Abstract
A model experiment was conducted using paraffin wax to clarify the residual stress generated during solidification and adhesion of molten droplets. In the experiment, molten paraffin droplets were dropped onto the center of a stainless steel substrate, and the strain generated on the substrate back surface was measured by strain gauge. The experiments were conducted with changing material of paraffin wax and substrate temperature. By comparing the experimental results, the influence of adhesion state along the interface on the strain was investigated. It was also found that wettability of paraffin wax on the substrate could affect the strain. A thermal-structural coupled analysis was conducted to quantitfy the effects of material properties of paraffin waxes, the geometry of coating and interfacial property between the substrate and the coating on the strain. According to the analytical result, it was found that the larger Young’s modulus, the larger stress-free temperature and the larger coefficient of thermal expansion lead to the larger strain. It was also shown that the strain could be diminished when substrate temperature is low or melting point of paraffin wax is high, due to decrease in adhesion area on the interface between the substrate and the coating.
