含量及合金元素对低温盐浴渗铬层的影响

以45钢、T10钢及3Cr2W8V钢为例,使用OM、SEM等方法,研究了碳以及合金元素含量对低温盐浴渗铬层的影响.结果表明,钢的碳含量在低温盐浴渗铬过程中起到了促进作用,能增加渗铬层的深度,提高渗层的显微硬度和铬浓度,T10钢表面铬浓度为85.4％,45钢为81.3％,T10钢表面硬度为1 380 HV,45钢为1 290 HV;而合金元素则起到了阻碍作用,减少了渗铬层的深度,渗层的显微硬度和铬浓度均有所下降,3Cr2W8V钢表面硬度为1 280 HV,表面铬浓度为76.3％.     

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.