| Due to the low density, high thermal conductivity, good wear resistance and isotropic,particle reinforced aluminum matrix composites has widespread application prospect in aerospace, national defense and automobile industry. Materials are often in a state of high temperature, fever in these fields, study the creep property and behavior is the key for particulate reinforced aluminum matrix composites used in high temperature environment.However, a little of study of the creep about particle reinforced aluminum matrix composites is done in the world, to meet the need of application and study, based on the study of our research group and many researchers, the study in this paper focuses on the high temperature creep of SiO2/Al2O3（P）/Al composite, provides some experiments and theoretical base for the study of the creep property of particle reinforced aluminum matrix composites.In this thesis, the in-situ SiO2/Al2O3（P）/Al composites with different particle size and content are prepared by mechanical stirring method, which the matrix is industrial pure aluminum and the reinforcing particles is zircon sand tailings, the creep tensile tests of the composites were carried out under different temperature and load. Research results show that with the increase of temperature and load, the steady state creep rate of SiO2/Al2O3（P）/Al composites increases, the creep resistance of composites decreases; Additionally, the increasing of reinforcing particles contents can improve the composites creep performance,the creep resistance of composites is the best when reinforcing particle size is 75100μm. It is believed that the creep mechanism of in-situ SiO2/Al2O3（P）/Al composites is dislocation climb and enhanced control of the second phase through analysis of apparent stress exponent and apparent activation energy.According to the creep test datum, time-hardening creep constitutive equation of75100μm-7wt.% composites and pure aluminum matrix are concluded, based on the creep constitutive equation of pure aluminum matrix, the influence of Al2O3 reflection layer thickness on the creep behavior of materials was studied by using the finite element analysis software ABAQUS, the simulation results are closest to the experimental results when SiO2 particles complete response for Al2O3; and further studied the effects of different reinforcing particle content on the steady state creep rate of composites, simulation results were consistent with the experimental results, which can be used to explain the creep behavior. |
PDF Full Text Request