EFFECT OF TRACE ELEMENTS WITH ZERO SELF－INTERACTIONCOEFFICIENT ON CRYSTALLIZATION TEMPERATUREOF IRON CARBON ALLOYS

ＥＦＦＥＣＴＯＦＴＲＡＣＥＥＬＥＭＥＮＴＳＷＩＴＨＺＥＲＯＳＥＬＦ－ＩＮＴＥＲＡＣＴＩＯＮＣＯＥＦＦＩＣＩＥＮＴＯＮＣＲＹＳＴＡＬＬＩＺＡＴＩＯＮＴＥＭＰＥＲＡＴＵＲＥＯＦＩＲＯＮＣＡＲＢＯＮＡＬＬＯＹＳＺＨＡＩＱｉｊｉｅａｎｄＨＵＨａｎｑｉ（Ｄｅｐ...     

POST－DEFORMATION TENSILE PROPERTIES IN A RAPIDLY SOLIDIFIED POWDER METALLURGY MR64 ALLOY

ＰＯＳＴＤＥＦＯＲＭＡＴＩＯＮＴＥＮＳＩＬＥＰＲＯＰＥＲＴＩＥＳＩＮＡＲＡＰＩＤＬＹＳＯＬＩＤＩＦＩＥＤＰＯＷＤＥＲＭＥＴＡＬＬＵＲＧＹＭＲ６４ＡＬＬＯＹＯＣｕｉ，Ｚｈｏｎｇｑｉ；Ｌｉａｎｇ，Ｔｏｎｇｘｉａｎｇ；Ｃｈｅｎ，Ｐｕｑｕａｎ；Ｚｈａｎｇ，Ｊ...     

A COMPONENT-SPECIFIC ALLOY DESIGN OF TiAl INTERMETALLICS

ＡＣＯＭＰＯＮＥＮＴ－ＳＰＥＣＩＦＩＣＡＬＬＯＹＤＥＳＩＧＮＯＦＴｉＡｌＩＮＴＥＲＭＥＴＡＬＬＩＣＳＪ．Ｚｈａｎｇ;Ｄ．Ｘ．Ｚｏｕ;Ｚ．Ｚ．ＺｈａｎｇａｎｄＺ．ＹＺｈｏｎｇ（ＣｅｎｔｒａｌＩｒｏｎ＆ＳｔｅｅｌＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅ,Ｂｅｉ...     

EXPERIMENTAL RESEARCH ON DIRECTIONAL SOLIDIFICATION OF Al－4．5wt％Cu ALLOY BY ACRT METHOD

ＥＸＰＥＲＩＭＥＮＴＡＬＲＥＳＥＡＲＣＨＯＮＤＩＲＥＣＴＩＯＮＡＬＳＯＬＩＤＩＦＩＣＡＴＩＯＮＯＦＡｌ－４．５ｗｔ％ＣｕＡＬＬＯＹＢＹＡＣＲＴＭＥＴＨＯＤＪＩＥＷａｎｑｉ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｏｌｉｄｉｆｉｃａｔｉｏｎＰｒｏｃｅ...     

NICKEL-BASE ALLOY SHEET ALLOYS USED IN AEROSPACE APPLICATIONS

ＮＩＣＫＥＬ－ＢＡＳＥＡＬＬＯＹＳＨＥＥＴＡＬＬＯＹＳＵＳＥＤＩＮＡＥＲＯＳＰＡＣＥＡＰＰＬＩＣＡＴＩＯＮＳＪ．Ｈ．Ｔｕｎｄｅｒｍａｎｎ（ＩｎｃｏＡｌｌｏｙｓＩｎｔｅｒｎａｔｉｏｎａｌ,Ｉｎｃ．,Ｈｕｎｔｉｎｇｔｏｎ,ＷＶ２５７０５,ＵＳＡＭａｎｕｓ...     

A THERMODYNAMIC INVESTIGATION ON SPINODAL DECOMPOSITION BOUNDARY IN Cu－Ti ALLOYS

ＡＴＨＥＲＭＯＤＹＮＡＭＩＣＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＳＰＩＮＯＤＡＬＤＥＣＯＭＰＯＳＩＴＩＯＮＢＯＵＮＤＡＲＹＩＮＣｕ－ＴｉＡＬＬＯＹＳ￥ＷｅｉＹｉｎｇｈｕｉ；ＷａｎｇＸｉａｏｔｉａｎ（ＩｎｓｔｉｔｕｔｅｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎ...     

