Deformation Twinning, Slip, Martensite Formation and Crack Inhibition in the B2-Type Zr₅₀Pd₃₅Ru₁₅ Alloy

Abstract

Enhanced room temperature toughness of the Zr50Pd35Ru15B2 phase alloy was found to be a result of the activation of an additional deformation mode besides the b=[001] dislocation slip mode - {114}-type mechanical twinning. The twinning is a true one, i.e. there is no change in the ordered crystal structure. Another additional mode of plastic deformation, expected for more Pd rich alloys, is the formation of stress-induced martensite. The martensite was found to have a CrBtype structure.

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

“…Alternative In addition to theto dislocation slip occurring during modes of plastic deformation, there could can also be mechanical twinning and stress-induced martensitic phase transformation [22]. Twinning can re-orient portions of a grain to facilitate further dislocation motion, thereby compensating for inadequate numbers of independent slip systems [17,23].…”

“…TEM investigation indicated that the CrB-type B33 Mechanical twinning of {114}-type observed in B2 structure, <100>-type slip, and martensitic phase transformation were found to be responsible for the enhanced room temperature ductility of 6.6% elongation in the B2 structured Zr50Pd35Ru15 alloy [22,25]. 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>.…”

Transmission electron microscopy investigation of B27 martensitic phase in polycrystalline YCu intermetallic compound

“…So far the mechanism of B2→B27 phase transformation is not solved. A model similar to that published in [16] will be presented in a separate paper. In the present study the impurity phases such as Y 2 O 3 and YCu 2 were not observed in YCu specimens.…”

“…Twinning can re-orient portions of a grain to facilitate further dislocation motion, thereby compensating inadequate numbers of independent slip systems. Plastic deformation due to a martensitic phase transformation or redistribution of martensite variants has been observed in many shape memory alloys [16,17]. Ibarra et al [18] showed that YCu undergoes a B2 (CsCl-type) to B27 (FeB-type) martensitic phase transformation at about 140 K by neutron diffraction measurements.…”

The Hafnium-Platinum Phase Diagram

“…The compound ZrPd is the second long period analog of TiNi and is the basis of alloys having exceptional resistance to sliding wear. [2] The compound HfPt is the third long period analog of TiNi but its properties are not well known, due partly to the absence of a phase diagram for the Hf-Pt alloy system. The Hf-Pt system has become the last binary alloy system belonging to this class for which no phase diagram currently exists.…”