H. Momeni, H. Razavi, S. G. Shabestari,
Volume 8, Issue 2 (6-2011)
Abstract
Abstract: The supersolidus liquid phase sintering characteristics of commercial 2024 pre-alloyed powder was studied at different sintering conditions. Pre-alloyed 2024 aluminum alloy powder was produced via air atomizing process with particle size of less than 100 µm. The solidus and liquidus temperatures of the produced alloy were determined using differential thermal analysis (DTA). The sintering process was performed at various temperatures ranging from the solidus to liquidus temperatures in dry N2 gas atmosphere for 30 min in a tube furnace. The maximum density of the 2024 aluminum alloy was obtained at 610ºC which yields parts with a relative density of 98.8% of the theoretical density. The density of the sintered samples increased to the maximum 99.3% of the theoretical density with the addition of 0.1 wt. %Sn powder to the 2024 pre-alloyed powder. The maximum density was obtained at 15% liquid volume fraction for both powder mixtures.
A. Mohammadzadeh, A. Sabahi Namini, M. Azadbeh,
Volume 11, Issue 3 (9-2014)
Abstract
The rapidly solidified prealloyed alpha brass powder with a size range of 40 to 100 μm produced by water
atomization process was consolidated using liquid phase sintering process. The relationships between sintering
temperature, physic-mechanical properties and microstructural characteristics were investigated. Maximum
densification was obtained at 930 °C, under 600 MPa compacting pressure, with 60 min holding time. The
microstructure of the sintered brass was influenced by dezincification and structural coarsening during supersolidus
liquid phase sintering. As a consequence of Kirkendall effect atomic motion between Cu and Zn atoms caused to
dezincification at the grain boundaries and formation of ZnO particles on the pore surfaces. It was concluded that
microstructural analysis is in a well agreement with obtained physical and mechanical properties. Also, the amount of
liquid phase, which depends on sintering temperature, results in different load bearing cross section areas, and it
affects the type of fracture morphologies.
