Martensitic Transformation in  Single Crystals of Cu-Al-Ni Alloy
Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 180 40 Praha 8, Czech Republic
The martensitic transformations β1(D03)↔γ'1(2H), β1 ↔ β'1 (18R1) and γ'1↔ β'1 were investigated in the  oriented single crystals of Cu-14.3Al-4.1Ni (wt.%) alloy. Thermal cycling and deformation tests in tension and compression were performed to induce the transformation process. The experimental results were summarized in a non-equilibrium σ-T phase diagram (σ-T map) which exhibits single-phase regions β1 and γ'1 two-phase region β1 + γ'1and β'1 + γ'1 and three- phase regions β1+ β'1+ γ'1 The tensile and compression parts of the σ-T map are not identical. This ”tension-compression asymmetry" is compared with similar asymmetry observed for other crystal orientations.
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