Composite Casting Technology In The 5×××/7××× Aluminum Alloy Planar Solidification

In this paper,the research of the armor plate of the domestic industry,trying to realize the composite casting of laminated armor aluminum alloy,and the combination mechanism and control of the casting interface are studied deeply.In the full understanding of the development of planar solidification magnesium base to prepare composite material technology,study on the basic problem of the multi layer aluminum sheet solidification and casting.A clear and gradient composite interface condition was established,and the solidification control criterion of aluminum alloy multilayer and gradient composite slab was established.The main purpose of the study is to design and manufacture casting equipment in order to develop the application of 5xxx/7xxx aluminum alloy,for preparation of small scale experimental ?160 × 180mm round ingot based prepared large specifications of ?600mm×600mm ×180mm 5456/7055/5456 three layer of aluminum alloy composite slab.This study reveals the basic rules of the compound aluminum alloy surface solidification compound casting and the characteristics of the microstructure,composition and properties of the clad aluminum alloy.The influencesof various process conditions on the composite interface were also discussed,and the distribution and diffusion of the elements near the composite interface were analyzed,draw the following conclusions:(1)With the temperature of the interface,the interface of casting speed and cooling intensity of three kinds of process parameters,the detection method of single variable control and a variety of different results of process test analysis,to determine the 5456/7055 Aluminum Alloy two layer casting optimum parameters of composite process:casting speed of 20 mm/min,the optimum temperature is 620? on the interface,the best casting speed of 1mm/son the interface;(2)By measuring the thickness of element diffusion layer near the composite interface,it is found that the thickness of as cast diffusion layer increases with the increase of pouring temperature,and increases with thedecrease of casting speed.(3)The 5456/7055 Aluminum Alloy two layer composite casting process is applied to the optimum parameters of 5456/7055/5456 large size three layer planar composite,macro and micro interface clear and straight,no pores and inclusions,good metallurgical bonding,grain is fine and uniform.And has good tensile mechanical properties,the tensile strength at the interface at the casting state reaches 137.7 MPa,which basically realizes the requirement of the three layer composite;(4)To determine the 5×××/7××× aluminum alloy composite ingot heat treatment system,300?,4h+460?,24h+470?,4h multistage homogenization system in eliminating dendritic network and coarse eutectic grain boudary effect is the best.