The effect of precipitation hardening on the structure and mechanical and tribological properties of magnesium alloy WE54

The paper examined changes in the properties of magnesium alloy WE54 which occur as a result of precipitation hardening. Solution treatment was performed for 8 h at a temperature of 545 degrees C, followed by cooling in ice water (0 degrees C), and in hot water (95 degrees C). After the solution treatment, the examined alloy was aged at 250 degrees C for 8-48 h. The as-received alloy was characterised by a fine-grained structure comprised of solid solution alpha-Mg as well as Mg41Nd5 and Mg24Y5 precipitates. Zirconium-rich areas were also observed. The ageing of alloy caused the formation of phase beta, which consisted of compound Mg12NdY. It has been found that both the temperature of the coolant used during the solution treatment and the duration of ageing significantly affected mechanical properties. Tribological tests showed a more than fourfold reduction in the volumetric wear and a more than threefold reduction in the linear wear after ageing. (C) 2017 Elsevier Ltd. All rights reserved.