scholarly journals Microstructure and Mechanical Properties of Mg/2 wt.%SiCp Nanocomposite Fabricated by ARB Process

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zheng Lv ◽  
Xueping Ren ◽  
Wenjing Wang ◽  
Xiaodan Gao ◽  
Wenjie Li

Magnesium matrix nanocomposites (MMNC, the same below) containing 2 wt.% nanosized SiCp were fabricated through accumulative roll bonding (ARB). The microstructure and mechanical properties of Mg/2 wt.%SiCp nanocomposites are reported for various ARB cycles. To evaluate microstructure of the nanocomposites, the field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), and transmission electron microscope (TEM) were applied. After fourteen ARB cycles, the nanocomposite showed a homogeneous distribution of reinforcements and a significant reduction in average matrix grain size. Meanwhile, the nanocomposite revealed a higher percentage of recrystallization and lower intensity of basal texture as compared to monolithic Mg. Mechanical properties were investigated through tensile and microhardness tests. The strength and elastic modulus and microhardness of Mg/2 wt.%SiCp were found to be improved significantly from eight ARB cycles and reach maximum values at fourteen ARB cycles. The ultimate tensile strength, yield strength, microhardness, and elastic modulus of Mg/2 wt.%SiCp are considerably increased by 17.6%, 61.0%, 72.7%, and 80.8% as compared to raw Mg, respectively.

2016 ◽  
Vol 61 (2) ◽  
pp. 761-766 ◽  
Author(s):  
A. Zieliński ◽  
M. Sroka ◽  
A. Hernas ◽  
M. Kremzer

Abstract The HR3C is a new steel for pressure components used in the construction of boilers with supercritical working parameters. In the HR3C steel, due to adding Nb and N, the compounds such as MX, CrNbN and M23C6 precipitate during service at elevated temperature, resulting in changes in mechanical properties. This paper presents the results of microstructure investigations after ageing at 650, 700 and 750 °C for 5,000 h. The microstructure investigations were carried out using scanning and transmission electron microscopy. The qualitative and quantitative identification of the existing precipitates was carried out using X-ray analysis of phase composition. The effect elevated temperature on microstructure and mechanical properties of the examined steel was described.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2150 ◽  
Author(s):  
Su-Seong Ahn ◽  
Sharief Pathan ◽  
Jar-Myung Koo ◽  
Chang-Hyun Baeg ◽  
Chan-Uk Jeong ◽  
...  

In this research, various processing conditions were implemented to enhance the mechanical properties of Al-Si alloys. The silicon content was varied from hypoeutectic (Si-10 wt.%) to eutectic (Si-12.6 wt.%) and hypereutectic (Si-14 wt.%) for the preparation of Al-XSi-3Cu-0.5Fe-0.6 Mg (X = 10–14%) alloys using die casting. Subsequently, these alloys were hot-extruded with an optimum extrusion ratio (17:1) at 400 °C to match the output extruded bar to the compressor size. An analysis of the microstructural features along with a chemical compositional analysis were carried out using scanning electron microscope along with energy dispersive X-ray spectroscopy and transmission electron microscope. The SEM micrographs of the extruded samples displayed cracks in primary Si, and the intermetallic (β-Al5FeSi) phase was fragmented accordingly. In addition, the silicon phase was homogenously distributed, and the size remained constant. The mechanical properties of the extruded samples were enhanced by the increase of silicon content, and consequently the ductility decreased. By implementing proper T6 heat treatment parameters, coherent Al2Cu phases were formed in the Al matrix, and the Si phase was gradually increased along with the silicon content. Therefore, high tensile strength was achieved, reaching values for the Al-XSi-3Cu-0.5Fe-0.6Mg (X = 10–14%) alloys of 366 MPa, 388 MPa, and 420 MPa, respectively.


2014 ◽  
Vol 543-547 ◽  
pp. 3733-3736
Author(s):  
Rong Hua Zhang ◽  
Biao Wu ◽  
Xiao Ping Zheng

In this study, 8009 heat resistant aluminum alloy was synthesized by the spray atomization and deposition technique. The microstructure and mechanical properties of the alloy were studied using transmission electron microscopy, X-ray diffraction, and tensile tests. The secondary phases in the microstructure of the spray-deposited alloy were examined. The tensile test results indicate that the spray-deposited 8009 alloy both at room and elevated temperature displays superior tensile strength due to the presence of the thermally stable Al12(Fe,V)3Si particles.


