scholarly journals Influence of Milling Route on the Corrosion Passivation of Al-2%SiC Nanocomposites in Chloride Solutions

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1231
Author(s):  
Saud M. Almotairy ◽  
El-Sayed M. Sherif ◽  
Nabeel H. Alharthi ◽  
Hany S. Abdo ◽  
Hamad F. Alharbi ◽  
...  

In this work, the fabrication of three Al-2wt.% SiC nanocomposites processed by novel milling route was carried out. The beneficial influence of milling route on the corrosion passivation of the new fabricated composites was investigated. The cyclic polarization measurements have proved that increasing the time of ball milling highly reduced the corrosion of Al-SiC nanocomposite via reducing obtained corrosion current and so increasing the corrosion resistance. These results were affirmed by the electrochemical impedance spectroscopy experiments. The pitting corrosion of the manufactured composites was also reported, and its intensity decreased with the increase of ball milling time. The electrochemical experiments were also performed after expanding the exposure time in the chloride solution to 24 and 48. It was found that both the uniform and pitting corrosion decrease with prolonging the time. The study was complemented by examining the surface morphology and the elemental analyses for the different composites by using surface analyses techniques.

2011 ◽  
Vol 347-353 ◽  
pp. 3232-3237
Author(s):  
Zhong Qiu Cao ◽  
Ting Wang ◽  
Ke Zhang ◽  
Hui Zhang

Microstructural characteristics and electrochemical properties of Mg40Al60hydrogen storage alloy prepared by mechanical alloying (MA) method were studied by XRD, discharge capacities, polarization curves and electrochemical impedance spectroscopies(EIS). The intensities of XRD peaks become weak and XRD peaks have a broadening with the increment of ball milling time due to fine grain size and increased internal stress. The discharge capacities of the alloy increase before the alloyed powders were milled for 10h, but they decrease after the alloyed powders were milled for 10h with the increment of ball milling time. The discharge capacities are highest when the alloyed powders were milled for 10h. There are passive phenomena in polarization curves. The corrosion current densities increase with time at the beginning of ball milling and then decrease. The electrochemical impedance spectroscopies(EIS) are composed of a single capacitive loop and the electrode reaction is controlled by charge transfer at alloy/electrolyte interface.


2015 ◽  
Vol 830-831 ◽  
pp. 429-432 ◽  
Author(s):  
Udaya ◽  
Peter Fernandes

The paper illustrates Carbon nanotubes reinforced pure Al (CNT/Al) composites and fly ash reinforced pure Al (FA/Al) composites produced by ball-milling and sintering. Microstructures of the fabricated composite were examined and the mechanical properties of the composites were tested and analysed. It was indicated that the CNTs and fly ash were uniformly dispersed into the Al matrix as ball-milling time increased with increase in hardness.


2018 ◽  
Vol 768 ◽  
pp. 261-266 ◽  
Author(s):  
Ju Yun Kang ◽  
Guang Yao Chen ◽  
Bao Tong Li ◽  
Zi Wei Qin ◽  
Xiong Gang Lu ◽  
...  

In this paper, the BaZrO3(BZ) and BaZr0.97Y0.03O3-δ(BZY3) powders were prepared by using the industrial grade BaCO3, ZrO2and Y2O3powders combining the conventional solid state reaction. The BaZrO3(BZ) and BaZr0.97Y0.03O3-δ(BZY3) ceramics were fabricated at 1750°C. The effect of ball milling time and sintering aid (TiO2) on the sinterability of BaZr0.97Y0.03O3-δ(BZY3) ceramics were investigated, and the improved stability of BaZrO3refractory with Y2O3additive were studied according to the refractory-metal interaction. The results revealed that the particle size of BZY3 powders decreased first and then increased with the increasing of ball milling time from 6h to 12h, and the minimum particle size was only 2.252μm at 8h. When 2wt.%TiO2was added, the sintered pellet of BZY3 was the most densest and the relative density was above 95%. After melting the Ti2Ni alloy on the BZY and BZ ceramics, the thickness erosion layer of BaZrO3and BZY3refractories and Ti2Ni alloy is approximately 50μm and 20μm respectively, showing that BZY3 was more stable than BaZrO3refractory.


Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1926 ◽  
Author(s):  
Lei Zhang ◽  
Zhifu Huang ◽  
Yangzhen Liu ◽  
Yupeng Shen ◽  
Kemin Li ◽  
...  

Mo2NiB2-Ni cermets have been extensively investigated due to their outstanding properties. However, studies have not systematically examined the effect of the powder milling process on the cermets. In this study, Mo, Ni, and B raw powders were subjected to mechanical ball milling from 1 h to 15 h. XRD patterns of the milled powders confirmed that a new phase was not observed at milling times of 1 h to 15 h. With the increase in the mechanical ball milling time from 1 h to 11 h, raw powders were crushed to small fragments, in addition to a more uniform distribution, and with the increase in the mechanical ball milling time to greater than 11 h, milled powders changed slightly. Mo2NiB2-Ni cermets were fabricated by reaction boronizing sintering using the milled powders at different ball milling times. The milling time significantly affected the microstructure and mechanical properties of Mo2NiB2-Ni cermets. Moreover, the Mo2NiB2 cermet powder subjected to a milling time of 11 h exhibited the finest crystal size and the maximum volume fraction of the Mo2NiB2 hard phase. Furthermore, the cermets with a milling time of 11 h exhibited a maximum hardness and bending strength of 87.6 HRA and 1367.3 MPa, respectively.


2020 ◽  
Vol 861 ◽  
pp. 250-255
Author(s):  
Fang Wang ◽  
Ai Xia Chen ◽  
Chao Yang ◽  
Min Han Xu ◽  
Da Ming Du ◽  
...  

Cermet is an important new engineering material that not only maintains the excellent properties of ceramic materials, but also has the advantages of metal materials. In this paper, the encapsulated alumina-aluminum composite powder was prepared by ball milling and characterized, which laid a foundation for the development of high properties cermet materials. Through the analysis of experimental results, the conclusions are shown when the ball milling time is greater than 3 h, the alumina particles are more evenly distributed around the aluminum powder. the ball milling for 6 h may have reached a limit of the mixing uniformity of the two powder, so the ball milling is determined 6 h as the better ball milling time. Under the ball milling condition of 50 r/min, the distribution of alumina particles around the aluminum powder is more uniform around the aluminum powder than the ball mill under 75 r/min, the ball milling speed is preferably 50 r/min. As the content of aluminum powder increases, the distribution of alumina in aluminum powder is large and uniform, and there is a small amount of pinning. It provides a package-like composite for the preparation of cermet with a wrapped structure and the thermal conduction mechanism of the controlled cermet.


Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3483
Author(s):  
Shu Mei Lou ◽  
Chuan Dong Qu ◽  
Guang Xin Guo ◽  
Ling Wei Ran ◽  
Yong Qiang Liu ◽  
...  

Aluminum composites reinforced by graphene nanoplates(GNP) with a mass fraction of 0.5% (0.5 wt.% GNP/Al) were fabricated using cold pressing and hot pressing. An orthogonal test was used to optimize the fabrication parameters. Ball milling time, ball milling speed, and ultrasonic time have the largest influence on the uniformity of the graphene in the composites. Afterwards, the microstructure, interfacial properties, and fracture morphology of the composites obtained with different parameters were further analyzed. The results show that ball milling time and ball milling speed have obvious influences on the mechanical properties of the composite. In this paper, when the ball milling speed is 300 r/min and the ball milling time is 6 h, the dispersion uniformity of graphene in the 0.5 wt.% GNP/Al composite is the best, the agglomeration is the lowest, and the mechanical properties of the composites are the best, among which the tensile strength is 156.8 MPa, 56.6% higher than that of pure aluminum fabricated by the same process (100.1 MPa), and the elongation is 19.9%, 39.8% lower than that of pure aluminum (33.1%).


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