铌-铬复合溅射膜对锆合金基体的附着性

研究了铬膜和铌膜的复合对锆合金基体上制备的商流磁控溅射薄膜附着性的影响。使用扫描电镜(SEM)观察了膜层界面，用原子力显微镜(AFM)观察了膜层表而，用划痕法测定了薄膜的附着性。结果表明：膜／基界面结合良好，界面成分升降区狭窄；铬膜与铌膜组成的复合薄膜结合紧密；铬膜的组织为致密、边界孔洞少的纤维状晶粒，铬膜厚度为2μm时，晶粒仍为业微米级，但晶粒顶而已出现拱形；膜厚同为2μm时，外层1μm铌膜 内层1μm铬膜组成的复合膜的附着性分别是外层1μm铬膜 内层1μm铌膜组成的复合膜的2．35倍、2μm铬膜附着性的3倍，其原因在于膜层组织及力学性能变化、铌膜韧性好和复合顺序。因此，依靠铬膜厚度的增加米提高铬膜保护性的方法具有较大局限性，通过在一定厚度的铬膜外复合铌膜的方法则有较好的可行性。     

(NdPr)_(16)Fe_(76)B_8永磁体的磁畴结构和有关的磁性能

在热退磁状态,这种永磁体的基体晶粒一般为多畴结构,单个畴为180°片状畴,也有少量钉形畴和迷宫畴。测得平均畴宽为1.5μm。还观察到一些直径1μm左右的单畴晶粒和极个别直径3μm左右的单畴晶粒,计算出畴壁能γ=36mJ/m~2,交换常数A=4.5×10~(-11)J/m,畴壁厚度δ=15.7nm,临界单畴晶粒直径D_c=0.5μm。还讨论了晶界附近存在高磁场梯度与晶界两侧相邻磁畴内磁化方向的关系和微观组织对K,A和δ值的影响。     

微量元素Nb、C强化W-Lu_2O_3复合材料的组织及性能

采用机械球磨和放电等离子体烧结制备了W-Lu_2O_3和W-Nb-C-Lu_2O_3合金,通过场发射扫描电子显微镜(FE-SEM)、能谱(EDS)和透射电子显微镜(TEM)研究分析了合金复合粉末的形貌、合金烧结体表面形貌和断口形貌;测定了合金的致密度、热导率、硬度和强度。结果表明:在W-Lu_2O_3的基础上添加微量Nb和C对钨合金晶粒细化、致密化和强度提高有着明显的效果,W-Nb-C-Lu_2O_3合金的相对密度比W-Lu_2O_3提高了5.75%,达到了95.12%,晶粒尺寸由8~13μm细化到2~5μm,W-Nb-C-Lu_2O_3合金比W-Lu_2O_3合金的显微硬度和抗拉伸强度得到明显改善。     

激光抛光表面形貌的误差复映规律

目的探究激光抛光工艺中的表面形貌误差复映规律。方法首先采用纳秒光纤激光对不锈钢表面进行标刻加工制备微结构,再通过纳秒光纤激光对预制微结构的表面进行抛光加工,通过超景深显微镜测量加工后的表面形貌,分析表面形貌随加工参数的变化规律。其中纳秒光纤激光波长为1064 nm,脉宽约200 ns,最大激光功率为20 W。进行标刻时,激光功率设置为18 W,激光脉冲频率为20 kHz,扫描速度500 mm/s,通过多次重复标刻在不锈钢表面标刻出一定深度的凹槽。采用低功率(6、4、2、1、0.2 W)的纳秒激光对预制的局部微结构进行激光抛光处理,抛光过程的扫描线间距设置为10μm,扫描速度设置为200 mm/s,对包含凹槽的2 mm×2 mm的区域进行两次抛光处理。结果经标刻加工的微凹槽周围存在较大的边缘凸起;激光抛光能够有效降低凹槽边缘凸起高度,选择合适的抛光参数可将凹槽边缘凸起高度降低到2μm以下。对于高度大于10μm的边缘凸起,在激光功率大于2 W时,抛光后的边缘凸起高度随激光功率的增大而线性减小;在激光功率小于2 W时,边缘凸起高度随激光功率变化不明显。对于高度小于10μm的边缘凸起,激光抛光存在抛光饱和的现象——凸起高度随激光功率密度变化不明显。结论已有微结构的不锈钢表面经激光抛光会形成残留微结构,从而表现出一定的形状复映规律。经抛光处理后的沟槽边缘凸起的高度随着所使用的激光能量密度的增大而减小,基本服从线性变化规律。     

镁合金表面离子辅助蒸镀铝膜的耐蚀性研究

采用离子辅助热蒸镀技术在AZ91D镁合金表面沉积了厚度为100μm的单层铝膜及厚度为(25+25)和(50+50)μm的双层铝膜,并对试样表面进行喷丸+化学转化后处理,研究了铝膜的结构和耐蚀防护性能。结果表明:不同工艺的镀铝试样表面铝膜形貌相似,晶粒清晰、细小,呈柱状紧密排列,存在少许孔缝;双铝膜层中有明显的界面,界面处致密且结合紧密。经后处理,膜层表面致密性提高,并生成一层耐蚀化学转化膜。采用双层工艺铝膜能大幅度提高基体的耐腐蚀性能,100μm单层膜镀铝试样的盐雾寿命为6 h,(25+25)和(50+50)μm双层膜镀铝试样的盐雾寿命分别为72和460 h。(25+25)和(50+50)μm的镀铝试样自腐蚀电流密度分别为3.86×10-6和4.3×10-7A/cm~2,比基体降低了2~3个数量级。     

