Microstructure and properties of tetrapod-like ZnO whiskers reinforced Al matrix composite

Aluminum matrix composites reinforced by one-dimension structure whiskers have a wide range of applications. The paper is concerned with ZnO whiskers with peculiar tetrapod shape which were introduced to 66-1 Al alloys. 25 vol.% tetrapod-like ZnO whiskers (ZnOw) reinforced 66-1 Al matrix composites were fabricated by a squeeze casting process. The tetrapod-like ZnOw are well dispersed in the Al matrix. There are dimples, a few whisker and whisker pull-out in fracture surfaces of the composites, showing a mixture of brittle failure and ductile failure. The prepared composites possess higher strength, hardness and density than the 66-1 Al matrix alloy due to the addition of tetrapod-like ZnOw as reinforcement, and isotropic properties which is superior to other whisker reinforced Al matrix composites can be achieved owing to the peculiar structure.