Modeling of shear induced coarsening effects in semi-solid alloys
In long-term rheological shear experiments with semi-solid alloys,coarsening of the particles will falsify the interpretation of the experimental results.The coarsening is intensified by the shear induced convection and the mean size of the particles is changed significantly during the experiments.A simple model has been set up which takes the influence of the convection into account.The resulting growth law has been simplified for diffusion and convection dominated growth.The growth law was verified with shear experiments in a Searl-rheometer with A356 and tin-lead alloys.The experiments demonstrated that under convection the growth follows a linear time law and that the rate constant depends on the root of the shear rate.The correction of experimental results to gain the true viscosity function is demonstrated for a shear jump experiment with A356.
microstructure coarsening Ostwald ripening flow function viscosity rheology semi-solid alloys
M.MODIGELL A.POLA
AVT, Chair of Mechanical Process Engineering, RWTH Aachen University, Turmstr.46, D 52056 Aachen, Ge Dipartimento di Ingegneria Meccanica e Industriale, Uni.degli Studi di Brescia, via Branze 38, 25123
国际会议
北京
英文
1696-1701
2010-09-16（万方平台首次上网日期，不代表论文的发表时间）