Microstructure characterization and evaluation of mechanical properties of stir rheocast AA2024/TiB2 composite

2019 ◽  
Vol 54 (7) ◽  
pp. 981-997
Author(s):  
Semegn Cheneke ◽  
D Benny Karunakar
Keyword(s):  
Mechanical Properties ◽  
Dendritic Structure ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
Globular Structure ◽  
Cast Sample ◽  
X Ray ◽  
Weight Percentage ◽  
The Matrix ◽  
Fractured Surface

In this research, microstructure and mechanical properties of stir rheocast AA2024/TiB2 metal matrix composite have been investigated. The working temperature was 640℃, which was the selected semisolid temperature that corresponds to 40% of the solid fraction. Two weight percentage, 4 wt%, and 6 wt% of the TiB2 reinforcements were added to the matrix. The field emission scanning electron microscope micrographs of the developed composites showed a uniform distribution of the particles in the case of the 2 wt% and 4 wt% of the reinforcements. However, the particles agglomerated as the weight percentages of the reinforcement increases to 6%. The optical microscope of the liquid cast sample showed the dendritic structure, whereas the rheocast samples showed a globular structure. The X-ray diffraction analysis confirmed the distribution of the reinforcements in the matrix and the formation of some intermetallic compounds. Mechanical properties significantly improved by the addition of the reinforcements in the matrix. An increase in tensile strength of 13.3%, 40%, 28%, and 5% was achieved for the unreinforced rheocast sample, 2 wt%, 4 wt%, and 6 wt% reinforced rheocast samples respectively, compared to the liquid cast sample. An increase in 20% of hardness was attained for the composite with 2 wt% TiB2 compared to the liquid cast sample. According to the fractography analysis, small dimples were observed on the fractured surface of the unreinforced rheocast sample, whereas small and large voids were dominant on the fractured surface of the 2 wt% composite, which shows the ductile fracture mode.

Mechanical Properties of Dental Nanocomposites Reinforced with Polyhedral Oligomeric Silsesquioxane(POSS)

2009 ◽  
Vol 79-82 ◽  
pp. 345-348 ◽  
Author(s):  
Xiao Rong Wu ◽  
Wei Li Xie ◽  
Yi Sun ◽  
Shou Hua Sun
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Spectroscopic Technique ◽  
X Ray Diffraction ◽  
Flexure Strength ◽  
X Ray ◽  
Weight Percentage ◽  
The Matrix ◽  
Double Bond Conversion ◽  
Oligomeric Silsesquioxane

The objective of this study was to incorporate POSS-MA into the polymeric matrix to develop a new kind of nanocomposite. The effect of different weight percentage of POSS incorporated into the matrix on the mechanical properties was also evaluated. Infrared spectroscopic technique and X-ray diffraction were used to characterize their microstructures and double bond conversion. With only 2wt% POSS added, the nanocomposite’s flexural strength increased 15%, compressive strength increased 12%, hardness increased 15% and uncommonly, even the toughness of resins obviously increased. With 5wt% POSS polymerized, compressive strength increased from 192MPa to 251MPa and compressive modulus increased from 3.93GPa to 6.62GPa, but flexure strength began to decline from 87MPa to 75MPa. The nanocomposites incorporated with POSS showed greatly improved mechanical properties, and increased wear resistance and service life. The mechanism of reinforcement was also discussed.

scholarly journals Microstructure and Mechanical Properties of Al-Mg-Si Hybrid Composites Reinforced with SiC/TiO2

2021 ◽  
Vol 58 (1) ◽  
pp. 3076-3088
Author(s):  
Dr. Israa A. Al. Kadir Hanan K. Azeez
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Base Alloy ◽  
Casting Process ◽  
Stir Casting ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particulate Reinforcement ◽  
The Matrix

