Fracture behavior of a B2 Ni-30Al-20Fe-0.05Zr intermetallic alloy in the temperature range 300 to 1300 K

1992 ◽  
Vol 23 (6) ◽  
pp. 1691-1703 ◽  
Author(s):  
S. V. Raj
2018 ◽  
Vol 501 ◽  
pp. 200-207 ◽  
Author(s):  
Yanyun Zhao ◽  
Mengtian Liang ◽  
Zhenyu Zhang ◽  
Man Jiang ◽  
Shaojun Liu

1999 ◽  
Vol 30 (4) ◽  
pp. 1025-1038 ◽  
Author(s):  
W. O. Soboyejo ◽  
J. Dipasquale ◽  
F. Ye ◽  
C. Mercer ◽  
T. S. Srivatsan ◽  
...  

1990 ◽  
Vol 213 ◽  
Author(s):  
S. V. Raj ◽  
R. D. Noebe ◽  
I. E. Locci

ABSTRACTTensile tests were conducted on an extruded Ni-30(at.%)Al-20Fe-0.05Zr intermetallic alloy in the temperature range 300–1200 K and the microstructures were characterized by optical, scanning and transmission electron microscopy. The alloy did not exhibit any room temperature ductility and failed by transgranular cleavage at a stress of about 710 MPa. This mode of fracture was observed at and below 873 K with the total ductility being less than 2.5%. However, the failure mode changed to dimpled fracture, triple point cracking and rupture above 873 K. Scanning electron microscopy of the fracture surfaces revealed that transgranular cleavage failure had always originated at pre-existing defects. In these cases, the fracture stress exhibited a good correlation with the defect size in accordance with linear elastic fracture mechanics, where the critical stress intensity factor was estimated to be about 4 MPa m1/2.


2020 ◽  
Vol 27 ◽  
pp. 6-12
Author(s):  
Jaroslav Čech ◽  
Petr Haušild ◽  
Miroslav Karlík ◽  
Kateřina Nová ◽  
Filip Průša ◽  
...  

The study is devoted to the intermetallic alloy FeAl20Si20 (wt.%) with the potential applications in high temperature aggressive environments. The samples of the same chemical composition were prepared by spark plasma sintering from the different mechanically alloyed powders (pure elements and pre-alloyed powders). Differences in mechanical properties were characterized. Whereas no significant differences were found in hardness and Young´s modulus, fracture resistance was higher for the samples from pre-alloyed powders in which Palmqvist and lateral cracks were observed (contrary to the sample made of pure elements where only Palmqvist cracks were identified).


2021 ◽  
Vol 5 ◽  
pp. 58-64
Author(s):  
A. E. Sytschev ◽  
◽  
A. V. Karpov ◽  
A. V. Shcherbakov ◽  
◽  
...  

In this paper, we studied the effect of carbon (3 wt. %) on the electrical resistivity of materials based on Ni − Al and Ni – Al − C synthesized by the electrothermal explosion in the temperature range 300 – 1300 K in a vacuum of 2·10–3 Pa. During an electrothermal explosion, a Ni – Al-based melt is formed in a powder reactive medium, in which carbon is dissolved. It is shown that during the crystallization of the final product, due to its low solubility in NiAl, carbon is located on the surface of intermetallic NiAl grains in the form of multilayer graphite nanofilms 50 – 80 nm thick, filling the intergranular space. It is shown that the synthesized materials have a metallic conductivity, and the electrical resistivity in the measured temperature range of 300 – 1300 K increases monotonically for the Ni – Al-based alloy from 16 to 40 mW·cm and for the carbon-containing Ni – Al – C material from 22 to 60 mW·cm. The temperature coefficient of resistance (TCS) also increases from 1.45·10–3 K–1 for NiAl to 1.77·10–3 K–1 for NiAl/C. The slope of the resistivity curves in the studied temperature range of 300 – 1300 K remains constant and is well described by a linear function.


2015 ◽  
Vol 802 ◽  
pp. 303-308
Author(s):  
Ondrej Krpalek ◽  
Jan Valentin

Cold recycled mixes are used in many parts of the world as a standardized pavement rehabilitation technique. The quality of the mixes has been so far assessed by strength characteristics, water susceptibility and stiffness. In some cases frost resistance is determined as well. Nevertheless, especially for regions with winter seasons where temperatures are reaching values below 0°C, there are no standardized procedures and sufficient findings related to resistance to cracking and fracture behavior. Experimental study done at CTU in Prague describes three types of tests performed on 15 different cold recycled mixes. In parallel three standardized hot asphalt mixes were selected and used as well for a comparison of behavior in the range of low temperatures. Finally specimens acquired from an existing construction site where cold recycled technology was applied have been cored and tested mainly for crack propagation test. In general three tests have been selected and include crack propagation text on semi-cylindrical specimens, flexural strength test and relaxation test. Behavior in low temperature range and resistance to cracking has been tested in the temperature range of 0°C to-10°C.


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