SIPS 2018

DETAILLED PROGRAM OVERVIEW

Synthesis of Fe-Al Alloys by a Novel Reactive Infiltration Method
Srdjan Milenkovic¹;
¹IMDEA MATERIALS INSTITUTE, Getafe, Spain;
PAPER: 244/Manufacturing/Regular (Oral)
SCHEDULED: 15:15/Wed./Bossa (150/3rd)

ABSTRACT:
FeAl intermetallics are potential candidates to substitute Cr/Ni based (stainless) steel parts used in high volume end consumer products such as in the lock industry, electronics, process industry, and automotive industry, in order to reduce consumption of the critical raw materials [1,2]. Their impact would therefore be much higher if a cost effective industrial process would be available, that allows manufacturing complex 3-D geometries of almost unlimited shapes from small grain size (0.1-5 μm) high ductility material [3,4] In this work, a novel processing method has been investigated. It involves reactive infiltration of liquid Al into the porous Fe preforms, with the aim of obtaining fine grained Fe-Al. The feasibility of using pressureless infiltration process was examined. Initially, preliminary DTA experiments were conducted to analyse the effect of the melt temperature and composition on the thermodynamic effects of reaction between the preform and the melt. It was found that the pure Al melt interacts with Fe porous preform intensively with high exothermic effect, thus causing a great risk of melting of the preform or can lead to formation of rather porous material. In the next step, the feasibility of pressureless reactive infiltration was investigated using two different approaches. The first one is the drop casting of the melt into the preform being contained in a mould. The second one is the immersion method, which is applied by immersing the preform into the melt pool. In both cases, parameters like melt temperature, mould material, and time were investigated, and their influence on the final microstructure, morphology, and phase constitution has been discussed. Comparison and analysis of the outcomes of the DTA, drop casting, and immersion experiments provided useful results to understand main features of the reactive infiltration process and hints on how the process can be further optimized by a suitable heat management.

References:
[1] P. Kratochval, Intermetallics, 16 (2008) 587-591.
[2] D.G. Morris, M.A. Morris-Munoz, Intermetallics, 7 (1999) 1121-1129.
[3] N.S. Stoloff, Mater. Sci. Eng. A, 258 (1998) 1-14.
[4] N.S Stoloff, C.T Liu, S.C Deevi, Intermetallics, 8 (2000) 1313-1320.