A.S. Schneider, B.G. Clark,
C. P. Frick, P.A. Gruber, E. Arzt

Materials Science and Engineering A, Band 508, Seiten 241-246 (2009)

Recently, much work has focused on the size effect in face centered cubic (fcc) structures, however few pillar studies have focused on body centered cubic (bcc) metals. This paper explores the role of bcc crystal structure on the size effect, through compression testing of [001] and [235] Molybdenum (Mo) smallscale pillars manufactured by focused ion beam (FIB). The pillar diameters ranged from 200 nm to 5m. Results show that the relationship between yield stress and diameter exhibits an inverse relationship (y ?d?0.22 for [001] Mo and y ?d?0.34 for [235] Mo) weaker than that observed for face centered cubic (fcc) metals (y ?d?0.6 to ?1.0). Additional tests at various loading rates revealed that small-scale Mo pillars exhibit a strain rate sensitivity similar to bulk Mo.