| Solidification Structure of Inconel 718 Microalloying Elements |
1994 |
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| Authors:
Y. Murata; M. Morinaga; N. Yukawa; H. Ogawa; M. Kato; RESERVED SOURCE
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 | This paper concerned metals in some important way and contained information about, utilized, or discussed these subjects: basic topics: experimental materials and material types: fe-52ni-20cr-3nb-2mo, inconel 718, waspaloy materials related terms: chromium addition, cooling rate, iron addition, molybdenum addition, niobium addition, optical microscopy, precipitation, sem, solidification parameter values relevant to the data: temp 1200 c and above, temp 900 to 1199 c processing: microalloying miscellaneous and special technical terms: macrostructure, ... |
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| Solidification and Precipitation Behaviour of Inconel 718 and Waspaloy |
93 |
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| Authors:
Y. Murata; M. Morinaga; H. Ogawa; M. Kato; N. Yukawa; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)
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| The solidification and precipitation sequence of Inconel 718 and Waspaloy was examined by means of differential thermal analysis, optical microscopy, scanning electron microscopy, electron probe microanalysis and transmission electron microscopy; in addition, the microstructure of the alloys quenched from various temperatures was examined in order to identify the solidification and precipitation reactions, and also to determine the precipitation temperatures; the sequence of Inconel 718 was found to be (1) the ... |
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| Evaluation of the Phase Stability of Modified IN738LC Alloys With New Phacomp |
92 |
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| Authors:
J. S. Zhang; K. Matsugi; Y. Murata; M. Morinaga; N. Yukawa; VANDERBILT UNIV NASHVILLE TN
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| A study is done of compositions of hot corrosion-resistant single crystal super alloys for use in long-term high performance gas turbine applications; the New Phase Computation method is used to analyze superalloy IN- 738LC; it is found that the phase stability boundary of the system with high Cr content is similar to that of other single-crystal superalloys with lower Cr and higher Al contents; this implies that a desired balance ... |
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| Rapidly Solidified MC Carbide Morphologies of a Laser-Glazed Single- Crystal Nickel-Base Superalloy |
92 |
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| Authors:
H. M. Wang; J. H. Zhang; Y. J. Tang; Z. Q. Hu; N. Yukawa; ACADEMIA SINICA SHENYANG (CHINA) INST OF METAL RESEARCH
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| Rapidly solidified MC (TiC type) carbide morphology and its evolution with solidification cooling rate studied comprehensively for a laser-glazed hot- corrosion resistant single-crystal nickel-base superalloy; the rapidly solidified interdendritic MC carbide was found in flower-like or radially branching morphologies which are closely related to the solidification cooling rate; at a relatively low cooling rate (9000 K/sec), the carbide takes up the flower-like morphology, in which a few plates grow radially ... |
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| Mechanical Properties and Oxidation Resistance of Ti5Si3 and (Ti,X)5Si3 Intermetallic Compounds |
91 |
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| Authors:
Y. Murata; T. Higuchi; Y. Takeda; M. Morinaga; N. Yukawa; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| The solid solubilities of Ti5Si3 with vanadium and niobium additions were determined to be 18.5 at% and 15.6 at%; the mechanical properties of pure and alloyed Ti5Si3 were studied; the microhardness of Ti5Si3 remained fairly constant at 1200 HV from room to 1073 K, but beyond 1173 K there was a rapid decrease; a similar behavior was observed in alloyed Ti5Si3, except hardness started to decrease rapidly at a temperature ... |
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| New Crystal Structure Map for Intermetallic Compounds |
91 |
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| Authors:
Y. Takagi; J. Saito; M. Morinaga; N. Yukawa; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| Calculation of electronic structures by a discrete variational (DV)- XAlpha cluster method is the basis of a proposed new crystal structure map; a map for aluminides and silicides containing transition metals, M, was constructed using two electronic parameters; one is the d orbital energy level correlating with atomic size and electronegativity of elements, and the other is the bond order that is a measure of covalent bond strength between M ... |
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| Microstructural Effect on the Corrosion Behavior of Zirconium Alloys in a Sulfuric Acid Solution |
90 |
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| Authors:
W. Ito; T. Higashijima; H. Ezaki; M. Morinaga; N. Yukawa; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| Anodic polarization behavior of commercially pure Zr, Zircaloy-2 and Zr-binary alloys containing Sn, Fe, Ni, Cr, Mo, Ti, Hf, Nb was investigated in 20 mass% sulfuric acid at 303 K; corrosion current densities were measured with changing potential at a constant rate of 0.33 mV/s from the corrosion potential to 1.5 V (SCE); for pure Zr and its alloys those active noses which appear in stainless steel were not observed ... |
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| High Performance Single Crystal Superalloys Developed by the d-Electrons Concept |
88 |
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| Authors:
N. Yukawa; M. Morinaga; Y. Murata; H. Ezaki; S. Inoue; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| New single crystal superalloys of Ni-10at%Cr-12at%Al-Ti-Ta-W-Mo-Re have been developed by the d-electrons concept, which was devised on the basis of molecular orbital calculations of Ni based alloys. The process for the design of single crystal superalloys introduced in a previous study was modified to a more simple one and applied to the present study. The alloys were designed so as to have an optimum combination of the properties such as ... |
