Authors: Ricardo D Torres Carlos M Lepienski John J Moore Ivar E Reimanis
Publish Date: 2009/03/19
Volume: 40, Issue: 2, Pages: 187-195
Abstract
In this work dense NiAl/TiB2 composites with varying amounts of TiB2 were produced by combustion synthesis routes The morphology of the TiB2 phase in the composite has been modified by changing the reactants in the initial powder mixture In the first processing route NiAl and TiB2 phases were obtained from Ni Al Ti and B elemental powders In the second processing route TiB2 was added instead of Ti and B along with Ni and Al to produce NiAl and TiB2 phases The XRD performed on the products of both processing routes confirmed that the synthesized phases were indeed TiB2 and NiAl The NiAl grain size is smaller for the composites obtained in the first processing route In addition the first processing route leads to clusters of TiB2 submicron particles in which the matrix is either TiB2 or NiAl depending on the starting composition The second processing route results in less dense composites in which the matrix is the NiAl and the TiB2 exists as dispersed platelets The hardness H and Young’s modulus E were observed to be higher for composites produced by the first processing route This difference in the mechanical properties is caused by the difference in microstructure as well as the difference in porosity between the two processing routes
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