抄録
The coarsening behavior of Si precipitates for over-aging stage was observedin A1-1.03mass% Si alloy. The coarsening data were agreement with Lifshiz-Wagner theory on diffusion-controlled coarsening. The influence of this Ostwaldgrowth of Si precipitates on elevated temperature deformation in this alloy wasstudied at temperatures from 473K to 623K in air and at initial strain rates from 7.94×10-5 to 1.76×10-2S-1. It was showed that the steady state flow stress isdecreased with the Ostwald growth of Si precipitates. TEM observation revealed. that the interaction between dislocations and Si precipitates is of attractiveinteractiontype, indicating that the stress field of a dislocation is relaxed atthe Si precipitates/matrix interface.
