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(Mg₁3/Nb₂3/)O₃-PbTiO₃ (PMN-PT) components. PMN-PT (65/35) filament containing excess lead oxide (PbO) was used to fabricate a matrix layer-by-layer via FDC. SrTiO₃ (111) and (110) single crystals were embedded into the matrix. After heat treatment of 1250°C for 10 hours, the growth was approximately 2.5 mm from the SrTiO₃ (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 SrTiO₃ single crystal direction. As compared to matrix samples sintered under the same conditions, the d₃₃ value improved from 390 to 600 pC/N, dielectric constant from 2650 to ∼4500, and the loss tangent from 0.48% to 0.33% for (111) grown crystals. The (110) grown crystal values were improved to d₃₃ = 900 pC/N and K ∼ 4450. These techniques are being used to grow net-shape single crystal components such as 2-2 composites and spiral actuators.