TY - JOUR
T1 - Ultrasound assisted casting of an AM60 based metal matrix nanocomposite, its properties, and recyclability
AU - Dieringa, Hajo
AU - Katsarou, Lydia
AU - Buzolin, Ricardo
AU - Szakács, Gábor
AU - Horstmann, Manfred
AU - Wolff, Martin
AU - Mendis, Chamini
AU - Vorozhtsov, Sergey
AU - StJohn, David
PY - 2017/10/1
Y1 - 2017/10/1
N2 - An AM60 magnesium alloy nanocomposite reinforced with 1 wt % of AlN nanoparticles was prepared using an ultrasound (US) assisted permanent-mould indirect-chill casting process. Ultrasonically generated cavitation and acoustic streaming promoted de-agglomeration of particle clusters and distributed the particles throughout the melt. Significant grain refinement due to nucleation on the AlN nanoparticles was accompanied by an exceptional improvement in properties: yield strength increased by 103%, ultimate tensile strength by 115%, and ductility by 140%. Although good grain refinement was observed, the large nucleation undercooling of 14 K limits further refinement because nucleation is prevented by the formation of a nucleation-free zone around each grain. To assess the industrial applicability and recyclability of the nanocomposite material in various casting processes, tests were performed to determine the effect of remelting on the microstructure. With each remelting, a small percentage of effective AlN nanoparticles was lost, and some grain growth was observed. However, even after the third remelting, excellent strength and ductility was retained. According to strengthening models, enhanced yield strength is mainly attributed to Hall-Petch strengthening caused by the refined grain size. A small additional contribution to strengthening is attributed to Orowan strengthening.
AB - An AM60 magnesium alloy nanocomposite reinforced with 1 wt % of AlN nanoparticles was prepared using an ultrasound (US) assisted permanent-mould indirect-chill casting process. Ultrasonically generated cavitation and acoustic streaming promoted de-agglomeration of particle clusters and distributed the particles throughout the melt. Significant grain refinement due to nucleation on the AlN nanoparticles was accompanied by an exceptional improvement in properties: yield strength increased by 103%, ultimate tensile strength by 115%, and ductility by 140%. Although good grain refinement was observed, the large nucleation undercooling of 14 K limits further refinement because nucleation is prevented by the formation of a nucleation-free zone around each grain. To assess the industrial applicability and recyclability of the nanocomposite material in various casting processes, tests were performed to determine the effect of remelting on the microstructure. With each remelting, a small percentage of effective AlN nanoparticles was lost, and some grain growth was observed. However, even after the third remelting, excellent strength and ductility was retained. According to strengthening models, enhanced yield strength is mainly attributed to Hall-Petch strengthening caused by the refined grain size. A small additional contribution to strengthening is attributed to Orowan strengthening.
KW - AlN
KW - Magnesium alloy AM60
KW - Metal matrix nanocomposite (MMNC)
KW - Nanoparticles
KW - Strengthening mechanisms
UR - http://www.scopus.com/inward/record.url?scp=85030255651&partnerID=8YFLogxK
U2 - 10.3390/met7100388
DO - 10.3390/met7100388
M3 - Article
AN - SCOPUS:85030255651
SN - 2075-4701
VL - 7
JO - Metals
JF - Metals
IS - 10
M1 - 388
ER -