Study of conventional annealing and laser annealing of vitreloy1b zr-based BMG

Pavey, Jonathan Michael (2014). Study of conventional annealing and laser annealing of vitreloy1b zr-based BMG. University of Birmingham. M.Res.

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Abstract

The machining response of a Zr-based amorphous alloy (Zr44Ti11Cu10Ni10Be25) when subjected to nano-second laser machining is investigated. The surface integrity of laser machined fields in two sets of experiments is studied using scanning electron microscopy (SEM) followed by subsequent X-ray diffraction (XRD) analysis to observe any phase changes. The study shows that the highly attractive short-range atomic ordering of the material can be preserved by optimizing the laser machining conditions. It was demonstrated that the surface roughness achievable after nano-second laser machining was comparable with that attainable in micro milling.
This thesis also investigates the effects of an additional annealing stage using two different techniques. Previous research has shown that when certain amorphous alloys are reheated into their supercooled liquid region, surface features can be erased under the action of surface tension forces. This study performs annealing experiments using a hot plate setup as well as an in-situ hot stage microscopy setup. The results reveal that no subsequent erasure of features was seen for the Zr-based amorphous alloy and this is attributed to the fast oxidation rate associated with the alloy preventing a surface smoothening effect from occurring.

Type of Work:

Thesis (Masters by Research > M.Res.)

Award Type:

Masters by Research > M.Res.

Supervisor(s):