| 6005A aluminum alloy is an important construction material for traffic. In recent years, with the rapid development of the metro, high iron and other industries, the demands for properties of materials are enhanced, and further modified or enhanced 6005A alloy has become the research focus and priorities of the field of vehicle profiles. The in-situ Al3(Ti0.5Zr0.5)p/6005A is prepared successfully from Al-Ti-Zr systems via in-situ melt reaction. The OM, SEM, EDS, XRD and electronic universal testing machine are used to determine the solidification structures of the as-prepared composites, the morphologies and distributions of the in-situ reinforcement particles in the composites and the mechanism of pulsed magnetic field are investigated. The mechanical properties of the composite are investigated and their nature and mechanisms are analyzed.The process parameters on the solidification of Al3(Ti0.5Zr0.5)p/6005A MMCs are explored and optimized. The results show that the morphology and distribution of the particle associated with reaction temperature, reaction time, the quantity and ratio of powder, and the cooling mode. The optimum reaction time is about 3min, the initial reaction temperature is about 750℃, the selected reactants is collect for the mixed powder of K2ZrF6-K2TiF6, which's total theoretical revenue yield is 3vol. %, and the Ti/Zr ratio is 1:1. The improved method of etching and filtering extract effectively the reinforcement particle of in-situ composite, to obtain a lot of valuable information of the particles, like three-dimensional shape, size, chemical composition and structure, which can contribute to further analyze the grain growth habit, so as to form the foundation of control the grain in composites.The results of RE elements effect on Al3(Ti0.5Zr0.5)p/6005A solidification microstructure show that: due to the selective adsorption of RE atoms and inhibit the Al3(Ti0.5Zr0.5) particles grow up, the reinforcement particles get further refinement. When adding the single RE the second phases are granulated, supersized and fined. The blocky or stripy phases can be observed on the boundaries when the yttrium content is up to 0.25wt.%. When adding 0.25wt.% Y+0.10wt.% La the grains size of α-Al and second phases are further refined.In the Al-Ti-Zr system, solidification of in-situ composites under pulse modulated high-frequency magnetic field's results shows that: the size of Al3 (Ti0.5Zr0.5) compound particle is 1-3μm, and dispersing in the matrix uniform distribution. With the increase of frequency magnetic field, solidification of reinforced particles is more uniform distribution, showing a grown up after the first thinning, the best magnetic field frequency is about 2MHz.When under pulsed magnetic field a short time, there are low volume fraction and coarse particles; but when the time for too long, the number of particles decreased, some particles began reunion grew up, so the better role of time is about 2min. Remelting of Al3(Ti0.5Zr0.5)p/6005A composites results show that for Al-Ti-Zr system, with the melting times increasing, Al3(Ti0.5Zr0.5) particles grow rapidly and the number of particles decreased significantly, therefore get the optical melting times is 2.The mechanical properties of Al3(Ti0.5Zr0.5)p/6005A composite under pulse modulated high-frequency magnetic field results show that: with the magnetic field frequency increasing, the tensile strengthσb and yield strengthσs show obvious increased at first and then decreased, the elongation 5 change little. When the frequency is 2MHz,σb andσs reached a maximum, 305.8MPa and 279.1MPa, respectively, increased 8.7% and 7.1% than those without additional pulsed magnetic field, respectively; With actuation duration of magnetic field increasing,σs andσb also exists first and then reduced the elongation increased slightly, the best reaction time is about 2min. The tensile fracture morphology is also change from the plastic fracture to plastic-brittle mixed fracture mode. The strength mechanisms of the as-prepared Al3(Ti0.5Zr0.5)p/6005A composites are dispersion strength, fine-grained strength, solid -solution strength and dislocation.
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