Yet again Keith P. Walsh has been a source of ignorance and confusion. He contends that an alloy should be narrowly defined as:
"A homogeneous mixture or solid solution of two or more metals, the atoms of one replacing or occupying interstitial positions between the atoms of the other."
Based on this definition he contends that amalgams are NOT alloys. Well, of course they are.
His latest definition comes from here on the US Copper Development Association web site:
That same web site also contains this much broader definition that an alloy is:
=93A substance having metallic properties and composed of two or more elements, at least one of which is a metal.=94
You can find that one here:
=93A mixture with metallic properties composed of two or more elements of which at least one is a metal.=94
The 1998 Metals Handbook, Desk Edition, second edition very similarly defines an alloy as:
=93A substance having metallic properties and being composed of two or more chemical elements of which at least one is a metal.=94
The 1939 definition came from an ASM committee chaired by R. F. Mehl, who was head of the Department of Metallurgical Engineering at Carnegie Institute of Technology from 1935 to 1960: