Ni-Co/纳米金刚石复合镀层抗磨损性能的研究

采用电沉积法在45#钢样品表面制备了含有纳米金刚石的镍-钴合金基复合镀层。对复合镀层的显微硬度和微观结构进行了测试。并考察了阴极电流密度、镀液pH值等主要工艺参数对纳米复合镀层耐磨性的影响。结果表明：纳米金刚石的弥散强化作用，可以有效地提高镀层的硬度。在干摩擦条件下，纳米复合镀层的耐磨性是镍-钴合金镀层的3倍；     

化学复合镀镍-磷-金刚石镀速的研究

研究了在化学校镍磷合金镀液中加入金刚石微粒形成镍-磷-金刚石复合镀层的共沉积过程，分析镀液中各成分及操作条件对合金镀层沉积速度的影响，并对镀层的组织和性能进行了测试，结果表明：Ni—P—金刚石复合镀层镀速可达28μm/h，硬度可达HV0.11850左右。     

电沉积纳米镍-钴合金在金刚石工具制备中的应用研究

采用纳米镍-钴镀层制备电镀金刚石工具以期提高工具的性能。通过考察脉冲参数、细化添加剂、硫酸钴对镀层显微硬度的影响,得出结论:细化添加剂、硫酸钴都能细化晶粒,两者有竞争关系;改变峰值电流密度和开通时间可以细化晶粒,脉冲周期过短会造成晶粒粗化。镀层中钴的质量分数为9%,表面较光整,平均晶粒尺寸在14nm左右,显微硬度达到609HV。确定了制造金刚石工具最佳的电镀工艺参数,由其制得的工具平均寿命比纳米镍镀层材料工具高16%。     

电沉积纳米镍-钻合金在金刚石工具制备中的应用研究

采用纳米镍一钴镀层制备电镀金刚石工具以期提高工具的性能。通过考察脉冲参数、细化添加剂、硫酸钴对镀层显微硬度的影响,得出结论：细化添加剂、硫酸钴都能细化晶粒,两者有竞争关系;改变峰值电流密度和开通时间可以细化晶粒,脉冲周期过短会造成晶粒粗化。镀层中钴的质量分数为9％,表面较光整,平均晶粒尺寸在14nm左右,显微硬度达到609HV。确定了制造金刚石工具最佳的电镀工艺参数,由其制得的工具平均寿命比纳米镍镀层材料工具高16％。     

Ni-P金刚石化学复合镀层制备及摩擦磨损性能分析

目的研究不同粒径微米金刚石对Ni-P金刚石化学复合镀层摩擦磨损性能的影响。方法选择出一组优良的Ni-P化学镀工艺参数,在镀液中分别加入不同粒径的金刚石微粒,制备含不同粒径微米级金刚石颗粒的化学复合镀层。用SEM和XRD,观察并分析了不同粒径金刚石对热处理前后Ni-P金刚石化学复合镀层微观形貌和组织结构的影响;通过硬度和摩擦磨损实验,研究了不同粒径金刚石颗粒对复合镀层硬度及摩擦磨损性能的影响。结果制备的复合镀层厚度为30μm左右,金刚石质量分数达到21%~25%,且金刚石均匀分散在Ni-P镀层中。热处理前镀层为非晶结构,经过400℃×2 h的热处理后,镀层晶化为硬度更高的Ni3P。金刚石能提高镀层硬度,其中粒径为9μm的复合镀层硬度最高,达到1261HV。Ni-P金刚石复合镀层的摩擦系数为0.4~0.52,随着金刚石粒径的增大,摩擦系数不断减小。金刚石使镀层的磨损机制发生了变化,随着金刚石粒径的增大,硬质合金球的磨损加剧。结论随着金刚石粒径的增大,镀层硬度增加,摩擦系数减小,耐磨性增大。     

