Huaguan Li

Effects of Aging on the Evolution of Microstructure and Mechanical Properties of an Al – Li – Cu – Mg Alloy with Ag, Zr, Mn, and Zn Additives

The microstructure and the post-aging hardness of an Al – Li – Cu – Mg alloy is studied by the methods of transmission electron microscopy. Tensile tests are performed. The volume fraction and the size of the particles of the δ′, S and T1 phases are shown to be dependent on the aging temperature and time. The effect of the precipitates of the δ′, S and T1 phases on the hardening of the Al – Li – Cu – Mg alloy during aging is determined.

Effect of peer ply and cooling rate on the tensile properties of Al/Gf/PP laminate prepared by hot pressing

The glass fiber-reinforced polypropylene/AA2024 hybrid composite (short for Al/Gf/PP laminate) was prepared by hot pressing with anodized 2024-T3 aluminum alloy as the skin and thermoplastic glass fiber-reinforced polypropylene core as a substitute of thermosetting glass fiber-reinforced polymer (based on epoxy) in order to increase the productivity and reduce the production costs during manufacturing procedure. The effect of peel ply (release cloth) and cooling rate on the laminate was investigated elaborately in this work. The orientation of glass fiber is mainly influenced by the peel ply structure, resulting in the resin’s overflow during hot press. Moreover, different cooling rates due to various cooling methods significantly affected both the degree of crystallization of the matrix and deformation of the metal skin during the curing process. Finally, a new peel ply structure was adopted to prevent the fiber from spilling during hot press process, while bubbles were allowed to flow out normally along with partial resin. Finally, a novel cooling method to reduce the degree of polypropylene crystallization and control metal deformation was proposed.