Time schedule by speaker > Al-Mukadam Raschid

The so-called statistical approach is used to analyze the nucleation kinetics of a stoichiometric lithium disilicate melts when cooled from above the melting temperature (Tm) at various speeds. In this method, information is gained on the Poisson distributed lag-time of nucleation and the unique shape of the crystallization exotherm from > 200 repetitive cooling runs of the same liquid volume at shallow undercoolings. Using a novel setup comprising of a water-cooled HT-DSC, the upper limit of the cooling speed in the temperature range from Tm+50 K to Tm-150 K was increased by a factor of four as compared to standard gas-cooled DSC devices, which enables us now to analyze cooling speeds of three magnitudes of order. For cooling at high speed bimodal distributed lag-times are evident which can be explained by a change in the nucleation mechanism or by nucleation at two different nucleation sites.