Microstructural evolution of amorphous cobalt-rich magnetic alloys during magnetic field annealing

✍ Scribed by C.K. Kim

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 540 KB
• Volume: 38
• Category: Article
• ISSN: 0921-5107
• DOI: 10.1016/0921-5107(95)01517-5

✦ Synopsis

We have studied surface crystallization phenomenoil in Coirich amorphous alloys based on ('o,~5.,Fes(BSi) ,. Our results indicate that amorphous alloys can undergo surface crystallization in response to oxidation at temperatures well below the bulk crystallization temperature. We also add new details to this process, and in particular show that it involves a sequence of three steps: (1) formation of an amorphous borosilicate surface oxide layer: 12) depletion of the underlying amorphous metal of glass-stabilizing boron and silicon: and ~31 primar3 crystallization of the destabilized, metal-enriched sub-surface layer to an fcc or hop phase. The structure and morphology of the sub-surface crystallitcs depend on thc Si/B ratio as well as on temperaturc and time.