A novel approach to process high-performance lightweight reticulated porous materials

Abstract

Lightweight reticulated porous materials (LRPMs) with multi-layered struts had been fabricated using vacuum infiltration technique with clay/alumina infiltration slurries. Thermal shock experiments were carried out in order to assess the thermal shock resistance of the LRPMs. Moreover, the residual stresses and thermal stresses within the multi-layered struts were also predicted. The results pointed out that the clay/alumina infiltration slurries composition had a great influence on the thermal shock resistance of the LRPMs. With an increment of clay the residual tensile stresses within the coating layers turned to residual compressive stresses, which were contrary to the results of the matrix. The optimal content of clay in the infiltration slurries for improvement of the LRPMs thermal shock resistance was found to be 30 wt%, the residual strength ratio of the LRPMs reached the max value (87.13%). At the same time, the residual stresses within the coating layer and matrix were 78.64 MPa and 87.71 MPa respectively, which had a positive effect on the inhibition of cracks growth in the multi-layered struts. With a further increase in the clay content, both of the residual stresses and thermal stresses increased gradually, resulting in the deterioration of the LRPMs thermal shock resistance and mechanical properties.