A major reason to conduct solidification experiments in space is that the unique conditions accessible in reduced-gravity allow investigation of fundamental questions while limiting the influence of sedimentation or buoyancy-induced convection. When processing metallic alloys using containerless electromagnetic levitation, convection may be controlled over a wide range, spanning the laminar-turbulent transition, by proper selection of facility operating conditions. By measuring key thermophysical properties such as density, viscosity, and electrical resistivity on-orbit, the specific sample being processed may be characterized and the results used to update pre-mission magnetohydrodynamic model predictions of induced stirring within the droplet. Thus, convection becomes a controlled experimental parameter that can be applied to an investigation of how stirring influences the metastable-to-stable transformation during rapid solidification of FeCrNi alloys. For these alloys, the incubation or delay time is observed to be a weak function of undercooling and a strong function of applied convection.

Recently, piezoelectric speakers have been widely researched for smartphone application. Accrordingly, in this study, in order to develop the low temperature sintering Pb-free ceramics, the 0.965(Na0.5K0.5)0.97Li0.03(Nb0.96Sb0.04)O3-0.035(Bi0.5Na0.5)0.9(Sr)0.1ZrO3 ceramics for these devices were manufactured as a function of CuO addition and the their physical properties were investigated. At the manufactured ceramics, the coexistence phases of rhombohedral and tetragonal(R-T) phase were appeared. An average grain size of the specimen increased according to the increase of CuO addition until 1.5 mol% due to the formation of a liquid phase. The composition ceramics added with 2 mol% CuO showed the excellent physical properties of density = 4.496g/cm3, kp = 0.391, Qm = 88, εr = 1705, and d33 = 241pC/N. These results show that the ceramics added with 2 mol% CuO is an attractive candidate for lead-free piezoelectric actuator application.