Effect of Manganese Sulphide Size on the Precipitation of Tin Heterogeneous Nucleation in as-Cast Steel

2015 ◽  
Vol 34 (3) ◽  
Author(s):  
Guilin Sun ◽  
Bo Song ◽  
Sufen Tao ◽  
Zeyun Cai
Keyword(s):  
Contact Angle ◽  
Theoretical Model ◽  
Grain Boundaries ◽  
Heterogeneous Nucleation ◽  
Cast Steel ◽  
Nucleation Site ◽  
High Concentration ◽  
Heterogeneous Nucleation Site

AbstractTramp elements in steels such as tin have been thought harmful because of the hot brittleness at grain boundaries and will be enriched in new steels because of difficulty of removal. It has been an important and difficult matter for metallurgist to use these elements. In the present paper, the as-cast steel containing high concentration of tin is prepared in laboratory and tin precipitates at the manganese sulphide inclusions have been found. A theoretical model is established to calculate the size of manganese sulphide inclusions acted as the heterogeneous nucleation site of tin precipitation. The results show that the inclusions with the smaller contact angle between tin precipitate is more advantageous to be the nucleus of tin heterogeneous nucleation. In this experiment, the manganese sulphide inclusions whose size is 2~4 μm in diameter can act as the nuclei of the nucleation of tin precipitation.

scholarly journals Microstructural Stability of Ti based Composites Fabricated by Spark Plasma Sintering

2020 ◽  
Vol 321 ◽  
pp. 03023
Author(s):  
Yoshimi Watanabe ◽  
Miwa Hattori ◽  
Tadachika Chiba ◽  
Hisashi Sato
Keyword(s):  
Spark Plasma Sintering ◽  
Heterogeneous Nucleation ◽  
Elevated Temperatures ◽  
Nucleation Site ◽  
Layer By Layer ◽  
Microstructural Stability ◽  
Heterogeneous Nucleation Site ◽  
Pinning Effect ◽  
Plasma Sintering ◽  
Spark Plasma

In our previous study, the effects of TiC heterogeneous nucleation site particles on formability and microstructure of additive manufactured (AMed) Ti-6Al-4V products were studied. It was found that the addition of TiC particles decreased the grain size of primary β phase in AMed Ti-6Al-4V samples, since TiC particles act as heterogeneous nucleation sites. It is also found that the density of AMed Ti-6Al-4V samples could be increased by addition of TiC particles. It is expected that solid-state β-grain growth by the high temperature thermal cycles associated with layer-by-layer manufacturing can be suppressed by the pinning effect of TiC heterogeneous nucleation site particles. In this study, the pinning effect of heterogeneous nucleation site particles on microstructure of Ti at elevated temperatures is studied. For this purpose, Ti-0.3vol%TiC samples fabricated by spark plasma sintering (SPS) are used as the model materials, and microstructure and hardness of the samples heat treated at elevated temperatures are studied.

Mechanism on Heterogeneous Nucleation of the Primary Al Phase on TiAl3 of a Hot-Dip Zn-11%Al-3%Mg-0.2%Si Coating on Steel Sheet

2010 ◽  
Vol 638-642 ◽  
pp. 2787-2792 ◽  
Author(s):  
Kazuhiko Honda ◽  
Kohsaku Ushioda ◽  
Wataru Yamada
Keyword(s):  
Heterogeneous Nucleation ◽  
Steel Sheet ◽  
Steel Substrate ◽  
Ternary Eutectic ◽  
Dip Coating ◽  
Nucleation Site ◽  
Fiber Texture ◽  
Solidification Structure ◽  
Heterogeneous Nucleation Site ◽  
Perfect Lattice

The solidification structure of a hot-dip Zn-11%Al-3%Mg-0.2%Si coating with a Ti addition on a steel substrate was investigated. Steel sheet was coated using a laboratory hot-dip galvanizing simulator. The coating was subsequently characterized via optical and high resolution scanning electron microscopy with EBSD and high temperature X-ray diffractometry. The hot-dip coating consisted of a combination of a Zn/Al/MgZn2 ternary eutectic structure, primary Al phase and MgZn2 phase. TiAl3 acts as a heterogeneous nucleation site for Al, which was shown to have perfect lattice coherency with TiAl3 as epitaxial Al growth from the TiAl3 was found. The growth direction of Al is along <110> and has a random texture, whereas Zn has a rather strong ND//<0001> fiber texture.

scholarly journals Review, Role of L12 Modified (Al1−xMex)3Ti Intermetallic Compounds on Heterogeneous Nucleation of Alpha Aluminum Grains

2020 ◽  
Vol 326 ◽  
pp. 06008
Author(s):  
Yoshimi Watanabe
Keyword(s):  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Heterogeneous Nucleation ◽  
Nucleation Site ◽  
High Symmetry ◽  
Cast Aluminum ◽  
Heterogeneous Nucleation Site ◽  
Lattice Constants ◽  
Refining Performance

Al3Ti intermetallic compound with the tetragonal D022 structure undergoes a phase transformation to the high-symmetry L12 cubic structure by addition of third elements, Me. The lattice constants of some L12 modified (Al1−xMex)3Ti intermetallic compounds are closed to that of alpha aluminum. Therefore, it is expected that the addition of L12 modified (Al1−xMex)3Ti intermetallic compound particles show good grain refining performance of cast aluminum. In this paper, our recent results on novel refines containing heterogeneous nucleation site particles of L12 modified (Al1−xMex)3Ti intermetallic compounds have been reviewed.

