Mn-Al-C永磁合金相变动力学及τ相的稳定性

The Dynamics of Phase Transformation and Stability of r Phase for Mn-Al-C Alloy

摘要: 本文研究了成分为Mn 69.40%、Al 29.86%、C0.58%3元合金的相变动力学和3种不同成分Mn-Al-C合金的恒温转变过程,还用示差热分析法测定了合金在加热过程中相变的临界温度。实验结果表明:合金的恒温转变过程随成分不同而变化,处于亚共析成分时,τ相分解先析出γ相;处于过共析成分时,τ相分解先析出β-Mn相。τ相的稳定性取决于Mn/C比,含碳量一定,随Mn含量增加,τ相稳定性降低。必须使合金中的含碳量超过其在τ相内的溶解度极限,才能提高τ相的稳定性。

Abstract: The dynamics of phase transformation of the ternary alloy which consists of 69.40wt% Mn, 29.86wt%Al, 0.58wt% C, and constant temperature for three types of Mn-Al-C have been researched.The critical temperature of base transformation of the alloys were measured by DTA.It indicated that the transformation temperature for these alloy varied with the different compositions.In the sub-eutectic composition, phase decomposed, γ-Phase precipitated first. But in over-eutectic composition,β-Mn phase precipitated from τ-phase.When the content of C was constant,the stability of τ-phase decreased with the increase of Mn content.