A new microsecond pulse-heating system to investigate thermophysical properties of solid and liquid metals

A new discharge system for resistive self-heating has been constructed for the measurement of accurate thermophysical properties. A constant-current pulse is used to heat metals over a time interval of 50 to 100 s, reaching temperatures up to the boiling point. New techniques have been developed to obtain sound speeds in the pulse-heated sample, emissivities, and vapor pressure. A new pyrometer allows the extension of the measured temperature range down to the melting point of copper.     

用正电子湮没寿命技术研究塑性变形纯Ni的回复过程

本文用正电子湮没寿命方法研究了塑性变形镍(含0.01％杂质)的回复过程的特点及杂质在缺陷回复过程的作用和影响,计算了形变为10％的试样中的位错密度及形成空位团的有效空位浓度。     

Effects of SO2 and SO3 on the Na2SO4 induced corrosion of nickel

The effects of SO₂ and SO₃ in the environment on the hot corrosion behavior of Ni in the temperature range 750–950°C has been studied. Below the melting point of Na₂SO₄ (884°C), rapid corrosion takes place by formation of a Na₂SO₄-NiSO₄ melt, which can penetrate the porous oxide scale and give rise to sulfide information by coming in contact with the metal. The distribution of the sulfides depends on the SO₂ level in the ambient gas. Continued corrosion occurs by a sulfidation-oxidation mechanism. At temperatures above the melting point of Na₂SO₄, accelerated degradation occurs via dissolution of the surface scale, followed by reprecipitation of the oxide in a nonprotective form.Deceased     

OBSERVATION ON SPUTTERING SURFACE OF ALLOYS IN GLOW DISCHARGE

Glow discharge cathodic sputtering of alloys containing second phase precipitates or injectedoxide particles has been observed with energy dispersive X-ray spectrometer and scanningelectron microprobe.It was shown that the formation of cones during the sputtering in thesealloys is due to masking of the matrix by glow sputtering second phase precipitates or oxideparticles.At steady state,the density of cottes were found to be a function of the densities pre-cipitates or oxide particles in bulk alloy.In addition to the changes of local sputtering rate,theelectrostatic effect may play a role on the formation fo cones.     

液相化学还原法制备不同形貌的多晶纳米镍

采用液相化学还原法,在1,2-丙二醇体系中,分别使用吐温-80（Tween-80）、聚乙二醇-6000（PEG-6000）和十二烷基硫酸钠（SDS）与聚乙二醇-6000（PEG-6000）的混合物作为修饰剂,利用1,2-丙二醇还原相同母体醋酸镍,制备形貌分别为海绵体、纤维状、雪花状的多晶纳米镍;在水体系中,使用SDS为修饰剂,利用水合肼还原相同母体醋酸镍,制备球形多晶纳米镍。通过X射线衍射（XRD）、透射电子显微镜（TEM）、选区电子衍射（SAED）对纳米镍进行表征。利用傅立叶红外（FTIR）分析初步解释不同形貌纳米镍的形成机理。     

电梯用含氮节镍奥氏体不锈钢QN1701的组织和性能

借助Thermo-Calc热力学相图计算软件,开发了用于电梯的含氮节镍奥氏体不锈钢QN1701(12Cr17Mn7Ni2Cu2N),以代替443(019Cr21CuTi)超纯铁素体不锈钢。通过OM、SEM和电化学工作站等方法研究了QN1701和443不锈钢的组织及性能。N原子起着间隙固溶和细晶强化的作用,使QN1701不锈钢的屈服强度提高至400 MPa以上,达到443不锈钢的1.32倍。QN1701不锈钢的点蚀电位为241 mV,低于443不锈钢的289 mV,但其点蚀速率为9.10 g/(m2·h),低于443不锈钢的14.58 g/(m2·h)。在电梯用研磨拉丝表面状态下,QN1701不锈钢在质量分数为10%NaCl中性盐雾和干湿循环盐雾等加速腐蚀试验中的耐蚀性能均优于443不锈钢。分析发现,443不锈钢添加一定量的Nb、Ti稳定化元素所生成的(Nb,Ti)(C,N)析出相经研磨拉丝处理后,暴露于表面或被拖拽后留下微坑,导致其耐蚀能力急剧下降。综上所述,相较443不锈钢,QN1701不锈钢具有强度更高、伸长率更大和在研磨拉丝表面状态下耐蚀性更好等特点,这对于电梯轻量化设计和长寿命具有重要价值。     

印制板化学镀镍

介绍了采用金属Zn粒子悬浮液活化要镀镍的印制板(PCB)Cu电路表面,使其可以进行化学镀镍的工艺方法,它可以克服Pd-Sn活化的缺点.     

六方BN微颗粒表面化学镀Ni及动力学模型

以肼为还原剂在平均粒径为104μm的BN颗粒表面进行了化学镀Ni，提出了近球形颗粒表面“扩展-缩小自催化沉积”模型，较好地解释沉积量随时间的变化规律．依此模型推导了化学镀Ni沉积过程的动力学表达式．观测了不同沉积时间表面沉积Ni颗粒的SEM形貌变化规律，证实了动力学模型的正确性。     

土壤中侵蚀性离子对X70钢的侵蚀作用研究

采用极化曲线并结合E-pH图分析，研究了土壤中主要侵蚀性离子CO2-3、HCO-3、SO2-4、Cl-对管线钢X70钢的侵蚀作用。结果表明：在酸性介质中，SO2-4、Cl-2种离子对X70钢的侵蚀能力无明显差别；X70钢在含有SO2-4、Cl-离子的介质中发生活性溶解，由于含有多种钝性元素以及材料的组织结构较均匀，X70钢在此介质中的耐蚀性优于A3钢。但在含有CO2-3、HCO-3的碱性体系中，X70钢的耐蚀性随pH值变化。在含有HCO-3的弱碱体系（pH=8）中，X70钢具有一定的钝化能力，但A3钢的耐蚀性优于X70钢，在含有CO2-3的中等碱体系（pH=10）中，X70钢的耐蚀性优于A3钢，在含有CO2-3的强碱体系中,A3钢的耐蚀性优于X70钢。      

NICKEL-BASED ALLOYS IN GE AIRCRAFT TURBINES：PAST,PRESENT ＆ FUTURE

1. Introduction Freedom to travel anywhere in the world, both quickly and inexpensively, defines our modern era. Despite year-to-year variation, the long term demand for travel by airplane continues to grow. Three ma- jor systems comprise the modern airplane: the aircraft structure that encompasses the fuselage, wings, and landing gear; the avionics that enable flight through crowded skies in nearly all weather conditions; and the propulsion system that powers the aircraft. Improvements in mat…