Amorphous-ceramic Ni-based composite reinforced with Al2O3 processed by mechanical alloying and powder consolidation
Dariusz Oleszak, Tadeusz Kulik, Dmitro Kolesnikov 1,2 Wydział Inżynierii Materiałowej, Politechnika Warszawska, ul. Wołoska 141, 02-507 Warszawa, Poland 3 Instytut Wysokich Ciśnień PAN, ul. Sokołowska 29/37, 00-142 Warszawa, Poland
Quarterly No. 4, 2007 pages 195-199
DOI:
keywords: amorphous alloys, metallic-ceramic composites, mechanical alloying, powder compaction
abstract An attempt was made to obtain bulk metallic glasses composite by mechanical alloying followed by powder compaction. Ni-based amorphous matrix was fabricated by milling of a mixture of pure crystalline elements. Two types of Al2O3 powders were added (20 vol. %) as the ceramic phase: micrometer in size (50 μm) and nanopowder (80 nm). Mechanical alloying resulted in a full amorphization of the alloy. The addition of ceramic powder influenced the thermal stability of the amorphous phase. Especially in the case of nanopowders, the crystallization temperature of the first crystallization stage of amorphous phase was decreased by about 50oC. The applied parameters of isostatic pressing (1.5 GPa, 0.5 h, 440 and 480oC) resulted in partial crystallization of the alloy. It was verified by XRD and DSC studies. The quality of the compaction was checked by optical microscopy observations, revealing some micropores.