ABSTRACT
This chapter considers the microstructure of alloys within the binary system and its effects on properties. Aluminium is the main alloying element in all aluminium bronzes except those with high manganese content. It is primarily responsible for the mechanical and corrosion resisting properties of these alloys. An alloy which ends up consisting of only one phase is known as a 'single phase' alloy, although it may have gone through changes of crystalline structure during which it may have consisted of more than one phase. Duplex α+β′ alloys generally offer higher strength than the single phase α-alloys but are susceptible to corrosion by de-aluminification. Continuous eutectoid and its attendant danger can be readily avoided by limiting the aluminium content to 9.0% in binary alloys. The β-phase, shown in the equilibrium diagram, is an intermediate high temperature solution and has, according to many researchers, a random or disordered body-centred cubic structure.
