Effect of sintering temperature on fatigue crack propagation rate of sintered Ag nanoparticles

In this study, the effect of sintering temperatures on fatigue crack propagation rates of sintered Ag nanoparticles were investigated. Paris' law type fatigue crack propagation law between the fatigue crack propagation rate and the inelastic strain energy density range was found to hold at all test temperatures. The power exponent in the fatigue crack propagation law for the Ag nanoparticles sintered at 423 K was large and the fatigue crack propagation rate was fast with excessively brittle behavior. The stress and strain concentrations at neck parts interlinked with each other in damaged areas, in addition to the brittle grain boundary fractures, resulted in the excessively brittle behavior. On the other hand, the Ag nanoparticles sintered at 473 K showed more ductile behavior as pores decreases with sintering progression and the local strain concentrations were fewer compared to the Ag nanoparticles sintered at 423 K. However, with test temperature increasing, the grain boundary became viscous, so the power exponent in the fatigue crack propagation law and fatigue crack propagation rate at any sintering temperature decreased, causing only minor differences by sintering temperature in fatigue crack propagation rates.