Search

Abstract The PZT ceramics with different weight content from 78% to 89% were printed using the stereolithography method. The piezoelectric properties as well as the microstructure of the ceramics were investigated in detail. X-ray patterns and Raman spectra demonstrate that the steady PZT tetragonal phase has already formed in these sintered ceramics. Besides, the piezoelectric constant and dielectric constant were 212–345 pC/N and 760–1390, which were sligthly lower than that of the dry pressing disk. Furthermore, a two-dimensional ultrasound transducer array (8 × 8) was designed and developed to evaluate the properties of the 3D-printed PZT ceramics. [ABSTRACT FROM AUTHOR]

Abstract: The microstructure and electric properties of the rhombohedral–tetragonal morphotropic phase boundary (MPB) composition 0.8Bi1/2Na1/2TiO3–0.2Bi1/2K1/2TiO3 have been investigated. X-ray and electron diffraction results substantiate the co-existence of tetragonal and rhombohedral phases. The ferroelectric domains were clearly observed by electron microscopy. The oxygen octahedron tilting of the samples was studied by SAED. Both saturated polarization–electric field and butterfly shaped strain–electric field hysteresis loops prove that the MPB composition shows typical ferroelectric nature. The detailed microstructure–property characterization may shed light on the physical property of further work on BNT–BKT around morphotropic phase boundary. [Copyright &y& Elsevier]

Abstract: Two series of raw materials were adopted to form TiAl/Ti2AlC composites: Ti/Al/TiC and Ti/Al/C. Differential thermal analysis (DTA) of starting powers and X-ray diffraction (XRD) of samples sintered at different temperatures from 600°C to 1300°C by hot pressing were utilized to analyze the phase transformation and the mechanism of synthesis. Scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS) was utilized to investigate the morphology characteristics of the products. The experimental results showed that Ti reacted with Al to form TiAl intermetallics below 900°C; and above 900°C, TiAl reacted with TiC to produce dense TiAl/Ti2AlC composites. The products sintered at 1200°C had fine crystals and dense fibres, and the distribution of Ti2AlC particles in TiAl matrix was homogeneous. [Copyright &y& Elsevier]