Directional solidification of dilute Sn–Pb alloys

Abstract

Microstructure evolution and pattern formation during directional solidification of dilute Sn-Pb system were analysed. Planar, cellular and dendritic morphologies were obtained by adequate thermal gradient and interface velocity control. The samples were obtained from pure elements in concentrations of 0?05, 1?0 and 4?0 wt-%Pb. Growth was carried out in a Bridgman device in the velocity range of 0?38-30 mm s 21 at thermal gradients from 1?3 to 2?6uC mm 21 . The samples were examined using metallographic techniques to determine their morphology and dimensional characteristics. The system was analysed to describe the different stages of evolution of the morphology and transitions. It was observed that both primary cellular and dendritic spacing decreased with increasing velocity. However, in the cellular-dendritic transition zone, an important increase in spacing was detected and basically associated with convective effects during irregular cellular growth.

Directional Solidification of Sn-Ag-Cu Alloys

“…The growths were not quenched allowing the crystal to grow in all the sample, that is approximately 80 mm long. However some experiences were quenched to allow the observation of the microstructure at the interface during the crystal growth and to verify the directionality of growth [Ochoa et al (2012)]. The Figure 1 shows a directional growth of the ternary Sn-0.9%Cu-3.5%Ag as quenched.…”

“…Directional growth was performed in a Bridgman like apparatus, as has been previously reported by Fornaro et al (2006) and Ochoa et al (2012). The device consists of two chambers located in a cylindrical symmetry.…”

Directional Solidification of Sn-Cu6Sn5 In Situ Composites

“…Directional growth was performed with a Bridgman-like apparatus, as has been previously reported [39][40][41]. e device consists of two chambers located in a cylindrical symmetry.…”