Mechanical Properties, Aging Behavior and Microstructure Evolution of Mg-Nd-Zn-Zr Based Magnesium Matrix Composite Reinforced with Alumina Fibers

2012 ◽  
Vol 706-709 ◽  
pp. 687-692
Author(s):  
Li Ming Peng ◽  
Bin Hu ◽  
Wen Jiang Ding
Keyword(s):  
Electron Microscopy ◽  
Magnesium Alloys ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Magnesium Matrix Composite ◽  
Aging Behavior ◽  
Magnesium Matrix ◽  
Alumina Fibers

Metal matrix composites reinforced with discontinuous reinforcement (short fiber, whisker or particle) are attractive for applications requiring higher stiffness and strength than traditional alloys. Unlike continuously reinforced composites, where the properties are mainly influenced by fibers, the properties of the discontinuously reinforced composites seem to be influenced more by matrix properties. Most of the discontinuously reinforced composites are based on age-hardenable light alloys, so that aging treatments can be applied to develop the optimum properties of the composites. The aging behavior of discontinuously reinforced composites has been a subject of great interest both from scientific and technological view points. Recently developed NZ30K (Mg-3wt.%Nd-0.5wt.%Zn-0.5wt.%Zr) alloys exhibit higher specific strength at both room and elevated temperatures, better strength and creep resistance than the existing commercial magnesium alloys. Accordingly, this alloy can be considered as a candidate material for potential automobile applications, such as engine blocks and pistons, which experience high service temperature. Its use could save considerable mass weight in powertrain systems. However, low elastic modulus and wear resistance of magnesium alloys limit their widespread applications. Metal matrix composites have been proposed as the feasible and economical solution. The aim of this study is to investigate the effect of alumina fibers on the aging hardening kinetics and age-hardening efficiency of squeeze cast NZ30K/Saffil/15p magnesium matrix composite. The aging behavior has been examined using Vickers, combined with microstructure observation developed during heat treatment by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

scholarly journals The Microstructure of WE43 MMC Reinforced with SiC Particles

2016 ◽  
Vol 61 (1) ◽  
pp. 393-398 ◽  
Author(s):  
B. Dybowski ◽  
T. Rzychoń ◽  
B. Chmiela ◽  
A. Gryc
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Xrd Analysis ◽  
Stir Casting ◽  
Matrix Composites ◽  
Reaction Products ◽  
Plastic Properties ◽  
Sic Particles

It is well known that the properties of a metal matrix composites depend upon the properties of the reinforcement phase, of the matrix and of the interface. A strong interface bonding without any degradation of the reinforcing phase is one of the prime objectives in the development of the metal matrix composites. Therefore, the objective of this work is to characterize the interface structure of WE43/SiC particles composite. Magnesium alloys containing yttrium and neodymium are known to have high specific strength, good creep and corrosion resistance up to 250°C. The addition of SiC ceramic particles strengthens the metal matrix composite resulting in better wear and creep resistance while maintaining good machinability. In the present study, WE43 magnesium matrix composite reinforced with SiC particulates was fabricated by stir casting. The SiC particles with 15 μm, 45 μm and 250 μm diameter were added to the WE43 alloy. The microstructure of the composite was investigated by optical microscopy, scanning electron microscopy, scanning transmission electron microscopy and XRD analysis. YSi and Y2Si reaction products are observed at the interfaces between SiC particles and WE43 matrix in the composite stirred at 780°C. Microstructure characterization of WE43 MMC with the 45 μm, stirred at 720°C showed relative uniform reinforcement distribution. Moreover, the Zr-rich particles at particle/matrix interface were visible instead of Y-Si phases. In the case of composite with 15 μm particles the numerous agglomerates and reaction products between SiC particles and alloying elements were observed. The presence of SiC particles assisted in improving hardness and decreasing the tensile strength and plastic properties.

