A Study On Preparation And Performance Of Al₂O₃-ZrO₂/Al Composite Material

In the production of large-scale, ceramic reinforced aluminum matrix compositeapplications more widely. First, because the prices of raw materials which preparingcomposite materials is cheaper, while the preparation is simple and the compositematerials have a good performance. Therefore, the ceramic reinforced aluminumcomposites have broad prospects.Ceramic particle reinforced aluminum materials are prepared by conventionalpowder metallurgy, It has a poor interfacial wettability. To solve this problem,Al2O3-ZrO2/Al composite materials are prepared by hot pressing in this paper. Wealso study aluminum matrix composite microstructure and properties by the change ofAl2O3-ZrO2particle content and ratio. With Al(NO3)3·9H2O and ammonia as rawmaterials, nano Al2O3powder can be prepared by liquid precipitation. Powders arecharacterized on thermal behavior, phase composition and microstructure by TG-DTA,XRD, SEMand other means. The effects of the composites mechanicalproperties(Rockwell hardness, flexural strength, wear resistance, etc.) andmicrostructure by studing composition(Al2O3, ZrO2particle content of0%,6%,9%,12%and particle size) and hot pressing process(Hot temperatures560℃,570℃,580℃; Heating rate90℃/min; Holding time5min; Pressure20Mpa). Also analyzedthe effect of composites organizational structure and properties by studing AL2O3content of9%, and to explore its related mechanism.The results showing that, precursor which is prepared by precipitation methodcalcined at1000℃can be prepared particle size of about150nm, α-Al2O3powderparticles axis. Using α-Al2O3as the reinforcing member, when the pressingtemperature is580oC and α-Al2O3content is6%, relative density of the compositematerial reaches89.5%, Flexural strength reaches70Mpa, Because whenreinforcement content increasing, the composite internal organization dispersion, themain of Composite fracture is brittle fracture. When the hot pressing temperature is570℃and the content of Al2O3is9%, the relative density of the composite materialis87%, It has a good hardness and wear resistance at this time. The Hardness of composite than Al matrix increase by18%which reaches73HRB, abrasion ofcomposite is0.0639g. ZrO2as the reinforcement content is6%, while pressingtemperature is570℃, mechanical properties of the composites is that Hardness is69HRB, than the hardness of the substrate increased by11%, Flexural strength is54Mpa, abrasion of composite is0.1012g. At this time the performance is better,because the composite particles closely combined each other organizations together toform a sheet structure. When doped Al2O3-ZrO2composites reinforced, reinforcementcontent is6%, the relative density and mechanical properties of the material is better.When the mixing ratio of Al2O3-ZrO2is1:2, the hardness is73HRB, Flexural strengthis69Mpa, abrasion of composite is0.1071g. When the mixing ratio of Al2O3-ZrO2is2:1, the hardness is77HRB, Flexural strength is63Mpa, abrasion of composite is0.0665g. When the content of Al2O3is high, The hardness and wear resistance ofcomposites have improved.