Modelling of Diffusive and Massive Phase Transformation

2008 ◽  
pp. 67-86
Author(s):  
Jiří Vala
Keyword(s):  
Phase Transformation ◽  
Massive Phase

Modeling of solute drag in the massive phase transformation

2000 ◽  
Vol 48 (2) ◽  
pp. 461-468 ◽  
Author(s):  
M. Hillert ◽  
M. Schalin
Keyword(s):  
Phase Transformation ◽  
Solute Drag ◽  
Massive Phase

Observing massive phase transformation in a Fe–Mn–Al alloy

2006 ◽  
Vol 55 (9) ◽  
pp. 783-786 ◽  
Author(s):  
Wei-Chun Cheng ◽  
Chih-Kang Lai
Keyword(s):  
Phase Transformation ◽  
Al Alloy ◽  
Massive Phase

Massive Phase Transformation as a New Prospective on Microstructural Design in a Titanium Alloy - A Review

2020 ◽  
Vol 1000 ◽  
pp. 428-435
Author(s):  
Eung Ryul Baek ◽  
Ghozali Suprobo
Keyword(s):  
Mechanical Property ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
Martensitic Transformation ◽  
Massive Transformation ◽  
Ti Alloy ◽  
Α Phase ◽  
Massive Phase ◽  
Microstructural Design ◽  
And Diffusion

Microstructural design is generally applied to improve the mechanical property of titanium alloy by introducing different phase transformations and thermomechanical treatments. Aside from the martensitic and diffusion transformation, the occurrence of massive transformation occurs in Ti alloy. Massive transformation is categorized as civilian phase transformation, which resulted in the change of crystal structure of an alloy with a given composition without changing the chemical composition of its initial phase. It happened when the body centered-cubic β phase changed into hexagonal closed-pack α phase without decomposing into α+β. Massive transformation involves a diffusion and growth mechanism in a short-range and generally occurs during the introduction of high cooling rates to restrict the full diffusion mechanism. Owing to the nature of a rapid cooling rate as a requirement for massive transformation, the massive phase is normally found together with the product of martensitic transformation. On the other hand, the product of massive transformation is observed as a blocky grain with a featureless characteristic using optical microscopy and. Phase identification using electron backscattered diffraction shows that the region of αm shows only the presence of the α phase. It was reported for containing a high dislocation density similar to martensitic transformation. Specifically, in Ti alloy, the higher magnification using scanning electron microscopy shows fine sub-lamellar morphology, which observed as a combination product morphology between martensitic and diffusion transformation. It resulted in the mechanical property of the massive phase is between those two morphologies. Hence, it brings a new perspective on designing the microstructure of Ti alloy, which can be used to improve the mechanical property of Ti alloy.

A thick-interface model for diffusive and massive phase transformation in substitutional alloys

2006 ◽  
Vol 54 (15) ◽  
pp. 3953-3960 ◽  
Author(s):  
J SVOBODA ◽  
J VALA ◽  
E GAMSJAGER ◽  
F FISCHER
Keyword(s):  
Phase Transformation ◽  
Interface Model ◽  
Massive Phase ◽  
Substitutional Alloys

scholarly journals Nanowire Growth by an Electron-Beam-Induced Massive Phase Transformation

2014 ◽  
Vol 97 (12) ◽  
pp. 3733-3736 ◽  
Author(s):  
Shantanu Sood ◽  
Kim Kisslinger ◽  
Perena Gouma
Keyword(s):  
Phase Transformation ◽  
Electron Beam ◽  
Nanowire Growth ◽  
Massive Phase

Precipitation and strengthening behavior of massive δ-ferrite in dissimilar stainless steels during massive phase transformation

2008 ◽  
Vol 477 (1-2) ◽  
pp. 328-333 ◽  
Author(s):  
Chih-Chun Hsieh ◽  
Dong-Yih Lin ◽  
Ming-Che Chen ◽  
Weite Wu
Keyword(s):  
Phase Transformation ◽  
Stainless Steels ◽  
Δ Ferrite ◽  
Massive Phase

scholarly journals Nanotwin-assisted nitridation in FeNi nanopowders for synthesis of rare-earth-free magnets

2021 ◽  
Author(s):  
Jian Wang ◽  
Yusuke Hirayama ◽  
Zheng Liu ◽  
Kazuyuki Suzuki ◽  
Wataru Yamaguchi ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Rare Earth ◽  
Low Cost ◽  
Phase Interface ◽  
Orientation Relationships ◽  
Transformation Mechanism ◽  
Precursor Phase ◽  
Massive Phase ◽  
Feni Alloys ◽  
Feni Alloy

Abstract L10-ordered FeNi alloy (tetrataenite), a promising candidate for rare-earth-free and low-cost permanent magnet applications, is attracting increasing attention from academic and industrial communities. Highly ordered single-phase L10-FeNi is difficult to synthesis efficiently because of its low chemical order-disorder transition temperature (200–320 ℃). A non-equilibrium synthetic route utilizing a nitrogen topotactic reaction has been considered a valid approach, although the phase transformation mechanism is currently unknown. Herein, we investigated the basis of this reaction, namely the formation mechanism of the tetragonal FeNiN precursor phase during the nitridation of FeNi nanopowders. Detailed microstructure analysis revealed that the FeNiN precursor phase could preferentially nucleated at the nanotwinned region during nitridation and subsequently grew following a massive transformation, with high-index irrational orientation relationships and ledgewise growth motion detected at the migrating phase interface. This is the first report of a massive phase transformation detected in an Fe-Ni-N system and provides new insights into the phase transformation during the nitriding process. This work is expected to promote the synthetic optimization of fully ordered FeNi alloys for various magnetic applications.

Nucleation of the α / γ Massive Phase Transformation in Titanium- 48at% Aluminum

1998 ◽  
Vol 4 (S2) ◽  
pp. 538-539
Author(s):  
J.E. Wittig ◽  
W.H. Hofmeister
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
Electron Beam Melting ◽  
Lamellar Structure ◽  
Electromagnetic Levitation ◽  
Nucleation And Growth ◽  
Coherent Interface ◽  
Splat Quenching ◽  
Α Phase ◽  
Massive Phase

Massive phase transformations exhibit a change in crystal structure without a change in composition. Nucleation and growth of this difTUsionless transformation has been studied in numerous systems including Cu-Zn, Ag-Zn and Ag-Al. There is general agreement that heterogeneous grain boundary nucleation occurs with a rational orientation relationship with at least one of the parent grains, although growth of the massive product can often occur with a partially coherent interface.The typical Ti-48at%Al microstructure is a lamellar structure of hexagonal α2 (DO19 superlattice) and the ordered tetragonal γ phase (Ll0 with c/a = 1.01). Water or ice brine quenching of the high temperature disordered α phase results in a partial massive transformation of a into γ. Electron beam melting has been used to further suppress the equilibrium transformations. However, the current study uses rapid solidification by electromagnetic levitation and twin anvil splat quenching (cooling rates > 106 K/s) to capture earlier stages of the transformation.

Sign in / Sign up

Export Citation Format

Share Document