Micrograph 730 and full record

Micrograph no

730

Brief description

Magnesium alloy

Keywords

magnesium

Categories

Metal or alloy

System

Mg-Zn

Composition

Mg 94.05, Zn 5.62, Zr 0.19, Ce 0.10, Nd 0.03 (wt%) (RZ5 Alloy)

Standard codes

Reaction

Processing

As cast

Applications

RZ5 magnesium alloy is commonly used for wheels in both Formula One and Superbike competitions because of its high strength to weight ratio.

Sample preparation

Standard polishing techniques

Technique

Scanning electron microscopy (SEM) in backscattered electron imaging (BEI) mode

Length bar

200 μm

Further information

This RZ5 alloy is from an actual cast specimen. The billet was approximately 75mm diameter by 100mm in length. The cast billet has a characteristically rough surface, associated with the grain size of the sand used in the mould. This interaction between the cool mould and the hot casting, has an important role to play in the microstructure that develops throughout the billet. The microstructure varies as progression is made from the edge of the billet to the centre. The grains are approximately 200mm equiaxed. The grain boundary phase that is present is mainly composed of zinc and the rare earth elements and becomes sparser as the edge of the billet is approached.

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