FeAl多孔材料制备过程中烧结气氛对Al元素挥发及其抗水腐蚀的影响

以Fe、Al元素粉末为原料,采用粉末冶金法,通过偏扩散/反应合成烧结,制备FeAl金属间化合物多孔材料。通过XRD、SEM、EDS等表征手段,研究多孔试样烧结过程中基础元素的挥发及孔结构变化行为,并进行室温状态下的抗水腐蚀实验。结果表明,在1 000~1 300℃之间,随温度升高,试样在真空烧结过程中的质量损失率升高,在最终烧结温度为1 300℃、保温4 h的条件下,质量损失率为10.5%;而试样在氩气氛烧结过程中,随温度升高试样质量几乎没有变化;氩气氛烧结条件下制备的FeAl多孔材料的抗水腐蚀性能明显优于真空条件下制备的多孔试样。氩气氛条件下烧结制备FeAl金属间化合物多孔材料能够避免真空烧结过程中Al元素的挥发,从而有效提高FeAl金属间化合物多孔材料的抗水腐蚀性能。     

造孔剂(NH_4)_2CO_3含量对FeAl多孔材料性能的影响

以Fe、Al元素粉末为原料,通过添加造孔剂(NH4)2CO3,利用偏扩散/反应合成,制备具有可控孔结构特征、高孔隙率的FeAl多孔材料;采用XRD、SEM、OM及孔结构与力学性能检测等测试手段研究造孔剂(NH4)2CO3添加量对FeAl多孔材料的孔结构与力学性能的影响。结果表明,随造孔剂添加量增加,FeAl多孔材料的孔隙率升高,当造孔剂质量分数为15%时,孔隙率高达60%;力学性能随孔隙率增加而下降,抗弯强度与孔隙率呈指数递减关系;并得出了孔隙率与抗拉强度关系的定量方程σb=165(1-p)2.4。     

Preparation and characterization of novel porous Fe-Si alloys

Porous Fe-Si alloys with different nominal compositions ranging from Fe-10wt% Si to Fe-50wt% Si were fabricated through a reactive synthesis of Fe and Si elemental powder mixtures. The effects of Si contents on the pore structure of porous Fe-Si alloy were investigated in detail. The results showed that the open porosity, gas permeability and maximum pore size of the porous Fe-Si alloys increased with increasing Si contents, indicating that the porosity and pore size can be tailored by changing the Si contents. The pore structure parameter including the open porosity, gas permeability, maximum pore size obeyed the Hagen-Poiseuille formula with the constant G=0.035 m^-1Pa^-1s^-1 for the reactively synthesized porous Fe-Si alloys. The mechanical property of the porous Fe-Si alloys showed applicability in the filtration industries.