孔隙度对烧结不锈钢纤维多孔材料压缩性能的影响

Effect of porosity on compressive properties of porous sintered stainless steel fiber media

采用丝径为100μm的不锈钢纤维经松装烧结工艺制备了孔隙度在70％～95％之间的金属纤维多孔板材。在MTS858材料试验机上检测压缩性能，结果表明：孔隙度在82．8％以下的试件的面内应力应变曲线大致分为三个阶段，应变很低情况下的线性弹性区、屈服平台区和应力急剧增大情况下的致密化区，其中屈服平台区较长，说明该材料具有较强的能量吸收能力；随着孔隙度的增加，不锈钢纤维多孔材料的卸载模量、屈服强度减小，其中孔隙度为70％的烧结不锈钢纤维多孔材料的平均卸载模量为5．2GPa，平均屈服强度达到了23MPa；孔隙度大于90．1％的试件屈服强度很低，能量吸收能力很小。

Porous sintered 316L stainless steel fibers of 100μm in diameter were fabricated by loose sintering technology, with porosity from 70% -95%. And compressive properties of the porous sintcred stainless steel fiber media were investigated by using MTS 858 system at room temperature. The results indicate that the compressive stress-strain curves of porous sintered stainless steel fiber media, with porosity less than 82.8% exhibits three distinct regions （three deformation stages） under compressive loading, i. e. , elastic stage, a plateau stage that occurs after yielding and final densification region where the stress increases drastically. Moreover, compressive stress-strain curves of the porous sintered stainless steel fiber media present smooth and long plateau stages. Therefore, the porous sintered stainless steel fiber media show excellent energy absorption capacity. By increasing porosity, it is obvious that the compressive yield strength slumps. Moreover, the unloaded Young＇ s modulus gradually decreases with increase of porosity. It can be found that the average unloaded Young＇ s modulus and average compressive yield strength of the porous sintered stainless steel fiber media with porosity of 70% is 5.2GPa and 23MPa. Instead, when porosity is more than 90. 1% , the energy absorption capacity of the porous sintered stainless steel fiber media is very little.