Determination of slip systems and their relation to the high ductility and fracture toughness of the B2 DyCu intermetallic compound

Mechanisms of Ductility in CoTi and CoZr B2 Intermetallics

“…[6][7][8] While the behaviors discussed earlier are established ''rules of thumb'' for the behavior of B2 intermetallics, several highly ordered binary combinations are reported to accommodate significant plastic strains. These materials include combinations of rare earth and transition elements [9] such as YAg, [10] DyCu, [11] and YCu [12] as well as IVa-VIII intermetallic compounds, CoTi and CoZr, which are shown to accommodate room-temperature tensile strains of 2 [13] and 17 pct, [14] respectively. It is interesting that the only active slip system unambiguously identified at room temperature in all of these compounds is 100…”

Stability maps to predict anomalous ductility in B2 materials

“…3, where 001 slip ( 111 slip) is more favorable for systems lying to the right (left). Equation (9) translates to the slanted line in Fig. 3.…”

“…3 In contrast to B2 alloys, this new class of RM compounds have an exact stoichiometry, and are nearly elastically isotropic. 1 Following the discovery of the RM compounds, there have been several experimental 4,8,9 and theoretical 2,10-12 studies. Morris et al have hypothesized that the enhanced ductility in the Y-based compounds is due to the competing structural stability of B33 and B27 phases, obtained by introducing a periodic array of a 2 001 {110} superintrinsic stacking faults (SISF) to the B2 lattice.…”

TEM study of the martensitic phases in the ductile DyCu and YCu intermetallic compounds

“…In Zr50Co39Ni11 alloy the lenticular B33 martensites having lattice parameters The previous worksPrevious research has have shown that the dominate dominant slip systems in RM intermetallic compounds are {110}<001> and {100}<001>. The {110}<111> slip was also found to be active in DyCu, YAg, and YCu [8][9][10][11][12][13]. Based on the criterion of von Mises for generalized plastic deformation of a polycrystalline aggregate, the <001> dislocation slip can only provide onlys three independent slip systems, and the operation of <111> dislocations will satisfy the necessary von Mises requirement of five independent slip systems [14].…”

“…The operative slip systems determined by slip trace measurements are {110}<001> and {100}<001> for YAg, YCu, YZn, and DyCu, and {110}<111> for YAg and DyCu [8,9,12,13].…”