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Fabrication of nanostructured medical-grade stainless steel by mechanical alloying and subsequent liquid-phase sintering
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Open Access
Kaynak :
DSpace Makaleler
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer
Yazar(lar) :
E. Salahinejad , M. J. Hadianfard , Mohammad Ghaffari , S. B. Mashhadi , Ali Kemal Okyay
Konu :
Amorphous matrices, Eutectic alloys, Mechanically alloyed, Nano-structured, Rietveld, Stainless steel powders, Uniform distribution, X-ray mapping, Amorphous silicon, Austenitic stainless steel, Liquids, Manganese, Mechanical alloying, Nanocrystalline alloys, Silicon, Transmission electron microscopy, X ray diffraction, Sintering
Yıl :
2012
Metallurgical and Materials Transactions A
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This article focuses on the microstructure of medical-grade P558 (ASTM F2581) stainless steel produced by mechanical alloying and liquid-phase sintering. Rietveld X-ray diffraction and transmission electron microscopy reflect that the mechanically alloyed stainless steel powder is a nanocrystal dispersed amorphous matrix composite.Mn-11.5 wt pct Si eutectic alloy as additive improves densification of the synthesized P558 alloy via liquid-phase sintering mechanism. X-ray mapping shows that after sintering at 1323 K (105°C) for 1 hour, a uniform distribution of dissolved Mn and Si is achieved. Moreover, the development of a nanostructured, fully austenitic stainless steel after sintering at the same temperature is realized by X-ray diffraction and transmission electron microscopy.
DOI : 10.1007/s11661-012-1186-5
Anahtar Kelimeler : Amorphous matrices, Eutectic alloys, Mechanically alloyed, Nano-structured, Rietveld, Stainless steel powders, Uniform distribution, X-ray mapping, Amorphous silicon, Austenitic stainless steel, Liquids, Manganese, Mechanical alloying, Nanocrystalline alloys, Silicon, Transmission electron microscopy, X ray diffraction, Sintering, Article
Cilt: 43
Sayı: 8
ISSN: 1073-5623
Sayfa: 2994-2998
Sınıflandırma :
2
A simplified numerical analysis of the sheet tensile test
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
S. L. Semiatin , A. K. Ghosh , J. J. Jonas
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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A simplified numerical analysis of the tensile test for sheet metal specimens is presented with particular emphasis on the relationship between plastic flow parameters and tensile ductility. This analysis is based on a one-dimensional, “long wavelength” approximation in which the stress state is assumed to be uniaxial throughout the deformation. To account for the influence of necking and triaxiality on the flow behavior, however, an extended Bridgman correction for sheet specimens deformed under conditions of plane stress is employed. The governing equilibrium equation and boundary conditions are discretized to obtain computer solutions. Engineering stress-strain curves and strain distributions in deformed tensile specimens are compared to results from a more complex formulation previously published in the technical literature and show good agreement with it.
DOI : 10.1007/BF02670429
Anahtar Kelimeler : Metallurgical Transaction, Tensile Ductility, Diffuse Neck, Average Axial Stress, Strain Rate Distribution
ISSN: 1543-1940
Cilt: 16
Sayı: 12
Sayfa: 2291-2298
Sınıflandırma :
3
Dependence of total elongations of superplastic materials on m
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Chin Liu
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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The uniform stretching and thus the high total elongation of superplastic materials have been considered as the result of their highm values in the fundamental equation, σ = kέm, of superplastic flow. The relationships between them values and the total elongations including the experimental curves and the equations obtained for expressing them have been reviewed. The incorrect consideration ofim as a constant in the derivation of these equations and the illogical use ofm value corresponding to the strain of 30 to 50 pct (i.e., m30to50pct) for establishing these curves and for the confirmation of these equations have been analyzed and criticized.
DOI : 10.1007/BF02643988
Anahtar Kelimeler : Metallurgical Transaction, Nodular Cast Iron, Total Elongation, Superplastic Flow, Superplastic Material
ISSN: 1543-1940
Cilt: 17
Sayı: 4
Sayfa: 685-690
Sınıflandırma :
4
Phenomenology of Abnormal Grain Growth in Systems with Nonuniform Grain Boundary Mobility
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Brian L. DeCost , Elizabeth A. Holm
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Yıl :
2016
Metallurgical and Materials Transactions A
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We have investigated the potential for nonuniform grain boundary mobility to act as a persistence mechanism for abnormal grain growth (AGG) using Monte Carlo Potts model simulations. The model system consists of a single initially large candidate grain embedded in a matrix of equiaxed grains, corresponding to the abnormal growth regime before impingement occurs. We assign a mobility advantage to grain boundaries between the candidate grain and a randomly selected subset of the matrix grains. We observe AGG in systems with physically reasonable fractions of fast boundaries; the probability of abnormal growth increases as the density of fast boundaries increases. This abnormal growth occurs by a series of fast, localized growth events that counteract the tendency of abnormally large grains to grow more slowly than the surrounding matrix grains. Resulting abnormal grains are morphologically similar to experimentally observed abnormal grains.
