The Degradation Behavior Of B/Al Composite Subjected To Thermal Mechanical Cycling

The distribution of thermal stress in B/Al composite subjected to thermal-mechanical cycling (TMC) was simulated by ANSYS software; the evolvement of interface morphology and microstructure of B/Al composite subjected to thermal-mechanical cycling were observed by SEM and TEM, respectively, and the interfacial damage behavior was also studied. The TMC systems were as follows:Ⅰ-125℃~125℃under 10MPa, 30MPa and 110MPa;Ⅱ20℃~270℃under 110MPa.The results of the finite element simulation show that the thermal stress is concentrated nearby the interface between the fiber and the matrix. And it increases with the increasing of TMC cycles and the external tensile-loads in TMC systemⅠ, respectively. In TMC systemⅡ, it increases with the increasing of TMC cycles.The observation of the interface morphology shows that the interface of B/Al composite is degraded inconsistently during TMC. The degradation is more serious with the increasing of TMC cycles under the same external tensile-loads and of the external tensile-loads under the same TMC cycles.The microstructural observation shows that in TMC systemⅠ, the density of the dislocation in the matrix increases with the increasing of TMC cycles when the external tensile-loads are 10MPa and 30MPa, respectively. However, it increases in the initial stage under the external tensile-loads of 110 MPa but the recovery occurs in the matrix later. The dynamic recovery and then the dynamic recrystallization occur in the matrix in TMC systemⅡ.