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| Effect of Transition Elements on the Properties of MC Carbides in IN-100 Nickel-Based Superalloy, |
OCT 1986 |
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| Authors:
Y. Murata; K. Suga; N. Yukawa
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| The effect of nine transition elements on the morphology, distribution and composition of MC carbides (MCs) in a nickel-base superalloy, IN-100, was investigated by differential thermal analysis (DTA), microstructural observation and X-ray microanalysis. The doping with tantalum, tungsten and molybdenum caused a significant change in the morphology and distribution of MCs as well as the profile of DTA curve of IN-100. The compositions of the MC in IN-100 were TiC ... |
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| Solid-State Reaction for ZrC Formation in a Zr-Doped Nickel-Based Superalloy |
MAY 86 |
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| Authors:
Y. Murata; N. Yukawa
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| In a Zr-doped IN-100, the (Ni, Co)(sub 7)Zr(sub 2) phase formed during solidification, transformed into ZrC as the result of a reaction with the Ti-rich transition metal carbides at elevated temperatures. |
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| Effect of Transition Elements on the Composition, Morphology and Phase Stability of MC-carbide in IN-100 (Analysis of Solidification Behavior of High Alloys by Doping Method and Its Application--I), |
DEC 1985 |
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| Authors:
Y. Murata; N. Yukawa; K. Suga
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| In most nickel-base superalloys MC carbide is formed during solidification. Their morphology as well as phase stability at high temperature affects the strength of the superalloys. The purpose of this study is to investigate the effect of various transition elements on the composition, morphology and phase stability of the MC in IN-100. |
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| Prediction of MC-Carbide Compositions in Nickel-Base Superalloys (Analysis of Solidification Behavior of High Alloys by the Doping Method and Its Application--II), |
DEC 1985 |
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| Authors:
Y. Murata; N. Yukawa; K. Suga
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| It is important for the alloy design of nickel-base superalloys to predict the composition of MC carbide which is formed during solidification from melt. Although the compositions of MC in the superalloys have been reported so far, the relationship between the MC composition and the alloy composition remains unclear. In this study, an attempt is made to predict MC composition by calculation from the alloy composition based on the experimental ... |
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| Solidification Behavior of a Nickel-base Superalloy, IN-100 |
JAN 85 |
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| Authors:
Y. Murata; N. Yukawa; T. Noda; T. Mitani
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| Solidification behavior of IN-100 and effect of alloying elements on it were investigated by means of differential thermal analysis (DTA), microstructural observation, X-ray diffraction and EPMA analysis. Six phase reactions took place successively during cooling from the melt. The occurrence of two kinds of carbide reactions and M(sub 3)B(sub 2) eutectic reaction was identified for the first time in this study. SEM observation on the carbides, which were embossed on ... |
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| Analysis of Solidification Behavior and Alloy Design of a Nickel-Base Superalloy, IN-100 |
OCT 84 |
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| Authors:
N. Yukawa; Y. Murata; T. Noda; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| IN-100 and several alloys doped with different content levels of C, Al, Ti or B were investigated by means of differential thermal analysis (DTA), microstructural observation, X-ray diffraction, electron probe microanalysis (EPMA), tensile test at room temperature and stress rupture test at 760 C and 982 C. It was revealed that in IN-100 alloy six phase reactions took place successively during cooling from the melt. In particular, two eutectic reactions ... |
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| New PHACOMP and Its Applications to Alloy Design |
OCT 84 |
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| Authors:
M. Morinaga; N. Yukawa; H. Adachi; H. Ezaki; TOYOHASHI UNIV OF TECHNOLOGY (JAPAN)*
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| New PHACOMP was developed from the calculations of electronic structure of alloys by the DV-Xalpha cluster method. It is based on the first theoretical approach to the solid solubility problem of alloys, both solute and solvent being transition metals. The electron vacancy that is an important parameter in the current PHACOMP, is not used in the New PHACOMP. The validity of New PHACOMP was proved by examining about 25 ternary ... |
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| Effect of Cobalt on Microstructure and Strength of a Single Crystal Superalloy |
MAR 83 |
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| Authors:
A. Aoki; Y. Murata; N. Yukawa
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| Recent studies have revealed that Co influences microstructure and strength properties of conventional Ni-base superalloys, but little is known on the role of Co for recently developed single crystal (SC) superalloys. This study has been carried out to make clear the effect of Co on microstructure and strength of a SC superalloy. Tensile strength at 982 C decreased from 0% Co to 2.5% Co showing minimum, and increased with increasing ... |
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| THE CORRELATION BETWEEN MICROSTRUCTURE AND STRESS RUPTURE PROPERTIES OF A CO-CR-NI-W (HS-25) ALLOY |
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| Authors:
N. Yukawa; K. Sato
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