Anomalies of the plastic yield stress in the intermetallic compound Fe-30 at.% Al

The plastic properties of Fe-30 at.% Al were investigated in compression, c yclic tension/compression and shear tests between room temperature and 870 K. At elevated temperatures in all tests a positive temperature dependence of the yield stress was observed. At room temperature an asymmetry of the f low stress with respect to the deformation direction (tension or compressio n) was found, which disappeared for temperatures T greater than or equal to 570 K. The results are discussed on the basis of the present state of know ledge about the decoupling of D0(3)-superdislocations at elevated temperatu res and the deformation behaviour of b.c.c. metals at low temperatures. (C) 1999 Elsevier Science Ltd. All rights reserved.