scholarly journals Annealing effects in hot-deformed Al-Mn-Sc-Zr alloys

2016 ◽  
Vol 52 (05) ◽  
pp. 295-304 ◽  
Author(s):  
M. VLACH ◽  
I. STULÍKOVÁ ◽  
B. SMOLA ◽  
T. KEKULE ◽  
H. KUDRNOVÁ ◽  
...  
Keyword(s):  
2020 ◽  
Vol 142 (5) ◽  
pp. 1613-1623 ◽  
Author(s):  
Veronika Kodetová ◽  
Martin Vlach ◽  
Hana Kudrnová ◽  
Michal Leibner ◽  
Jaroslav Málek ◽  
...  

Author(s):  
Martin Vlach ◽  
Jakub Čížek ◽  
Veronika Kodetová ◽  
Tomáš Kekule ◽  
František Lukáč ◽  
...  

Author(s):  
D.M. Vanderwalker

Aluminum-lithium alloys have a low density and high strength to weight ratio. They are being developed for the aerospace industry.The high strength of Al-Li can be attributed to precipitation hardening. Unfortunately when aged, Al-Li aquires a low ductility and fracture toughness. The precipitate in Al-Li is part of a sequence SSSS → Al3Li → AlLi A description of the phases may be found in reference 1 . This paper is primarily concerned with the Al3Li phase. The addition of Zr to Al-Li is being explored to find the optimum in properties. Zirconium improves fracture toughness and inhibits recrystallization. This study is a comparision between two Al-Li-Zr alloys differing in Zr concentration.Al-2.99Li-0.17Zr(alloy A) and Al-2.99Li-0.67Zr (alloy B) were solutionized for one hour at 500oc followed by a water quench. The specimens were then aged at 150°C for 16 or 40 hours. The foils were punched into 3mm discs. The specimens were electropolished with a 1/3 nitric acid 2/3 methanol solution. The transmission electron microscopy was conducted on the JEM 200CX microscope.


1985 ◽  
Vol 46 (C8) ◽  
pp. C8-181-C8-185
Author(s):  
A. E. Lee ◽  
S. Jost ◽  
Ch. N.J. Wagner ◽  
L. E. Tanner
Keyword(s):  

2020 ◽  
pp. 114-119

Experimental and theoretical study Porphyrin-grafted ZnO nanowire arrays were investigated for organic/inorganic hybrid solar cell applications. Two types of porphyrin – Tetra (4-carboxyphenyle) TCPP and meso-Tetraphenylporphine (Zinc-TPP)were used to modify the nanowire surfaces. The vertically aligned nanowires with porphyrin modifications were embedded in graphene-enriched poly (3-hexylthiophene) [G-P3HT] for p-n junction nanowire solar cells. Surface grafting of ZnO nanowires was found to improve the solar cell efficiency. There are different effect for the two types of porphyrin as results of Zn existing. Annealing effects on the solar cell performance were investigated by heating the devices up to 225 °C in air. It was found that the cell performance was significantly degraded after annealing. The degradation was attributed to the polymer structural change at high temperature as evidenced by electrochemical impedance spectroscopy measurements.


2020 ◽  
Author(s):  
Rong Yuan ◽  
Xie Yao-Ping ◽  
Tong Li ◽  
Chen-Hao Xu ◽  
Mei-Yi Yao ◽  
...  

2021 ◽  
Author(s):  
Fabian Garmroudi ◽  
Michael Parzer ◽  
Alexander Riss ◽  
Nikolas Reumann ◽  
Bernhard Hinterleitner ◽  
...  

Engevista ◽  
2017 ◽  
Vol 19 (4) ◽  
pp. 975
Author(s):  
Mauro Quaresma Lobato ◽  
Emerson Rodrigues Prazeres ◽  
Renan Gouvea Dias ◽  
José Maria Do Vale Quaresma
Keyword(s):  

A microestrutura resultante da solidificação afeta diretamente as propriedades mecânicas de um produto. A velocidade, a taxa de resfriamento e os gradientes térmicos, tem grande influência na determinarão do grau de refino da estrutura. Portanto, conhecer as informações relativas aos aspectos relacionados durante todo o processo de solidificação é fundamental quando se deseja produzir um material. O trabalho apresentado a seguir foi realizado com intuito de estudar e comparar as ligas Al-0,05%Cu-[0,35-0,45]%Fe-0,3%Si-0,15%Zr e Al-0,05%Cu-[0,35-0,45]%Fe-0,3%Si-0,22%Zr. Foi utilizado para solidificação um simulador físico, na forma de uma câmara retangular com seis faces (Molde Unidirecional Horizontal) contendo uma única face metálica, capaz de extrair calor de forma mais intensa quando comparada com as outras cinco faces. Com isso, foi possível avaliar o comportamento termofísico das ligas, como velocidade de solidificação e taxa de resfriamento, comportamento macroestrutural e microestrutural. Foi observado que a maior afinidade metal/molde contribuiu para a menor velocidade de resfriamento e taxa de solidificação para a liga Al-Cu-Fe-Si-0,22%Zr. Comparando as taxas de resfriamento com as macroestruturas, notou-se que menores taxas contribuíram para formação de grãos mais equiaxiais. Notou-se que o teor de Zr e a taxa de resfriamento exercem uma grande influência na organização do Ferro e do Silício ao longo do lingote. O maior teor de Zr e baixas taxas favorecem a maior concentração de Silício no entorno da estrutura eutetica do Al-Fe.


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