Role of matrix alloy chemistry on the interfacial reaction and solidification of metal matrix composites

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.

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TEM examination of 2014-SiC metal matrix composite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105692 ◽

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.

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CFD Simulation and Experimental Validation of Solidification of Metal Matrix Composites (MMC) in the Presence of Cooled Fibers

Heat Transfer, Volume 2 ◽

10.1115/imece2004-60290 ◽

2004 ◽

Author(s):

R. S. Amano ◽

J. Xie ◽

E. K. Lee ◽

P. K. Rohatgi

Keyword(s):

Metal Matrix Composites ◽

Metal Matrix ◽

Cfd Simulation ◽

Applied Pressure ◽

Casting Process ◽

Processing Parameters ◽

Matrix Composites ◽

Primary Alpha ◽

Parametric Studies ◽

Solidification Of Metal

A new experimental configuration for the casting of metal matrix composites (MMCs) using Al-4.5 wt pct Cu have been used to obtain finer microstructures around the fiber reinforcement. The new configuration allows the fibers to be extended out the mold and cooled by a heat sink. By doing so, the solidification can be made more rapid, and more primary alpha-aluminum phase can be formed on the surface of the fibers. It is believed that this can lead to improvement in the properties of the composite. CFD simulation of the solidification of Al-4.5 wt pct Cu in the casting process has been carried out by using commercial CFD code. Parametric studies on the effects of different processing parameters on solidification time have been simulated using the CFD code. These parameters include, but are not limited to, the pouring temperature of the liquid melt, sink temperature, fiber length extended out of the mold, the mold initial temperature, fiber conductivity, applied pressure, and fiber bundle diameter. Selected simulation results are compared with the available experimental data obtained from the UWM Center for Composites.

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