中文摘要：

为了在热形成，预先渗出的 Mg-6Zn 镁合金的谷物生长行为和它与溶质和第二个阶段的关联期间控制谷物尺寸，分发被调查。等温的退火在一个 Gleeble-1500 thermo 机械的模拟器上被进行。吝啬的谷物尺寸 D _{每个退火的标本的 g} 被量的金属组织学技术测量。Mg-6Zn 合金的谷物生长动力学在 473-623  K 退火了被最少的方形的线性回归方法作为 Dg4−Dg04=2.25×1011exp (−95450/RT ) t 获得。从 2 的理论价值的谷物生长代表 n = 4 的偏差可以被归因于将延迟的溶质锌和第二个阶段的存在边界迁居。为样品的谷物尺寸的不一致的分发预先渗出的显微镜的观察表演或在低温度退火了仔细与好、分散的秒的不一致的分发有关分阶段执行然而并非到溶质锌的不一致的分发。这显示第二个阶段卡住效果在微观结构精炼起一个重要作用。

英文摘要：

In order to control the grain size during hot forming,grain growth behavior of a pre-extruded Mg-6Zn magnesium alloy and its correlation with solute and second phase distribution were investigated.Isothermal annealing was conducted on a Gleeble-1500 thermo-mechanical simulator.The mean grain size Dg of each annealed specimen was measured by the quantitative metallography technique.The grain growth kinetics of the Mg-6Zn alloy annealed at 473-623 K was obtained as Dg^4- Dg0^4=2.25 ×10^11 exp（-95450）by the least square linear regression method.The deviation of grain growth exponent n = 4 from the theoretical value of 2 may be attributed to the presence of solute zinc and second phases which will retard the boundary migration.Microscopic observations show that the non-uniform distribution of grain size for samples pre-extruded or annealed at low temperatures is closely related to the non-uniform distribution of fine and dispersed second phases but not to the non-uniform distribution of solute zinc.This indicates that second phase pinning effect plays an important role in microstructure refinement.