Crack propagation in conventional and high copper dental amalgam as a function of strain rate

Dental amalgam prepared from high copper and conventional alloys was evaluated for its compressive strength as a function of deformation rate. Results showed that the compressive strength rose to a maximum as deformation rate increased and then began to fall at higher deformation rates. Crack propagation predominated through the gamma 1 phase and around copper containing particles at lower strain rates. Cracks also occurred through copper containing original particles where the stress at fracture was sufficiently high.