Question

A _____ cooling rate solidifies metallic glass made from iron- base alloys.

(a) 10^oC s^-1

(b) 100^oC s^-1

(c) 1000^oC s^-1

(d) 10000^oC s^-1

The question was asked in a national level competition.

Question is taken from Soft and Hard Magnetic Materials in chapter Magnetic & Insulating Materials of Engineering Material & Metallurgy

Answer 1

The correct answer is (d) 10000^oC s^-1

To explain I would say: Metallic glasses produced from iron-base alloys are used to provide a reduction in core losses. When such an alloy is cooled at 104^oC s^-1, it solidifies into a ribbon-shaped metallic glass instead of crystallization.