Effect of Ti and Zr Combined Modification on Microstructures and Mechanical Properties of Mg₉₅Y_2.5Zn_2.5 Alloy Containing LPSO and W Phases

Abstract

In order to develop a high performance Mg-Y-Zn alloy containing LPSO phase in the condition of lower Y/Zn atomic ratio, the effect of Ti and Zr on microstructures and mechanical properties of Mg 95 Y 2.5 Zn 2.5 alloy was investigated. Although the a-Mg grains can be refined by adding Ti and Zr separately, the best refinement effect can be obtained by the combined addition of them. More importantly, the formation of LPSO phase was promoted by adding them in as-cast Mg 95 Y 2.5 Zn 2.5 alloy. Meanwhile, the growth model of W phase was transformed from divorced eutectic to cooperative eutectic. In this case, the LPSO/W interface became continuous, which degraded the mechanical properties of as-cast alloys. After extrusion, the increased LPSO phase caused by adding Ti and Zr greatly improved the strength of as-extruded alloy.

Effects of Phase Content and Evolution on the Mechanical Properties of Mg95Y2.5Zn2.5 and Mg93.1Y2.5Zn2.5Ti1.6Zr0.3 Alloys Containing LPSO and W Phases

“…Compared with Mg 95 Y 2.5 Zn 2.5 alloy, Mg 93.1 Y 2.5 Zn 2.5 Ti 1.6 Zr 0.3 alloy possesses smaller grain size and more 18R‐LPSO phase, indicating that combined addition of Ti and Zr not only significantly refines the grains, but also promotes the formation of 18R‐LPSO phase. The effects of Ti and Zr addition on the 18R‐LPSO phase is discussed by Wu et al which can be attribute to the change in concentration of solute atoms Y and Zn when LPSO begins to form . With the increase of 18R‐LPSO content in Mg 93.1 Y 2.5 Zn 2.5 Ti 1.6 Zr 0.3 alloy, the direction of its growth is also very obvious (Figure b).…”

“…In our previous study, the relative content of LPSO phase and W phase can be changed by the addition of alloying elements Ti and Zr in the Mg 95 Y 2.5 Zn 2.5 alloy . In this study, the Mg 95 Y 2.5 Zn 2.5 alloy containing LPSO phase and W phase was selected as the research object.…”

Mn‐promoting formation of a long‐period stacking‐ordered phase in laser‐melted Mg alloys to enhance degradation resistance

“…Meanwhile, the LPSO phase was distributed in the grain interior as well as arranged in a parallel lamellar structure, which could play a role in inhibiting the extension of degradation process among the neighboring grains. The LPSO phase formed only when the atomic ratio of rare earth elements to Zn was >1 and its content increased with increasing content of rare earth elements . However, the content of rare earth elements in Mg alloys should be controlled in the context of biocompatibility.…”

“…The LPSO phase formed only when the atomic ratio of rare earth elements to Zn was >1 and its content increased with increasing content of rare earth elements. [18,19] However, the content of rare earth elements in Mg alloys should be controlled in the context of biocompatibility.…”

Influence of Ni Alloying on the Precipitation of Quasicrystal Phase in As‐Cast Mg96.5Zn1Y1.5Mn1 Alloy

“…Owing to the remarkable mechanical properties, Mg–Y–Zn alloys have gained unexpected attention during the past few decades . Generally, long period stacking ordered (LPSO, Mg 12 Zn 1 Y 1 ) structure, quasicrystal phase (I phase, Mg 3 Zn 6 Y 1 ) and W phase (Mg 3 Zn 3 Y 2 ) could be precipitated in Mg–Y–Zn alloys by adjusting the Zn/Y atomic ratio .…”