Microstructural changes in an extruded MgZnY alloy reinforced by quasicrystalline I-phase by small additions of calcium, manganese and cerium-rich mischmetal

• In-situ HEXRD and DSC techniques are employed to identify phase transformations.
• The existence of I-phase is not altered by manganese addition to Mg93Zn6Y1 (wt.%).
• Calcium addition promotes Mg6Zn3Ca2 formation instead of I-phase.
• Mischmetal addition induces the formation of coarse T-phase particles.
• Texture depends on the nature of second phases and therefore of the extrusion pressure.

The effects of calcium, manganese and cerium-rich mischmetal additions on the microstructure and texture of the extruded Mg6Zn1Y (wt.%) alloy have been investigated. The microstructure of the alloys consisted of a magnesium matrix embedding second phase particles aligned along the extrusion direction. The nature and volume fraction of the second phases depended on the alloying element. Thus, Ce-rich mischmetal promoted the formation of T-phase while calcium additions resulted in the formation of a ternary MgZnCa compound. Only, manganese additions did not affect the existence of the I-phase present in the ternary alloy. The texture was measured and it was found that calcium addition has a significant effect weakening the extrusion texture.