The aims of thiswork is to investigate the effect of adding different weight percents of TiO2 and SiC 1.5:0,3:0, 4.5:0, 0:1.5, 0:3, 0:4.5, 1.5:1.5, 3:3, 4.5:4.5 particulate reinforcement on the mechanical properties andmicrostructure properties of base alloy Al-Mg-Si.By stir casting process, base alloy and hybrid composites were developed.  By using stiffness and tensile measures, the mechanistic properties of the basic alloy and hybrid composites were calculated.The topography of fracture surfaces was inspected using the scanning electron microscope (ESM) and energy dispersive spectroscopy ( EDS).The findings shows, with a weight rise of 4.5% by the TIO2 / SIC up to 4.5%, Improved absolute tensile power, strength of output and hardness. In contrast, the elongationrate is decreased, The optical microscope inspection shows that the particles in the matrix without any valves are distributed evenly. The X-Ray diffraction manifested the presence of different phases and intermetallic compounds Mg5Si6, Mg2Si, Al2O3, Mg6Si3.3., Al3Mg2 and Al3Ti.

Effects of Extrusion on the Mechanical Properties and Damping Capacity of Mg-1.8Cu-0.5Mn Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 257-260 ◽  
Author(s):  
Zhen Yan Zhang ◽  
Li Ming Peng ◽  
Xiao Qin Zeng ◽  
Lin Du ◽  
Lan Ma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tensile Tests ◽  
Optical Microscope ◽  
Damping Capacity ◽  
X Ray Diffraction ◽  
Dynamic Mechanical Analyzer ◽  
X Ray ◽  
Solute Atoms

Effects of extrusion on mechanical properties and damping capacity of Mg-1.8wt.%Cu -0.5wt.%Mn (MCM1805) alloy have been investigated. Tensile tests and dynamic mechanical analyzer were respectively used to measure tensile properties and damping capacity at room temperature of as-cast and as-extruded MCM1805 alloy. The microstructure was studied using optical microscope, X-ray diffraction and scanning electron microscope with an energy dispersive X-ray spectrometer. Granato-Lücke model was used to explain the influences of extrusion on damping capacity of MCM1805 alloy. The results showed that extrusion dramatically decreases the grain size but has little influence on phase composition and solute atoms concentration of MCM1805 alloy, and the grain refinement was the dominant reason for the obvious increase of tensile properties and decrease of internal friction of MCM1805 alloy.

scholarly journals Effect of CNT Contents on the Microstructure and Properties of CNT/TiMg Composites

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1620
Author(s):  
Xiaomin Yuan ◽  
Haonan Zhu ◽  
Huiling Ji ◽  
Yiwei Zhang
Keyword(s):  
Cross Section ◽  
Optical Microscope ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure Observation ◽  
The Matrix ◽  
Scanning Electron

Carbon nanotubes (CNTs), dispersed in absolute ethanol, were evenly mixed into Ti/MgH2 powders by wet milling. Then, we applied the vacuum hot-pressed sinteringmethod to the CNTs/TiMg composite materials. An optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and a field emission scanning electron microscope (FESEM) were used for the microstructure observation and phase analysis of samples. The mechanical properties were measured via the micro-vickers hardness. The results show that the main phases in the composites were Ti, Mg and C. Meanwhile, a small amount of Ti-Mg solid solution phase was also found. The cross-section morphology of the composites shows that the melted magnesium fills the grain interface during extrusion and that the composites have a better compactness.The microstructures of the composites have been greatly refined as the CNT contents increased. The structure of the composites was further refined when 0.5 wt.% CNTs were added. The fracture surface is obviously a ductile fracture. The microhardness increases obviously with the CNT content increasing. When the content of the CNTs is 1.0 wt.%, the microhardness of the composites reaches 232 HV, which is 24% higher than that of the matrix.