DOI : 10.1007/s11661-016-3673-6
Anahtar Kelimeler : Grain Size Distribution, Texture Component, Growth Event, Abnormal Growth, Boundary Mobility
ISSN: 1543-1940
Cilt: 48
Sayı: 6
Sayfa: 2771-2780
Sınıflandırma :
5
Pretransformation phenomena as revealed by elastic waves
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
T. R. Finlayson
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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There exists a number of examples of evidence for the approaching onset of a martensitic trans-formation in alloys in studies of the dependence of sound velocity on a thermodynamic variable(e.g., temperature). Such evidence is an anomalous temperature dependence for the velocity of a particular sound wave (and hence specific elastic constant for single crystal data), which in some cases has aided our understanding of the phase transformation mechanism. Attenuation anomalies which are occa-sionally reported in conjunction with velocity anomalies are not so well understood.
DOI : 10.1007/BF02652525
Anahtar Kelimeler : Metallurgical Transaction, Elastic Constant, Martensitic Transformation, Elastic Wave, Phonon Branch
ISSN: 1543-1940
Cilt: 19
Sayı: 2
Sayfa: 185-191
Sınıflandırma :
6
A TEM study of microstructural changes during retrogression and reaging in 7075 aluminum
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Nguyen Cong Danh , Krishna Rajan , W. Wallace
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Microstructural changes occurring during retrogression, and during retrogression plus reaging in 7075-T6 aluminum alloy have been investigated by means of transmission electron microscopy, and related to mechanical properties. TEM results indicate that the drop in strength during the initial stage of retrogression was due to the partial dissolution of G.P. zones while the growth of the semi-coherentη ′ was responsible for the rapid recovery of strength. It is suggested that the retrogression and reaging treatment resulted in the increase in volume fraction of G.P. zones and especially η′ precipitates over both the T6 and retrogressed conditions, therefore significantly improving the strength of the alloy.
DOI : 10.1007/BF02645554
Anahtar Kelimeler : Metallurgical Transaction, Stress Corrosion Crack, Transmission Electron Microscopy Result, Precipitate Size, Zone Dissolution
ISSN: 1543-1940
Cilt: 14
Sayı: 9
Sayfa: 1843-1850
Sınıflandırma :
7
Effect of Mg 2 Si particles on the elevated temperature tensile properties of squeeze-cast Mg-Al alloys
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Min Soo Yoo , Kwang S. Shin , Nack J. Kim
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Kaydet
DOI : 10.1007/s11661-004-0268-4
Anahtar Kelimeler : Material Transaction, Ultimate Tensile Strength, Squeeze Casting, Directionally Solidify, Eutectic Cell
ISSN: 1543-1940
Cilt: 35
Sayı: 5
Sayfa: 1629-1632
Sınıflandırma :
8
The deformation behavior of a vanadium-strengthened dual phase steel
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
R. G.Davies
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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A study has been made of the mechanical properties of dual phase (martensite plus ferrite) structures produced when a V containing HSLA steel is cooled in a controlled manner from either the austenite or austenite plus ferrite phase fields. Such a heat treatment results in the pearlite regions and carbide particles of the standard V steel being replaced by martensite; this leads to a decrease in the yield stress and an increase in ductility while the tensile strength is essentially unchanged. The fatigue of dual phase steels is slightly superior in the high strain life (ductility controlled) region and slightly inferior in the low strain life (yield dominated) region when compared to standard V steel. The replacement of the pearlite and cementite particles which can nucleate cracks, by more ductile martensite islands results in improved Charpy impact properties. The strength and the ductility of the dual phase materials is shown to be in agreement with a theory of composites with two ductile phases. This theory then allows one to understand the relative importance of various microstructural features in controlling strength and ductility. In this way it is found that the key to the superior elongation (at a constant tensile strength) is largely due to the high strength (fine grained), highly ductile ferrite matrix.
