| Magnesium alloy,Mg-Li alloy and Aluminum alloy are getting more and more extensive attentions in aerospace and electronic industry as light alloy with excellent performances.Layered metal composites with a performance better than any of its components,are produced by rolling homogeneous or heterogeneous sort of metal materials together,resulting in an outstanding performance which is a combination of all the remarkable performances from each of the components.With a poor corrosion resistance,Magnesium alloy and Mg-Li alloy are used in a very limited range of areas.Coating a Aluminum layer which has a good corrosion resistance with a dense oxide film on the surface over Mg and Mg-Li alloy can gain a new kind of layered metal composites having both of their excellent performances.In this thesis,Al/AZ31B,Al/Zn/LA91 and 2024Al/Zn/LA91 layered metal composites were produced using vacuum hot pressing.The microstructure morphology of their layer interfaces were observed by SEM and optical microscope.And their layer interfaces were also tested by XRD and EDS.The results showed that the layers of composites are combined by atom diffusion.Micro-hardness testings for the three kind of composites are conducted,the result proved that,the hardness of the interface diffusion zone of metal composite is higher than that of the matrix on both sides.The shear strength test,quasi-static and dynamic compression performance tests had been carried on Al/AZ31B,Al/Zn/LA91 and 2024 Al/Zn/LA91 three layered metal composites which were preperated by vacuum hot pressing with different process parameters.The results showed that the best preparation technology of Al/AZ31B composite is 3 MPa pressure,temperature of 400?for 2 hours.The best preparation technology of both Al/Zn/LA91 and 2024 Al/Zn/LA91 composites are 3 MPa pressure,temperature of 340?for2 hours.A summary of dynamic compression performance and maximum anti-shearing performance of Al/AZ31B,Al/Zn/LA91 and 2024Al/Zn/LA91 layered metal composites under the condition of similar strain rate(10~3/s)was made in this research.The maximum strength of Al/AZ31B,Al/Zn/LA91 and 2024Al/Zn/LA91 composites are 269.85MPa,303.07MPa and 387.18MPa respectively.The maximum anti-shearing strength are 21.32MPa,27.14MPa and 34.40MPa respectively.This result proved that,the overall mechanical properties of Mg-Zn-Al composite produced by vacuum hot pressing are higher than that of Mg-Al composite.Moreover,the overall mechanical properties of 2024Al/Zn/LA91 composite are higher than that of Al/Zn/LA91 composite which is produced under the equivalent conditions. |
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