An amorphous metal (also known as metallic glass or glassy metal) is a solid metallic material, usually an alloy, with disordered atomic-scale structure. Most metals are crystalline in their solid state, which means they have a highly ordered arrangement of atoms. Amorphous metals are non-crystalline, and have a glass-like structure.
In real life, metallic glasses are usually produced as thin films or tiny droplets because their formation requires extremely rapid cooling, and only thin films or tiny droplets have a surface-area-to-volume ratio that allows heat to be removed fast enough. Metallic glasses thicker than 1 millimeter are called "bulk metallic glass" (BMG). Production of BMG typically requires the use of complicated alloys of multiple metals with different atomic radii, such that the atoms are unable to form a crystal lattice during the cooling period. Pure single-metal or simple-alloy glasses require rapid cooling "in the order of millions of degrees Celsius a second" to prevent crystallization.
The magic system I am developing would allow for essentially instantaneous cooling of a large (on the order of centimeters thick, or even meters thick, not just millimeters thick) volumes of molten metal from white-hot to ice-cold. Because of this, mages should be able to produce, for example, a bronze or iron sword or anvil made entirely of bulk metallic glass. Would this actually be useful in a pre-industrial society, as cutting implements or other tools? Basically, would the properties of bulk metallic glass bronze/iron be better or worse than regular crystalline bronze/iron?
Wikipedia claims (without citation) that "batches of amorphous steel with three times the strength of conventional steel alloys have been produced", and that "the material structure also results in low shrinkage during cooling, and resistance to plastic deformation." Citing the paper "Microhardness and abrasive wear resistance of metallic glasses and nanostructured composite materials", which "reports on as-cast bulk zirconium-based, lanthanum-based, and palladium-based metallic glasses and on melt-spun aluminum-based amorphous ribbons", it claims that "the absence of grain boundaries, the weak spots of crystalline materials, leads to better resistance to wear and corrosion."
I essentially want to know if these properties carry over to theoretical bulk glasses like an entire sword made from glassy bronze or steel. I've found sources claiming that metallic glasses are brittle, which would not be a good property in a sword, unless the force required to cause brittle fracture was greater than the forces experienced in combat. However, such sources are referring to complex-alloy glasses rather than single-metal or simple-alloy glasses.