镍基粉末高温合金中的夹杂物

介绍了用等离子旋转电极法(PREP)制造的镍基高温合金粉末中的夹杂物及其对热等静压(HIP)和[热等静压 锻造(F)]成形件组织和性能的影响。通过掺夹杂物试验结果，系统阐述了尺寸为50～500μm的不同类型夹杂物在HIP和(HIP F)态的形貌及其对粉末高温合金低周疲劳寿命的影响，并提出了去除和控制夹杂物的有效措施。     

电沉积镍基合金的研究进展

从电沉积的工艺条件、电沉积机理以及电沉积层的性能和应用等几个方面，概述了ＮｉＣｏ、ＮｉＦｅ、ＮｉＭｏ、ＮｉＰ等四种常见电沉积镍基合金的研究与开发现状。     

Development of Electrodeposited Nickel Base Alloys

从电沉积的工艺条件、 电沉积机理以及电沉积层的性能和应用等几个方面， 概述了Ni-Co、 Ni-Fe、 Ni-Mo、 Ni-P等四种常见电沉积镍基合金的研究与开发现状。     

Characterization of Nickel Diffusion and its Effect on the Microstructure of Nickel PM Steels

Admixing pure elements to powder mixes can cause the formation of heterogeneous microstructures in sintered parts. For instance, nickel is renowned for forming nickel-rich areas (NRA) in powder metallurgy (PM) nickel steels due to its poor diffusivity in iron matrix (or lattice). The present work is aimed at characterizing the principal diffusion mechanisms of nickel and their influence on microstructures and properties of PM nickel steels. A new wavelength dispersive X-ray spectrometry (WDS) approach linking line scans and X-ray maps to concentration maps is proposed. Grain boundary and volume diffusion coefficients of admixed nickel have been determined in PM nickel steels using Suzuoka’s equation. Results also show that nickel distributes itself in the iron matrix mainly by surface and grain boundary diffusion.     

Protective Coatings on Heat-Resistant Nickel Alloys (Review)

The literature on materials for protective coatings on heat-resistant nickel alloys and methods for their production is reviewed in order to generalize the results and determine the principal directions for solution of the problem under consideration. It is shown that a promising approach is the development of layered composite ceramic coatings which, thanks to a graded variation of properties, are able to provide an optimal combination of adherence, mechanical strength, and corrosion and heat resistance. The methods of physical vapor deposition, plasma spraying, and electron-beam deposition remain the principal industrial processes for coating deposition.     

Creep/Corrosion of Two Nickel Alloys in Combustion Gas

Nickel 201 and Inconel 600 have been creep and corrosion tested in combustion gas and in an inert atmosphere consisting of argon. At constant temperature, nickel exhibited an improved creep resistance in combustion gas relative to that in argon, probably due to a hardening effect caused by the in-diffusion of impurities along creep dislocations. Creep increased the corrosion attacks on nickel due to cracks in the protective surface scale and an enhanced diffusion along dislocations formed during creep. On the other hand, corrosion had a negative influence on the creep properties of Inconel 600. On the basis of the tertiary creep rate this effect could be associated with the formation of large oxide inclusions and cracks beneath the specimen surface. The creep/corrosion properties of the small grained as-received Inconel 600 were considerably improved by a pretreatment giving large grains and a dense dispersion of carbides on grain boundaries and within grains. Generally, it was demonstrated that the creep rate has a stronger influence than the total strain on the corrosion attacks. The deep corrosion attacks during fast creep are entirely creep-induced, and are attributed to crack formation in the protective oxide scale due to the specimen straining. Formerly with Central Institute for Industrial Research, Oslo, Norway     

反射光谱法测定合金中铁和镍

报道一种反射光谱法测定合金中铁和镍的新方法．该方法以滤纸转移试样,并选择性富集待测组分,反射光谱法测定．讨论了该方法的测定条件等．应用于铝合金中铁和合金钢中镍的测定,取得了满意结果．     

探究微波消解-光度法测定镍基合金中镍

对微波消解溶解高温合金试样和使用光度法测定高温合金中镍含量进行了探究。微波消解节省了传统常压下溶样时间;光度法测定镍基合金中镍,保证了结果的准确度和精密度,比传统重量法和滴定法更简便。     

Automatic Control System for Thermal State of Reverberatory Furnaces in Production of Nickel Alloys

Metallurgist - The paper describes the development of an automated digital system for monitoring and controlling the thermal regime of gas reverberatory furnaces for fire refining of nickel based...     

