Discovery of plate-shaped athermal ω phase forming pairs with α′ martensite in a Ti–5.26 wt.% Cr Alloy

Plate-shaped athermal ω phase (ωP) has been observed for the first time in an as-quenched Ti–5.26 wt.% Cr alloy, forming a plate pair with α′ martensite. The orientation relationship is determined as: [01¯1]β // [21¯1¯0]ωp // [0 0 0 1]α′, (2 2 2)β // (0 0 0 1)ωp 0.5° away from (112¯0)α′, with the habit plane (54¯4¯)β // (06¯61)ωp // (34¯10)α′. Such observations are explained well using the edge-to-edge matching model. The singular α′/ωP interface implies that α′ martensite is likely to act as a heterogeneous nucleation site for ωP.