Evaluation of Fixturing for Compression Testing of Metal Matrix and Polymer/Epoxy Composites

Author(s):  
RM Lamothe ◽  
J Nunes
2017 ◽  
Vol 755 ◽  
pp. 44-51
Author(s):  
Anton S. Bychkov ◽  
Alexander A. Karabutov ◽  
Elena V. Savateeva ◽  
Yulia G. Sokolovskaya ◽  
Vasily P. Zarubin ◽  
...  

Theoretical assessments are given for the use of the through-transition technique of broadband ultrasonic spectroscopy to determine porosity of heterogeneous materials. Experimental measurements of local porosity of composites using the through-transition technique are presented. Dependences of elastic moduli on the concentration of hardening particles and porosity of metal matrix isotropic composite found. Experimental relationship between the phase velocity of longitudinal acoustic waves and the power of structural noise in samples of graphite epoxy composites is obtained.


1997 ◽  
Author(s):  
Eric Preissner ◽  
Eyassu Woldesenbet ◽  
Jack Vinson ◽  
Eric Preissner ◽  
Eyassu Woldesenbet ◽  
...  

1994 ◽  
Vol 10 (6) ◽  
pp. 558-564 ◽  
Author(s):  
F. Bonollo ◽  
B. Molinas ◽  
I. Tangerini ◽  
A. Zambon

Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.


Author(s):  
A. Lawley ◽  
M. R. Pinnel ◽  
A. Pattnaik

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.


Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
P. K. Liaw

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.


Author(s):  
W. M. Sherman ◽  
K. M. Vedula

The strength to weight ratio and oxidation resistance of NiAl make this ordered intermetallic, with some modifications, an attractive candidate to compete with many superalloys for high temperature applications. Recent studies have shown that the inherent brittleness of many polycrystalline intermetallics can be overcome by micro and macroalloying. It has also been found that the high temperature mechanical properties of NiAl can be enhanced through the addition of Nb by powder metallurgical techniques forming a dispersed second phase through interdiffusion in a polycrystalline matrix. A drop in the flow stress is observed however in a NiAl-2 at.% Nb alloy after 0.2 % strain during constant strain rate hot compression testing at 1025°C. The object of this investigation was to identify the second phase and to determine the cause of the flow stress drop.


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