Growth of net-shape PMN-PT single crystal components by fused deposition of ceramics (FDC) and templated grain growth (TGG) techniques

The net-shape capabilities of Fused Deposition of Ceramics (FDC) and the cost efficient growth technique of templated grain growth (TGG) have been combined to fabricate single crystal Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (PMN-PT) components. PMN-PT (65/35) filament containing excess lead oxide (PbO) was used to fabricate a matrix layer-by-layer via FDC. SrTiO/sub 3/ (111) and (110) single crystals were embedded into the matrix. After heat treatment of 1250/spl deg/C for 10 hours, the growth was approximately 2.5 mm from the SrTiO/sub 3/ (111) single crystal to the tip of the grown area. The same process was used to grow (110) PMN-PT single crystals as well. X-ray diffraction and x-ray mapping studies have shown that the grown crystals closely match the PMN-PT (65/35) composition, and are oriented in the SrTiO/sub 3/ single crystal direction. As compared to matrix samples sintered under the same conditions, the d/sub 33/ value improved from 390 to 600 pC/N, dielectric constant from 2650 to /spl sim/4500, and the loss tangent from 0.48% to 0.33% for (111) grown crystals. The (110) grown crystal values were improved to d/sub 33/ = 900 pC/N and K /spl sim/ 4450. These techniques are being used to grow net-shape single crystal components such as 2-2 composites and spiral actuators.