Development of Microstructure in Silicon-Aluminum-Bronze

The aim of present study was to determine the sequence of micro-structural development during continuous cooling from temperatures approaching the solidus, in an as cast silicon- aluminum bronze alloy having composition Cu-6 % Al-2% Si-0.6% Fe. This alloy has good resistance to sea-water corrosion and low magnetic permeability. This alloy is used in marine and chemical applications where corrosion resistance is a prime requirement. A study of the development of microstructure during continuous cooling from the solidus temperature showed that at high temperatures the alloy consisted of beta and alpha phases in which the alpha-phase had a Widmanstatten morphology. As the temperature is lowered Fe5Si3 particles formed throughout the microstructure and this is followed by the formation of Fe3Si2 precipitates in the α-grains. On further cooling the beta phase is transformed into gamma2.