Healing solders: A numerical investigation of damage-healing experiments

The effect of liquid-assisted healing (LAH) of solder materials is investigated by means of experiments and numerical modelling. An in-situ heating experiment shows the material transport due to viscous flow into a surface cavity and, thus, motivates the development of the semi-solid viscous flow model. The mechanical healing effect is illustrated through a damage-healing experiment, where cylindrical samples are loaded under cyclic tension until fracture. A healing procedure allows for crack closure due to viscous material transport and a subsequent post-healing loading sequence shows the regain of mechanical properties. A finite element model of the experiment is used for further analysis of the damage-healing behaviour. In particular, the role of the microstructural mobility parameter is discussed based on model evaluations.