Effect of two-stage isothermal annealing on microstructure CuAl10Fe5Ni5 bronze with additions of Si, Cr, Mo, W and C

The aim of this study was to investigate the effect of a two-step isothermal annealing respectively at 1000 ˚C for 30 min, then at the range of 900÷450 ˚C increments 50 ˚C on the microstructure CuAl10 Ni5Fe5 bronze with additions of Si, Cr, Mo, W and C, cast into sand moulds. The study concerned the newly developed species, bronze, aluminium-iron-nickel with additions of Si, Cr, Mo, W and C. In order to determine the time and temperature for the characteristic of phase transitions that occur during heat treatment of the test method was used thermal and derivation analysis (TDA). The study was conducted on cylindrical test castings cast in the mould of moulding sand. It was affirmed that one the method TDA can appoint characteristic for phase transformations points about co-ordinates: τ (s), t (˚C), and to plot out curves TTT for the studied bronze with their use. It was also found that there is a five isothermal annealing temperature ranges significantly altering the microstructure of examined bronze