Understanding the crystallography of the eutectoid microstructure in a Zn–Al alloy using the edge-to-edge matching model

The orientation relationship (OR) between the β(Zn) phase and the α(Al) phase and the corresponding habit planes in a Zn–Al eutectoid alloy were accurately determined using convergent beam Kikuchi line diffraction patterns. In addition to the previously reported OR: [112¯0]β∥[110]α, (0002)β∥(1¯11)α, two new ORs were observed. They are: [112¯0]β∥[110]α, (1¯101)β 0.82° from (0 0 2)α and [1¯100]β∥[112]α, (0 0 0 2)β 4.5° from (1¯11)α. These ORs can be explained and understood using the recently developed edge-to-edge matching model.