Fatigue Strength Degradation of AlSi12CuNiMg Alloy Due to High Temperature Exposure: A Structural Investigation

0434887 - ÚFM 2015 RIV NL eng C - Conference Paper (international conference)
Konečná, R. - Nicoletto, G. - Kunz, Ludvík - Svoboda, Milan - Bača, A.
Fatigue Strength Degradation of AlSi12CuNiMg Alloy Due to High Temperature Exposure: A Structural Investigation.
XVII International Colloquium on Mechanical Fatigue of Metals (ICMFM17). Amsterdam: Elsevier, 2014 - (Gulagliano, M.; Vergani, L.), s. 43-46. Procedia Engineering, 74. ISSN 1877-7058.
[ICMFM 2014 International Colloquium on Mechanical Fatigue of Metals /17./. Verbania (IT), 25.06.2014-27.06.2014]
Institutional support: RVO:68081723
Keywords : Al-Si alloys * Fatigue strength * Structural investigation * Age hardening * Precipitates
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The strengthening mechanism based on the formation of precipitates (Guinier-Preston (GP) zones) during decomposition of a metastable supersaturated solid solution is stable and effective below temperatures, which are typically overcome in the piston region facing the combustion chamber. Therefore, pistons experience a progressive loss of strength due to over-aging during service. This contribution reports of a structural investigation on a eutectic AlSi12CuNiMg alloy before and after fatigue testing at high temperatures (up to 350 °C). Metallography, color etching, SEM and TEM are used to elucidate the following aspects: 1) the structural features of the alloy (dendrites of α−phase, primary Si particle size and distribution, morphology and distribution of intermetallic phases); 2) the evolution of the strengthening mechanism (GP zones) with high temperature exposure.
Permanent Link: http://hdl.handle.net/11104/0238862