Experimental study on ratcheting behavior of eutectic tin-lead solder under multiaxial loading

A series of uniaxial and multiaxial ratcheting experiments have been conducted on 63Sn-37Pb solder alloys. It is shown that eutectic tin-lead solder is cyclic softening under uniaxial, pure torsional and axial/torsional ratcheting loading. Even low-level stress can cause high ratcheting strain. The rate of ratcheting strain remains steady and does not decay rapidly. Under constant axial stress and cyclic shear strain, the axial ratcheting strain and its rate rise with increase of the axial stress and shear strain range, but loading history and its sequence have no clear influence on the ratcheting behavior. The axial ratcheting strain rate is found to be strongly dependent on applied shear strain rates in axial/torsional ratcheting experiments. Axial ratcheting strain rates increase with decreasing shear strain rates.