Ask A Scientist Materials Science Archive

name         Alex D.
grade        4-5
location     TX

Question -  Are alloys created by melting the metals into liquids,
blending them, and then allowing them to cool and harden?
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Yes, alloys are created that way for the most part.  Alloys are actually 
defined by certain standards created by different agencies around the 
world, with the American Society for Testing and Materials (ASTM) being 
the most common here in the U.S.  What these societies do is standardize 
the definition of alloys.  That is to say, they write the recipe for alloy 
manufacturers to use in order to make alloys.  Take stainless steel for 
instance.  First of all there are different grades (or recipes) of 
stainless steel, with 304 and 316 being the most common.  If you order 
316, the steel manufacturer will melt iron and add various amounts of 
carbon, chromium, and other metals per the ASTM specification.  Then, 
depending on the properties you want, the manufacturer will allow the 
steel to harden at a certain cooling rate and form it into the shape you 
want delivered to your place of business.  He may also do post processing 
(after the shaping) treatments like stress relieving or stress hardening 
to again give you different properties to your steel.  The main thing 
about alloys is you are chemically mixing the materials to form the 
alloy.  This usually involves high temperatures and metals in liquid 
form.  Hope this answers your question.  Thanks for using NEWTON.

Chris Murphy, P.E.
Air Force Research Laboratory
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That is not the only way alloys are formed, but it is the most common way.
However, not all metals are soluble in one another so melting and mixing
does not guarantee that an alloy will form.

Vince Calder
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