The heat treatment process and mechanism of QAl10-4-4 aluminum bronze were investigated to explore heat treatment specification for parts conforming to bushing. The microstructure and mechanical properties of QAl10-4-4 aluminum bronze with different solid solution and aging parameters were analyzed by metallographic analysis and tensile test. When the solution temperature is 950 ℃

a large number of β and β′ phases are generated in the structure with a small amount of α phase and k phase residues

which exhibits high strength without cracking tendency.With the increase of aging temperature and holding time

the eutectoid reaction of β and β′ phases tends to be complete

where the strength and hardness are decreased

while the plasticity and toughness are increased. Considering synergetic toughness and plastic toughness

the ideal heat treatment system is presented as follows: solid solution at 950 ℃ for 1.5 h and aging at 670 ℃ for 3 h.