DOI : 10.1007/BF02647169
Anahtar Kelimeler : Ferrite, Austenite, Martensite, Metallurgical Transaction, Flow Stress
ISSN: 1543-1940
Cilt: 9
Sayı: 1
Sayfa: 41-52
Sınıflandırma :
9
Sliding wear behavior of some Al-Si alloys: Role of shape and size of Si particles and test conditions
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
B. K. Prasad , K. Venkateswarlu , O. P. Modi , A. K. Jha , S. Das , R. Dasgupta , A. H. Yegneswaran
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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In this investigation, effects of the shape and size of silicon particles have been studied on the sliding wear response of two Al-Si alloys, namely, LM13 and LM29. The LM13 alloy comprised 11.70 pct Si, 1.02 pct Cu, 1.50 pct Ni, 1.08 pct Mg, 0.70 pct Fe, 0.80 pct Mn, and remainder Al. The LM29 alloy contained 23.25 pct Si, 0.80 pct Cu, 1.10 pct Ni, 1.21 pct Mg, 0.71 pct Fe, 0.61 pct Mn, and remainder Al. Wear tests were conducted under the conditions of varying sliding speed and applied pressure. The alloys were also characterized for their microstructural features and mechanical properties. The presence of primary silicon particles in the alloy led to a higher hardness but lower tensile properties. Further, refinement in the size of the primary particles improved the mechanical properties of the alloy system. The wear behavior of the alloys was influenced by the presence of primary Si particles and was a function of their size. Samples with refined but identical microconstituents (e.g., pressure cast vs gravity cast LM29 in terms of the size of primary Si particles and dendritic arm spacing) exhibited better wear characteristics. Their overall effect was further controlled by the test conditions. It was observed that test conditions leading to the generation of an optimal degree of frictional heating offer the best wear resistance. This was attributed to the reduced microcracking tendency of the alloy system otherwise introduced by the Si particles. The reduced microcracking tendency in turn allows the Si phase to carry load more effectively and impart better thermal stability to the alloy system. This caused improved wear resistance under the circumstances. Further, the primary Si particles improved the wear resistance of the alloy system (e.g., gravity-cast LM29 vs gravity-cast LM13) under high operating temperature conditions. Additional thermal stability and protection offered to the matrix by the primary Si phase, under the conditions of reduced microcracking tendency, were the reasons for the improved wear characteristics of the alloy system. Conversely, a reverse effect was produced at low operating temperatures in view of the predominating microcracking tendency. The study suggests that shape, size, microcracking tendency, and thermal stability of different microconstituents greatly control the mechanical and tribological properties of these alloys. The extent of effective load transfer between the phases plays an important role in this regard. Further, the overall effect of these factors is significantly governed by the test conditions.
DOI : 10.1007/s11661-998-0315-7
Anahtar Kelimeler : Material Transaction, Wear Rate, Frictional Heating, Wear Characteristic, Slide Wear Behavior
ISSN: 1543-1940
Cilt: 29
Sayı: 11
Sayfa: 2747-2752
Sınıflandırma :
10
Deformation and Fracture from Nano to Macro: Honoring W.W. Gerberich’s 70th Birthday
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
David Bahr , Neville Moody , James Lucas
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Yıl :
2007
Metallurgical and Materials Transactions A
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DOI : 10.1007/s11661-007-9313-4
ISSN: 1543-1940
Cilt: 38
Sayı: 13
Sayfa: 2153-2153
Sınıflandırma :
11
Determination of friction coefficient for sheet materials under stretch-forming conditions
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
R. T. Fox , A. M. Maniatty , D. Lee
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Kaydet
DOI : 10.1007/BF02650306
Anahtar Kelimeler : Metallurgical Transaction, Friction Coefficient, Deep Drawing, Subgrain Boundary, Galvanize Steel
ISSN: 1543-1940
Cilt: 20
Sayı: 10
Sayfa: 2179-2182
Sınıflandırma :
12
The role of crack tip strain rate in the stress corrosion cracking of high strength steels in water
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
R. M. Rieck , A. Atrens , I. O. Smith
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Creep tests have been performed on fracture mechanics specimens of as-quenched 4340 and 3.5NiCrMoV rotor steel to confirm the importance of crack tip strain rate in causing stress corrosion cracking. By allowing creep in a noncracking environment, dry air for the high strength steels tested, cracking did not occur when water, the corrosive solution, was later added to the system. Thus, it is possible to inhibit stress corrosion in spite of conditions otherwise conducive to crack growth. Conditions necessary to restart cracking were also tested. The importance of this result in terms of the mechanism of stress corrosion and difficulties in measuring KISCC is discussed.
