Structures and properties of Al2O3/Fe composite honeycombs fabricated by plasticizing powder extrusion
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摘要: 为制备性能优良的Al2O3/Fe复合型蜂窝材料,首先以316 L合金粉末、Al2O3粉末和黏结剂为原料,通过粉末增塑挤压及在1 200℃氩气气氛中烧结2 h获得了Al2O3/Fe复合型蜂窝材料;然后,借助SEM、XRD及万能试验机研究了添加Al2O3对Al2O3/Fe复合型蜂窝材料组织与性能的影响。结果表明:金属粉末颗粒在烧结过程中结合形成γ-Fe基体网状组织,表面有呈多边形几何状形态的Cr2O3形成;添加少量的Al2O3可以抑制Cr从基体中析出,降低表面Cr2O3的含量,使金属颗粒烧结结合更为紧密,组织表面更加光滑;随着Al2O3含量的增加,蜂窝材料表面与催化活性涂层的结合能力增强,复合型蜂窝材料的抗压强度先升高后降低;在Al2O3含量为5.0wt%时,抗压强度达26 MPa。所得结论表明5.0wt% Al2O3/Fe复合型蜂窝材料力学性能最佳,表面涂覆性能优良。Abstract: In order to fabricate Al2O3/Fe composite honeycombs with high-performances, 316L alloy powder, Al2O3 powder and binder were used as raw materials, Al2O3/Fe composite honeycombs were obtained by plasticizing powder extrusion and sintering at 1 200℃ for 2 h in argon atmosphere firstly. Then, the effects of adding Al2O3 on the structures and properties of Al2O3/Fe composite honeycombs were investigated by SEM, XRD and universal testing machine. The results show that metal powder particles bind together to form γ-Fe matrix network structure during sintering process, and Cr2O3 with polygon geometric shape is formed on the surface. Adding a small amount of Al2O3 can inhibit the precipitation of Cr from matrix and reduce the amount of Cr2O3 on the surface, which makes the sintering combination of metal powder particles more compact and the surface of structure more smooth. With Al2O3 content increasing, the bonding capacity for the surface of honeycomb materials with catalytic activity coating enhances, compressive strength of the composite honeycomb increases at first and then decreases, and when Al2O3 content is 5.0wt%, the compressive strength reaches 26 MPa. The conclusions obtained show that the mechanical properties of 5.0wt% Al2O3/Fe composite honeycomb are the best, and the surface paintability is preferable.
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Key words:
- Al2O3/Fe /
- metallic honeycomb /
- plasticizing powder extrusion /
- carrier material /
- 316L stainless steel
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