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DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE ...

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scanning electron micrograph of a pyramidal indent on a sintered LFBT specimen. The<br />

average diagonal distance used for the hardness calculation is 44 µm, which yields a<br />

Vickers hardness number VPN479. This hardness is 23.8% greater than the value<br />

(VPN387) from extrapolation of the BT-Ni composite hardness data in Chapter 5. The<br />

higher hardness value here is probably due to the higher sintered density of the LFBT<br />

specimen, in comparison to the 91%-96% theoretical density for the BT/Ni specimens<br />

where the porosity allows more plastic deformation.<br />

Figure 6.11 SEM of a pyramidal indent on a sintered LFBT specimen<br />

6.3.6. Energy Dispersive Spectroscopy (EDS) Characterization<br />

Examination by EDS reveals that LFBT and BT:Ni=1:4 Ni'(m) components have<br />

good cohesion and form an integral device. There is no noticeable inter-diffusion<br />

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