Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

1994 ◽  
Vol 364 ◽  
Author(s):  
K. Ito ◽  
T. Yano ◽  
H. Inui ◽  
M. Yamaguchi

AbstractThe deformation behavior of MoSi2 single crystals has been studied in the temperature range of -196<1500°C. While [001]-oriented crystals can be plastically deformed only above 1300°C, plastic flow is possible from temperatures as low as room temperature for single crystals with orientations other than [001]. Five slip systems, {110)<111], {011)<100], {010)<100], {023)<100] and {013)<331], are identified to be operative, depending on crystal orientation. An anomalous increase in CRSS is observed in the intermediate temperature range for the former three slip systems. Schmid’s law is generally valid for the soft modes, {110)<111], {011)<100] and {023)<100]. In contrast, the CRSS for the hard mode, {013)<331], strongly depends on crystal orientation with the higher values for orientations closer to [001].


2012 ◽  
Vol 706-709 ◽  
pp. 1122-1127 ◽  
Author(s):  
Shinji Ando ◽  
Masayuki Tsushida ◽  
Hiromoto Kitahara

Zn and Al are major alloying elements of Mg alloys. Main slip system of Mg is a basal slip and the CRSS increases with Zn or Al content. According to von-Mises criterion, five kinds of independent slip systems are required for uniform deformation, so it is necessary to activate non-basal slip systems to show good ductility. However, it has not become clear the effect of Zn or Al for non-basal slip systems yet. To investigate deformation behavior of magnesium crystal by non-basal slip, Mg-Zn and Mg-Al single crystals were stretched in the [110] direction and Mg-Zn single crystals were compressed in the [0001] direction. {112}<23> second order pyramidal slip was activated in Mg-0.1at%Zn and Mg-0.5at%Al. On the other hand, {101} twin was mainly activated in Mg-1.0at%Al alloy. Yield stress due to the pyramidal slip of magnesium decreased by 0.1at%Zn addition, however they increased with addition of aluminum..


2007 ◽  
Vol 561-565 ◽  
pp. 459-462
Author(s):  
Katsushi Tanaka ◽  
Hiromitsu Ide ◽  
Yoshinori Sumi ◽  
Kyosuke Kishida ◽  
Haruyuki Inui

Compressive deformation of L10-ordered single crystals of FePd whose c/a ratio less than unity have been investigated from room temperature to 823 K. The results show that the critical resolved shear stress (CRSS) for octahedral glide of ordinary dislocations is smaller than that of super-lattice dislocations in all the temperature range investigated, that is the opposite sense to the case of Ti-56 mol% Al. The CRSS for ordinary dislocations virtually independent to the temperature. On the other hand, the CRSS for super dislocations exhibits a weak positive temperature dependence from room temperature up to 573 K and decreases in higher temperatures.


Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 67 ◽  
Author(s):  
Umer Masood Chaudry ◽  
Kotiba Hamad ◽  
Jung-Gu Kim

In the present work, Ca-induced plasticity of AZ31 magnesium alloy was studied using electron backscattered diffraction (EBSD) measurements supported by viscoplastic self-consistent (VPSC) calculations. For this purpose, alloy samples were stretched to various strains (5%, 10%, and 15%) at room temperature and a strain rate of 10−3 s−1. The EBSD measurements showed a higher activity of non-basal slip system (prismatic slip) as compared to that of tension twins. The VPSC confirmed the EBSD results, where it was found that the critical resolved shear stress of the various slip systems and their corresponding activities changed during the stretching of the alloy samples.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenghao Chen ◽  
Bhaskar Paul ◽  
Sanjib Majumdar ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
...  

AbstractThe plastic deformation behavior of single crystals of two transition-metal diborides, ZrB2 and TiB2 with the AlB2 structure has been investigated at room temperature as a function of crystal orientation and specimen size by micropillar compression tests. Although plastic flow is not observed at all for their bulk single crystals at room temperature, plastic flow is successfully observed at room temperature by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> in ZrB2 and by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> in TiB2. Critical resolve shear stress values at room temperature are very high, exceeding 1 GPa for all observed slip systems; 3.01 GPa for {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> slip in ZrB2 and 1.72 GPa and 5.17 GPa, respectively for {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> slip in TiB2. The identified operative slip systems and their CRSS values are discussed in comparison with those identified in the corresponding bulk single crystals at high temperatures and those inferred from micro-hardness anisotropy in the early studies.


1999 ◽  
Vol 13 (29n31) ◽  
pp. 3758-3763 ◽  
Author(s):  
AUGUST YURGENS ◽  
DAG WINKLER ◽  
TORD CLAESON ◽  
SEONG-JU HWANG ◽  
JIN-HO CHOY

The c-axis tunneling properties of both pristine Bi2212 and its HgBr 2 intercalate have been measured in the temperature range 4.2-250 K. Lithographically patterned 7-10 unit-cell heigh mesa structures on the surfaces of these single crystals were investigated. Clear SIS-like tunneling curves for current applied in the c-axis direction have been observed. The dynamic conductance d I/ d V(V) shows both sharp peaks corresponding to a superconducting gap edge and a dip feature beyond the gap, followed by a wide maximum, which persists up to a room temperature. Shape of the temperature dependence of the c-axis resistance does not change after the intercalation suggesting that a coupling between CuO 2-bilayers has little effect on the pseudogap.


1979 ◽  
Vol 27 (7) ◽  
pp. 1219-1230 ◽  
Author(s):  
S. Hanada ◽  
H. Yamamoto ◽  
O. Izumi

2014 ◽  
Vol 2014 (0) ◽  
pp. _OS0125-1_-_OS0125-2_
Author(s):  
Shinji ANDO ◽  
Kazuki FUKUSHIMA ◽  
Masayuki TSUSHIDA ◽  
Hiromoto KITAHARA

2014 ◽  
Vol 783-786 ◽  
pp. 341-345 ◽  
Author(s):  
Shinji Ando ◽  
Atsushi Kodera ◽  
Kazuki Fukushima ◽  
Masayuki Tsushida ◽  
Hiromoto Kitahara

According to von-Mises criterion, five kinds of independent slip systems are required for uniform deformation, so it is necessary to activate non-basal slip systems to show good ductility. However, it has not become clear the effect of Zn or Al for non-basal slip systems yet. To investigate deformation behavior of magnesium crystal by non-basal slip and alloying effect for the non-basal slip, pure magnesium and Mg-Al-Zn single crystals were stretched in the [110] direction. While {112}<23> second order pyramidal slip was activated at room temperature in pure magnesium, {101}<23> first order pyramidal slip became active slip at higher temperature. In Mg-Al-Zn alloy single crystal, {101} twin also activated by adding aluminum. These results indicate that active non-basal slip systems and twin in magnesium strongly depend on deformation temperature and alloying elements.


2005 ◽  
Vol 488-489 ◽  
pp. 775-778
Author(s):  
Tsing Zhou ◽  
Goroh Itoh ◽  
Yohei Iseno ◽  
Yoshinobu Motohashi

The hot-rolled and extruded AZ31 specimens are subjected to tensile tests at room and elevated temperatures. At room temperature, the yield stress of the hot-rolled specimen is significantly higher than that of the extruded, the reason for which is related to the different textures developed in the two type specimens, as well as the different slip systems activated. At elevated temperatures, the strain rate sensitivity and the activation energy are obtained to characterize the deformation mechanism of the alloy during the temperature range of 423~573K.


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