DOI : 10.1007/BF02651655
Anahtar Kelimeler : Stress Intensity, High Strength Steel, Stress Corrosion, Stress Corrosion Crack, Crack Opening Displacement
ISSN: 1543-1940
Cilt: 20
Sayı: 5
Sayfa: 889-895
Sınıflandırma :
13
Thermodynamics of B2 intermetallic compounds with triple defects: a Bragg-Williams model for (Ni,Co)Al
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
J. Breuer , E. J. Mittemeijer , F. Sommer
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Applying the Bragg-Williams approximation, a pair interaction model has been developed for describing the composition and temperature dependence of thermodynamic properties of ternary intermetallic B2 phases. Taking the activities and the integral enthalpies of formation as input data, values for the enthalpy and the entropy of bonds between atoms have been obtained. An analytical expression has been derived for the dependence of the concentration of point defects (vacancies and antistructure atoms) on composition and temperature. The model has been applied successfully to the available experimental data for the Ni-Al, Co-Al, and Ni-Co-Al systems. It has been shown that the values calculated accordingly for the effective enthalpy (and entropy) of formation of vacancies agree well with those from experimental observations and theoretical ab initio calculations.
DOI : 10.1007/s11661-001-0191-x
Anahtar Kelimeler : Enthalpy, Material Transaction, NiAl, Integral Enthalpy, Entropy Parameter
ISSN: 1543-1940
Cilt: 32
Sayı: 9
Sayfa: 2157-2166
Sınıflandırma :
14
Transformation Superplasticity of Cast Titanium and Ti-6Al-4V
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Qizhen Li , Edward Y. Chen , Douglas R. Bice , David C. Dunand
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Yıl :
2007
Metallurgical and Materials Transactions A
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Samples of unalloyed titanium and Ti-6Al-4V with a cast, coarse-grain structure were subjected to simultaneous mechanical loading and thermal cycling about their transformation range to assess their capability for transformation superplasticity. Under uniaxial tensile loading, high elongations to failure (511 pct for titanium, and 265 pct for Ti-6Al-4V) and an average strain-rate sensitivity exponent of unity are observed. Samples previously deformed superplastically to a strain of 100 pct show no significant degradation in room-temperature mechanical properties as compared to the undeformed state. Biaxial dome bulging tests confirm that transformation superplasticity is activated under thermal cycling and faster than creep deformation. The cast, coarse-grained titanium and Ti-6Al-4V have similar transformation-superplasticity characteristics as wrought or powder-metallurgy materials with finer grains. This may enable superplastic forming of titanium objects directly after the casting step, thus bypassing the complicated and costly thermomechanical processing steps needed to achieve fine-grain superplasticity.
DOI : 10.1007/s11661-006-9020-6
Anahtar Kelimeler : Strain Increment, Cycling Period, Alpha Case, Apex Height, Creep Stress Exponent
ISSN: 1543-1940
Cilt: 38
Sayı: 1
Sayfa: 44-53
Sınıflandırma :
15
The growth of creep cavities in a low alloy steel
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
C. D. Hamm , R. Pilkington
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Kaydet
Experimental observations of cavity sizes and spacings, after creep of a low alloy steel, are used to assess the applicability of some theoretical models for cavity growth. It is suggested that, for this type of material, various factors may control the growth of cavities, dependent on their size and the test temperature. There also exists a need for accurate diffusion data under these testing conditions.
DOI : 10.1007/BF02647829
Anahtar Kelimeler : Metallurgical Transaction, Creep Test, Cavity Size, Stress Dependence, Cavity Growth
ISSN: 1543-1940
Cilt: 13
Sayı: 10
Sayfa: 1739-1745
Sınıflandırma :
16
Fatigue of annealed and cold worked stable and unstable stainless steels
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
G. Schuster , C. Altstetter
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Fatigue crack growth rates (FCGR) in AISI 301 and 302 austenitic stainless steel alloys have been measured in controlled load cycles withR = 0.05. Both annealed and cold rolled conditions were examined. The austenite phase of the AISI 301 alloy was unstable under stress and transformed martensitically to α′ to a much greater extent than the AISI 302 alloy. At low values of mean stress the unstable alloy had a lower FCGR than the more stable 302 alloy. The FCGR increased with mean stress until values of mean stress ⪞70 MPa, where the FCGR was independent of mean stress and was the same for both alloys. Various metallographic and macroscopic measurements were made to try to understand this behavior. It was concluded that residual compressive stress due to transformation at the crack tip was responsible for the lower crack growth rates of the unstable 301 alloy. Cold worked specimens had significantly lower crack growth rates than the annealed specimens, and both alloys behaved identically.
