Magnesium Alloy Sheet with Low Gd Content, High Ductility and the Hot Rolling Technology Thereof

Abstract

The present invention discloses a magnesium alloy sheet with low Gd content and high ductility and its hot rolling technology, which belongs to the field of metal material technology. The chemical components of the magnesium alloy sheet, based on the mass percent, take up respectively: 0.9˜2.1% as Zn, 0.2˜0.8% as rare earth element, namely Gd, 0˜0.9% as Mn, and the rest as Mg. The magnesium alloy sheet of the present invention is added with relatively lower rare earth element, Gd, which reduces the alloy costs; in addition, magnesium alloy has good rolling performance, which can realize continuous, multi-pass and large-deformation rolling, and also ensure the sheets rolled have non-basal texture and high room-temperature elongation which reaches 35˜50%, wherein the elongation, δ, in the rolling direction is no less than 35% and that in the horizontal direction no less than 45%.

1 . A magnesium alloy sheet with low Gd content and high ductility, wherein the sheet belongs to Mg—Zn—Gd series and calculated as per mass percent, with chemical components: 0.9˜1.9% Zn, 0.4˜0.8% Gd, 0˜0.9% Mn and the rest is Mg;
 the room-temperature elongation of the sheet is 35˜50%. and the elongation in the rolling direction is ≧35% and that in the horizontal direction ≧45%. 
 
     
     
         2 . (canceled) 
     
     
         3 . A hot rolling technology of the magnesium alloy sheet with low Gd content and high ductility according to  claim 1 , comprising the flowing steps:
 1) homogenization treatment of ingots: maintain the temperature of the ingots of magnesium alloy with the chemical components for 0˜120 hours under 300˜525° C.;   2) hot rolling of ingots: Rolling temperature: 250˜525° C.; rolling reduction of each pass: 35˜50%; return the ingots back to the furnace every time after rolling of 1˜5 passes, heat them up to the rolling temperature and keep the temperature for 5˜60 minutes before further rolling, with the total rolling reduction being 80˜95%; and   3) annealing of rolled sheets: the rolled sheets are annealed for 0.5˜120 hours under 250˜500° C.   
     
     
         4 . The hot rolling technology of the magnesium alloy sheet according to  claim 3 , wherein the ingots of Step 1), round or square, are manufactured with metal mold and sand gravity casting or with semi-continuous casting method. 
     
     
         5 . The hot rolling technology of the magnesium alloy sheet according to  claim 3 , wherein during the rolling of Step 2), the preheating temperature of the roller is: room temperature to 400° C.