In Situ Tensile Texture Analysis of a New Mg-RE Alloy

2016 ◽  
Vol 879 ◽  
pp. 779-783
Author(s):  
Wei Min Gan ◽  
Yuan Ding Huang ◽  
Yu Ling Xu ◽  
Michael Hofmann ◽  
Karl Ulrich Kainer ◽  
...  

A new Mg-RE (rare earth) alloy was previously developed by micro-alloying method (RE< 0.4 wt.%), which achieves a high ductility and good corrosion resistance. In-situ tensile test via neutron and synchrotron diffraction were performed to investigate first the deformation behaviour; and second the texture evolution which can be related to the deformation mechanism, and finally to understand why the as-cast Mg-RE alloys show such a high tensile ductility.Preliminary results showed that a dominated basal fibre texture was gradually developed with the increase of tensile strain. However, before the sample was broken a (10.0) fibre texture showed a similar intensity to that in (00.2), which means more activations of the non-basal slip planes during tensile deformation. This could also contribute to a relatively high elongation of this new Mg-RE alloy at room temperature. Further discussion will be showed together with the microstructures.

2014 ◽  
Vol 939 ◽  
pp. 25-30
Author(s):  
Jozef Zrník ◽  
Ondrej Muránsky ◽  
Petr Sittner

The paper presents results ofin-situneutron diffraction experiments aimed on monitoring the phase evolution and load distribution in transformation induced plasticity (TRIP) steel when subjected to tensile loading. Tensile deformation behaviour of two TRIP-assisted multiphase steel with slightly different microstructures resulted from different thermo-mechanical treatments applied was investigated byin-situneutron diffraction. The steel with lower retained austenite volume fraction (fγ=0.04) and higher volume fraction of needle-like bainite in the α-matrix exhibits higher yield stress (sample B, 600MPa) but considerably lower elongation in comparison to the steel with higher austenite volume fraction (fγ=0.08), granular bainite and ferrite matrix (sample A, 500 MPa). The neutron diffraction results showed that the applied tensile load is redistributed at the yielding point in a way that the retained austenite bears a significantly larger load than the α-matrix during the TRIP steel deformation. Steel sample with higher volume fraction of retained austenite and less strong ferrite matrix proved to be a better TRIP steel with respect to strength, ductility and the side effect of the strain induced austenite-martensite transformation. The transforming retained austenite in time of loading provides potential for higher ductility of experimental TRIP steel but at the same time acts as a reinforcement phase during the further plastic deformation.TRIP steel, austenite conditioning, austenite transformation, structure, retained austenite, tensile deformation, neutron diffraction, load partitioning, mechanical properties.


2011 ◽  
Vol 465 ◽  
pp. 390-394 ◽  
Author(s):  
Jozef Zrník ◽  
Ondrej Muránsky ◽  
Petr Šittner ◽  
E.C. Oliver

The paper presents results of in-situ neutron diffraction experiments aimed on monitoring the phase evolution and load distribution in TRIP steel when subjected to tensile loading. Tensile deformation behaviour of TRIP steel with different initial microstructures showed that the applied tensile load is redistributed at the yield point and the harder retained austenite (Feγ) bears larger load then ferrite (Feα) matrix. After load partioning is finished, macroscopic yielding comes through simultaneous activity of the martensite transformation (in the austenite) and plastic deformation process in ferrite. The steel with higher volume fraction of retained austenite and less stronger ferrite appears to be a better TRIP steel having efficient structure for better plasticity purpose.


2014 ◽  
Vol 782 ◽  
pp. 99-103
Author(s):  
Jozef Zrník ◽  
Ondrej Muránsky ◽  
Petr Šittner

The paper presents results ofin-situneutron diffraction experiments aimed on monitoring the phase evolution and load distribution in TRIP steel when subjected to tensile loading. Tensile deformation behaviour of TRIP steel with different initial microstructures showed that the applied tensile load is redistributed at the yield point and the harder retained austenite (Feγ) bears larger load then ferrite (Feα) matrix. After load partioning is finished, macroscopic yielding comes through simultaneous activity of the martensite transformation (in the austenite) and plastic deformation process in ferrite. The steel with higher volume fraction of retained austenite and less stronger ferrite appears to be a better TRIP steel having efficient structure for better plasticity purpose.


Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 858
Author(s):  
Zichao Luo ◽  
Masahiko Yoshino ◽  
Motoki Terano ◽  
Akinori Yamanaka

Microstructure control is of vital importance in tailoring physical properties of metallic materials. Despite the enormous efforts devoted to the study of microstructure evolution during recrystallization, most previous research has been conducted under non-simple conditions, either applying complex deforming boundary conditions or employing specimens with sophisticated crystalline structure. These complexities hinder comprehensive understanding of the fundamental aspects in texture evolution and make it even harder to penetrate the already intricate recrystallization behaviors. The present study aims at a detailed evaluation of widely used phenomenological model in reproducing experimentally observed deformation characteristics under simple crystalline structure and deformation condition, as well as the prediction of nucleation sites during static recrystallization. In situ electron back-scattering diffusion (EBSD) observations were performed to record texture change during static recrystallization of single crystal pure iron specimens after tensile deformation. CP-FEM (crystal plasticity finite element method) method was employed to simulate deformed texture. Deformation heterogeneity characterized by kernel average misorientation maps derived from EBSD data and numerical calculations were compared. The former data shows deformation heterogeneity sensitive to localized microstrain while the later delivers an effective meso-scale deformation distribution. Observed approximate nucleation sites have shown a qualitative coincidence with highly distorted regions in numerical calculations.


Author(s):  
S. Naka ◽  
R. Penelle ◽  
R. Valle

The in situ experimentation technique in HVEM seems to be particularly suitable to clarify the processes involved in recrystallization. The material under investigation was unidirectionally cold-rolled titanium of commercial purity. The problem was approached in two different ways. The three-dimensional analysis of textures was used to describe the texture evolution during the primary recrystallization. Observations of bulk-annealed specimens or thin foils annealed in the microscope were also made in order to provide information concerning the mechanisms involved in the formation of new grains. In contrast to the already published work on titanium, this investigation takes into consideration different values of the cold-work ratio, the temperature and the annealing time.Two different models are commonly used to explain the recrystallization textures i.e. the selective grain growth model (Beck) or the oriented nucleation model (Burgers). The three-dimensional analysis of both the rolling and recrystallization textures was performed to identify the mechanismsl involved in the recrystallization of titanium.


Sign in / Sign up

Export Citation Format

Share Document