Evaluation of compacted cementitious composites for porous bearings

The use of porous materials as a restrictor in aerostatic bearings provides many advantages over conventional restrictors, such as small variation of temperature, high damping, high operational speeds, limited wear, and capacity to support radial, axial, and combined loading. A design of experiment (DOE) was carried out to evaluate cold-pressed cementitious composites as an air restrictor in thrust bearings. The physical and mechanical properties such as the apparent porosity, permeability, and elastic modulus were investigated in this work, thus verifying the structural and flow characteristics of the composites for such application. The composites fabricated with low compacting pressure and small silica particles provided the material requirements for porous bearings.