Size-dependent fracture behavior of GaN pillars under room temperature compression

Nanoscale ◽  
2020 ◽  
Vol 12 (45) ◽  
pp. 23241-23247
Author(s):  
Sufeng Fan ◽  
Xiaocui Li ◽  
Rong Fan ◽  
Yang Lu
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Power Device ◽  
Compression Tests ◽  
Single Crystalline ◽  
Size Dependent ◽  
Electron Microscopes

Single crystalline GaN pillars are characterized by in situ compression tests inside electron microscopes, showing distinct size-dependent fracture behavior at room temperature for potential microelectronics, power device and MEMS applications.

Ductility and Fracture Behavior of Single Crystalline Ni3Al with Boron Additions

1988 ◽  
Vol 133 ◽  
Author(s):  
F. E. Heredia ◽  
D. P. Pope
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Strengthening Effect ◽  
Single Crystalline ◽  
B Additions ◽  
High Temperature Tensile ◽  
Tension Compression Asymmetry ◽  
Positive Effect

ABSTRACTLow and high temperature tensile tests were performed on single crystals of pure Ni3Al and Ni3Al+B in order to determine the effect of B additions on the ductility and fracture behavior. Tests were carried out in air at a constant strain rate of 1.3 × 10−3 s−1. The orientations tested were [001] for which the yield stress in tension is always greater than in compression, and those for which the tension/compression asymmetry is zero ([T=C]) for each particular composition. At room temperature, the results show a positive effect of B additions on both the fracture stress and on the ductility. The ductility at 800K appears to decrease monotonically with B additions. The largest ductilities are found for [T=C] at room temperature where an improvement of about 26% (resolved strain) for an addition of 0.2 at% B was obtained. However, the most dramatic increase in ductility occurs for the [001] oriented samples at room temperature where a 55% improvement was measured over that of pure Ni3Al. Fracture surfaces show a combination of massive slip, some cleavage, and heavily dimpled areas. These observations show that B additions not only increase the ductility of polycrystalline Ni3Al, as has been previously observed by many investigators, but also that of the already-ductile single crystalline material, indicating that a “bulk effect” should be added to the grain boundary strengthening effect of B when explaining the improvement in ductility of polycrystalline Ni3Al due to B additions.

Nanoindentation and Bending Fracture Behavior of Flexible Sulfide Thin Films Grown at Near Room Temperature With in Situ Tensile/Compressive Stress

2019 ◽  
Vol 21 (7) ◽  
pp. 1801329 ◽  
Author(s):  
Da Bin Kim ◽  
Seung Min Lee ◽  
Jin Woo Jang ◽  
Bhaskar Chandra Mohanty ◽  
Yong Soo Cho
Keyword(s):  
Thin Films ◽  
Compressive Stress ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Bending Fracture

scholarly journals Effect of Different Jackfruit Puree Concentrations on the Mechanical Properties of Jackfruit Frozen Confection

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Amiruddin Mat Johari ◽  
Nur Aliaa Abd Rahman ◽  
Roseliza Kadir Basha ◽  
Azhari Samsu Baharudin ◽  
Mohd Afandi P. Mohammed ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
Room Temperature ◽  
Relaxation Test ◽  
Compression Stress ◽  
Compression Tests ◽  
Stress Relaxation Test ◽  
Test Device ◽  
Mindstorms Ev3

Jackfruit frozen confection has been mechanically characterised in situ by using compression tests. There are no available studies on the mechanical behaviour of jackfruit frozen confection.   The aim of this study is to identify the mechanical properties of jackfruit frozen confections formulated with different concentrations of jackfruit puree. In this study, the experimental analyses are conducted using a compression test device made from LEGO Mindstorms EV3. The portable device is placed inside a freezer to enable the measurements to be done in low temperatures (-20oC). This is to overcome the limitation of an actual texture analyser which can only be operated at room temperature. The mechanical properties of jackfruit frozen confections at different jackfruit puree concentrations (10%, 20% and 30%) are obtained using the tester and analysed. The tests conducted are uniaxial compression, stress relaxation test and multi-step stress relaxation test. It has been observed that frozen confection with 20% jackfruit puree concentration (JF20) is able to withstand a higher force of compression (27.79kPa) compared to the ones with 10% (JF10) and 30% (JF30) concentrations, at 21.15kPa and 10.48kPa, respectively. For stress relaxation test, JF30 has the highest increasing stress for a strain of 0.05 to 0.2 but it decreases at a strain of 0.3 to 0.4. The results of the multi-step relaxation test on JF30 show agreement with the other two tests where the stress decays starting from the 3rd step until the 5th step of the test. This study provides information on the behaviour of jackfruit frozen confection when subjected to compression and stress that imitates the movement during consumption.

