Study on the fluidity of AZ91+xRE magnesium alloy

Influence of section thickness, pouring temperature, mould temperature and content of rare earth (RE) element on the fluidity of AZ91 magnesium alloy has been studied through fluidity specimens with different section thicknes s cast in metal mould. The results show that the relation curve of filling length versus section thickness can be divided into two parts: (i) the fill ing length in the thin section increases slowly with increasing section thi ckness, after a critical thickness; and (ii) the filling length in the thic k section increases rapidly with increasing section thickness. Elevating th e pouring temperature has little influence on the fluidity in the thin sect ion, but increases the filling length in the thick section remarkably. As m ould temperature increases, the fluidity in the thin section increases a li ttle, but the fluidity in the thick section rapidly increases. As RE conten t increases, the fluidity in the thin section changes from increasing to de creasing, and the fluidity in the thick section changes from increasing to decreasing, and to increasing again. Moreover, the critical thickness separ ating region of thin and thickness section behavior moves to higher values. (C) 1999 Elsevier Science S.A. All rights reserved.