7 results on '"Waras, Abdul"'
Search Results
2. Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process
- Author
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Yuhong Jiao, Jianfeng Zhu, Xuelin Li, Chunjie Shi, Bo Lu, Fen Wang, and Waras Abdul
- Subjects
SiC/MgAl2O4/MgO/Al–Mg–Si composite ,in situ growth ,flash pyrolysis of phenolic resin ,casting process ,mechanical strength ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
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.
- Published
- 2021
- Full Text
- View/download PDF
3. Enhanced electromagnetic wave absorption of engineered epoxy nanocomposites with the assistance of polyaniline fillers
- Author
-
Jiang Guo, Zhuoran Chen, Xiaojian Xu, Xu Li, Hu Liu, Shaohua Xi, Waras Abdul, Qing Wu, Pei Zhang, Ben Bin Xu, Jianfeng Zhu, and Zhanhu Guo
- Subjects
Polymers and Plastics ,F300 ,Materials Science (miscellaneous) ,Materials Chemistry ,Ceramics and Composites ,F200 - Abstract
In this work, the engineered polyaniline (PANI)/epoxy composites reinforced with PANI-M (physical mixture of PANI spheres and fibers) exhibit significantly enhanced electromagnetic wave absorption performance and mechanical property. Due to the synergistic effect of PANI fillers with different geometries, the reflection loss of 10.0 wt% PANI-M/epoxy could reach − 36.8 dB at 17.7 GHz. Meanwhile, the mechanical properties (including tensile strength, toughness, and flexural strength) of PANI/epoxy were systematically studied. Compared with pure epoxy, the tensile strength of epoxy with 2.0 wt% PANI-M was improved to 86.2 MPa. Moreover, the PANI spheres (PANI-S) and PANI fibers (PANI-F) were prepared by the chemical oxidation polymerization method and interface polymerization method, respectively. The characterizations including scanning electron microscope, Fourier transform infrared spectra, and X-ray diffraction were applied to analyze the morphology and chemical and crystal structures of PANI filler. This work could provide the guideline for the preparation of advanced engineered epoxy nanocomposites for electromagnetic wave pollution treatment. Graphical abstract
- Published
- 2022
4. In-situ synthesis, microstructure and mechanism of SiC/Al–Mg–Si composites: Effects of Mg addition
- Author
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Waras Abdul, Li Xuelin, Chunjie Shi, Yuhong Jiao, Zhao Xu, Jianfeng Zhu, Fen Wang, and Lu Bo
- Subjects
010302 applied physics ,Ostwald ripening ,Materials science ,Scanning electron microscope ,Process Chemistry and Technology ,Composite number ,Alloy ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Transmission electron microscopy ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,engineering ,symbols ,Composite material ,0210 nano-technology ,Pyrolysis - Abstract
The SiC/Al–Mg–Si composite was obtained by in-situ synthesis, and the effects of Mg addition were investigated in this process. Mechanism of in situ SiC growth in the Resin–Al–Mg–Si system was investigated by fabricating and characterizing a SiC/Al–Mg–Si composite under moderate conditions. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) were used to analyze the phase and its microstructure, with the aim of investigating the evolvement of grains in the alloy matrix. Mg2Si formed under higher Mg added conditions, which decreased the molten liquid and Si solute concentrations. Tiny amounts of MgO and MgAl2O4 proved that the pyrolysis gas of resin reacts slightly with the matrix. The key conditions of in-situ synthesis SiC were found that the Mg addition and the Si concentration in the molten alloy were 3%–5% and over 17. 27 % respectively. Ostwald ripening was used to explain the decrease in tiny SiC grains at elevated temperatures. In situ SiC growth is controlled by the interfacial reaction-diffusion mixed model through two different routes in the molten alloy. Two modes of in-situ synthesis were suggested. The intermediate product and template for in situ SiC growth are Al4C3, and Si was shown to diffuse into its particles gradually. Flowing Si in molten alloy reacted with pyrolysis C directly. Specimens validated the peak bending strength with a rise in temperature. The maximal bending strength was 251.89 MPa.
- Published
- 2020
5. Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process
- Author
-
Waras Abdul, Fen Wang, Lu Bo, Jianfeng Zhu, Chunjie Shi, Yuhong Jiao, and Xuelin Li
- Subjects
Materials science ,SiC/MgAl2O4/MgO/Al–Mg–Si composite ,Alloy ,Composite number ,engineering.material ,lcsh:Technology ,Flexural strength ,Ultimate tensile strength ,General Materials Science ,Ceramic ,Composite material ,lcsh:Microscopy ,lcsh:QC120-168.85 ,lcsh:QH201-278.5 ,lcsh:T ,Communication ,in situ growth ,flash pyrolysis of phenolic resin ,mechanical strength ,Microstructure ,casting process ,Compressive strength ,lcsh:TA1-2040 ,visual_art ,visual_art.visual_art_medium ,engineering ,lcsh:Descriptive and experimental mechanics ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,lcsh:Engineering (General). Civil engineering (General) ,Pyrolysis ,lcsh:TK1-9971 - Abstract
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.
- Published
- 2021
6. Carbon-Coated SnO2/Ti3C2 Composites with Enhanced Lithium Storage Performance
- Author
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Wang, Zijing, primary, Wang, Fen, additional, Liu, Kaiyu, additional, Zhu, Jianfeng, additional, and Waras, Abdul, additional
- Published
- 2019
- Full Text
- View/download PDF
7. Carbon-Coated SnO2/Ti3C2 Composites with Enhanced Lithium Storage Performance.
- Author
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Wang, Zijing, Wang, Fen, Liu, Kaiyu, Zhu, Jianfeng, and Waras, Abdul
- Subjects
COMPOSITE materials ,METALLIC composites ,RARE earth oxides ,TIN oxides ,AMORPHOUS carbon ,METALLIC oxides ,TRANSITION metal oxides ,DIFFUSION coefficients - Abstract
Tin-based anode materials including oxides, composites oxides, and tin-based alloys are identified as promising candidates for energy storage attributed to the highest theoretical specific capacity. We introduce Ti
3 C2 -MXene as structural skeletons and amorphous carbon as conductive networks for tin oxide in this work. Herein, carbon-coated kernel-like SnO2 coupling with two-dimensional (2D) layered structure Ti3 C2 -MXene (C@SnO2 /Ti3 C2 ) composites were prepared by a hydrothermal reaction and a further calcination process. The fabricated C@SnO2 /Ti3 C2 nanocomposites exhibit smaller charge transfer resistance, larger Li+ diffusion coefficient, and better cycling stability than SnO2 /Ti3 C2 and pure Ti3 C2 . Most of all, C@SnO2 /Ti3 C2 nanocomposites display excellent initial capacity of 1531.5 mAh g−1 at current density of 100 mA g−1 and show outstanding rate performance of 540 mAh g−1 even after 200 cycles. In our work, we will provide a new research idea for the composite materials of metal oxides and two-dimensional layered materials in the field of electrode materials for batteries. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
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