No abstract

No abstract

No abstract

No abstract

Lead-free piezoelectric ceramic (Ba 0.85 Ca 0.15 )(Zr 0.1 Ti 0.9 )O 3 (BCZT) has been synthesised by solid-state sintering method and the effect of grain size on ferroelectric, piezoelectric, dielectric, mechanical and piezo-electro-mechanical properties was systematically studied. The compacted powders were sintered at three temperatures i.e. 1450°°C, 1500°C and 1550°C for an optimised duration of 5 h and they have exhibited well resolved morphotropic phase boundary with an average grain size ranging from 10 to 25 µm. Enhanced piezoelectric charge, d 33 ∼ 560 pC/N and voltage, g 33 ∼ 14.3 mV m/N coefficients were obtained for the 1450°C sintered BCZT sample. A maximum strain of around ∼0.14% was obtained which is comparable to that of lead-based piezoelectrics. Variation of relative permittivity with temperature revealed that the curves are independent of frequency, indicating the typical relaxor ferroelectric nature of the samples. A systematic study on cyclic loading was performed to evaluate piezo-electro-mechanical coefficients at different loads which showed hysteresis behaviour. High value of elastic modulus (E) and hardness (H) i.e. 262.7 ± 38.1 GPa and 13.7 ± 1.7 GPa were exhibited by samples sintered at 1450°C, which is higher than that of BCZT synthesised by wet-chemical methods. The results are discussed.

For BCN-NAM, under HRPSoC cycling conditions, the dominating elementary process is the formation of PbO instead of PbSO4.

The effect of alloying to TiPd and TiPt on phase transformation temperature, phase equilibria, and shape recovery were investigated for TiPt and TiPd base high-temperature shape memory alloys. Ru, Ir, Co and Zr were chosen for additional elements and Zr was found as the most effective element to improve shape recovery of TiPd and TiPt.

No abstract