Effect of Severe Plastic Deformation on the Characteristics of a PM Aluminum Alloy
The paper deals with the influence of severe plastic deformation on the typical powder metallurgy (PM) microstructural characteristics, such as porosity, of a PM aluminum alloy. A commercial ready-to-press aluminum based powder was used as material to be investigated. After applying different compacting pressures (400, 500, 600 and 700 MPa), specimens were debinded in a ventilated furnace at 400 °C for 60 min. Sintering was carried out in a vacuum furnace at 610 °C for 30 min. The specimens were ECAPed for 1 pass. The dimensional and morphological porosity of investigated materials were measured individually for each pore. Results show that ECAP generates shearing stress breaking down the oxide film; this, coupled to particles deformation under local constraints, enables strong bonding and stability. Therefore, ECAP supports next progressive decreasing of pore size as well as strongly influences both dimensional and morphological porosity characteristics, considering that small pores evolve easily to a circular form. Moreover, ECAP cause strong bonding between adjacent particles, which results in a significant increase of mechanical properties.
Zhengyi Jiang, Shanqing Li, Jianmin Zeng, Xiaoping Liao and Daoguo Yang
M. A. Grande et al., "Effect of Severe Plastic Deformation on the Characteristics of a PM Aluminum Alloy", Advanced Materials Research, Vols. 189-193, pp. 2838-2841, 2011