A quantitative atom probe study of the Nb excess at prior austenite grain boundaries in a Nb microalloyed strip-cast steel

2012 ◽  
Vol 60 (13-14) ◽  
pp. 5049-5055 ◽  
Author(s):  
Peter J. Felfer ◽  
Chris R. Killmore ◽  
Jim G. Williams ◽  
Kristin R. Carpenter ◽  
Simon P. Ringer ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Prior Austenite ◽  
Cast Steel ◽  
Atom Probe ◽  
Austenite Grain ◽  
Strip Cast ◽  
Prior Austenite Grain

scholarly journals Complex Precipitates of TiN-MCx in GCr15 Bearing Steel

2019 ◽  
Author(s):  
Qianren Tian ◽  
Guocheng Wang ◽  
Xinghu Yuan ◽  
Qi Wang ◽  
Seetharaman Sridhar
Keyword(s):  
Volume Fraction ◽  
Early Stage ◽  
Nucleation Site ◽  
Bearing Steel ◽  
Precipitation Behavior ◽  
Heterogeneous Nucleation Site ◽  
Bearing Steels ◽  
Advancing Front ◽  
Gcr15 Bearing Steel ◽  
Second Phases

Nitride and carbide are the second phases which play an important role in the performance of bearing steel, and their precipitation behavior is complicated. In this study, TiN-MCx precipitations in GCr15 bearing steels were obtained by non-aqueous electrolysis, and their precipitation mechanisms were studied. TiN is the effective heterogeneous nucleation site for Fe7C3 and Fe3C, therefore, MCx can precipitate on the surface of TiN easily, its chemistry component consists of M3C and M7C3 (M = Fe, Cr, Mn) and Cr3C2. TiN-MCx with high TiN volume fraction, TiN forms in early stage of solidification, and MCx precipitates on TiN surface after TiN engulfed by the solidification advancing front. TiN-MCx with low TiN volume fraction, TiN and MCx form in late stage of solidification, TiN can not grow sufficiently and is covered by a large number of precipitated MCx particles.

The Microchemistry of Grain Boundaries in Ni3Al

1988 ◽  
Vol 133 ◽  
Author(s):  
D. N. Sieloff ◽  
S. S. Brenner ◽  
Hua Ming-Jian
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Atom Probe ◽  
High Concentration ◽  
Field Ion Microscopy ◽  
Boron Clusters ◽  
Ion Microscopy

ABSTRACTGrain boundary regions in B-doped as well as B-free Ni3AI were studied by field-ion microscopy and atom probe microanalysis. In the ductile, recrystallized, Ni-rich alloys the segregation of boron was often accompanied by an enrichment of nickel. Such an enrichment was not observed at boundaries in B-free alloys. Boron was also observed to segregate to the boundaries in a 25.2A1 - IB alloy which was reported to contain boron clusters. Such clusters were not observed, instead a high concentration of boron pairs were found.

scholarly journals Grain Growth in Polar Ice: II. Application

1986 ◽  
Vol 32 (112) ◽  
pp. 425-433 ◽  
Author(s):  
R.B. Alley ◽  
J.H. Perepezko ◽  
C.R. Bentley
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Growth Rates ◽  
Boundary Migration ◽  
Ice Core ◽  
Ice Cores ◽  
Geometric Constraints ◽  
Polar Ice ◽  
High Concentration ◽  
Micro Particles

AbstractGrain growth observed in polar ice that is not deforming rapidly can be accounted for if concentrations and distributions of extrinsic materials (microparticles, bubbles, and dissolved impurities) are characterized fully. Dissolved impurities segregate to grain boundaries and slow grain growth in all cold glacial ice. The high concentration of soluble impurities in Wisconsinan ice from the Dome C (Antarctica) ice core (and perhaps other ice cores) probably causes the small grain-sizes observed in that ice. Microparticles have little effect on grain growth in ordinary ice. In ice layers that appear dirty owing to concentrations of volcanic tephra (such as in the Byrd Station (Antarctica) ice core) or of morainal material, micro particles reduce grain-growth rates significantly. The relatively high vapor pressure of ice allows rapid growth and high mobility of intergranular necks, so grain growth in firn is limited by boundary migration rather than by neck growth. Bubbles formed by pore close-off at the firn-ice transition are less mobile than grain boundaries, causing bubble-boundary separation whenever geometric constraints are satisfied; however, such separation reduces grain-growth rates by only about 10%. The observed linear increase of grain area with time is thus predicted by theory, but the growth rate depends on soluble-impurity concentrations as well as on temperature.

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