DENDRITIC GROWTH OF THE BINARY SUCCINONITRILE-CAMPHOR SYSTEM

Succinonitrile (SCN)–2 wt% Camphor (CAMP) alloy was unidirectionally solidified with a constant temperature gradient (G = 3.01 K/mm) at different growth rates (V = 6.5–113 μm/s) and with a constant growth rate (V = 6.5 μm/s) at different temperature gradients (G = 1.93 - 3.01 K/mm). Microstructural parameters (primary dendrite arm spacings, λ1, secondary dendrite arm spacings, λ2, dendrite tip radius, R, and mushy zone depth, d) were measured as a function of growth rate and temperature gradient. The experimental results have been compared with theoretical models and previous experimental works. The stability constant (σ) for this alloy system was calculated and compared with similar experimental results.Dendrites, directional solidification, organic compounds

INFLUENCE OF THE SOLIDIFICATION PARAMETERS ON DENDRITIC MICROSTRUCTURES IN UNSTEADY-STATE DIRECTIONALLY SOLIDIFIED OF LEAD–ANTIMONY ALLOY

Pb-9.3wt.%Sb alloy was directionally solidified upwards under argon atmosphere under the two conditions; with different temperature gradients, (G = 0.93–3.67 K/mm) at a constant growth rate (V = 17.50 μm/s) and with different growth rates (V = 8.30–497.00 μm/s) at a constant (G = 3.67 K/mm) in a Bridgman furnace. The dependence of characteristic microstructure parameters such as primary dendrite arm spacing (λ1), secondary dendrite arm spacing (λ2) and dendrite tip radius (R) on the growth rate (V) and the temperature gradient (G) were determined by using a linear regression analysis. A detailed analysis of microstructure were also made and compared with the theoretical models and similar experimental works on dendritic solidification in the literature.Dendrites, Pb-Sb alloy, microstructures, solidification, crystal growth

Solid-liquid interfacial energy of camphene

The Gibbs-Thomson coefficient and the solid-liquid interfacial energy for camphene have been measured to be (8.58 ± 0.96) × 10-8 K m and (4.43 ± 0.49) × 10-3 J m-2, respectively, by a direct method. The grain boundary energy of camphene has also been calculated to be (8.36 ± 0.92) × 10-3 J m-2 from the observed grain boundary groove shapes. © 1999 Elsevier Science S.A. All rights reserved.The authors would like to thank Erciyes University Research Foundation for financial support to the project

Directional solidification of pure succinonitrile and succinonitrile- salol alloys

Pure succinonitrile (SCN) and succinonitrile-salol alloys with four different concentrations of salol were unidirectionally solidified at five different growth rates in a temperature gradient. The microstructure parameters, viz., the primary dendrite arm spacing ?1, dendrite tip radius R and mushy zone depth d, were measured. The dependence of the microstructure parameters on the solidification parameters for pure SCN and SCN-Salol alloys were determined via linear regression analysis. The results are compared with published data

Dependency of the thermal and electrical conductivity on temperatures and compositions of Zn in the Al-Zn alloys

The variations of thermal conductivity (K) with temperature for Al–xZn (x = 5, 10, 20, 30, 50 and 60 wt. %) alloys were measured by using a radial heat flow furnace. The variations of electrical conductivity (?) of solid phases with temperature for the studied alloys were determined from the Wiedemann-Franz and Smith-Palmer equations by using the measured values of K from the plots of K. The thermal temperature coefficient (? TTC ) and the electrical temperature coefficient (? ETC ) were obtained. Dependency of the ? TTC and ? ETC on the composition of Zn in the Al-Zn alloys was also investigated. According to the present experimental results, K of Al–Zn alloys linearly decrease with increasing temperatures up to the melting temperature for each composition and exponentially decrease with the increasing Zn content. On the other hand, the ? of Al based Al-Zn alloys exponentially decrease with increasing temperature and Zn content. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.Firat University Scientific Research Projects Management UnitThis project was supported by the Erciyes University Scientific Research Project Unit under Contract No: FDK-2013-4756. The authors would like to thank Erciyes University Scientific Research Project Unit for their financial support