Preparation and Thermal Properties of BN and LPSO Hybrid Reinforced Magnesium Matrix Composite

2021 ◽  
Vol 1035 ◽  
pp. 900-905
Author(s):  
Lan Qing Xia ◽  
Shu Sen Wu ◽  
Chen Li ◽  
Wei Guo ◽  
Shu Lin Lü
Keyword(s):  
Thermal Properties ◽  
Magnesium Alloy ◽  
Matrix Composite ◽  
Coefficient Of Thermal Expansion ◽  
Hexagonal Boron Nitride ◽  
Matrix Composites ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Lpso Structure ◽  
Reinforcing Particle

Hexagonal boron nitride (h-BN) is a ceramic material with high thermal conductivity (TC) and low coefficient of thermal expansion (CTE), which can improve multiple thermal properties of metal-matrix composites as a reinforcing particle, but its wettability with metal melt is very poor. In order to enhance the wettability between the h-BN and magnesium alloy melt, the electroless plating was used to coat a thin layer of pure nickel on h-BN particles, which was proved to be effective and efficient in this study. The results showed that by adding Y element to magnesium alloy melt to consume Ni element melted from the nickel-plating layer, the long period stacking ordered (LPSO) structure composed of Mg-Ni-Y was successfully formed, and the magnesium matrix composite reinforced by hybrid h-BN and LPSO structure was obtained. After ultrasonic treatment (UT), the TC of the magnesium composite containing 3 vol% h-BN and 14.16 vol% LPSO is 99.92 W/(m·K), which is a 8.3% enhancement compare to the composite without UT. The average CTE (293-373 K) of the composite is 18.36×10-6 K-1, which is reduced by 29.4% compared with pure magnesium.

scholarly journals Reactivity and Microstructure of Al2O3-Reinforced Magnesium-Matrix Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Maher Mounib ◽  
Matteo Pavese ◽  
Claudio Badini ◽  
Williams Lefebvre ◽  
Hajo Dieringa
Keyword(s):  
Chemical Reaction ◽  
Metal Matrix ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Magnesium Matrix ◽  
Eutectic Region ◽  
Magnesium Matrix Composites ◽  
Transmission Electron ◽  
The Matrix

Performances of metal matrix composites (MMCs) rely strongly on the distribution of particles within the metal matrix but also on the chemical reaction which may occur at the liquid-solid interfaces. This paper presents the chemical reaction between aluminum based particles Al2O3and Al2O3-AlOOH with magnesium alloys matrixes AZ91 and EL21, respectively, and studies the microstructure of these reinforced composites. Different methods such as transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and XRD were used to highlight these chemical reactions and to identify products. Results demonstrate the formation of MgO particles within the matrix for both composites and also the dissolution of aluminum in the eutectic region in the case of EL21.

A Review on CNT Reinforced Aluminium and Magnesium Matrix Composites

2014 ◽  
Vol 591 ◽  
pp. 120-123 ◽  
Author(s):  
B. Vijaya Ramnath ◽  
Chakravarthi Parswajinan ◽  
Chinnadurai Elanchezhian ◽  
S. Venkatesan Pragadeesh ◽  
P. Ravichandra Ramkishore ◽  
...  
Keyword(s):  
Metal Matrix ◽  
Considerable Increase ◽  
Polymer Matrix Composites ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Base Metals ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
Reinforcing Agent ◽  
Allotropic Form

Carbon Nanotubes (CNT) are one allotropic form of carbon, which have some unique characteristics that make them a suitable reinforcing agent in various types of composites. CNT reinforced composites are gaining more attention in recent days. Reinforcing with CNT leads to increase in strength without considerable increase in weight. Many metal matrix composites (MMCs) with base metals like aluminium, magnesium, copper, nickel etc., and polymer matrix composites (PMCs) have been fabricated and experimented with CNT as one of their reinforcing agents and corresponding results have been recorded. This paper reviews a few of these recordings on Al and Mg MMCs and also some future development in this field.

Microanalysis and characterization of protective coatings used in metal-matrix composites

1995 ◽  
Vol 53 ◽  
pp. 546-547
Author(s):  
Jason R. Heffelfinger ◽  
Robert R. Kieschke ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Protective Coatings ◽  
Glass Tube ◽  
Ceramic Fiber ◽  
Matrix Composites ◽  
Alumina Fiber ◽  
Reaction Products ◽  
Alumina Fibers

Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and parallel-aquistion electron-energy loss spectrometry (PEELS) have been used to investigate various coating schemes used in alumina-fiber reinforced titanium alloys. The high-temperature properties of metal-matrix composites (MMC's) depend greatly on the interface between the ceramic fiber and metal matrix. The chemical and mechanical properties of this interface may be tailored by coating the alumina fibers with various materials. In this work, emphasis has been placed on the chemical aspect of the coatings and their role in inhibiting the reaction between the alumina fiber and the titanium matrix. The brittle nature of the reaction products, Ti3Al and TiAl, weakens the composite and thus leads to its ultimate failure.The composites are made of α-alumina fibers (Nextel 610 with a mean diameter of ~12 mm) which are first coated with thin protective layers such as Y2O3 and Nb followed by a coating of β-titanium alloy (TIMETAL 21S Ti -15Mo -3A1 -2Nb -0.2Si.) Several thousand fibers are then placed together inside a glass tube and HIP-ped (Hot Isostatic Press) at temperatures of ~900°C and times of ~2 hours to attain a dense composite.

