Production of Cu/Al2O3 composites by kobo-type forming
Marek Kostacki*, Włodzimierz Bochniak**, Andrzej Olszyna*** *Politechnika Warszawska, Wydział Inżynierii Materiałowej, ul. Wołoska 141, 02-507 Warszawa **Akademia Górniczo-Hutnicza, Katedra Struktury i Mechaniki Ciała Stałego, al. Mickiewicza 30, 30-059 Kraków ***Politechnika Warszawska, Wydział Inżynierii Materiałowej, ul. Wołoska 141, 02-507 Warszawa
Quarterly No. 4, 2006 pages 29-34
DOI:
keywords: metal-ceramic composites, dispersion strengthening, plastic deformation, KOBO-type forming
abstract The aim of the paper is to presents investigation of production Cu/Al2O3 composites obtaining by KOBO method. The idea of Kobo-type forming originates from the studies of the effect of the change of the scheme of loading and it’s influence on materials structure. The starting materials was Cu and Al2O3 powders, average grain size 32 μm and 134 nm respectively (Figs. 1, 2). The powders were mixed by homogenization. After drying, the powders were granulated, isostatically consolidated under a pressure of 120 MPa and sintered (Fig. 6). Plastic deformation of Cu/Al2O3 samples (with and without sintering) were performed. The final product has the rod shape 8 mm in diameter and 1 meter length approximately. However composites with 10 vol.% of Al2O3 reinforcement does not show monolithic form, on the base of researches was fund, that in both cases (with and without sintering) is possible to obtain a dens composite material. Composite with les than 10 vol.% of Al2O3 shows a relative density ≥ 90%, and hardness of 83 HV0.5 (value obtained for the Cu+5vol.%Al2O3 composite (Fig. 11).