SIR ROBERTSAUSTEN,WILLIAM,CHANDLER - HIS ROLE IN THE DEVELOPMENT OF BINARY DIAGRAMS AND MODERN PHYSICAL METALLURGY

This biographical sketch of Sir William Chandler Roberts-Austen was mo tivated by the centennial anniversary of his famous report of 1897. In the discussion session, Roberts-Austen presented his so-called ''firs t'' T-x diagram for the Fe-C system, Though not itself an equilibrium phase diagram, it became one in 1899 when H.W.B. Roozeboom modified an updated (''second'') version in accordance with the phase rule of J., W. Gibbs, In 1875 Sir William pioneered the use of T-x diagrams for al loy systems, even before reliable thermocouples were available, Eventu ally, after Chatelier's Pt, Pt-10 % Ph thermocouple proved reliable fo r high temperature work, Roberts-Austen incorporated it in his own rev olutionary invention: a mechanical autographic temperature recorder, E lectronic versions are still used in all modern industrial plants and research labs.