scholarly journals On the Hot Pressing of Oxide Materials

1962 ◽  
Vol 11 (108) ◽  
pp. 528-534 ◽  
Author(s):  
Y. Hamano
Keyword(s):  
Author(s):  
T. E. Mitchell ◽  
P. B. Desch ◽  
R. B. Schwarz

Al3Zr has the highest melting temperature (1580°C) among the tri-aluminide intermetal1ics. When prepared by casting, Al3Zr forms in the tetragonal DO23 structure but by rapid quenching or by mechanical alloying (MA) it can also be prepared in the metastable cubic L12 structure. The L12 structure can be stabilized to at least 1300°C by the addition of copper and other elements. We report a TEM study of the microstructure of bulk Al5CuZr2 prepared by hot pressing mechanically alloyed powder.MA was performed in a Spex 800 mixer using a hardened steel container and balls and adding hexane as a surfactant. Between 1.4 and 2.4 wt.% of the hexane decomposed during MA and was incorporated into the alloy. The mechanically alloyed powders were degassed in vacuum at 900°C. They were compacted in a ram press at 900°C into fully dense samples having Vickers hardness of 1025. TEM specimens were prepared by mechanical grinding followed by ion milling at 120 K. TEM was performed on a Philips CM30 at 300kV.


1998 ◽  
Vol 77 (4) ◽  
pp. 1033-1037 ◽  
Author(s):  
Y. Park, S. A. Song H., G. Kim

1980 ◽  
Vol 41 (C6) ◽  
pp. C6-479-C6-484 ◽  
Author(s):  
O. F. Schirmer
Keyword(s):  

2020 ◽  
Author(s):  
Junbo Wang ◽  
Yanyan Cui ◽  
Qingsong Wang ◽  
Kai Wang ◽  
Xiaohui Wang ◽  
...  

<p>Layered Li<i><sub>x</sub></i>MO<sub>2</sub> materials, a new class of high-entropy oxides, have been synthesized by nebulized spray pyrolysis. Specifically, the lattice structure of Li(Ni<sub>1/3</sub>Mn<sub>1/3</sub>Co<sub>1/3</sub>)O<sub>2</sub> (NCM111) cathode material has been replicated successfully while increasing the number of cations in equimolar proportions, thereby allowing transition to high-entropy oxide materials.</p>


2019 ◽  
Author(s):  
Seoin Back ◽  
Kevin Tran ◽  
Zachary Ulissi

<div> <div> <div> <div><p>Developing active and stable oxygen evolution catalysts is a key to enabling various future energy technologies and the state-of-the-art catalyst is Ir-containing oxide materials. Understanding oxygen chemistry on oxide materials is significantly more complicated than studying transition metal catalysts for two reasons: the most stable surface coverage under reaction conditions is extremely important but difficult to understand without many detailed calculations, and there are many possible active sites and configurations on O* or OH* covered surfaces. We have developed an automated and high-throughput approach to solve this problem and predict OER overpotentials for arbitrary oxide surfaces. We demonstrate this for a number of previously-unstudied IrO2 and IrO3 polymorphs and their facets. We discovered that low index surfaces of IrO2 other than rutile (110) are more active than the most stable rutile (110), and we identified promising active sites of IrO2 and IrO3 that outperform rutile (110) by 0.2 V in theoretical overpotential. Based on findings from DFT calculations, we pro- vide catalyst design strategies to improve catalytic activity of Ir based catalysts and demonstrate a machine learning model capable of predicting surface coverages and site activity. This work highlights the importance of investigating unexplored chemical space to design promising catalysts.<br></p></div></div></div></div><div><div><div> </div> </div> </div>


2014 ◽  
Vol 56 (3) ◽  
pp. 213-217 ◽  
Author(s):  
Serkan Islak ◽  
Durmuş Kır ◽  
Halis Çelik

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