High temperature deformation of dispersion strengthened Al-Al4C3 composite

摘要

The mutual relationship between mechanical properties and microstructure changes in Al-A_(1_4)C_3 composite system is characterised by tensile test in wide range of testing temperatures. The dominant mechanism of plastic deformation at the deformation temperatures up to 300 deg regardless of used strain rate was dislocation glide. In temperature region from 300 to 450 deg and for lower strain rates the grain boundary glide participates in deformation process. The phenomenon of superplasticlike behaviour was observed at deformation temperature of 450 deg and the strain rate #epsilon#=10~(-1)s~(-1). The dispersion strengthened system has been tested at 400 deg by creep and fatigue superimposed on creep stress as well. The different loading schedules were defined by the stress ratio R. The criteria used to analyse the resistance to creep, or creep-fatigue, were the life to fracture and the strain to fracture.