Characterization of microstructures and age hardening of Fe_1鈭?xAl_xV_x alloys

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• 作者：P.A. Ferreiró ; s^a ; P.R. Alonso^a ; P.H. Gargano^a ; P.B. Bozzano^a ; H.E. Troiani^b ; ^c ; A. Baruj^b ; ^c ; G.H. Rubiolo^a ; ^b ; ^{rubiolo@cnea.gov.ar" class="auth_mail}
• 关键词：A. Iron aluminides (based on Fe3Al) ; B. Alloy design ; B. Age-hardening ; E. ab-initio calculations ; F. Calorimetry ; F. Electron microscopy ; transmission
• 刊名：Intermetallics
• 出版年：July, 2014
• 年：2014
• 卷：50
• 期：Complete
• 页码：65-78
• 全文大小：4342 K

文摘

The Fe-rich corner of the Fe-Al-V system has shown phase separation into disordered A2 and ordered L2₁ phases. In a former work we model this ordering reaction by using ab-initio thermodynamics. The approach is now employed to suggest the Fe_1鈭?xAl_xV_x alloys in order to reduce the Al content by increasing the addition of vanadium looking for a better ductility of the solid solution which can be afterwards strengthened by coherent L2₁ precipitates. Four alloys with compositions in the range 0.08聽<聽X聽<聽0.15 were studied. The phase transition temperatures and microstructures of the alloys were characterized by differential scanning calorimetry (DSC) and transmission electron microscopy (TEM), respectively. The region (A2聽+聽L2₁) occurs for 0.10聽<聽X聽<聽0.15 up to maximum temperature of 720聽掳C, higher temperatures causes the appearance of (A2聽+聽B2), B2 and (B2聽+聽L2₁) regions. The microstructure in the (A2聽+聽L2₁) region consists of nanosized precipitates of L2₁ phase in A2 matrix which morphology evolutes with temperature and ageing time. The hardness values, measured at room temperature, for the alloys with X聽<聽0.125 and ageing temperature between 650 and 700聽掳C are comparable to those obtained with other Fe-Al based alloys.