Effect of Electromagnetic Stirring on Microstructure of In Situ Synthesized (Al2O3+Al3Zr)P/Al Composites

2011 ◽  
Vol 284-286 ◽  
pp. 94-97
Author(s):  
Hong Ming Wang ◽  
Bing Zhao ◽  
Yan Qiong He ◽  
Yi Nan Zhao ◽  
Gui Rong Li ◽  
...  

(Al2O3+Al3Zr)P/Al composites were in situ synthesized from Al-Zr(CO3)2 system. In the process of in situ reaction, electromagnetic stirring (EMS) is employed to improve the conditions of reaction between reactants powder and melt. The results indicate that the Lorenz force improves the kinetic condition and accelerates the nucleation of endogenetic particulates. The optimized electromagnetic density is 0.025T. Scanning electronic microscope (SEM) observation demonstrates that the sizes of reinforced particulates are controlled at 1~2 μm. Moreover, the particulates are well distributed in Al matrix.

2013 ◽  
Vol 23 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Xinhua Chen ◽  
Hongxiang Zhai ◽  
Wenjuan Wang ◽  
Shibo Li ◽  
Zhenying Huang

2010 ◽  
Vol 654-656 ◽  
pp. 2931-2934
Author(s):  
Hyun Bom Lee ◽  
Hiroyasu Tezuka ◽  
Equo Kobayashi ◽  
Tatsuo Sato ◽  
Kee Do Woo

A planetary ball milling (PBM) technique was employed to fabricate mechanically alloyed (MA processed) Al-Nb2O5 composite powder. Nano or sub-micron sized Nb2O5 particles were homogeneously embedded in the Al particles after milling for various periods. None of cracks, by-products and pores were observed in the areas between embedded Nb2O5 particulates and Al matrix powder after milling. The sequence of the in-situ reaction was confirmed by DSC, XRD measurements, optical microscopy and EPMA. The specific temperature of the in-situ reaction was between 650 and 700°C. Al-based metal matrix composites (MMC) reinforced with the sub-sieve sized θ-Al2O3 particulates and Al3Nb intermetallic compound were successfully fabricated by the in-situ reaction process. The substituted Nb by the in-situ reaction was fully reacted with Al to form the Al3Nb intermetallic compound during sintering. A number of sub-sieve sized θ-Al2O3 particulates and Al3Nb intermetallic compound formed by the in-situ reaction between Al and Nb2O5 were homogeneously distributed in the Al matrix during sintering. Nano sized θ-Al2O3 particulates are preferentially distributed near the Al3Nb intermetallic compound and no by-products are formed in the interfaces with the Al matrix.


2021 ◽  
Vol 560-561 ◽  
pp. 126043
Author(s):  
Mayumi Mujin ◽  
Michihiko Nakamura ◽  
Megumi Matsumoto
Keyword(s):  

2020 ◽  
Vol 48 (11) ◽  
pp. 1356-1364
Author(s):  
Jun HAN ◽  
Yang-shuo LIANG ◽  
Bo ZHAO ◽  
Zi-jiang XIONG ◽  
Lin-bo QIN ◽  
...  

Author(s):  
Jia-Feng Fan ◽  
Guo Liu ◽  
Xue-Shi Zhuo ◽  
Xiao-Feng Zhang ◽  
Jun-Li Feng ◽  
...  

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chunzheng Lv ◽  
Lirong He ◽  
Jiahong Tang ◽  
Feng Yang ◽  
Chuhong Zhang

AbstractAs an important photoconductive hybrid material, perylene/ZnO has attracted tremendous attention for photovoltaic-related applications, but generally faces a great challenge to design molecular level dispersed perylenes/ZnO nanohybrids due to easy phase separation between perylenes and ZnO nanocrystals. In this work, we reported an in-situ reaction method to prepare molecular level dispersed H-aggregates of perylene bisimide/ZnO nanorod hybrids. Surface photovoltage and electric field-induced surface photovoltage spectrum show that the photovoltage intensities of nanorod hybrids increased dramatically for 100 times compared with that of pristine perylene bisimide. The enhancement of photovoltage intensities resulting from two aspects: (1) the photo-generated electrons transfer from perylene bisimide to ZnO nanorod due to the electric field formed on the interface of perylene bisimide/ZnO; (2) the H-aggregates of perylene bisimide in ZnO nanorod composites, which is beneficial for photo-generated charge separation and transportation. The introduction of ordered self-assembly thiol-functionalized perylene-3,4,9,10-tetracarboxylic diimide (T-PTCDI)/ ZnO nanorod composites induces a significant improvement in incident photo-to-electron conversion efficiency. This work provides a novel mentality to boost photo-induced charge transfer efficiency, which brings new inspiration for the preparation of the highly efficient solar cell.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.


Sign in / Sign up

Export Citation Format

Share Document