Effects of Ti addition on the Fe-9Al-30Mn-1C alloy have been investigated such as mechanical properties, phase transformation and density. Based on the present study, some main results are described as followings. The microstructure of the as-cast alloys are essentially a mixture of dendrite austenite (γ) matrix and ferrite (α) particles. After being hot forged and solution heat-treated, the microstructures of the alloys are essentially single y matrix. In the meantime, when the Ti added, some (Ti,Fe)C{sub}x carbides precipitated within T matrix. The (Ti,Fe)C{sub}x is belonging to FCC structure with lattice parameters a = 0.457nm. In addition, with increasing the solution heat treated temperature or times, the quantity of (Ti,Fe)C{sub}x carbides would increase, and resulted in the finer grain size. Moreover, when the solution heat4reated temperature been about 1250℃, the (Ti,Fe)C{sub}x carbides are no more belonging to FCC structure. When increased the Ti element added in Fe-9Al-30Mn-1C alloy, the ultimate strength, yield strength and hardness would increased from 75.45kg/mm{sup}2 to 104.56kg/mm{sup}2, 57.2kg/mm{sup}2 to 81.56kg/mm{sup}2, 88.9 to 100.2 HR{sub}B, respectively. In addition, the elongation would decrease from 58.0% to 7.6% when Ti added. The density examinations show that the relationship between the chemical compositions and the density are nearly ρ (g/cm{sup}3) = 7.8451-0.1228Al%-0.0045Mn%-0.0566C%-0.23Ti%. (The error = 1.35%) Moreover, during the aging processes, a γ→γ→K→γ→K→K' phase transformation was observed within the austenite matrix.
Fe-Al-Mn-C alloy Microstructure Machinability Dendritic structure