School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Micron. 2012 Feb;43(2-3):278-84. doi: 10.1016/j.micron.2011.09.001. Epub 2011 Sep 17.
Compressive properties of Al matrix composite reinforced with Ti-6Al-4V meshes (TC4(m)/5A06 Al composite) under the strain rates of 10(-3)S(-1) and 1S(-1) at different temperature were measured and microstructure of composites after compression was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Compressive strength decreased with the test temperature increased and the strain-rate sensitivity (R) of composite increased with the increasing temperature. SEM observations showed that grains of Al matrix were elongated severely along 45° direction (angle between axis direction and fracture surface) and TC4 fibres were sheared into several parts in composite compressed under the strain rate of 10(-3)S(-1) at 25°C and 250°C. Besides, amounts of cracks were produced at the interfacial layer between TC4 fibre and Al matrix and in (Fe, Mn)Al(6) phases. With the compressive temperature increasing to 400°C, there was no damage at the interfacial layer between TC4 fibre and Al matrix and in (Fe, Mn)Al(6) phases, while equiaxed recrystal grains with sizes about 10 μm at the original grain boundaries of Al matrix were observed. However, interface separation of TC4 fibres and Al matrix occurred in composite compressed under the strain rate of 1S(-1) at 250°C and 400°C. With the compressive temperature increasing from 25°C to 100°C under the strain rate of 10(-3) S(-1), TEM microstructure in Al matrix exhibited high density dislocations and slipping bands (25°C), polygonized dislocations and dynamic recovery (100°C), equiaxed recrystals with sizes below 500 μm (250°C) and growth of equiaxed recrystals (400°C), respectively.
在应变速率为 10(-3)S(-1)和 1S(-1)、不同温度下，测量了 Ti-6Al-4V 网增强 Al 基复合材料（TC4(m)/5A06 Al 复合材料）的压缩性能，并通过扫描电子显微镜（SEM）和透射电子显微镜（TEM）对复合材料压缩后的微观结构进行了表征。压缩强度随测试温度的升高而降低，复合材料的应变率敏感性（R）随温度的升高而增加。SEM 观察表明，在 25°C 和 250°C 下，应变速率为 10(-3)S(-1)时，Al 基体晶粒沿 45°方向（轴方向与断裂面之间的角度）严重拉长，TC4 纤维被剪切为几部分。此外，在 TC4 纤维和 Al 基体之间的界面层以及（Fe，Mn）Al(6)相中产生了大量裂纹。随着压缩温度升高到 400°C，TC4 纤维和 Al 基体之间的界面层以及（Fe，Mn）Al(6)相中没有损坏，而在 Al 基体的原始晶界处观察到尺寸约为 10 μm 的等轴再结晶晶粒。然而，在应变速率为 1S(-1)、温度为 250°C 和 400°C 时，复合材料中发生了 TC4 纤维与 Al 基体的界面分离。在应变速率为 10(-3)S(-1)、温度从 25°C 升高到 100°C 的过程中，Al 基体中的 TEM 微观结构表现出高密度位错和滑移带（25°C）、多边形位错和动态回复（100°C）、尺寸小于 500 μm 的等轴再结晶晶粒（250°C）和等轴再结晶晶粒的生长（400°C）。