INVESTIGATION ON THIN－WALL EFFECT OF A DIRECTIONALLY SOLIDIFIED SUPERALLOY BY USING TUBULAR SPECIMENS

ＩＮＶＥＳＴＩＧＡＴＩＯＮＯＮＴＨＩＮ－ＷＡＬＬＥＦＦＥＣＴＯＦＡＤＩＲＥＣＴＩＯＮＡＬＬＹＳＯＬＩＤＩＦＩＥＤＳＵＰＥＲＡＬＬＯＹＢＹＵＳＩＮＧＴＵＢＵＬＡＲＳＰＥＣＩＭＥＮＳＲ．Ｚ．ＣｈｅｎａｎｄＨ．Ｗ．Ｚｈａｎｇ（ＢｅｉｊｉｎｇＩｎｓｔｉｔｕｔ...     

SUBSTITUTION BEHAVIOR OF ALLOYING ELEMENTS IN INTERMETALLIC COMPOUND，TiAl

ＳＵＢＳＴＩＴＵＴＩＯＮＢＥＨＡＶＩＯＲＯＦＡＬＬＯＹＩＮＧＥＬＥＭＥＮＴＳＩＮＩＮＴＥＲＭＥＴＡＬＬＩＣＣＯＭＰＯＵＮＤ，ＴｉＡｌＸＵＤｏｎｇｓｈｅｎｇ；ＳＯＮＧＹａｎ；ＬＩＤｏｎｇ；ＨＵＺｈｕａｎｇｑｉ（ＩｎｓｔｉｔｕｔｅｏｆＭｅｔａｌＲｅｓｅａ...     

DEVELOPMENT OF NEW EROSION-CORROSION RESISTANT CUPRONICKEL ALLOYS

ＤＥＶＥＬＯＰＭＥＮＴＯＦＮＥＷＥＲＯＳＩＯＮＣＯＲＲＯＳＩＯＮＲＥＳＩＳＴＡＮＴＣＵＰＲＯＮＩＣＫＥＬＡＬＬＯＹＳ①ＷａｎｇＪｉｈｕｉ，ＪｉａｎｇＸｉａｏｘｉａａｎｄＬｉＳｈｉｚｈｕｏＩｎｓｔｉｔｕｔｅｏｆＭｅｔａｌＲｅｓｅａｒｃｈ，Ｃｈｉｎｅｓ...     

INFLUENCE OF CERIUM CONTENT ON DAMPING CAPACITIES OF AS-SPRAY DEPOSITED HIGH SILICON ALLOY ZA27

ＩＮＦＬＵＥＮＣＥＯＦＣＥＲＩＵＭＣＯＮＴＥＮＴＯＮＤＡＭＰＩＮＧＣＡＰＡＣＩＴＩＥＳＯＦＡＳＳＰＲＡＹＤＥＰＯＳＩＴＥＤＨＩＧＨＳＩＬＩＣＯＮＡＬＬＯＹＺＡ２７①ＬｉｕＹｏｎｇｃｈａｎｇ，ＬｕＹｉｌｉ，ＹａｎｇＧｅｎｃａｎｇ，ＺｈｕＺｈｅｎｇａｎ...     

PROPERTIES, WELDABILTTY AND APPLICATIONS OF ADVANCED WROUGHT SUPERALLOYS FOR GAS TURBINE ENGINES

Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability.Critical properties of advanced wrought superalloys for gas turbine applications include high temperature strength, thermal stability, oxidation resistance and fatigue resistance.In this paper, the properties of twelve wrought solid-solution-strengthened and six age-hardenable superalloys are compared.Weldability is an important attribute and can be a major limiting factor in the use of certain alloys.Weldability test methods are discussed and the resistance of alloys to solidification cracking and strain-age cracking is compared.The use of weldability testing in the development of modern wrought superalloys is discussed with several examples cited.Finally, alloy selection for gas turbine components is outlined, taking into account both alloy properties and fabricability.     

