Deformation mechanisms and microtensile behavior of single colony Ti–6242Si

High Throughput Assays for Additively Manufactured Ti-Ni Alloys Based on Compositional Gradients and Spherical Indentation

“…The lattice orientations of the grains in the indented zones were not measured in this work. Although the grain orientation is expected to play an important role in the indentation properties of hcp metals [45][46][47][48][49], these dependencies are most clearly seen in indentations performed with smaller indenter tips where the indented zones are fully embedded in a single grain. In fact, most of the prior work on the use of spherical indentation stress-strain curves was focused on single-phase coarse-grained polycrystalline samples [10,37].Only recently, these protocols have begun to be applied to multiphase polycrystalline samples [7].…”

A Case Study in Hardening of Cd-Ag Alloys with Solute Concentration

“…β-lath shearing was inhibited in these circumstances, but not so for orientations favouring prism slip. The planar slip observed by Savage et al [24,25] also occurs near α-β interfaces in single colonies and the stress concentrations which develop at the interfaces were relieved by room temperature creep processes. They showed that in the sample oriented for a1 basal slip, relatively easy slip transmission occurs across β laths.…”

“…Simultaneous occurrence of two phases is very much evident from the optical micrograph ( fig. 7) of Cd-29.40Ag alloy also Savage et al [24,25] also suggested that for thicker β laths dense pile-ups of dislocations are observed at the exit α-β interface, suggesting relatively easy a2 transmission within the β phase, but difficulty in exiting of b2 dislocations from the β phase at the α-β interface. For a3 basal slip, large pile-ups of near-edge a3 dislocations are observed in the α phase at the α-β interfaces, showing the large resistance to slip developed at the β laths for a3 basal slip.…”

“…In the present study, for hcp1 phase with c/a ratio > 1.633, slip takes place in the basal plane and for hcp2 phase (Ti, Zr type) with c/a ratio <1.633, slip takes place in the prismatic plane [19]. Another explanation for decrease of microhardness in case of Cd-29.40Ag and Cd-44.80Ag and increase immensely in case of Cd-48.7Ag can be cited from the conclusion of work of Neeraj et al, Suri et al Savage et al and others on the theory of co-growth of bcc and hcp phase [20][21][22][23][24][25][26] in Titanium alloy system, where it was assumed a bcc phase and hcp phase can grow simultaneously by sharing common closed packed planes, (111) of bcc (described as β-phase) and (0001) plane of hcp phase (described as α-phase) as schematically drawn in fig. 6.…”

“…However, colonies oriented for a2 showed much edge dislocation pile-up at the α-β interfaces and a correspondingly much higher resistance. Work by Savage et al [25] established that the α-β laths in Ti-6Al-2Sn-4Zr-2Mo maintain approximately the BOR, and single-colony tests indicated the inhibition of slip transmission for systems in which the α hcp phase was well oriented for basal slip. β-lath shearing was inhibited in these circumstances, but not so for orientations favouring prism slip.…”