P. Y. Dalvi

Bio: P. Y. Dalvi is an academic researcher. The author has contributed to research in topics: Cubic zirconia & Calcination. The author has an hindex of 1, co-authored 1 publications receiving 5 citations.

Influence of calcia addition and calcination temperatures on sintering and stabilization of zirconia

Abstract: The influence of amount of calcia addition and calcination temperature on the sintering characteristics of zirconia was studied. The extent of stabilization was studied by X-ray diffraction. It was noticed that the optimum amount of calcia addition to obtain high density without cracking was 0.50 to 0.75 wt%. Higher amount of calcia addition and higher calcination temperature resulted in lowered density.Stabilization of zirconia with calcia addition, i.e. the formation of cubic phase, is found to be a function of amount of calcia added. The cubic solid solution formation took place mainly between 1000° and 1200°c. With the addition of 5.0 wt% of CaO, about 85% of cubic phase is formed at 1200°C and 100% at 1700°C.

Synthesis and characterization of fully/partially stabilized zirconia powders

Abstract: Synthese de poudres de zircone stabilisee par CaO, caracterisation par analyse thermique differentielle, frittage

Sintering of Zirconia with Various Stabilizers

Abstract: Usefulness of pure zirconia as a refractory material becomes limited due to phase transformation which results in volume changes. These phase transfromations can be suppressed by various stabilizers.It is observed that additions up to 5 wt % of various decomposable and non-decomposable stabilizers like CaCO3 MgCO3, Y2O3 and CaF2 result in formation of cubic zirconia phase from 15 to 90% between 1000° and 1200°C. However, the formation of cubic phase more than 35%, seems to be affecting the sinterability. Properties like densification, microstructure, cubic phase formed have been studied with these stabilizers.Data obtained reveals that nature of stabilizers and amount of cubic phase formed are factors influencing the densification and microstructure of resultant partially stabilized zirconia.

Influence of Thermal Cycling on Sintering and Stabilization of Zirconia

Abstract: The phase transformations in zirconia take place between 900°-1000° and 1200°c while heating, and between 1000° and 800°–600°C while cooling causing material movement. Hence, effect of amount of CaO and CaF2 additions and calcination temperature on densification and stabilization was studied by thermal cycling between 1200° and 700°C (lower range) and 1400° and 700°c (higher range) up to 25 thermal cycles.It was observed that higher densification can be obtained by thermal cycling at lower temperature compared to the temperature required in normal sintering process, particularly so, with CaO additions. High density was attained with CaO additions up to 2 % compared to equivalent amount of CaF2 additions in the lower temperature range. In general, uncalcined compositions attained high density which decreased with increasing calcination temperature. Thermal cycling promoted stabilization. The reaction was almost completed within 5 thermal cycles.

Strength and Thermal Fatigue Properties of CaO-Partially Stabilized Zirconia (Ca-PSZ)

Abstract: During sintering studies on zirconia with calcia in the range of 0.50 to 5.0 wt%, properties like crushing strength and thermal shock resistance were measured. Samples containing 15 to 90% cubic zirconia phase were subjected to crushing strength test at room temperature as well as high temperature up to 1200°C and thermal fatigue test from 1400°C to room temperature.The results show that mixtures containing up to 2 wt% of calcia (uncalcined or calcined up to 1000°C) developed up to 40% of cubic phase, and exhibited better mechanical strength as well as better thermal fatigue resistance.