Consolidation of single and double layers ceramic structure

Basically, the performance of ceramic structure is essential for the development of ceramic system or component. This performance can be controlled from the early stage i.e preparation of raw material up till the final stage i.e. finishing steps. In this work, ceramic processing parameters at interm...

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Bibliographic Details
Main Author: Ismail, Nur Farhani
Format: Thesis
Published: 2012
Subjects:
Online Access:http://eprints.uthm.edu.my/3711/
http://eprints.uthm.edu.my/3711/1/NUR_FARHANI_BINTI_ISMAIL.pdf
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Summary:Basically, the performance of ceramic structure is essential for the development of ceramic system or component. This performance can be controlled from the early stage i.e preparation of raw material up till the final stage i.e. finishing steps. In this work, ceramic processing parameters at intermediate stage (consolidation) were considered to obtain good properties and structure of alumina ceramic. The microstructure, mechanical and physical properties of the green and sintered alumina ceramic pellets (single and double layer) were investigated. Some modification during consolidation (drying and firing) which focuses on the particle characteristics, drying techniques, additive and types of sintering were conducted. Three drying techniques (room, oven and microwave) were performed to the single and double ceramic alumina. Several factors which are identified as strong influence towards the sintered body i.e. characteristics (particle size and particle size distribution), MgO additive and sintering types (conventional and HIP technique) were selected as controlled parameters during the sintering step. All samples were fabricated using uniaxial press prior to the consolidation stage and were characterized using standard procedures. Based on the observation and measurement, it was found that the microwave drying technique produced a homogenous and uniform microstructure compared to the other drying techniques for both green and sintered bodies. The density value of 25 μm sintered body (Al2O3) with microwave drying technique shows an increment value from 3.551 g/cm3 to 3.624 g/cm3 compared to others drying technique. The same phenomena were also observed with the addition of MgO. In fact, the highest density value was obviously shown with alumina pellets sintered under HIP with same drying technique. In general, the increased of density value causes a reduction of porosity thus produce a good and hard sintered structure for all sintered samples.