Investigating the Physical and Mechanical Properties of TiO2 Varistor Materials Prepared with Various Dopants

Abstract

Varistors are the most efficient devices for the protection of power transmission lines and electronic devices against excessive transient surges. The current trends that require varistors with more functions have led to research to develop new ceramic varistor material and titanium dioxide (TiO 2 ) is the emerging new material. In this research nanosized TiO 2 was taken as the base materials to which a small amount of impurities was added as dopants for enhancing the properties. Ta 2 O 5 , WO 3, Bi 2 O 3 and Co 3 O 4 were used as dopants where the percentage of Bi 2 O 3 and Co 3 O 4 was fixed; 0.5% and 0.2% respectively. Samples were prepared with different weight percentages of dopants and sintered at a constant temperature of 1300˚C with 2 hour's holding time to observe the effect of these dopants on physical and mechanical properties of nanosized TiO 2 . Analysis was undertaken to evaluate the properties of the nanosized TiO 2 , such as green density, fired density, fired strength, axial and radial shrinkage. It was found that with the composition of 98.1% TiO 2 +0.7% Ta 2 O 5 +0.5% WO 3 +0.2%Co 3 O 4 +0.5%Bi 2 O 3 have a significant influence on the physical and mechanical properties, which is anticipated to improve the performance of varistor. With the improvement in the physical and mechanical properties of TiO 2 , the composite material has potential application in low voltage application devices.

Sintering temperature effects on the properties of stainless steel 316L compact fabricated by metal injection moulding

“…The sintered compacts were then analysed for its physical properties. The density of each compact was measured using Archimedes principles (Daud et al, 2014) following MPIF standard 42. The density was estimated by the averaging five replication samples of SS 316L compacts for each sintering temperature involved.…”

Graphene Oxide as An Efficient Photocatalyst For Photocatalytic Reduction of CO2 Into Solar Fuel

“…Several semiconductors such as zirconium oxide [14], gallium oxide [15], magnesium oxide [16], zinc sulfides [17], cadmium sulfides [18], bismuth sulfide [19], graphitic carbon nitride [20] and titanium oxide (TiO2) [21] have been employed as photocatalyst. Among all, TiO2 has been the widely reported photocatalyst because of its unique properties, high stability, availability and non-toxicity [22][23][24][25]. However, photocatalytic activity of TiO2 is limited due to large bandgap energy and electrons-holes recombination problem.…”