【摘要】 利用金相、扫描、EBSD和透射等方法对Fe-23Al合金时效过程中的有序畴结构进行表征,并借助模拟手段分析有序畴形成的微观机制。结果表明:经高温固溶处理后,Fe-23Al合金中形成500μm的等轴晶粒,未发现有序畴。随后在625℃,1h时效时,晶粒内部形成沿着某一方向规则排列的有序畴。根据EBSD和TEM分析可以得知,有序畴和无序畴之间的取向差角保持为45°,主要是由于Fe-23Al合金时效过程中发生有序化转变。利用微观相场动力学模型对有序畴形成过程进行模拟,证实这种有序化转变的机制为失稳有序化。更多还原

【Abstract】 The special regular arrangement of ordered domains within grains during aging in Fe-23at%Al(Fe-23Al) alloys was investigated by OM(metallographic microscopy),SEM(scanning electron microscopy),EBSD(electron backscattered diffraction) and HTEM(high resolution transmission electron microscopy) methods.The results show that around 500 μm equiaxed grains are formed during high temperature solid solution,and square ordered domains are formed along certain direction within grains after 625 ℃ aging for 1 h.According to EBSD and HTEM results,misorientations between ordered and disordered domains remain 45°,which is attributed to ordering transformation during aging in Fe-23Al alloys.The ordering transformation is an instability ordering mechanism,which is confirmed by simulation results of phase field kinetic.更多还原