含纳米金刚石的复合镍刷镀层的摩擦学特性

利用电刷镀技术将ＴＮＴ／ＲＤＸ（５０／５０）混合炸药爆炸后生成的爆炸黑粉（由超微细纳米金刚石，石墨及无定形碳等组成）与快速镍刷镀液混合制备了一种含纳米金刚石的镍盐复合镀层，并对其摩擦磨损性能及机械性能等进行了研究。结果表明，含纳米金刚石的镍基复合镀层其显微镜硬度比快速镍镀层的有明显提高，其耐磨性比快速镍刷镀层提高两倍，其摩擦系数降低了４０％，并且在试验范围内其减摩擦对磨性能随着的纳米金刚石含量增加     

晶粒尺寸对纳米晶钴摩擦磨损性能的影响

采用脉冲电沉积法制备了不同晶粒尺寸的纳米晶钴镀层,考察了晶粒尺寸对纳米晶钴硬度和摩擦磨损性能的影响.结果表明:随着晶粒尺寸的减小,钴镀层的硬度显著升高,符合经典的Hall-Petch效应;而纳米晶钴的抗磨性并没有随着晶粒的减小而显著增加,同时其摩擦系数随着晶粒的减小而略有增加.     

纳米金刚石/镍电刷镀复合镀层机械性能研究

本文对普通快速镍镀层和纳米金刚石/镍复合镀层的显微硬度和耐磨性进行了研究,分析了纳米颗粒含量、镀层厚度、加热温度等参数对纳米复合镀层显微硬度及摩擦性能的影响。结果表明:由于纳米金刚石的弥散强化作用,使得复合镀层的硬度和耐磨性大幅提高,摩擦系数明显降低。镀液中纳米金刚石含量约30g/L时,镀层硬度最高为650HV,经过300℃处理,硬度仍能保持在480HV之上。     

钢基镍磷合金PTFE复合涂层耐磨耐蚀性能研究

目的 研究钢基镍磷合金PTFE复合涂层的耐磨性能及耐蚀作用机理.方法 在钢基材料表面制备镍磷合金镀层,采用电化学蚀刻技术在镀层表面形成纳米多孔结构,并经PTFE复合改性处理,制备了耐磨耐蚀的复合涂层.采用扫描电子显微镜对钢基镍磷合金PTFE复合涂层的微观形貌进行了表征,分别采用球盘式磨损、电化学试验评价了复合涂层的耐磨损、耐蚀性能,并通过白光干涉仪对复合涂层的磨痕形貌进行了分析.结果 复合改性涂层未改变镍磷合金镀层硬度性质.在球盘摩擦磨损试验中,随摩擦时间的延长,镍磷合金镀层的摩擦系数从0.12持续升至0.40;复合改性涂层的摩擦系数从0.08升至0.20左右,并保持稳定,与镀层相比,其摩擦系数有效降低,耐磨性能提高.由极化曲线可得,复合改性涂层的腐蚀电流最低,为1.53μA,且出现一个钝化区间.通过电化学阻抗谱图与等效电路拟合结果可知,镍磷合金镀层0.01 Hz的整体阻抗模值为1.44×104?·cm2,经复合改性后,镀层在0.01 Hz时的整体阻抗增加为2.75×104?·cm2.结论 电化学蚀刻+PTFE复合改性处理能有效提高镍磷合金镀层的耐蚀耐磨性能.     

纳米金刚石粒径对Ni-P化学复合镀层耐磨性和耐腐蚀性的影响

为提高化学镀镀层的耐磨性和耐腐蚀性,采用化学镀制备含不同粒径的纳米金刚石Ni-P-D复合镀层,通过SEM、XRD、摩擦磨损试验、磨粒磨损试验和电化学试验,探究纳米金刚石粒径对Ni-P镀层微观形貌、力学性能、摩擦磨损性能、磨粒磨损性能和耐腐蚀性能的影响。经化学复合镀可以得到与基体结合良好,厚度约为30 μm,含纳米金刚石的Ni-P-D复合镀层;含50 nm 金刚石的Ni-P-D复合镀层的硬度最高,抗摩擦磨损和磨粒磨损性能最好;随着纳米金刚石粒径减小,Ni-P-D复合镀层的摩擦系数和抗腐蚀能力提高,含5 nm金刚石的Ni-P-D复合镀层的摩擦系数最小,抗腐蚀能力最强。      

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

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 Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

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.     

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.