In recent years, considerable effort has been devoted to the study of ordered intermetallics. Some of these ordered intermetallics, especially those based on aluminides, such as Fe3Al, possess many attractive properties for structural use at elevated temperature in harsh environments [1, 2]. In general, the aluminides contain sufficient amounts of aluminum to form, in oxidizing environments, oxide scales that are often compact and protective. These intermetallics have relatively low density, high melting point, good thermal conductivity, and superb high-temperature strength. As a result, these intermetallics are particularly suited for structural applications at elevated temperatures. However, the aluminides generally exhibit brittle fracture and low ductility at ambient temperatures [3, 4]. Recent studies have shown that Fe3Al aluminides are intrinsically ductile, and the poor ductility commonly observed in air tests is caused mainly by extrinsic effects [5–7]. Moisture-induced hydrogen embrittlement has been recognized as one of the major causes of low ductility. These attempts have led to the development of more ductility and stronger Fe3Al based alloys for structural applications. However, little effort has been devoted to the behavior of this alloy at high strain rate under tensile impact at present. This paper reports a comprehensive study of the dynamic mechanical behavior of Fe3Al under tensile impact and emphasis is placed on understanding the environmental effect on fracture behavior. Fig. 1 is a schematic diagram of the self-designed bar-bar tensile impact apparatus with a rotating disc. The specimen is glued to slots in the ends of the input bar and the output bar using high shear-strength adhesive agent. As the hammer of the high-speed rotating disc impacts the block, the short metal bar, made of aluminum alloy, breaks and an approximately rectangular input stress impulse wave is transmitted through the input bar to the specimen. A partial impulse wave is reflected to the input bar and the survival wave