中文摘要：

通过包覆热轧得到Ti-47Al-2Nb-2Cr-0.2W合金薄板。板材合金组织是由细小的γ相颗粒和层片状的晶团组成的双态组织。然而,热轧后合金板材组织不均匀,沿轧制方向具有明显方向性。研究在α相区热处理轧后的板材,结果显示通过不同热处理方式可得到不同晶粒尺寸及晶界形貌的全层片组织;平均晶粒尺寸随着保温时间的延长而增大,晶粒长大因子为0.2,晶粒长大激活能约为225kJ/mol。粗大的层片状晶团可以通过控制冷却方式及保温时间而得到有效细化。

英文摘要：

The Ti-47Al-2Nb-2Cr-0.2W alloy sheets were obtained by hot pack rolling. The as-rolled sheet has an inhomogeneous duplex microstructure composed of elongated gamma grains and lamellar colonies. Heat treatments were conducted on the as-rolled sheets. The results show that the microstructures with different sizes and grain boundary morphologies were developed after different heat treatments. A coarse fully lamellar structure can be refined if the heating time, together with the cooling rate, is appropriately controlled. The grain growth exponent is found to be approximately 0.2, and the activation energy of grain boundary migration of the alloy is around 225 kJ/mol.