DOI : 10.1007/BF02662374
Anahtar Kelimeler : Fatigue, Metallurgical Transaction, Fatigue Crack, Crack Growth Rate, Crack Opening Displacement
ISSN: 1543-1940
Cilt: 14
Sayı: 10
Sayfa: 2077-2084
Sınıflandırma :
17
The alpha ⇆ gamma transformation in iron powders
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Alain Couture , Roch Angers
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Kaydet
The alpha ⇆ gamma transformation in various size fractions of three different types of iron powder was studied by differential thermal analysis. The alpha-to-gamma transformation temperature increases considerably with decreasing particle size and with the number of thermal cycles through the transformation for a given particle size. The gamma-to-alpha transformation temperature decreases with decreasing particle size and remains about constant during thermal cycling through the transformation.
DOI : 10.1007/BF02644440
Anahtar Kelimeler : Metallurgical Transaction, Thermal Cycle, Transformation Temperature, Iron Powder, Differential Thermal Analysis Curve
ISSN: 1543-1940
Cilt: 17
Sayı: 1
Sayfa: 37-44
Sınıflandırma :
18
Internal hydrogen effects on tensile properties of iron- and nickel-base superalloys
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
P. D. Hicks , C. J. Altstetter
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Kaydet
Two nickel-base alloys [superalloys INCONEL 718 (IN718) and INCONEL 625 (IN625)] and one iron-base superalloy (A286) were chosen to study the effects of internal H charging on their room-temperature slow strain rate mechanical behavior. Uniform internal H contents ranged from 0 to 50 wt ppm H (0 to 3000 at. ppm H), and a strain rate of 8.5 X 10-7 m/s was used with notched strip specimens. The three alloys showed varying losses in strength and ductility, and the strongest alloy, IN718, showed a decrease of 67 pet in ductility for a dissolved H content of 40 wt ppm. Superalloy A286 showed a corresponding 50 pet decrease in ductility, and IN625 showed a 29 pet loss in ductility. Fractographic evidence and the marked decrease in strength of the alloys lead the authors to conclude that the enhanced localized plasticity mechanism for H embrittlement is possibly operative in these face-centered cubic (fcc) alloys.
DOI : 10.1007/BF02782416
Anahtar Kelimeler : Metallurgical Transaction, Hydrogen Embrittlement, Slow Strain Rate Test, Uncharged Specimen, Notched Tensile Strength
ISSN: 1543-1940
Cilt: 21
Sayı: 1
Sayfa: 365-372
Sınıflandırma :
19
A model for the FCC→HCP transformation, its applications, and experimental evidence
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
S. Mahajan , M. L. Green , D. Brasen
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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A model for the FCC→HCP transformation is proposed. It is envisaged that the dislocation reaction




$${\overline 1 }$$

may govern the nucleation of six-layer HCP crystal. A macroscopic HCP region forms when these nuclei, located at different levels within a localized slipped region, growth into each other. The observed orientation dependence of the strain-induced martensite and the coexistence of HCP and twinned regions have been rationalized in terms of the proposed model. In addition, the supporting evidence has been developed by examining the crystallographic features of faulted regions in partially transformed Co-6.25 wt pct Fe alloy by transmission electron microscopy.
DOI : 10.1007/BF02661642
Anahtar Kelimeler : Martensite, Metallurgical Transaction, Habit Plane, Slip Region, Coherent Twin Boundary
ISSN: 1543-1940
Cilt: 8
Sayı: 2
Sayfa: 283-293
Sınıflandırma :
20
Microstructure and mechanisms of cyclic deformation in aluminum single crystals at 77 K: Part II. Edge dislocation dipole heights
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
M. E. Kassner , M. A. Wall
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Aluminum single crystals were cyclically deformed at 77 K and the dislocation substructure was analyzed. The dipole height in the presaturation microstructure is approximately independent of location, being equal in the dipole bundles (or veins) and within the channels, perhaps suggesting a homogeneous stress distribution. The maximum dipole height suggests a strength approximately equal to the flow stress, while the average dipole height suggests a strength over a factor of 2 higher than the flow stress. The stress to move a dislocation through a dipole bundle is also calculated to be approximately equal to the flow stress.
