Grain growth in nanograined aluminum oxide by high-pressure torsion: Phase transformation and plastic strain effects

2018 ◽  
Vol 152 ◽  
pp. 11-14 ◽  
Author(s):  
Ikuro Fujita ◽  
Kaveh Edalati ◽  
Xavier Sauvage ◽  
Zenji Horita
2017 ◽  
Vol 56 (5) ◽  
pp. 2576-2580 ◽  
Author(s):  
Hadi Razavi-Khosroshahi ◽  
Kaveh Edalati ◽  
Hoda Emami ◽  
Etsuo Akiba ◽  
Zenji Horita ◽  
...  

2011 ◽  
Vol 239-242 ◽  
pp. 1300-1303
Author(s):  
Hong Cai Wang ◽  
Minoru Umemoto ◽  
Innocent Shuro ◽  
Yoshikazu Todaka ◽  
Ho Hung Kuo

SUS316L austenitic stainless steel was subjected to severe plastic deformation (SPD) by the method of high pressure torsion (HPT). From a fully austenitic matrix (γ), HPT resulted in phase transformation from g®a¢. The largest volume fraction of 70% a¢ was obtained at 0.2 revolutions per minute (rpm) while was limited to 3% at 5rpm. Pre-straining of g by HPT at 5rpm decreases the volume fraction of a¢ obtained by HPT at 0.2rpm. By HPT at 5rpm, a¢®g reverse transformation was observed for a¢ produced by HPT at 0.2rpm.


2016 ◽  
Vol 109 ◽  
pp. 300-313 ◽  
Author(s):  
X.H. An ◽  
Q.Y. Lin ◽  
G. Sha ◽  
M.X. Huang ◽  
S.P. Ringer ◽  
...  

1995 ◽  
Vol 52 (13) ◽  
pp. 9107-9110 ◽  
Author(s):  
Guoliang Gu ◽  
Yogesh K. Vohra ◽  
Keith E. Brister

2013 ◽  
Vol 103 (3) ◽  
pp. 034108 ◽  
Author(s):  
Kaveh Edalati ◽  
Takeshi Daio ◽  
Yoshifumi Ikoma ◽  
Makoto Arita ◽  
Zenji Horita

2017 ◽  
Vol 32 (23) ◽  
pp. 4317-4326 ◽  
Author(s):  
Marlene Walpurga Kapp ◽  
Oliver Renk ◽  
Thomas Leitner ◽  
Pradipta Ghosh ◽  
Bo Yang ◽  
...  

Abstract


2010 ◽  
Vol 654-656 ◽  
pp. 334-337 ◽  
Author(s):  
Innocent Shuro ◽  
Minoru Umemoto ◽  
Yoshikazu Todaka ◽  
Seiji Yokoyama

SUS 304 austenitic stainless steel was subjected to severe plastic deformation (SPD) by the method of high pressure torsion (HPT). From a fully austenitic matrix (γ), HPT resulted in phase transformation to give a two phase structure of austenite (γ) and martensite (α') by the transformation γα'. The phase transformation was accompanied by an increase in hardness (Hv) from 1.6 GPa in the as annealed form to 5.4 GPa in the deformed state. Subsequent annealing in temperature range 250oC to 450oC resulted in an increase in both α' volume fraction and hardness (6.4 GPa). Annealing at 600oC resulted in a decrease in α' volume fraction hardness.


2019 ◽  
Vol 10 (5) ◽  
pp. 692-703
Author(s):  
Fauziana Lamin ◽  
Ahmad Kamal Ariffin Ahmad Kamal Ariffin ◽  
Intan Fadhlina Mohamed

Purpose The purpose of this paper is to examine the plasticity behaviour of aluminium alloys in high-pressure torsion (HPT) compressive loading stage. It is a part of the strengthen lightweight material development through severe plastic deformation. Design/methodology/approach A finite element simulation of HPT compression stage by displacement control incremental loading was proposed by taking into account an unconstraint HPT configuration. The quasi-static condition was utilised, by embedding strain hardening plasticity constitutive model and considering frictional effects, to assess the plasticity behaviour of aluminium alloys, particularly AA2024 and AA6082. Findings The present investigation clearly indicates that the deviation of material flow as a result of sticking condition of µ⩾0.5, was found to be negligible. An inhomogeneous material flow along the sample radial and thickness direction was evident, producing a stress concentration at the edge of the loaded surface, indicating the anticipated region of failure. The effective plastic strain in the compression stage was also found to be significant. Based on the effective strain response, plasticity behaviour of the compressed sample was predicted. Originality/value This paper demonstrates the plasticity behaviour of the analysed aluminium alloys. Since the mechanical properties produced by the deformed material are closely related to the exerted plastic deformation, understanding the phenomenon associated with the plastic strain development is essential. The outcome of this research will assist in seizing the opportunities of improving both material properties and the HPT procedures.


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