Study on Properties of Carbon Nanotube/Magnesium Matrix Composite

2005 ◽  
Vol 488-489 ◽  
pp. 897-900 ◽  
Author(s):  
You Shou Zhang ◽  
Yi Yu Xue ◽  
Sinian Li ◽  
Jin Huang ◽  
Cai Hua Huang
Keyword(s):  
Carbon Nanotube ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Die Casting ◽  
Boundary Structure ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Magnesium Metal ◽  
Argon Gas ◽  
Chemical Plating

Under the protection of argon gas, carbon nanotube reinforced magnesium metal matrix composite was made by stirring carbon nanotube into magnesium melts and formed by die casting. TEM and EDS methods were introduced to analyze boundary structure and chemical composition between carbon nanotube and magnesium metal matrix. The mechanical carbon nanotube properties of the composite were tested. Nickel chemical plating surface of carbon nanotube is favorable to adhesion of carbon nanotube to magnesium. Tests show that carbon nanotube, especially chemical nickel-plated one, has excellent role in strengthening the magnesium. The structure of magnesium was fined .The tensile strength, elongation, hardness and elastic modulus of the composite are improved.

Electron Microscopy of Metal-Matrix Composites

1970 ◽  
Vol 28 ◽  
pp. 404-405
Author(s):  
A. Lawley ◽  
M. R. Pinnel ◽  
A. Pattnaik
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Critical Evaluation ◽  
Elastic Behavior ◽  
Matrix Composites ◽  
Directionally Solidified ◽  
Fracture Characteristics ◽  
Broad Program

As part of a broad program on composite materials, the role of the interface on the micromechanics of deformation of metal-matrix composites is being studied. The approach is to correlate elastic behavior, micro and macroyielding, flow, and fracture behavior with associated structural detail (dislocation substructure, fracture characteristics) and stress-state. This provides an understanding of the mode of deformation from an atomistic viewpoint; a critical evaluation can then be made of existing models of composite behavior based on continuum mechanics. This paper covers the electron microscopy (transmission, fractography, scanning microscopy) of two distinct forms of composite material: conventional fiber-reinforced (aluminum-stainless steel) and directionally solidified eutectic alloys (aluminum-copper). In the former, the interface is in the form of a compound and/or solid solution whereas in directionally solidified alloys, the interface consists of a precise crystallographic boundary between the two constituents of the eutectic.

TEM examination of 2014-SiC metal matrix composite

1988 ◽  
Vol 46 ◽  
pp. 726-727
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
P. K. Liaw
Keyword(s):  
Metal Matrix Composite ◽  
Metal Matrix Composites ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Tensile Deformation ◽  
Microstructural Characterization ◽  
Thin Foil ◽  
Matrix Alloy ◽  
Matrix Composites ◽  
Ion Milling

Aluminum-based metal matrix composites offer unique combinations of high specific strength and high stiffness. The improvement in strength and stiffness is related to the particulate reinforcement and the particular matrix alloy chosen. In this way, the metal matrix composite can be tailored for specific materials applications. The microstructural characterization of metal matrix composites is thus important in the development of these materials. In this study, the structure of a p/m 2014-SiC particulate metal matrix composite has been examined after extrusion and tensile deformation.Thin-foil specimens of the 2014-20 vol.% SiCp metal matrix composite were prepared by dimpling to approximately 35 μm prior to ion-milling using a Gatan Dual Ion Mill equipped with a cold stage. These samples were then examined in a Philips 400T TEM/STEM operated at 120 kV. Two material conditions were evaluated: after extrusion (80:1); and after tensile deformation at 250°C.

In vitro corrosion behavior and cytotoxicity property of magnesium matrix composite with chitosan coating

2015 ◽  
Vol 22 (3) ◽  
pp. 829-834 ◽  
Author(s):  
Yi-long Dai ◽  
Kun Yu ◽  
Liang-jian Chen ◽  
Chang Chen ◽  
Xue-yan Qiao ◽  
...  
Keyword(s):  
Corrosion Behavior ◽  
Matrix Composite ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Chitosan Coating
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