Study On Aluminum Based Lightweight Laminated Composites

The research of micro laminated composite originated from shell nacre,whose overall tensile strength and fracture toughness are much higher than that of aragonite phase.This phenomenon has attracted extensive attention of experts and scholars.There are more and more laminated composite materials prepared by the combination of different metals.Their large and multiple properties are better than that of single metal,which are widely used in military,aerospace,construction and other fields.In this paper,the structure design of two kinds of aluminum alloy micro laminated composites is carried out,the hot pressing sintering process is explored,the Al-Cu and Al-Mg-Ti micro laminated composites are prepared,and the interface structure,hardness,mechanical,conductive and thermal conductivity are analyzed.The main research results are as follows:?1?With the increase of hot pressing temperature,the types and thickness of diffusion layer increase.For the aluminum copper laminated material,the good combination of metal can be achieved by hot pressing temperature 530?and hot pressing time 4 hours.The order of formation of the diffusion layer is to form CuAl₂ and Cu₉Al₄ phases first,then CuAl and finally Cu₃Al₂.?2?The rolling results show that the diffusion layer breaks and embeds into the Al layer to form a direct combination of pure metals.The increase of the deformation rate leads to the monotonous decrease of the conductivity and the thermal conductivity.However,the conductivity of the Al-Cu laminated samples is significantly higher than that of the non rolled samples.When the deformation rate is 30%,the performance is the best and the conductivity is the highest 21.2%??3?For Al-Mg-Ti laminated composites,the best bending strength is 211.9MPa.The fracture cracks of the diffusion layer are straight and perpendicular to the base metal,and the fracture cracks of the base metal show 135°and 45°propagation,accompanied by branch cracks.When the Al/Mg side is in tension,the bending strength is higher,and when the Al/Ti side is in compression,the compressive strength is higher.?4?The reasonable preparation process of Al-Cu laminated composite is:hot pressing sintering and rolling composite,hot pressing sintering process is to keep temperature at 570?for 4h,preheat at 500?0.5h.And then conduct 30%single pass rolling deformation.For Al/Mg/Ti laminated composites,the best stacking method is to stack large Mg in the middle of Al and Ti,and to stack Al/Ti laminated composite on both sides.