Anomalous Fatigue Behavior and Fatigue-Induced Grain Growth in Nanocrystalline Nickel Alloys

Fatigue failure due to repetitive loading of metallic devices is a pervasive engineering concern. The present work reveals extraordinary fatigue resistance in nanocrystalline (NC) alloys, which appears to be associated with the small (<100 nm) grain size inhibiting traditional cyclic damage processes. In this study, we examine the fatigue performance of three electrodeposited NC Ni-based metals: Ni, Ni-0.5Mn, and Ni-22Fe (PERMALLOY). When subjected to fatigue stresses at and above the tensile yield strength where conventional coarse-grained (CG) counterparts undergo low-cycle fatigue failure (<10⁴ cycles to failure), these alloys exhibit exceptional fatigue lives (in some cases, >10⁷ cycles to failure). Postmortem examinations show that failed samples contain an aggregate of coarsened grains at the crack initiation site. The experimental data and accompanying microscopy suggest that the NC matrix undergoes abnormal grain growth during cyclic loading, allowing dislocation activity to persist over length scales necessary to initiate a fatigue crack by traditional fatigue mechanisms. Thus, the present observations demonstrate anomalous fatigue behavior in two regards: (1) quantitatively anomalous when considering the extremely high stress levels needed to drive fatigue failure and (2) mechanistically anomalous in light of the grain growth process that appears to be a necessary precursor to crack initiation.     

Influence of Surfacing Technologies on Structure Formation of High-Temperature Nickel Alloys

Metallurgist - The paper presents the results of studying the formation of structure and properties of metals when using additive technologies, such as arc and laser surfacing of highly alloyed...     

Specifics of Producing Disk Blanks for Gas-Turbine Engines using Granules of Super Heat-Resistant Nickel Alloys

Metallurgist - The paper discusses the specifics of chemical composition, hot isostatic pressing (HIP), and heat treatment of granulated heat-resistant nickel alloys characterized by high long-term...     

Investigation and Development of Technological Parameters for the Vacuum Melting of Corrosion-Resistant Refractory Nickel Alloys

Metallurgist - We perform investigations aimed at the development of the main technological parameters of melting of high-chromium corrosion-resistant refractory nickel alloys in vacuum induction...     

掺杂对氢化燃烧合成镁基储氢合金性能的影响

借助XRD、SEM和自制放氢量的测试装置研究了掺杂对氢化燃烧合成镁镍储氢合金性能的影响。结果表明：三种掺杂中以掺富铈镧系金属产生的镁镍氢化物最多,掺铜产生镁镍氢化物的晶格畸变最为明显。晶胞分析显示Mg_2NiH_4的晶胞参数都有一定的变化。300℃、0．1 MPa下放氢速率的测量显示,掺杂降低了放氢温度,放氢速率一般为6～10 min。掺铜放氢量为2．68％,掺钛放氢量为2．35％,掺富铈镧系金属放氢量为3．10％,掺钛、掺富铈镧系金属活化可适当提高吸放氢量。     

极化电极电位滴定法直接测定镍基电热合金中镍

镍基合金中镍可以用丁二酮肟乙醇溶液直接滴定,以恒电流电位滴定法指示终点。所用的极化电极系统为,极电电流为2uA。滴定在PH11的氨性缓冲溶液中进行,温度保持在40～50℃左右。滴定曲线在等当点有—个尖锐的峰。大量的普通金属离子:Mn~(2+)、Fe~(2+)、Al~(3+)、Fe~(3+)、RE~(3+)、Ti~(4+)、Sn~(4+)、V(V)、Mo(Ⅵ)、W(Ⅵ)、Cr(Ⅵ)及适量的Cr~(3+)、Cu~(2+)、Co~(2+)以及阴离子均不干扰,滴定具有较高的选择性。     

从废高温镍钴合金中浸出镍和钴的试验研究

研究了采用"苏打焙烧-碱浸出铝、钼-氯气浸出钴、镍、铁等-TBP萃取除铁-中和水解除铬-P204萃取除微量杂质-N235萃取分离镍、钴"工艺处理废高温镍钴合金,重点考察了从废镍钴合金中浸出镍和钴,讨论了苏打焙烧温度和碱浓度对铝、钼浸出率的影响,碱浸渣氯气浸出电位、浸出时间、废合金粒度、添加剂的加入等因素对镍、钴浸出率的影响.试验确定了从废高温镍钴合金中浸出镍、钴的工艺优化条件.综合条件下,镍、钴平均浸出率分别为99.30%和97.67%,浸出渣中镍、钴质量分数平均为0.51%和0.44%.     

镍对Fe-Cr系软磁合金耐蚀性及磁性能的影响

在实验室熔炼了添加不同量镍的Fe-Cr系软磁合金,研究了其耐点蚀、盐雾腐蚀、浸泡腐蚀以及大气腐蚀的能力,并测量了其磁性能.结果表明,在Cr13系软磁合金中加入质量分数大于1.0%的镍可明显提高其耐蚀能力,但造成磁性能的显著下降;在Cr17系软磁合金中加入质量分数小于2.0%的镍,磁性能没有明显变化.