Effect of corrosion on mechanical and biological properties of nano-silver joints

In order to explore the mechanical and biological properties of nano-silver joints in corrosive environment, two series of experiments were carried out from the mechanical and biological perspectives. For mechanical perspectives， a) Two sandwich-like gold-plated copper (3×5×10 mm)-nano-silver-gold-plated copper (3×5×10 mm) samples were corroded for 24h in 3% NaCl solution at 45.5 ℃ (heating table temperature 50℃). The microstructural evolution of corrosion products of nano-silver sintered joints were analyzed by scanning electron microscopy (SEM). b) Twenty shear specimens were divided into two groups, corroded for 0h and 24h respectively. Besides, the corrosion shear strength of sintered nano-silver joints was measured. In order to explore the effects of nano-silver on organisms after it enters the body due to corrosion, the survival rate and apoptotic morphology of hamster lung cells were measured after incubation in nutrient solution containing 150, 175 and 200 μmol/l nano-silver for 24h. Through the above tests, it is found that the shear strength of joint decreases obviously after corrosion, and the fracture mode changes from interlayer failure to interfacial fracture. Biological experiments showed that the survival rate of hamster lung cells decreased with the increase of nano-silver concentration.