High-temperature tensile tests and activation volume measurement of free-standing submicron Al films

Tensile tests on free-standing, 200-nm-thick Al films were conducted between room temperature and 200 degreesC. Applied strain rates were in the range 1x10(-8)-2x10(-6)/s. At a temperature of 200 degreesC a saturation of the flow stress was observed. The strain required to achieve steady-state saturation is of the order of 2x10(-3), which is much smaller than for bulk Al. From the observed strain rate sensitivity of the saturation stress we calculate an activation volume Omega(act)=60b(3), which is small compared to the value of 700b(3) observed in bulk Al (b is the magnitude of Burgers vector). (C) 2002 American Institute of Physics.