INFLUENCE OF CHANGING THE HEAT FLOW DIRECTION ON THE CRYSTAL GROWTH DIRECTION DURING DIRECTIONAL SOLIDIFICATION.

Camphene-1. 2% cyclohexanol, which freezes like metals, has been used for the investigation of crystal growth during directional solidification with a continuously-changing heat-flow direction. The interface morphology of the columnar crystal changed according to the heat flow, and this led to a change in the growth direction of the columnar crystals. For cellular growth, the cells lay between the 001 direction and the heat flow direction, and approached more closely to the 001 direction as the ratio of the temperature gradient to the growth rate decreased. For dendritic growth, the trunks grew in the 001 direction and did not at all change the direction of the heat flow. In contrast, the sidebranches were very much affectd by the heat flow direction - the side branches on the side against the heat flow direction developed faster. The direction of columnar crystals tended to follow the heat flow direction, but a different mechanism operated depending on the interface morphology.