摘要
Semi-solid isothermal heat treatment was proposed to directly process cold-rolled ZL104 aluminum alloys and obtain semi-solid bil-lets.The effects of two process parameters,namely,temperature and processing time,on the microstructure and hardness of the resulting bil-lets were also experimentally examined.Average grain size(AGS)increased and the shape factor(SF)of the grain improved as the process temperature increased.The SF of the grain also increased with increasing processing time,and the AGS was augmented when the processing time was prolonged from 5 to 20 min at 570℃.The hardness of the aluminum alloy decreased because of the increase in AGS with increasing temperature and processing time.The optimal temperature and time for the preparation of semi-solid ZL104 aluminum alloys were 570℃and 5 min,respectively.Under optimal process parameters,the AGS,SF,and hardness of the resulting alloy were 35.88μm,0.81,and 55.24 MPa,respectively.The Lifshitz-Slyozov-Wagner relationship was analyzed to determine the coarsening rate constant at 570℃,and a rate constant of 1357.2μm3/s was obtained.
基金
This research was financially supported by the Funda-mental Research Funds for the Central Universities(Grant Nos.XZY012019003 and XZD012019009)
the China Postdoctoral Science Foundation(Grant No.2018M 643627)
the fund of the State Key Laboratory of Solidifica-tion Processing in Northwestern Polytechnical University,China(Grant No.SKLSP 201921)
the Open Founda-tion of the State Key Laboratory of Fluid Power and Mechat-ronic Systems,China(Grant No.GZKF-201912).
