When compared with pure metals alloys are usually...

Question

a) Tougher and stronger

b) Harder and stronger

WHY???

Answer 1

If this is a choice between a) and b), then I will answer: a)

Why?... because alloys allow the best properties of all the individual elements within the alloy to be manifest.

By itself, copper is fairly mallable, but when you add some zinc, the bronze alloy is much less mallable so a bronze knife would hold an edge much better than a copper knife.  The amorphous copper is now a slightly more organized crystalline structrure with the addition of the elements that make bronze.

By itself, iron is tough and hard, but it will oxidize readily.  Add some carbon, nickel, a bit of chromiun and you have stainless steel.  The steel is stronger than the iron and because of the chromium it will resist oxidation of the iron (it won't rust as fast as plain iron).  The amourphous iron is now steel with a more organized crystalline structure at the atomic level -- giving much more strength to the steel over plain iron.

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