DOI : 10.1007/s11661-999-1009-5
Anahtar Kelimeler : Material Transaction, Strain Amplitude, Cyclic Deformation, Dislocation Substructure, Saturation Stress
ISSN: 1543-1940
Cilt: 30
Sayı: 13
Sayfa: 777-779
Sınıflandırma :
21
Orientation relationship between β -Mn and L2 1 matrix in a Cu 2 MnAl alloy
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
K. C. Chu , T. F. Liu
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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In the as-quenched condition, the microstructure of the Cu2MnAl alloy was L21 phase containing extremely fine L-J precipitates. This result is different from that reported by other workers in the as-quenched Cu2MnAl alloy. When the as-quenched alloy was aged at 350 °C, γ-brass precipitates started to appear within the L21 matrix. The orientation relationship between the γ-brass and the L21 matrix was determined to be cubic to cubic. This result is consistent with that observed by other workers in the aged Cu-Mn-Al alloy. When the alloy was aged at 460 °C, the γ-brass precipitates disappeared and platelike β -Mn precipitates occurred within the L21 matrix. As the aging temperature was increased to 560 °C, the morphology of the β-Mn precipitates changed from platelike to granular shape. Electron diffraction examinations indicated that in spite of the morphology change the same orientation relationship between the β-Mn and the L21 matrix is maintained, and it could be best stated as follows:

% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9vqpe0x% c9q8qqaqFn0dXdir-xcvk9pIe9q8qqaq-dir-f0-yqaqVe0xe9Fve9% Fve9qapdbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaiikaGqaai% aa-jdacaaIXaGaaGimaiaacMcadaWgaaWcbaGaeqOSdiMaeyOeI0Ia% a8xtaiaa-5gaaeqaaOGaai4laiaac+cacaGGOaGaaGymaiaaicdaca% aIWaGaaiykamaaBaaaleaacaWGTbaabeaakiaacYcacaWFGaGaaiik% aiqaigdagaqeaiaa-jdacaaIWaGaaiykamaaBaaaleaacqaHYoGycq% GHsislcaWFnbGaa8NBaaqabaGccaGGVaGaai4laiaacIcacaaIWaGa% aGymaiaaicdacaGGPaWaaSbaaSqaaiaad2gaaeqaaOGaaiilaiaa-b% cacaGGOaGaaGimaiaaicdacaaIXaGaaiykamaaBaaaleaacqaHYoGy% cqGHsislcaWFnbGaa8NBaaqabaGccaGGVaGaai4laiaacIcacaaIWa% GaaGimaiaaigdacaGGPaWaaSbaaSqaaiaad2gaaeqaaaaa!6626!


$$(210)_{\beta - Mn} //(100)_m , (\bar 120)_{\beta - Mn} //(010)_m , (001)_{\beta - Mn} //(001)_m $$


This result is in disagreement with that reported by Kuzobski et al. in the aged Cu2MnAl alloy. In their study, it was concluded that both the morphology of the β -Mn precipitates and the orientation relationship between the β -Mn and the L21 matrix would vary with the aging temperature.
DOI : 10.1007/s11661-999-0170-1
Anahtar Kelimeler : Material Transaction, Orientation Relationship, Aging Temperature, Iced Brine, Reflection Spot
ISSN: 1543-1940
Cilt: 30
Sayı: 7
Sayfa: 1705-1716
Sınıflandırma :
22
Kinetics of the phase transformation in a Ti-15Mo-5Zr-3AI alloy as studied by X-ray diffraction
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Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
V. B. Rao , C. R. Houska
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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The alloy Ti-15Mo-5Zr-3Al is a metastatale β-alloy. X-ray diffraction data are obtained on the time-temperature-transformation behavior of this alloy as it decomposes into the hexagonal α-phase and the body centered cubic β-phase of a higher Mo concentration. Special X-ray techniques are described to overcome the problems encountered due to rolling and annealing textures as well as grain size. Lattice parameter data from the β-phase permit an approximate phase diagram to be determined.
