(西北工業(yè)大學(xué) 凝固技術(shù)國家重點(diǎn)實(shí)驗(yàn)室，西安 710072)
摘 要: 基于微觀相場動力學(xué)理論，建立B2型金屬間化合物的沉淀動力學(xué)方程，研究Fe-Al合金時(shí)效處理時(shí)B2-FeAl有序疇界的形成和遷移。結(jié)果表明： B2-FeAl金屬間化合物有序疇的形核孕育期隨時(shí)效溫度的升高而延長，隨Al含量的增加而縮短；有序疇的長程序參數(shù)隨時(shí)效溫度的升高而降低，隨Al含量的增加而先增大后減小；有序疇界始終向其曲率中心運(yùn)動，且在曲率較大的地方其運(yùn)動速率較大；有序疇界的遷移遵循Rm(t)-Rm(0)=kt (m≈2)，m 受合金成分和時(shí)效溫度的影響很小，但k 的絕對值隨著Al含量的降低而減小，隨時(shí)效溫度的升高而增大。
關(guān)鍵字: 微觀相場；B2-FeAl金屬間化合物；形核孕育期；長程序參數(shù)；有序疇界
（State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The precipitation kinetics function of B2 type intermetallic compound was established based on the microscopic phase-field kinetics theory，and it was used to investigate the formation and the motion of B2-FeAl ordered domain boundaries during aging of Fe-Al alloy. The results demonstrate that the nucleation incubation period of B2-FeAl ordered domains becomes longer with the increase of aging temperature，and it becomes shorter with the increase of Al content. The long-range order parameter of ordered domains decreases with the growth of aging temperature，and it first increases then decreases with the increase of Al content. The ordered domain boundaries move to their own centre of curvature all the time, and they move faster at where the curvature of ordered domain boundary is bigger. The rule Rm(t)-Rm(0)=kt (m≈2) is obeyed when the ordered domain boundaries migrate, the value of m is affected very slightly by aging temperature and alloy composition, but the absolute value of k decreases with the decrease of Al content，increases with the increase of aging temperature.
Key words: microscopic phase-field; B2-FeAl intermetallics compound; nucleation incubation period; long-range order parameter; ordered domain boundary
