cast
To reproduce an object, such as a piece of sculpture, by means of a mould (usually of plaster) taken from it. A cast is also the copy so produced.
bronze
An alloy of copper containing more than one per cent of tin, and sometimes other metals as well (most notably lead). It is more easily melted and cast than pure copper as well as being harder and more durable.
Text source: The Oxford Concise Dictionary of Art Terms (2nd Edition) by Michael Clarke