High-strength Al87Ni8La5 bulk alloy produced by spark plasma sintering of gas atomized powders

2009 ◽  
Vol 24 (9) ◽  
pp. 2909-2916 ◽  
Author(s):  
Sergio Scudino ◽  
Kumar B. Surreddi ◽  
Hoang V. Nguyen ◽  
Gang Liu ◽  
Thomas Gemming ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Room Temperature ◽  
Bulk Material ◽  
High Strength ◽  
Compression Tests ◽  
Bulk Alloy ◽  
Plasma Sintering ◽  
Spark Plasma

In situ devitrification and consolidation of gas atomized Al87Ni8La5 glassy powders into highly dense bulk specimens was carried out by spark plasma sintering. Room temperature compression tests of the consolidated bulk material reveal remarkable mechanical properties, namely, high compression strength of 930 MPa combined with plastic strain exceeding 25%. These findings demonstrate that the combined devitrification and consolidation of glassy precursors by spark plasma sintering is a suitable method for the production of Al-based materials characterized by high strength and considerable plastic deformation.

scholarly journals Deformation and Fracture Behavior of TiAl in Compression Tests at Room Temperature

1992 ◽  
Vol 33 (9) ◽  
pp. 802-810 ◽  
Author(s):  
Katsuhiko Nonaka ◽  
Kazuo Tanosaki ◽  
Masayoshi Fujita ◽  
Akihiko Chiba ◽  
Takeshi Kawabata ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Room Temperature ◽  
Compression Tests ◽  
Deformation And Fracture

Tensile and Fracture Behavior of NbSS/Nb5Si3 In Situ Composites Prepared by Arc Melting

2005 ◽  
Vol 297-300 ◽  
pp. 507-514
Author(s):  
Jin Hak Kim ◽  
Tatsuo Tabaru ◽  
Michiru Sakamoto ◽  
Shuji Hanada
Keyword(s):  
Base Composition ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Secondary Phase ◽  
Secondary Phases ◽  
In Situ Composites ◽  
Arc Melting ◽  
Negative Effect ◽  
Base Composite

Nb-base in-situ composites, which have the base composition of Nb-18Si-5Mo-5Hf, have been investigated in microstructure, hardness (Hv*), Young’s modulus (E), tensile properties and fracture behavior. The microstructures of all composites examined consist of NbSS matrix and Nb5Si3 secondary phases. No secondary phase such as Nb2C appeared. The crystal structure of Nb5Si3 is Mn5Si3-type when C replaces 2mol%-Nb, though typical structures of a (Cr5B3-type) and b (W5Si3-type) as in the base composition when W replaces. W addition is effective in increasing Hv* and E of both phases as expected. However, C alloying is somewhat beneficial only in Nb5Si3 with a noticeable negative effect in NbSS. Furthermore, the composite exhibits the highest strength at 1473 K, while the base composite exhibits the highest at room temperature. The fracture behavior is independent of the compositions and it is controlled by cleavage fractures of Nb5Si3, decohesion of NbSS/Nb5Si3 interface and ductile rupture of NbSS depending on the testing temperatures.

scholarly journals Deformation and Fracture Behavior of a TiAl Intermetallic Compound in Compression Tests at Room Temperature

1991 ◽  
Vol 55 (10) ◽  
pp. 1045-1053
Author(s):  
Katsuhiko Nonaka ◽  
Kazuo Tanosaki ◽  
Masayoshi Fujita ◽  
Akihiko Chiba ◽  
Takeshi Kawabata ◽  
...  
Keyword(s):  
Intermetallic Compound ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Compression Tests ◽  
Deformation And Fracture ◽  
Tial Intermetallic Compound
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