DOI : 10.1007/BF02658345
ISSN: 1543-1940
Cilt: 10
Sayı: 3
Sayfa: 355-358
Sınıflandırma :
23
Interfaces in MoSi 2 -SiC In Situ composites synthesized by melt processing
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Daniel J. Tilly , Jan P. A. Löfvander , Marc DeGraef , Carlos G. Levi
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Interfaces between the primary β-SiC and the surrounding MoSi2 matrix in melt-synthesized in situ composites have been investigated, with emphasis on the chemistry and crystallographic relationships developed during solidification. Primary SiC growth occurs with {002} and {111} facets, both of which are found to template the subsequent nucleation and epitaxial growth of the MoSi2 matrix. Eight independent orientation relationships (ORs) were identified, involving the following combinations of planes:




$$\begin{gathered} \left\{ {002} \right\}_{Sic} \parallel \left( {001} \right)_{MoSi_2 } \left( {3 rotational variants} \right), or \{ 101)_{MoSi_2 } \hfill \\ \left\{ {111} \right\}_{Sic} \parallel (001)_{MoSi_2 } , or \{ 100)_{MoSi_2 } \left( {2 rotational variants} \right),or \{ 101)_{MoSi_2 } \hfill \\ \end{gathered} $$

The interfacial relationships were rationalized using coincident site lattice arguments as well as energetic simulations based on the Grey-Bohr algorithm. The latter analysis suggests that the multiplicity of relationships arises from local effects associated with the size and shape of the adsorbate layers preceding the formation of the MoSi2 nuclei. An amorphous carbon layer, 2- to 5-nm thick, was detected at all interfaces and some of the matrix grain boundaries. This interphase is believed to evolve by solid-state precipitation of C during postsolidification cooling and is, in principle, metastable. The C interphase enables easy debonding and thus may have important implications for the mechanical performance of materials involving SiC/MoSi2 constituents.
DOI : 10.1007/s11661-997-0120-8
Anahtar Kelimeler : Material Transaction, Translation Vector, Coincident Site Lattice, Coincident Site, Pure MoSi
ISSN: 1543-1940
Cilt: 28
Sayı: 9
Sayfa: 1901-1911
Sınıflandırma :
24
Wear resistance and high-temperature compression strength of Fcc CuCoNiCrAl 0.5 Fe alloy with boron addition
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Chin-You Hsu , Jien-Wei Yeh , Swe-Kai Chen , Tao-Tsung Shun
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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This study discusses the wear resistance and high-temperature compression strength of CuCoNiCrAl0.5Fe alloy with various amounts of boron addition. Experiments show that within the atomic ratio of boron addition from x=0 to x=1.0 in CuCoNiCrAl0.5FeB
x
(referred to as B-0 to B-1.0 alloys), the alloys are of fcc structure with boride precipitation. The volume fraction of borides increases with increasing boron addition. The corresponding hardness increases from HV 232 to HV 736. Wear resistance and high-temperature compression strength are significantly enhanced by the formation of boride. The alloys with boride are less tough. The superior wear resistance of B-1.0 alloy, which is even better than SUJ2 wear-resistant steel, indicates that the CuCoNiCrAl0.5FeB
x
alloys have potential applications as ambient- and high-temperature mold, tool, and structural materials.
DOI : 10.1007/s11661-004-0254-x
Anahtar Kelimeler : Material Transaction, Wear Resistance, Boride, Boron Content, Boron Addition
ISSN: 1543-1940
Cilt: 35
Sayı: 5
Sayfa: 1465-1469
Sınıflandırma :
25
Depth of melt- pool and heat- affected zone in laser surface treatments
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
P. H. Steen , P. Ehrhard , A. Schüssler
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Predictions of penetration depthsd
α of a melt pool and/or transformation-hardening zone as influenced by laser power and scan speed are developed based on a simple conduction balance in the solid metal substrate. The prediction isd
α/d ∼p -1/2—(θα — —)Q
-1 whered is the laser beam width, θα is the ratio of “penetration temperature” to substrate far-field temperature, andP andQ are the dimensionless laser-scan speed and absorbed power, respectively. This scaling law, alternatively derived as an asymptotic limit of a classical closed-form solution, applies for moderate scan speeds and power. Evidence that it captures the dom-inant experimental behavior in cases of no meltingand melting is presented. The predicted depths also compare favorably to numerical simulations by finite elements (a three-dimensional (3D) workpiece of finite extent).
DOI : 10.1007/BF02647988
Anahtar Kelimeler : Material Transaction, Penetration Depth, Peclet Number, Solidification Front, Molten Zone
ISSN: 1543-1940
Cilt: 25
Sayı: 2
Sayfa: 427-435
Sınıflandırma :
26
Radiation effects in high-temperature superconductors: A brief review
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Don M. Parkin
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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A brief review of the published results on radiation effects in high-temperature superconductors is given. The focus is on six observations: lack of ionization damage, displacement damage, displacement thresholds near 20 eV, effects on transition temperature and critical current, amorphization, and atomic site- and sublattice-specific damage processes. It is concluded that these new ceramic superconductors have a very complex interaction with radiation fields. For ambient-temperature, fast-neutron irradiation, they show effects similar to those observed for A-15 superconductors. However, their total response is far more complex.