PROPERTIES, WELDABILITY AND APPLICATIONS OF ADVANCED WROUGHT SUPERALLOYS FOR GAS TURBINE ENGINES

Alloy selection and alloy design both require consideration of an array of material attributes, including in-service properties, weldability and fabricability. Critical properties of advanced wrought superaUoys for gas turbine applications include high temperature strength, thermal stability, oxidation resistance and fatigue resistance. In this paper, the properties of twelve wrought solid-solution-strengthened and six age-hardenable superalloys are compared. Weldability is an important attribute and can be a major limiting factor in the use of certain alloys. Weldability test methods are discussed and the resistance of alloys to solidification cracking and strain-age cracking is compared. The use of weldability testing in the development of modern wrought superalloys is discussed with several examples cited. Finally, alloy selection for gas turbine components is outlined, taking into account both alloy properties and fabricability.     

A Nanocrystalline Ni2(Cr,Mo) Intermetallic with Potentially Useful Combination of Properties for Gas Turbine Seal Ring Applications

Seal rings are installed for each turbine stage in gas turbine engines to minimize the loss in gas pressure and maintain engine efficiency. During service, seal rings become susceptible to failure by thermal fatigue as demonstrated by a case study. Therefore, a lower coefficient of thermal expansion is among the most important requirements for these applications. We show that long-range ordering in a Ni-Cr-Mo alloy can be used to synthesize a nanocrystalline intermetallic compound combining high strength, high ductility, low coefficient of thermal expansion, and an adequate oxidation resistance up to at least 700?°C. Twinning rather than slip is found to be the predominant deformation mechanism of the intermetallic compound, which is correlated with the crystallography of the disorder-to-order transformation and microstructure evolution. This could explain the enhanced plasticity of the intermetallic compound. The combination of enhanced plasticity, low-thermal expansion, and nano-sized crystals is expected to improve the resistance to thermal fatigue failure.     

Improvement and Micro-mechanism of a Low Expansion Superalloy

ＩｎｔｒｏｄｕｃｔｉｏｎＣｈｒｏｍｉｕｍｆｒｅｌｏｗｅｘｐａｎｓｉｏｎｓｕｐｅｒａｌｌｏｙｓｂａｓｅｄｏｎｔｈｅｓｙｓｔｅｍＦｅＮｉＣｏＮｂＴｉａｒｅａｔｒａｃｔｉｖｅｆｏｒａｅｒｏｓｐａｃｅａｎｄｌａｎｄｂａｓｅｄｇａｓｔｕｒｂｉｎｅ...     

钼及钼合金表面高温防护涂层的研究进展

系统总结了国内外关于钼及钼合金表面高温防护涂层的最新研究成果，分析了钼在不同温度区间的氧化特征，并基于涂层组织结构稳定性、涂层缺陷、涂层与基体界面结合强度、界面物理和化学相容性、氧扩散等多方面，概述了钼及钼合金表面高温防护涂层的性能要求。归纳了现阶段应用于钼及钼合金表面的高温防护涂层体系，主要包括单一硅化物涂层、改性的硅化物涂层、硅化物基梯度复合涂层、铝化物涂层、耐热合金涂层和氧化物涂层，重点讨论了涂层的成分和结构对其抗高温氧化性能的影响。同时，对比介绍了钼及钼合金表面高温防护涂层常用的制备方法，主要包括料浆烧结法、包埋渗法、等离子喷涂法、熔盐法、化学气相沉积法、磁控溅射法等。最后，对钼及钼合金表面高温防护涂层现阶段存在的问题及未来发展方向进行了展望。     

钛合金表面耐磨性能及抗氧化性能的研究现状

钛合金具有密度小、质量轻、比强度高、比刚度高、良好的耐腐蚀性和耐热性、塑韧性好以及优良的加工性等优点,广泛应用于航空航天、交通运输、石油化工、体育器械及生物医疗等众多领域。但钛合金摩擦系数大、易黏着、耐磨性能差、高温(700℃)条件下氧化严重、不易润滑等缺点,大大限制了钛合金的应用和发展。介绍激光熔覆、磁控溅射、离子注入等常见的钛合金表面改性技术的研究现状,指出各种改性技术对钛合金耐磨性能、高温抗氧化性能的改善效果,并探讨各种改性技术的优缺点。在此基础上提出综合提高钛合金耐磨性和高温抗氧化性的新思路并展望其发展前景。     