Effects of Annealing Treatment on the Microstructure and Mechanical Properties of Magnesium Alloy Sheets

2013 ◽  
Vol 303-306 ◽  
pp. 2524-2527 ◽  
Author(s):  
Lei Wang ◽  
Guang Hui Min ◽  
Pan Pan Gao ◽  
Xin Ying Wang ◽  
Hua Shun Yu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Annealing Temperature ◽  
Annealing Treatment ◽  
Optical Microscope ◽  
Icosahedral Phase ◽  
Alloy Sheet ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
X Ray

The microstructure of magnesium alloy sheets (nominal composition Mg–6Zn–Y in at. %) was investigated with the Optical Microscope (OM), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) technique after the annealing treatment. Tensile test at room temperature was performed to show the influence of annealing treatment on mechanical properties. Experimental results indicate that there are a large number of twin crystals appearing in microstructure of the extruded Mg-Zn-Y alloy sheet at 350 °C. The distinct icosahedral phase appears on the α-Mg matrix in granular form and the strength gets largely improved to the maximum. The uniform distribution of isometric crystal contributes to the best elongation at the annealing temperature of 400 °C.

Microstructural Evaluation of Semi-Solid and Thixoformed Parts of LM28 Aluminum Alloy

2012 ◽  
Vol 192-193 ◽  
pp. 136-141
Author(s):  
S.G. Shabestari ◽  
P. Ghaemmaghami ◽  
H. Saghafian ◽  
A. Osanlo
Keyword(s):  
Mechanical Properties ◽  
Morphological Changes ◽  
Physical And Mechanical Properties ◽  
Primary Silicon ◽  
Optical Microscope ◽  
Globular Structure ◽  
Cooling Slope ◽  
The Matrix ◽  
Semi Solid ◽  
Cooling Slope Casting

Attractive physical and mechanical properties of aluminum alloys make them very interesting for the automotive industry. The commercial way for manufacturing LM28 alloy is die-casting, but this process encounters several problems such as shrinkage and gas porosities. Their good mechanical properties and high resistance to wear are because of the presence of hard primary silicon particles distributed in the matrix. Therefore, the size and morphology of primary silicon and also the structure of α-Al particles in hypereutectic Al–Si alloys influence the mechanical properties of the alloys. In this research, a new process of manufacturing of this alloy has been developed using LM28 feedstock produced through cooling slope casting. The feedstocks produced via cooling slope casting had a partial globular structure that contained globules, rosettes and dendrites of α-Al. These feedstocks were thixoformed under three different pressures. The primary dendrites and rosettes changed to globular structure. The microstructure of thixoformed parts contained α-Al globules, small primary Si particles dispersed between these globules, and Al-Si eutectic phase. The mechanism of the formation of α-Al globules by this process was explained. Microstructures of as cast specimens, feedstocks produced via cooling slope, specimens that were heat treated in the semi-solid temperature and thixoformed specimens were studied with optical microscope and image analysis. The morphological changes during these processes were interpreted.

scholarly journals Microstructure and Mechanical Properties of Multicomponent Metal Ti(C,N)-Based Cermets

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 927
Author(s):  
Xuelei Wang ◽  
Qiufeng Wang ◽  
Zhaojun Dong ◽  
Xiaoqian Zhou ◽  
Xiaoliang Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Dispersive Spectrometry ◽  
Bending Strength ◽  
Binder Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
Weight Percentage ◽  
Microstructure And Mechanical Properties ◽  
Backscatter Scanning Electron Microscopy

Ti(C,N)-based cermets with multicomponent ingredients were prepared using vacuum sintering technology. The effect of molding agents, binder phase and sintering temperature on Ti(C,N)-based cermets were studied. The optimum molding performance was obtained by adding 2% polyvinyl alcohol (PVA-1788). The microstructure and mechanical properties of Ti(C,N)-based cermets were investigated. The Ti(C,N)-based cermet with a weight percentage of TiC:TiN:Ni:Co:Mo:WC:Cr3C2:C = 40:10:20:10:7:8:4:1 and sintered at 1450 °C had the optimal mechanical properties. The relative bending strength, Vickers hardness, elastic modulus and wear resistance were 2010 MPa, 15.01 GPa, 483.57 GPa and 27 mg, respectively. Additionally, X-ray diffraction (XRD), backscatter scanning electron microscopy pictures (SEM–BSE), energy dispersive spectrometry (EDS) and optical micrographs of Ti(C,N)-based cermets were characterized.

