Processing and development of copper oxide porous media via aqueous colloidal method

Full text: This work describes the production aqueous colloidal processing of copper oxide porous media using vegetal carbon as space holder and slip casting as conformation technique. The carbon used was milled to obtain the desired particle size. Suspensions with 35% in volume of solids, copper oxide powder and increasing values of carbon 0, 15, 30 and 45%, were stabilized with 1,0 % in mass of potassium hydroxide and its pH adjusted to 10. The homogenization was carried out using ball milling (polyethylene jar and alumina balls) for 3h with the addition of binder, 1% in mass, during the last hour. The developed pieces, with 20 mm in diameter, were submitted to a heat treatment process for carbon removal and particle sinterization. The heat treatment was 550 °C for 1h with rate of 5 °C/min followed by 900 °C for 1h. The carbon oxidation temperature of 500 °C was determined though thermogravimetry (TG). Sinterization temperatures from 650 - 950 °C were tested to obtain mechanical resistance and small percentage of retraction. The porous media was characterized through X-ray diffraction, electronic microscopy, pycnometry, porosity, and thermal analysis (dilatometry, TG). References: [1] Sánchez-Herencia, A. J., Aqueous Colloidal Processing Of Nickel Powder, Acta Materialia, V. 49, Issue 4, 23 Feb. 2001, Pgs 645-651. [2] Yin Zhang, Preparation and properties of bimodal porous apatite ceramics through slip casting using different hydroxyapatite powders, Ceramics Int., V. 36, Issue 1, Jan. 2010, Pgs 107-113. [3] Souza, L.P. de F., Production and characterization of ceramic pieces obtained by slip casting using powder wastes, J. of Materials Processing Tech., V. 145, Issue 1, 1 Jan. 2004, Pgs 14-20. (author)