Applications of hydrostatic extrusion for compacting composites of Ti3Al intermetallic powders
Katarzyna Samsel, Halina Garbacz, Krzysztof J. Kurzydłowski, Mariusz Kulczyk 1-3 Wydział Inżynierii Materiałowej, Politechnika Warszawska, ul. Wołoska 141, 02-507 Warszawa, Poland 4 Instytut Wysokich Ciśnień PAN, ul. Sokołowska 29/37, 01-142 Warszawa, Poland
Quarterly No. 3, 2007 pages 130-134
DOI:
keywords: intermetallic phases, composites, hydrostatic extrusion
abstract A hydrostatic extrusion method was used to compact Ti3Al intermetallic powders. The powders (Ti3Al and Ti3Al+Al2O3 wt. %) were encapsulated in copper blanks and subjected to the hydrostatic extrusion under high pressure. The diameter of copper encapsulates was reduced from 10 to 4 mm. The extruded samples were etched in concentrated nitric acid to remove the copper containers. The microstructure of compacts was examined using scanning electron microscopy. On edge of compacts the layer of consolidated Ti3Al powder was observed. Microstructure observation after micro-hardness measurement have shown that that layer wasn’t sintered. The mechanical properties of the materials in the initial state and after hydrostatic extrusion were characterized by HV0.2 micro-hardness measurements. The examinations have shown that micro-hardness of the samples increases with increasing extrusion ratio. The influence of using copper capsules was investigated by Energy Dispersion Spectroscope. The results are discussed in terms of the optimizing microstructure and properties of the composites in question. As result of investigations the cracking prevention method of compacts was developed.