DOI : 10.1007/BF02698234
Anahtar Kelimeler : Metallurgical Transaction, Radiation Effect, Electron Irradiation, Neutron Data, Ceramic Superconductor
ISSN: 1543-1940
Cilt: 21
Sayı: 5
Sayfa: 1015-1019
Sınıflandırma :
27
On the slopes of phase boundaries
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Arthur D. Pelton
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
Yayıncı Web Sitesi
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Kaydet
Several simple equations are derived which can be used to check binary phase diagrams for thermodynamic consistency. In many cases, the only thermodynamic data required are the entropies of fusion.
DOI : 10.1007/BF02645150
Anahtar Kelimeler : Entropy, Metallurgical Transaction, Alloy Phase Diagram, Binary Phase Diagram, Allotropic Transformation
ISSN: 1543-1940
Cilt: 19
Sayı: 7
Sayfa: 1819-1825
Sınıflandırma :
28
Hydrogen embrittlement of 1100 aluminum
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
M. R. Louthan , A. H. Dexter
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
Yayıncı Web Sitesi
Tam Metin
Kaydet
DOI : 10.1007/BF02641980
Anahtar Kelimeler : Metallurgical Transaction, Fracture Mode, Hydrogen Embrittlement, Intergranular Fracture, Intergranular Crack
ISSN: 1543-1940
Cilt: 6
Sayı: 8
Sayfa: 1655-1657
Sınıflandırma :
29
Displacive Phase Transformation and Surface Effects Associated with Confocal Laser Scanning Microscopy
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
Junhak Pak , Dong Woo Suh , H. K. D. H. Bhadeshia
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Yıl :
2012
Metallurgical and Materials Transactions A
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Kaydet
The influence of the free surface on martensitic transformation was examined by comparing the highest temperature at which martensite forms (MS), as measured using dilatometry, with surface observations using confocal laser scanning microscopy. It is found that the proximity of the surface during confocal microscopy permits martensitic transformation to occur at a higher temperature with a reduced free energy change. This is because the strain energy from the shape deformation accompanying the growth of martensite is reduced at a free surface. The second observation is that plates of martensite tend to coalesce as they approach the free surface where there is reduced constraint. The general observations are backed by calculating the strain energy caused by a subsurface edge dislocation as a function of the orientation of its Burgers vector relative to the free surface.
DOI : 10.1007/s11661-012-1264-8
Anahtar Kelimeler : Austenite, Martensite, Free Surface, Bainite, Martensitic Transformation
ISSN: 1543-1940
Cilt: 43
Sayı: 12
Sayfa: 4520-4524
Sınıflandırma :
30
Measurement of the mechanical state of a low alloy steel at elevated temperature
Dergi Makalesi

Dergi Makalesi
Kaynak :
Springer Link
Dergi:
Metallurgical and Materials Transactions A
Yayıncı:
Springer Link
Yazar(lar) :
D. A. Woodford
Konu :
Metallic Materials, Characterization and Evaluation of Materials, Structural Materials, Surfaces and Interfaces, Nanotechnology
Metallurgical and Materials Transactions A
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Tam Metin
Kaydet
Load relaxation tests on a Cr-Mo-V steel are used to generate stress-strain rate curves at high temperature. It is shown that the mechanical state as described by these curves is sensitive to the deformation history, such that the alloy undergoes a hardening and subsequent softening as strain is accumulated. However, these changes are quite small in successive tests and it is shown that results at different temperatures can be made to coincide by a suitable translation of the strain rate scale at nearly constant mechanical state. The result is a stress-strain rate curve over about twelve orders of magnitude in strain rate so that initial creep rates at stresses far beyond the range covered at each temperature can be estimated. A previously proposed analytical expression for similar data on high purity aluminum fits the present data surprisingly well. From this expression a mechanical state, or hardness parameter, σ*, is obtained. For any value of stress, the value of σ* and its associated parameter, ε*, uniquely define the strain rate.
DOI : 10.1007/BF02642296
Anahtar Kelimeler : Creep Rate, Master Curve, Inelastic Strain, High Purity Aluminum, Single Master Curve
ISSN: 1543-1940
Cilt: 6
Sayı: 9
Sayfa: 1693-1697
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