金属基带的连续非接触式电化学抛光

目的研发一种适合工业生产连续带材的非接触式电化学抛光方法。方法采用以磷酸-硫酸为主要氧化剂的环保型电化学抛光液对金属基带进行电化学抛光,研究阳极电流密度(JA)、电解液温度(t)、基带与电极间的距离(L)和走带速度(v)对基带表面粗糙度的影响,优化抛光工艺条件。结果优化的工艺条件如下:JA为1500~2500 A/m2,t为40~80℃,L为4~12 mm,v为0.5~1.8 m/min。在此工艺条件下进行电化学抛光,极为有效地降低了金属基带的表面粗糙度,光亮度达到镜面状态,原子力显微镜测试5μm×5μm范围内的表面平均粗糙度值低于1.0 nm。结论该抛光工艺实现了千米级基带的连续性抛光,达到工业化生产要求。     

HP40合金表面原位制备复合氧化层

采用原位氧化法于H2和水蒸汽形成的低氧分压环境中,在HP40合金表面制备复合氧化膜。用XRD、EDS和SEM分别表征合金表面氧化膜的物相、成分、形貌,以及在氧化层截面上各组元的线和面分布状态。结果表明,随着制备温度的升高,合金表面MnCr2O4尖晶石逐渐增加,其形貌由针状逐渐变为颗粒状,颗粒尺寸小于1μm;氧化膜的总厚度为7μm,由外向内分别为MnCr2O4尖晶石、Cr2O3和SiO2 3层。     

60Mn3Al3Ni2CrVNb调质型低密度钢奥氏体晶粒长大行为

研究了60Mn3A13Ni2CrVNb调质型低密度钢的奥氏体晶粒长大行为,并分析了析出相对奥氏体晶粒长大行为的影响机理.结果 表明,在不同加热温度下(950～1250℃),随加热温度升高,实验钢的奥氏体晶粒逐渐增大,其中,1100℃以下加热时晶粒生长缓慢,1100℃及以上加热时,晶粒粗化明显,其晶粒粗化温度约为1100℃,此外存在1250℃加热时晶粒再次显著粗化现象.显微组织分析表明碳化铌是影响实验钢奥氏体晶粒长大行为的关键因素,且碳化铌的尺寸具有重要影响,实验钢中存在3种尺寸的碳化铌析出相,分别为小于50 nm、0.2～0.35 iμm、大于1μm.1100℃及以上加热时,尺寸小于50 nm的微小碳化铌析出相固溶,对奥氏体晶界的钉扎作用减弱,是1100℃及以上加热时晶粒粗化的主要原因;1250℃加热时,0.2～0.35 μm的碳化铌析出相固溶,导致1250℃加热时晶粒显著粗化;尺寸大于lμm的碳化铌析出相即使在1250℃保温12 h也难以溶解.     

不同Al含量Cu-Al合金内氧化后的组织对比

不同Al含量(0.16%、0.3%和0.5%)的Cu-Al合金薄板使用Cu2O粉末包埋法内氧化,制备Cu-Al2O3弥散强化铜合金,并对其微观组织进行分析。结果表明,合金的内氧化层表层晶粒均比内部晶粒明显细小,表面晶粒为5~30μm,内部晶粒为30~100μm;随内氧化时间增加,内氧化层深增加,但随Al含量增加而减小;内氧化层的微观组织为大量细小γ-Al2O3相弥散分布在铜基体上;内氧化层表层γ-Al2O3粒子大小为20~50 nm,间距为50~150 nm,γ-Al2O3粒子与基体Cu的界面匹配关系是(022)Cu//(220)γ,为共格界面。     

喷丸工艺对TC4钛合金梯度纳米晶结构的作用规律

目的通过改变喷丸的压力或时间,在钛合金表面制备出剧烈塑性变形(SPD)层较厚、硬度较高的梯度纳米晶结构。方法改变喷丸压力(0.3~0.6 MPa)或喷丸时间(15~60 min),调控TC4钛合金表面梯度纳米晶结构的变形层厚度和纳米晶晶粒尺寸。利用金相显微镜观察塑性变形层截面的组织形貌,通过X射线衍射仪(XRD)和透射电子显微镜(TEM)确定喷丸表面纳米晶的晶粒尺寸,通过显微硬度计对塑性变形层的截面硬度进行研究。结果一定喷丸压力(0.6MPa)下,SPD层和总变形层厚度分别在喷丸25、30 min时达到饱和值78μm和143μm。一定喷丸时间(25 min)下,SPD层和总变形层的厚度随喷丸压力的增加而增厚,在0.4 MPa时达到饱和,分别为78μm和120μm。当SPD层厚度进入饱和阶段后,表层晶粒大小和硬度强化程度都趋于稳定;在0.6 MPa下,当表面α相细化至稳定阶段时,晶粒尺寸为30~90 nm,表面硬度提高约30%。结论喷丸SPD层及总变形层的厚度随喷丸时间的延长或喷丸压力的增大而增厚,当SPD层厚度趋于饱和后,表面晶粒尺寸和硬度强化程度都已饱和。     

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.     

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.     

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.