Mechanical Properties of Hot Extruded Al (Mg)-MnO2 Composites

2015 ◽  
Vol 813-814 ◽  
pp. 84-89 ◽  
Author(s):  
S. Ghanaraja ◽  
D.J. Dileep Kumar ◽  
K.S. Ravikumar ◽  
B.M. Madhusudan

Many of our modern technologies require materials with unusual combinations of properties that cannot be met by the conventional metal alloys, ceramics and polymeric materials. This is especially true for materials that are needed for aerospace, underwater and transportation applications. An economical way of producing metal matrix composite (MMC) is the incorporation of the particles into the liquid metal and casting. The objective of this work is to reinforce Al 1100-Mg alloy with different wt% of MnO2 (0, 3, 6, 9 and 12) was added by melt stirring method and Hot Extrusion is carried out. Microstructural Studies using Scanning Electron Microscopy (SEM) and Mechanical property like hardness and tensile properties have been investigated for extruded base alloy and composites.

2013 ◽  
Vol 19 (2) ◽  
pp. 276-284 ◽  
Author(s):  
George Vander Voort ◽  
Beatriz Suárez-Peña ◽  
Juan Asensio-Lozano

AbstractThe present study investigates the effect of the solidification strategy for AA 6063 alloy on the surface appearance of anodized extrusions. The microstructure of the samples was analyzed using both light optical microscopy and scanning electron microscopy. Results show that if heavy segregation occurs from rapid solidification, coarse Mg2Si particles form, thus reducing the potential for precipitation strengthening by the finer β-Mg2Si developed in the solid state. Differentially-strained regions formed during hot extrusion induce differences in particle size for magnesium silicide (Mg2Si) precipitates. Anodizing generates surface roughness due to Mg2Si particle dissolution and AlFeSi decohesion, which is related to both particle size and deformation. During anodizing, an oxide layer forms on the surface of the extruded products, which can lead to streak formation, usually a subject of rejection due to unacceptable heterogeneous reflectivity.


Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1979 ◽  
Author(s):  
Jing Zhang ◽  
Shibo Li ◽  
Shujun Hu ◽  
Yang Zhou

Ti3C2Tx MXene, a new 2D nanosheet material, is expected to be an attractive reinforcement of metal matrix composites because its surfaces are terminated with Ti and/or functional groups of –OH, –O, and –F which improve its wettability with metals. Thus, new Ti3C2Tx/Al composites with strong interfaces and novel properties are desired. To prepare such composites, the chemical stability of Ti3C2Tx with Al at high temperatures should be investigated. This work first reports on the chemical stability of Ti3C2Tx MXene with Al in the temperature range 500–700 °C. Ti3C2Tx is thermally stable with Al at temperatures below 700 °C, but it reacts with Al to form Al3Ti and TiC at temperatures above 700 °C. The chemical stability and microstructure of the Ti3C2Tx/Al samples were investigated by differential scanning calorimeter, X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy.


1995 ◽  
Vol 18 (3) ◽  
pp. 137-144 ◽  
Author(s):  
K. V. R. Prasad ◽  
K. B. R. Varma

Ceramics obtained from quenching melts of prereacted polycrystalline Bi2V5.5exhibit grain orientation (~ 55%). Microstructural studies carried out using scanning electron microscopy (SEM) on subsequently annealed ceramics show ferroelectric domains. These post-annealed ceramics possess dielectric anisotropies of about 1:1.2 at 300 K and 1:4.3 in the vicinity of the Curie temperature (~ 730 K) between the directions parallel and perpendicular to the quenching direction. The dielectric constants of the samples, obtained by quenching the melts, are higher than that of the post-annealed ceramics. Electrically poled and thermally cycled samples of both as-quenched and post-annealed exhibit ferroelectric hysteresis loops at 300 K.


Author(s):  
Xiaochun Li ◽  
Zhiwei Li

Permalloy NiFe matrix nanocomposite layers were electroplated on a copper substrate. The volume fraction of nano-sized Si3N4 particles in NiFe matrix was controlled by the addition of various percentages of Si3N4 particles in the NiFe electrolyte. The nanocomposite layers were analyzed by a scanning electron microscopy (SEM). Microhardness test was performed. With nano-sized Si3N4 particles in the NiFe matrix, the microhardness of NiFe was improved. The samples were then annealed at 800 °C for about 20 hours. The microhardness declined more with more Si3N4 particles in the NiFe matrix. The analysis result from Energy Dispersive Spectrometer (EDS) in the SEM showed that the hardness declination could be caused by the segregation of Si3N4 in the NiFe matrix. Finally this paper presents nanocomposite micromolds fabricated by electroplating onto polymer molds that were fabricated by micro-stereolithgraphy.


