粉末增塑挤压制备Al_2O_3/430L复合型蜂窝材料的组织与性能

Structure and properties of Al_2O_3/430L composite honeycombs fabricated by plasticizing powder extrusion

为制备性能优良的Al_2O_3/430L复合型蜂窝载体材料,本文以430L不锈钢合金粉末、Al_2O_3粉末、粘结剂为原料,采用粉末增塑挤压技术挤压成形,并在1 100℃真空中烧结2 h获得Al_2O_3/430L复合型蜂窝材料.借助SEM、XRD及万能试验机,研究了添加Al_2O_3对Al_2O_3/430L复合型蜂窝材料的组织与性能的影响.研究表明:金属粉末颗粒在烧结过程中结合形成的基体组织为α-Fe(Cr),在基体晶粒间孔隙处和表面弥散分布着Al_2O_3颗粒.添加少量的Al_2O_3可提高烧结密度,制件表面光滑.随着Al_2O_3添加量增加,蜂窝材料表面负载催化涂层的能力增强;抗压强度随Al_2O_3添加量的增加先升高后降低,在Al_2O_3含量为2.5wt.%时,最大抗压强度达27 MPa.添加2.5wt.%Al_2O_3所制备的Al_2O_3/430L复合型蜂窝材料力学性能最佳、表面负载催化涂层的能力优良.

To fabricate Al2O3 /430L composite honeycombs with high-performance, with pure 430L powder, Al2O3 and a binder as raw materials, Al2O3 /430L composite honeycombs were fabricated by plasticizing powder extrusion and sintering at 1100℃ for 2 h under vacuum conditions. The effect of adding Al2O3 on the microstructure and properties of Al2O3 /430L composite honeycombs has been investigated by SEM, XRD and universal testing machine.The results show that,by sintering at 1100 ℃ for 2 h in a vacuum, metal powder particles were jioned together to formα-Fe matrix, and Al2O3 is distributed on the surface and pore of matrix. Adding a small amount of Al2O3 can improve the density of sintered part, and make the part surface smooth. Increasing the amount of Al2O3 can improve the surface bonding strength of honeycomb carriers with catalytic coating . Compressive strength of the part increases at first and then decreases with the increase of the content of Al2O3, and the peak value reaches at 2.5wt.%Al2O3 and maximum compressive strength 27 MPa.The Al2O3 /430L composite honeycombs with 2.5wt.%Al2O3 have best mechanical properties and high surface coating adhesion.