scholarly journals The Effect of Incorporating Silica Stone Waste on the Mechanical Properties of Sustainable Concretes

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3832 ◽  
Author(s):  
Saeid Abbasi ◽  
Mohammad Hemen Jannaty ◽  
Rabar H. Faraj ◽  
Shahriar Shahbazpanahi ◽  
Amir Mosavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Sustainable Construction ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Sem Images ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Matrix ◽  
First Time

Incorporating various industrial waste materials into concrete has recently gained attention for sustainable construction. This paper, for the first time, studies the effects of silica stone waste (SSW) powder on concrete. The cement of concrete was replaced with 5, 10, 15, and 20% of the SSW powder. The mechanical properties of concrete, such as compressive and tensile strength, were studied. Furthermore, the microstructure of concrete was studied by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy analysis (EDX), Fourier transformed infrared spectroscopy (FTIR), and X-Ray diffraction (XRD) tests. Compressive and tensile strength of samples with 5% SSW powder was improved up to 18.8% and 10.46%, respectively. As can be observed in the SEM images, a reduced number of pores and higher density in the matrix can explain the better compressive strength of samples with 5% SSW powder.

Effect of Ca on Microstructure and Properties of Mg-Al-Si Alloys

2011 ◽  
Vol 194-196 ◽  
pp. 1369-1373 ◽  
Author(s):  
Chun Xiang Xu ◽  
Hui Ju ◽  
Yang Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Chinese Script ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ca Addition ◽  
The Matrix ◽  
Morphology Modification ◽  
Scanning Electron

Effect of Ca addition on the morphology modification in Mg-7Al-0.8Zn-0.2Mn-1Si (AS71) alloys has been investigated using X-ray diffraction (XRD), optical microscopy (OM), and scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and various testing machines. The results show that when adding 0.1 wt% Ca, a small fraction of Mg2Si change from Chinese script type to polygonal type; with the Ca addition up to 0.3 wt%, edges and angles of polygonal type Mg2Si phase are changed; further increase in Ca addition, the morphology of Mg2Si is changed to strip-like or spot-like one. Meanwhile, the addition of Ca results in the morphology of β- Mg17Al12 phase changing from discontinuous net-like to dispersive island-like. Ca exists as solid-soluting atomic in the matrix with small Ca addition while in the form of CaSi2 with large Ca addition. Optimal mechanical properties can be achieved when Ca addition is 0.3 wt%.

Microstructural and Mechanical Properties of Polyester/Nanoclay Nanocomposites: Microstructure-Mixing Strategy Correlation

2011 ◽  
Vol 1312 ◽  
Author(s):  
Hamid Dalir ◽  
Rouhollah D. Farahani ◽  
Vireya Nhim ◽  
Benjamin Samson ◽  
Martin Lévesque ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Roll Mill ◽  
The Matrix ◽  
Polyester Matrix ◽  
Excellent Improvement

ABSTRACTDifferent nanoclay mixing strategies using a three-roll mill and ultrasonication is proposed to obtain the desired polyester/nanoclay dispersion, intercalation, and exfoliation. The dispersion states of the modified nanoclay in polymer with 2, 4 and 6 wt% loading were characterized with X-ray diffraction, scanning electron microscopy (SEM), and low and high magnification transmission electron microscopy (TEM). The mechanical properties of the clay-reinforced polyester nanocomposites were a function of the nature and the content of the clay in the matrix. The nanocomposite containing 4 wt% modified Cloisite® 15A exhibits excellent improvement in modulus (by ~51%) and tensile strength (by ~12%) with a decrease in fracture strain (by ~26%) and fracture energy (by ~17%). These mechanical characteristic changes can be attributed to the dispersion, intercalation, and exfoliation of the nanoclays inside the polyester matrix.

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