Preparation And Properties Of High Porosity ZLD104/aluminum Core Alumina Fiber Composite Foam

Infiltration metal foam sound absorption material have many excellent properties,such as high strength and tenacity,high temperature resistance,not moisture absorption deliquescence,highly recyclable and etc.It has a broad application prospect in the field of sound absorption and noise reduction.But the low porosity infiltration metal foams have the problem of low sound absorption coefficient and sound absorption dip.And the same time,infiltration metal foams with high porosity also have the lack of preparation technology and low strength.The high porosity fiber composite metal sound absorption material can be a good solution to these questions.In this paper,the micro porous structure with high porosity ZLD104/alumina fiber with aluminum core composite foam were prepared by infiltration casting method based on ZLD104 alloy.The mechanical properties and sound absorption properties of high porosity ZLD104/alumina fiber with aluminum core composite foam were studied,the main results of the study are shown as following:(1)The micro porous structure with high porosity ZLD 104/alumina fiber with aluminum core composite foam were prepared by modified infiltration casting based on ZLD 104 alloy.The prepared composite foams,its pore size is that the main pore size is 0.5mm and the secondary pore size is 0.2mm,the porosity is 77%～90%.The pore wall are porous pore wall structure with the main pore were separated by a secondary pore,The fibers are distributed in the composite foam are embedded in the pore wall,through the pore,or the end of fiber stretched in the pore.(2)The test results of different porosity of fiber composite foam compresive properties shown that:The yield strength of composite foam decreasing with the increase of porosity,and raising with the decrease of the fiber diameter,increasing with the increase of fiber content.When the porosity increased from 71%to 90%,the yield strength of the composite foams decreased from 18.16MPa to 0.33MPa.When the porosity is 90%,fiber content is 5vol.%,and the fiber diameter decreased from 0.20mm to 0.0mm,the yield strength increased from 0.33MPa to 0.95MPa;When the porosity is 90%,fiber diameter is 0.10mm,and the fiber content increased from 2vol.%to 14vol.%,the yield strength increased from 0.85MPa to 2.25MPa.Compared with alloy foam,when the porosity is about 82%,fiber diameter is 0.10mm and the fiber content is 5vol.%,the yield strength of composite foam increased from 0.83MPa of alloy foam to 4.55MPa.(3)The test results of different porosity of fiber composite foam sound absorption property shown that:When porosity is 81.29%,the 5vol.%fiber composite foam achieved the maximum absorption coefficient of 0.88.Compared with the alloy foam,the sound absorption coefficient is increased by 10%,the sound absorption peak moved from 2000Hz to 1850hz,and the sound absorption low valley moved from 4000Hz to 3450hz,the sound absorption coefficient of the vally is increased from 0.72 to 0.77,which improves 6.94%.(4)The test results of high porosity fiber composite foam sound absorption properties shown that:When the porosity is 81.29%,the fiber diameter is 0.1mm and the fiber content is 5vol.%,the composite foam with high porosity obtained the best sound absorption properties.Its average sound absorption coefficient is 0.88,the sound absorption peak is at 1850～2000Hz,the sound absorption low valley is at 3450Hz,and the sound absorption coefficient of the vally is 0.77.(5)The sound absorption property of fiber composite foam is related to its acoustic impedance,its size is determined by the pore size,porosity,fiber content and fiber diameter of the composite foams.When the pore size is smaller,the porosity is higher,the fiber diameter is smaller the fiber content is morer,the acoustic impedance of the composite foam is higher,and the sound absorption property is the better.