2013 ◽  
Vol 281 ◽  
pp. 426-429
Author(s):  
Tao Chen ◽  
Hua Wu ◽  
Qing Hui Wang

PVD method is used to deposit (Ti,Al)N coatings on the surface of W6Mo5Cr4V2 steels. The value of bias voltage changes from -100V to -400V. X-ray diffraction (XRD), Scanning electron microscope(SEM) and UNMT-1 were employed to analysis the microstructure and mechanical properties of (Ti,Al)N coatings. The research results showed that the microstructure and mechanical properties of coatings became better when the value of bias voltage was -400V. The size and quantity of particles on coatings both decreased obviously. The adhesion between coatings and substrates increase to 54.6N. The hardness of (Ti,Al)N coatings rise to 39.7N.


2011 ◽  
Vol 399-401 ◽  
pp. 259-263 ◽  
Author(s):  
Xue Min Wang ◽  
Pei Zhu Li

With the aid of optical microscope, transmission electron microscope, scanning electron microscope, the processing and chemical composition on the microstructure and mechanical properties of low alloy wear resistance steels have been investigated. The results show that by multi-alloying design and TMCP processing the low alloy wear resistance steels has good synthetic properties. The lath martensite, multi phase microstructure composed of bainite and retained austenite film could be obtained after direct quenching. The lath martensite with retained austenite shows better wear resistance than bainite. Under the two bodies abrasive wear condition the characteristics of worn surface reveals that the main wear mechanism is micro-cutting.


2016 ◽  
Vol 716 ◽  
pp. 464-471 ◽  
Author(s):  
Wojciech Skuza ◽  
Henryk Paul ◽  
Katarzyna Berent ◽  
Mariusz Prazmowski ◽  
Piotr Bobrowski

In this study, unalloyed titanium (Gr.1) and deoxidized high phosphorus copper plates were joined through explosive welding process. Different stand-off distances were used to investigate their influence on the microstructure and mechanical properties of the clad fabricated at the same amount of explosive charge. Microstructures near-the-interface were examined with the use of scanning electron microscope equipped with energy dispersive X-ray spectrometer and then microhardness measurements were carried out on the clad. Microstructure examinations showed that with increasing stand-off distance the length and amplitude of the waviness and the quantity of melted zones in areas near-the-interface increase. The inclusions of the melted zones are formed behind the wave crests on titanium side or within the wave vortex. Microhardness measurements indicate a significant increase of both plates microhardness, especially near-the-interface.


2021 ◽  
Vol 1035 ◽  
pp. 175-181
Author(s):  
Qing Hao Zhang ◽  
Lan Luo ◽  
Yong Liu ◽  
Zi Hui Xu

The effect of cryogenic treatment (CT) on the microstructure and mechanical properties of the as-extruded Mg–3.5Zn–0.6Gd alloy was investigated. The results showed that W-phase newly appeared in cryogenic treatment samples but without notable second phase amount increasing. There was also no remarkable grain refinement. But the amount of twins reduced greatly, the strong basal texture {0001} rotated and increased. The intensity of plane (0002) diffraction peak was weakened along with planes ( 1 0-1 0 ) ( 1 0-1 1 ) being enhanced in X-ray diffraction pattern. The change in mechanical properties was not obvious. The mechanism of the microstructure evolution is discussed as well.


2020 ◽  
Vol 67 (1) ◽  
pp. 13-19
Author(s):  
Bastri Zeka ◽  
Boštjan Markoli ◽  
Primož Mrvar ◽  
Blaž Leskovar ◽  
Mitja Petrič

AbstractLithium additions to Al offer the promise of substantially reducing the weight of alloys, since each 1 wt. % Li added to Al reduces density by 3 % and increases elastic modulus. In the present work, the effect of 1.46 wt. % Li addition to AlSi7Mg (containing 7.05 wt. % Si and 0.35 wt. % Mg) was studied. The alloy showed reduced density and higher hardness after natural ageing. Experimental work showed that micro-structural and mechanical properties changed with Li addition. It was observed that 0.80 wt. % Li addition resulted in formation of new phase AlLiSi which has a great effect to increase hardness of AlSi7Mg. According to Scanning Electron Microscope (SEM) and X-ray diffraction analysis it was confirmed that the addition of Li causes formation of different phases which are: α-Al, β-Si and AlLiSi.


2014 ◽  
Vol 1063 ◽  
pp. 69-72
Author(s):  
Cai Nian Jing ◽  
Ji Chao Fan ◽  
Shu Bo Xu ◽  
Yi Sheng Zhang

In this paper, the microstructure and mechanical properties of 0.15C-1.5Mn-0.3Si steels after quenching and partitioning (Q&P) process was studied. The microstructure of experimental steels was characterized by optical microscope (OM), scan electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD), and mechanical properties were performed through uni-axial tensile tests. The microstructure evolution during Q&P process was also discussed together with mechanical properties. The investigated steels show excellent strength and ductility product of 10.76GPa% with retained austenite content of 11.08%. The microstructure mainly consists of lath martensite and retained austenite at room temperature, which promotes persistent work hardening during deformation.


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