Physical properties of cement composites designed for aerostatic bearings
- 152 Downloads
This paper investigates the physical properties of cement composites based on ordinary Portland cement (OPC) and silica particles as a potential material for porous aerostatic bearings for precision engineering applications. A full factorial design (2241) was carried out to study the effects of silica properties (size and geometry) and uniaxial pressure (10 and 30 MPa) on the composite properties, namely bulk density, apparent porosity and intrinsic permeability of the ceramic composites. Scatter graphs were plotted to identify the existence of significant correlations between parameters. The cementitious composite manufactured with small silica particles, non-spherical shape and low level of compaction pressure exhibited the most appropriate properties for the proposed application. In addition, mathematical models obtained from the response-correlation plots are potentially important tools for the development and design of new composites for porous bearing applications.
KeywordsCementitious composites Aerostatic porous bearings Mechanical properties Full experimental design, precision engineering
The authors would like to thank the Department of Mechanical Engineering at the University of Bath, UK, and also the Department of Civil and Structural Engineering at the University of Sheffield, UK, for their support with the laboratory techniques. This project was funded by Capes, the Brazilian Ministry of Education Agency, to which the authors would also like to acknowledge.
- 2.Slocum A (1992) Precision machine design. Prentice Hall, New JerseyGoogle Scholar
- 6.Gargiulo EP, Gilmour PW (1968) A numerical solution for the design of externally pressurised porous gas bearings: thrust bearings. J Lubrif Technol Trans ASME Oct.: 810–817Google Scholar
- 7.Murti PRK (1976) Analysis of externally pressurised gas porous bearings. J Lubrif Technol Trans ASME 43:404–408Google Scholar
- 13.Recommendations of RILEM (1979) CPC 11.3: absorption of water by immersion under vacuum. June 1979Google Scholar
- 21.Robinson AT (1964) Permeability of tungsten matrices as a function of density, particle size and shape. Trans ASM 57:650–657Google Scholar
- 22.Cliffel EM Jr, Smith WE, Schwope AD (1966) Theory and applications of controlled permeability. Mod Dev Powder Met 3:114–128Google Scholar
- 24.Smith DW, Marth T (1980) An examination of the effects of pore morphology on gas flow through sintered compacts. Mod Dev Power Met 12:835–854Google Scholar