Development of bimorph vibrator using lead free BNT piezoelectric film deposited by hydrothermal method
PZT piezoelectric film synthesized hydrothermally has been studied actively in our laboratory. However, it is apprehended recently that PZT affects health and the environment, because PZT is chemical compound containing lead. Therefore, we tried to synthesize lead free BNT piezoelectric film on titanium substrate hydrothermally. The synthesized BNT films on titanium substrates were evaluated with SEM image, XRD pattern and EDS. We fabricated bimorph vibrators with synthesized lead free BNT film and evaluated their performances.
Effect of sintering temperature on microstructure of hydrothermally prepared bismuth sodium titanate ceramics
Abstract Bismuth sodium titanate (Bi 1/2 Na 1/2 TiO 3 or BNT) powders were prepared by the hydrothermal route with starting chemicals containing Bi(NO 3 ) 3 .5H 2 O, NaNO 3 and Ti[i-OPr] 4 in a PTFE-lined autoclave. After hydrothermal treatment at 200 °C for 20 h, the powders were filtered and washed with deionized water until the pH of the washing solution was 10. After drying in an oven at 100 °C for 5 h, white powders of BNT were obtained. X-ray diffraction (XRD) patterns of BNT fine powders show that well developed crystallite with a pure perovskite phase have been formed. The powders were pressed into disc shape of 10 mm in diameter and 1.6 mm thick. The green bodies were sintered in close alumina crucible at 800, 900, 1000 and 1050 °C for 3 h, to obtain the highest density. The microstructure of the powders and ceramics were investigated by scanning electron microscopic (SEM) technique.
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.