Development of low thermal expansion superalloy

Alloy 903 and Alloy 909 are well-known Fe-Co-Ni-Al-Ti-Nb alloys with controlled low thermal expan-sion, but they have some properties that can be improved. To improve stress-accelerated grain boundary oxidation embrittlement of Alloy 903 and instability of theγ phase of alloy 909, two new alloys with good stress-rupture ductility, high creep-rupture strength, high tensile strength at high temperature, and good controlled thermal expansion were developed. These property improvements were accomplished by the combination of optimizing the Fe-Co-Ni ratio of the matrix and stabilizing theγ phase with the addition of aluminum.     

Molybdenum silicide based materials and their properties

Molybdenum disilicide (MoSi₂) is a promising candidate material for high temperature structural applications. It is a high melting point (2030 °C) material with excellent oxidation resistance and a moderate density (6.24 g/cm³). However, low toughness at low temperatures and high creep rates at elevated temperatures have hindered its commercialization in structural applications. Much effort has been invested in MoSi₂ composites as alternatives to pure molybdenum disilicide for oxidizing and aggressive environments. Molybdenum disilicide-based heating elements have been used extensively in high-temperature furnaces. The low electrical resistance of silicides in combination with high thermal stability, electronmigration resistance, and excellent diffusion-barrier characteristics is important for microelectronic applications. Projected applications of MoSi₂-based materials include turbine airfoils, combustion chamber components in oxidizing environments, missile nozzles, molten metal lances, industrial gas burners, diesel engine glow plugs, and materials for glass processing. In this paper, synthesis, fabrication, and properties of the monolithic and composite molybdenum silicides are reviewed.     

Nicrofer 5923 hMo,ein neuer hochkorrosionsbeständiger Werkstoff für die Chemische Industrie,die Umwelttechnik und verwandte Anwendungen

Alloy 59, a new highly corrosion resistant material for the chemical process industry, environmental pollutioncontrol and related applications

1 Vortrag anläßlich der ACHEMA '91, Frankfurt/Main, 09.–15. Juni 1991.

A new nickel-chromium-molybdenum alloy, Alloy 59 has been designed to withstand severest corrosive conditions as encountered in chemical process industry and today's environmental pollution control systems. This alloy, which is composed of about 59% nickel, 23% chromium and 16% molybdenum is compared to the common NiCrMo-alloys Alloy C-276, Allo C-4, Alloy 22 and Alloy 625. Conditions of corrosion testing have been varied between oxidizing and reducing mineral acids combined with differing halide contaminations. Furthermore, corrosion data in hot concentrated sulfuric acid and in technical relevant solutions of flue gas desulfurization plants are given. The general resistance to corrosion in sulfuric acid and in hydrochloric acid is highlighted in isocorrosion diagrams. Alloy 59 has an excellent resistance to uniform and localized corrosion in all these environments. The new Alloy 59 clearly outperforms the other NiCrMo-alloys C-276, C-4 and 22 as well under oxidizing conditions as in the strongly reducing hydrochloric acid environment. The time-temperature-sensitization-diagram demonstrates the alloy's excellent thermal stability and reveals an improvement compared to Alloy 22 or the well-known Alloy C-276. Alloy 59, therefore, can be used in the as-welded condition without any additional solution annealing treatment. The excellent corrosion resistance is not impaired if the alloy is processed or fabricated to equipment even in larger sections. Weldability with a matching filler metal is without problems as demonstrated i.a. in the varestraint test.     

低热应变镁合金研究综述

镁和镁基合金是重要的轻量化金属材料,广泛应用于汽车、通讯、航空等领域。由于镁合金热膨胀系数较高,当应用于精密器件时易导致组装精密度降低、力学性能下降等问题。因此需要研发低热应变镁基材料,以满足此类应用的要求。本文对降低镁合金热膨胀系数的原理及方法进行综述,归纳比较了合金化、复合材料和特殊加工工艺等调整镁合金热膨胀系数的主要方法的原理,总结出高熔点元素合金化、高硬度颗粒掺杂、低热膨胀系数纤维掺杂以及热处理结合挤压加工方法等降低镁合金热膨胀系数的有效方法,并对未来该领域的研究趋势进行了展望。