| Title |
Rheological Behaviors of the Hypoeutectic A357 Al Alloy : Pseudoplasticity |
| Authors |
고영진(Young Jin Ko),윤의박(Eui Pak Yoon),이재철(Jae Chul Lee),이호인(Ho In Lee) |
| Abstract |
Effects of various thermomechanical treatments on the microstructure and rheological behaviors of the semi-solid A357 alloy were studied using a concentric cylindrical viscometer. The size and morphology of primary solid particles during continuous cooling were influenced by shear rates and cooling rates. Faster cooling rate was observed to result finer microstructures. On the other hand, at a given cooling rate increased shear rates tend to force the primary particles agglomerate together. At a given volume fraction solid the viscosity of the slurry decreases with decreasing cooling rates and increasing shear rates. The strain rate sensitivity, which is the measure for the pseudoplastic behavior, was measured to be -1.3∼-1.6 within the fraction of solid range of 0.45∼0.65. |