Physical Characterization and Microstructure Evaluation of Titanium Dioxide Semiconductor Discs Processed with BindersShahida Begum*, MNM Ansari, LM Keong and T Velloo
Centre for Advance Materials, Department of Mechanical Engineering, University Tenaga Nasional, Putrajaya, Malaysia
- *Corresponding Author:
- Shahida Begum
Centre for Advance Materials
Department of Mechanical Engineering
University Tenaga Nasional, Putrajaya, Malaysia
E-mail: [email protected]
Received Date: August 07, 2013; Accepted Date: September 12, 2013; Published Date: September 18, 2013
Citation: Begum S, Ansari MNM, Keong LM, Velloo T (2013) Physical Characterization and Microstructure Evaluation of Titanium Dioxide Semiconductor Discs Processed with Binders. J Material Sci Eng 2:126. doi: 10.4172/2169-0022.1000126
Copyright: © 2013 Begum S, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The processing of TiO2 semiconducting materials has a long route with numerous contributing variables. The binder plays an important role in the development of this electro-ceramic material. Higher density and strength of a green body are critical not only for handling at its green state but also to avoid the causes of flaw formation during sintering. Use of appropriate binder can lead to improve characteristics of powder which will reduce density gradient in the green body during compaction. Enhanced green properties can consequently lead to higher fired strength of the varistor discs. The binder system is anticipated to have an influence on the grain growth and microstructure which in turn affect the electrical performance. To investigate this phenomenon, TiO2 powder doped with 0.2% of Ta2O5 was processed with and without binder polyvinyl alcohol. The prepared samples were characterized by evaluating the physical properties like green density, fired density, axial and radial shrinkage, micro hardness and compressive strength. It was observed that TiO2 processed with binder exhibited better properties compared to powder processed without binder. The higher percent of binder enhanced the properties further. XRD revealed that the diffraction angle peak was similar to that of pure TiO2. SEM analysis indicated that the average grain size was larger for discs prepared with higher percent of binder. It is anticipated that the larger grain size will improve varistor properties in terms of low voltage applications.