The Role of Microstructure in Mixed Mode Fracture

本研究的目的是研究含有两种析出物的铝合金的复合型断裂。通过平面应变和弯曲试验考察了拉伸和压缩时的变形行为。对不同颗粒尺寸和颗粒间距的试件，观察了剪切局部化的形貌和程度、空洞的形核和长大以及断口形貌。表面粗糙度是确定的，并与表面塑性不稳定性有关。对两相界面附近的位错-裂纹尖端构型进行了理论计算。

The objective of this research program is to study mixed-mode fracture of aluminum alloys containing two types of precipitates. Deformation behavior is examined in tension and compression, using plane strain and bend tests. The topography and extent of shear localization, void nucleation and growth, and fractography are followed for specimens with different particle sizes and particle spacings. Surface roughness is determined and related to surface plastic instability. Theoretical calculations are carried out for dislocation-crack tip configurations near a two-phase interface.