Fabrication of ceramic preforms based on Al2O3 CL 2500 powder

Purpose: The aim of a work is to elaborate the method of manufacturing the porous, ceramic preforms based on Al2O3 particles used as the reinforcement in order to produce modern metal matrix composite materials. Design/methodology/approach: Semi-finished products were manufactured by the method of sintering of ceramic powder. The preform material consists of powder Condea Al2O3 Cl 2500, however, as the forming factor of the structure of canals and pores inside the ceramic, agglomerated framework the carbon fibres Sigrafil C10 M250 UNS were used. The investigations of the structure of powder Al2O3 Condea Cl 2500, the used carbon fibres and the obtained ceramic preforms on the scanning electron microscope (SEM) have been made. The measurement of permeability of the obtained materials on the specially designed station has also been made. Findings: The obtained preforms are characterised by volumetric participation of ceramic phase of 15 - 31%, what is the result of differential addition of the pores forming factor, and the high permeability indicates on “the open porosity”. Research limitations/implications: The basic limit of the mentioned method is the possibility of obtaining preforms of porosity less than 85%, where in case of using the ceramic fibres the pores can be more than 90% of material volumetric. Practical implications: The manufactured ceramic preforms are widely used as the reinforcement to produce the composite materials by the method of infiltration. That method allows manufacturing the metal elements locally reinforced and the near-net shape composite products. Originality/value: The received results show the possibility of obtaining the new preforms being the cheaper alternative for semi-finished products based on the ceramic fibres and the use of carbon fibres as the pores forming agent indicate that it is the high-quality process.