DESIGN, ASSEMBLY AND CHARACTERIZATION OF COMPOSITE ...

Figure 4.9 Sintered nickel lattices: a) bowtie, cubic, and ring lattices; b) lattices
containing large spanning features; c) SEM image of nickel filaments in a nickel lattice.
......................................................................................................................................... 133
Figure 5.1 Temperature profiles for firing rod-shaped specimens, with the same heating
ramp rate for all specimens at 5 °C/min, and no isothermal hold. .................................. 142
Figure 5.2 Temperature profile for co-sintering of composites ...................................... 143
Figure 5.3 Schematic illustrations of direct blending anionic PAA-stabilized BT and
cationic PEI-stabilized Ni suspensions: a) before mixing, electrostatic-bridging only
occurs at interface between two suspensions; b) after rigorous mixing, two phases are
homogenized by shear stress, and flocculation occurs between BT and Ni particles ..... 146
Figure 5.4 Oscillatory behavior for the φsolids=0.43 composite inks and BT ink: G' as a
function of τ .................................................................................................................... 148
Figure 5.5 Optical images of Ni(m) cylinders before and after firing: a) BT:Ni=1:4 green
bodies, and b) fired Ni(m), from left to right: BT:Ni=4:1, 3:2, 2:3, and 1:4. ................. 150
Figure 5.6 Sintering strain of pure BT and Ni(m) inks. .................................................. 151
Figure 5.7 Vickers hardness number as a function of BT ratio in BT-Ni composites (error
bars for 0.2 and 0.4 BT compositions are too short to show on this plot). ..................... 155
Figure 5.8 Optical micrographs of sintered Ni(m): a) BT:Ni=4:1 and b) BT:Ni=3:2. The
bright islands are Ni, grey matrix is are BT, and the dark spots are pores. .................... 156
Figure 5.9 Co-sintered compositional graded bow-tie stripe network of BT:Ni=4:1 Ni(m)
(20Ni80BT) and pure BT before annealing. ................................................................... 158
Figure 5.10 Co-sintered compositional graded structures: a) MLCC composite lattices of
BT:Ni=2:3 Ni(m) (dark color) and pure BT (cream color), annealed; b) cross-section of
the MLCC composite lattice denoting the electrodes and dielectric filaments. ............. 161
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