Varying Sintering Temperature Research Articles

Fabrication of PZT-polymer composite materials having 3-3 connectivity for hydrophone applications

Lanthanum-modified lead zirconate titanate (PZT) powder and volatilisable polymethylmethacrylate (PMM) polymer particles have been used for fabrication of porous sintered ceramics of interconnected porosity varying from 25% to 59%. Sintered ceramics are converted into piezoelectric PZT-polymer composites by incorporating silicone rubber elastomer followed by electroding and poling. Influence of the variation of PZT-PMM ratio and sintering temperatures on the open and closed porosity of the sintered ceramics as well as volume fraction PZT in the composites has been studied and correlated for the optimization of piezoelectric properties. The PZT-polymer composites possess low density, considerably high piezoelectric voltage coefficient and considerably lower ageing characteristics and are therefore considered suitable for designing highly sensitive hydrophone systems.

Effect of Sintering Temperatures on Mechanical Properties of Fe—P—Mo Powder Premixes

AbstractIn the present investigation, the effect of varying sintering temperatures (1050–1200°C) on the mechanical properties of Fe–P–Mo powder compacts sintered for 45 min in a dry hydrogen atmosphere was studied. Molybdenum content in iron or phosphorus- containing iron was varied from 1 to 4 wt-% while phosphorus was in the range 0 to 0·6 wt-%. It was observed that with an increase in sintering temperature there was an increase in linear shrinkage and mechanical properties of all the alloy systems. However, the magnitude of increase in properties was greater in the case of P-containing Fe–Mo compacts than in plain Fe-Mo compacts. The results are discussed on the basis of diffusivity data for the various alloying elements and liquid-phase sintering modes. PM/0203

Effects of sintering temperature on microstructure and magnetic properties of NiFe<sub>2</sub>O<sub>4</sub> prepared from nano size powder of NiO and Fe<sub>2</sub>O<sub>3</sub>

Polycrystalline NiFe2O4 was prepared by solid state reaction from nano size powder of NiO and Fe2O3 which were synthesized by wet chemical method. The inverse spinel single phase of the sample has been confirmed by the X-ray diffraction patterns. SEM micrographs of the samples revealed that the grain size increases and the porosity decreases with the increase in sintering temperature and has great influence on the magnetic properties of NiFe2O4 . Enhancement of real part of initial permeability (μ′) as a function of frequency has been observed with the increase in sintering temperature. Temperature dependence real part of initial permeability has been observed at various sintering temperature and gives the manifestation of Hopkinson effect. Variation of Curie temperature (Tc) has been found with the variation of sintering temperature. Key words: Sintering temperature; Microstructure; Magnetic properties DOI: 10.3329/jbas.v34i2.6865Journal of Bangladesh Academy of Sciences, Vol. 34, No. 2, 189-195, 2010