用原子显微镜纳米压痕法研究Gr／Al复合材料热循环后的微观力学性能

采用原子力显微镜纳米压痕法测量了Gr/Al复合材料热循环后界面附近的纳米硬度和塑性变形能力的分布。随热循环次数的增加，纤维和基体中的纳米硬度小，而基体的塑性变形能力增加。纳米硬度和塑性变形能力的大小是随距纤维／基体界面的距离的变化而变化的。纳米硬度的变化可提供有关残余应变方面的信息，这是因为材料内部局部区域的弹性或塑性残余应变会影响此处的硬度大小。

AFM-based Nanoindentation Studies of Micromechanical Properties in Gr/Al Composites after Thermal Cycling

Thermal cycling conditions are among the most sever environmental conditions for composites and have a great effect on the micromechanical properties near interfaces.An AFM(atomic force microscope)-based nanoindentation method was employed to measure the nanohardness and the plastic deformation capacity near interfaces in graphite fiber reinforced aluminum alloy matrix composites(Gr/Al)after thermal cycling.With increasing of thermal cycles, the nanohardness values of both fibers and the matrix decrease and the plastic deformation capacity of the matrix increases.Both of the changes in the nanohardness and the plastic deformation capacity are dependent of the distance to the fiber-matrix interface.Changes in nanohardness can provide important information about residual strains because the local elastic or plastic residual strains have effects on the local hardness.