2002 ◽  
Vol 8 (I1) ◽  
pp. 20-20

Topic: Characterization of Non-Conductive or Charging Materials by Microbeam AnalysisThe goal of this topical conference is to present the state of the art for materials characterization of non-conductive or charging materials using microbeam analysis. Examples of charging materials include polymeric materials, ceramic materials, and photoresist materials in the microelectronic industry. Also, the characterization of biological specimens will be covered because they are prone to problems related to charging. These materials are of great technological importance and their characterization is still a great challenge because they charge when analyzed with an electron beam. The techniques of microbeam analysis that will be considered are: X-ray Microanalysis in the Electron Microprobe, Low Voltage Scanning Electron Microscopy, Environmental Scanning Electron Microscopy, Analytical Electron Microscopy with Field Emission Transmission Electron Microscopy, and Focused Ion Beam Milling for specimen preparation. World experts will present papers on these topics. Papers from this topical conference will be published in a special issue of Microscopy & Microanalysis.


Author(s):  
KSK Sasikumar ◽  
KP Arulshri ◽  
K Ponappa ◽  
M Uthayakumar

Metal matrix composites are difficult to machine in traditional machining methods. Abrasive water jet machining is a state-of-the art technology which enables machining of practically all engineering materials. This article deals with the investigation on optimization of process parameters of abrasive water jet machining of hybrid aluminium 7075 metal matrix composites with 5%, 10% and 15% of TiC and B4C (equal amount of each) reinforcement. The kerf characteristics such as kerf top width, kerf angle and surface roughness were studied against the abrasive water jet machining process parameters, namely, water jet pressure, jet traverse speed and standoff distance. Contribution of these parameters on responses was determined by analysis of variance. Regression models were obtained for kerf characteristics. Contribution of traverse speed was found to be more than other parameters in affecting top kerf width. Water jet pressure influenced more in affecting kerf angle and surface finish. The microstructures of machined surfaces were also analysed by scanning electron microscopy. The scanning electron microscopy investigations exposed the plastic deformation cutting of hybrid 7075 aluminium metal matrix composite. X-ray diffraction analysis results proved the non-entrapment of abrasive particle on the machined surface.


Author(s):  
Pedram Farhadipour ◽  
M Sedighi ◽  
Mohammad Heydari vini

In this study, warm accumulative roll bonding process has been used to produce metal matrix composite (Al/1% Al2O3). The microstructure and mechanical properties of composites have been studied after different warm accumulative roll bonding cycles by tensile test, Vickers micro-hardness test and scanning electron microscopy. The scanning electron microscopy results reveal that during higher warm accumulative roll bonding cycles, the layers of alumina particles are broken. It leads to the generation of elongated dense clusters with smaller sizes. This microstructure evolution leads to improve the hardness, strength and elongation during the accumulative roll bonding process. The results demonstrated that the dispersed alumina clusters improve both the strength and toughness of the composites. Also, an extra pass of cold rolling on the final warm accumulative roll bonding product shows the ability to obtain further strength. In general, warm accumulative roll bonding process would allow fabricating metal particle reinforced with high uniformity, good mechanical properties and high bonding strength.


1989 ◽  
Vol 03 (11) ◽  
pp. 877-885
Author(s):  
C.Y. HUANG ◽  
H.H. TAI ◽  
M.K. WU

Scanning electron microscopy, energy dispersive X-ray spectroscopy, and polarized light microscopy have shown that the addition of AgO to the E uBa 2 Cu 3 O y and GdBa 2 Cu 3 O y systems results in the growth of very large grains. Distribution of silver particle appears to influence the grain formation and growth in the superconducting composites.


2015 ◽  
Vol 667 ◽  
pp. 280-285
Author(s):  
Ning Li ◽  
Jian Meng Huang ◽  
Wei Zeng Chen ◽  
Bin Wang

The amorphous-nanocrystal Ni-Mo deposits were obtained by electrodeposition in alkaline nickel carbonate solution. X-ray diffraction (XRD), scanning electron microscopy (SEM) and modern technologies were used to describe the content, microstructure and morphology of the deposits. The electrochemical characteristics of Ni-Mo deposits were electrolyzed in 33°C, 7 mol/L NaOH electrolytic solutions. The results showed that when I was 100 mA·cm−2, the hydrogen evolution potential of Ni-Mo21.76 was lower than amorphous Ni-Mo26.36 and 250mV lower than the nanocrystal Ni cathode. And the Ni-Mo deposits with more amorphous phase content would be in lower hydrogen evolution overpotential, a higher exchange current density, and a better electrolytic stability. These due to the amorphous combined with nanocrystal, lager contact surface and binding energy of Ni-Mo structure.


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