Role of the Microstructure on the Deformation Behavior in Mg12ZnY with a Long-Period Stacking Ordered Structure

2008 ◽  
Vol 1128 ◽  
Author(s):  
Koji Hagihara ◽  
Naoyuki Yokotani ◽  
Akihito Kinoshita ◽  
Yuya Sugino ◽  
Hiroyuki Yamamoto ◽  
...  

AbstractThe influence of a heat-treatment on the plastic deformation behavior in Mg12ZnY with a long-period stacking ordered (LPSO) structure was investigated by using crystals grown by the Bridgman method. Annealing of the crystal at 798 K for 3 days induced the change in the crystal structure of Mg12ZnY from the 18-fold rhombohedral structure (18R) to the 14-fold hexagonal structure (14H). The plastic behavior of those LPSO crystals showed a large variation depending on the loading axis in both crystals, because of the limitation of operative deformation modes in them. The change in the stacking sequence in the LPSO crystals did not show a large influence on the plastic deformation behavior at room temperature.

2004 ◽  
Vol 842 ◽  
Author(s):  
Koji Hagihara ◽  
Tetsunori Tanaka ◽  
Takayoshi Nakano ◽  
Yukichi Umakoshi

ABSTRACTIn Ni-Ti-Nb ternary system, there are some geometrically close-packed (GCP) phases with long-period stacking sequences of a close-packed plane (CPP). Among them, our focus is on the Ni3(Ti0.90Nb0.10) crystals with Pb3Ba-type rhombohedral structure with nine-fold stacking sequence. Compression tests were conducted using the single crystals and the temperature and orientation dependences of plastic deformation behavior were investigated in comparison with those of D024-Ni3Ti crystals with the four-fold stacking sequence. The K-W locking of screw dislocation was found to occur not only in the compounds such as Ni3Al and Ni3Ti with a relatively small unit cell, but also even in complex compounds with longer-period stacking structures by slip on the common CPP in the GCP structures.


2005 ◽  
Vol 502 ◽  
pp. 145-150 ◽  
Author(s):  
Yukichi Umakoshi ◽  
Koji Hagihara ◽  
Takayoshi Nakano

Plastic deformation behavior including anomalous strengthening of Ni3X-type compounds with D019, D0a and D024 structure were examined and summarized, focusing on the correlation between deformation characteristics and features of their crystal structures.


2002 ◽  
Vol 753 ◽  
Author(s):  
Koji Hagihara ◽  
Takayoshi Nakano ◽  
Yukichi Umakoshi

ABSTBACTIn this paper, our recent results on the plastic deformation behaviors of Ni3X-type hcp-based GCP compounds, such as D0a-Ni3Nb, D019-Ni3Sn and D024-Ni3Ti, are summarized. The similarity and difference of their plastic behavior are discussed focusing on the correlation with the characteristic features of their crystal structures. The criterion for the occurrence of yield stress anomaly (YSA) by slip on the basal plane is also discussed.


2010 ◽  
Vol 18 (5) ◽  
pp. 1079-1085 ◽  
Author(s):  
K. Hagihara ◽  
A. Kinoshita ◽  
Y. Sugino ◽  
M. Yamasaki ◽  
Y. Kawamura ◽  
...  

2021 ◽  
Author(s):  
Wenqi Liu ◽  
Zinan Li ◽  
Sven Bossuyt ◽  
Antti Forsström ◽  
Zaiqing Que ◽  
...  

Metals made by additive manufacturing (AM) have intensely augmented over the past decade for customizing complex structured products in the aerospace industry, automotive, and biomedical engineering. However, for AM fabricated steels, the correlation between the microstructure and mechanical properties is yet a challenging task with limited reports. To realize optimization and material design during the AM process, it is imperative to understand the influence of the microstructural features on the mechanical properties of AM fabricated steels. In the present study, three material blocks with 120×25×15 mm3 dimensions are produced from PH1 steel powder using powder bed fusion (PBF) technology to investigate the anisotropic plastic deformation behavior arising from the manufacturing process. Despite being identical in geometrical shape, the manufactured blocks are designed distinguishingly with various coordinate transformations, i.e. alternating the orientation of the block in the building direction (z) and the substrate plate (x, y). Uniaxial tensile tests are performed along the length direction of each specimen to characterize the anisotropic plastic deformation behavior. The distinctly anisotropic plasticity behavior in terms of strength and ductility are observed in the AM PH1 steel, which is explained by their varied microstructure affected by the thermal history of blocks. It could also be revealed that the thermal history in the AM blocks is influenced by the block geometry even though the same process parameters are employed.


2019 ◽  
Vol 812 ◽  
pp. 45-52
Author(s):  
Ping Song ◽  
Wen Bin Li ◽  
Xiao Ming Wang

In this paper, the effects of temperature and strain rate on the plastic deformation behavior of 5052 aluminum alloy were investigated by quasi-static tensile test and split Hopkinson pressure bar (SHPB) experiments. Meanwhile, the stress-strain relations obtained through these experiments were employed for calibrating Johnson-Cook (J-C) plastic flow constitutive parameters of 5052 aluminum alloy. The results show that the strain rate sensitivity of 5052 aluminum alloy is insignificant in the range of 0.001s-1~3000s-1, while temperature has a great effect on the material plastic behavior. The experimental data are basically consistent with the predicted outcome of J-C constitutive model.


2006 ◽  
Vol 980 ◽  
Author(s):  
Koji Hagihara ◽  
Mayumi Mori ◽  
Yukichi Umakoshi

AbstractPlastic deformation behavior of Ni3V with D022 structure was examined using the single crystals containing two dominant variants of three. Three deformation modes were confirmed to be operative depending on temperature and loading orientation. {111}1/6<112] twinning and/or {111}<110] slip is dominantly operative at low temperatures, but {111}1/2<112] slip is activated at high temperatures accompanied by a rapid drop of yield stress.


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