Shaji Gopalakrishnan - Academia.edu (original) (raw)
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Papers by Shaji Gopalakrishnan
Lithium niobate piezocomposite transducers have been made for ultrasonic measurements up to 500°C... more Lithium niobate piezocomposite transducers have been made for ultrasonic measurements up to 500°C. The piezocomposites were made by dicing y/36°-cut lithium niobate single crystal using an automatic dicing saw and filling with zirconia cement. Piezocomposite thickness was 1 mm, pillar width 0.4-0.8 mm, kerf width 0.5 mm, volume fraction of lithium niobate 30-40%. A transducer with an operating frequency 2.6-3.3 MHz was designed and fabricated with a steel case. This was used to demonstrate detection of artificial defects in a steel block, using high temperature couplant, up to 400°C. Stability of the high temperature properties and structure of lithium niobate was verified by impedance measurements and x-ray diffraction for lithium niobate single crystal and piezocomposite heated in air up to 500°C.
Lithium niobate piezocomposite transducers have been made for ultrasonic measurements up to 500°C... more Lithium niobate piezocomposite transducers have been made for ultrasonic measurements up to 500°C. The piezocomposites were made by dicing y/36°-cut lithium niobate single crystal using an automatic dicing saw and filling with zirconia cement. Piezocomposite thickness was 1 mm, pillar width 0.4-0.8 mm, kerf width 0.5 mm, volume fraction of lithium niobate 30-40%. A transducer with an operating frequency 2.6-3.3 MHz was designed and fabricated with a steel case. This was used to demonstrate detection of artificial defects in a steel block, using high temperature couplant, up to 400°C. Stability of the high temperature properties and structure of lithium niobate was verified by impedance measurements and x-ray diffraction for lithium niobate single crystal and piezocomposite heated in air up to 500°C.