TY - CHAP

T1 - Hot tearing susceptibility of Mg-5Nd-xZn alloys

AU - D'Elia, Francesco

AU - Tolnai, Domonkos

AU - Mendis, Chamini Lakshi

AU - Hort, Norbert

N1 - Conference code: 145

PY - 2016

Y1 - 2016

N2 - Magnesium-neodynium-zinc (Mg-Nd-Zn) alloys are promising candidates as creep resistant alloys. Further, Nd is a rare earth (RE) addition with lower solid solubility and a relatively lower cost. Hence, the use of such alloys may result in a feasible and cost effective alternative for enhancing Mg alloy use in high temperature applications. Nevertheless, studies on the castability of Mg-Nd-Zn alloys are lacking. As such, the aim of this research was to investigate the hot tearing susceptibility of Mg-5Nd-xZn (x= 0, 3, 5, 7 wt%) alloys during permanent mold casting. Specifically, a constrained-rod casting mold equipped with a load cell was used to characterize hot tearing severity and determine the onset temperature of hot tearing. The onset solid fraction of hot tearing was subsequently determined via thermodynamic software. The results suggest that hot tearing severity increased initially with addition of Zn (up to 5 wt%), but then decreased with further addition to 7 wt%. This was likely attributed to both the low onset solid fraction of hot tearing (i.e. 0.5) recorded for this alloy, which enabled enhanced feeding and opportunity to heal developing hot tears, as well as the divorced eutectic structure observed which may have facilitated late stage feeding of eutectic liquid and hence limit the alloy's susceptibility to hot tearing.

AB - Magnesium-neodynium-zinc (Mg-Nd-Zn) alloys are promising candidates as creep resistant alloys. Further, Nd is a rare earth (RE) addition with lower solid solubility and a relatively lower cost. Hence, the use of such alloys may result in a feasible and cost effective alternative for enhancing Mg alloy use in high temperature applications. Nevertheless, studies on the castability of Mg-Nd-Zn alloys are lacking. As such, the aim of this research was to investigate the hot tearing susceptibility of Mg-5Nd-xZn (x= 0, 3, 5, 7 wt%) alloys during permanent mold casting. Specifically, a constrained-rod casting mold equipped with a load cell was used to characterize hot tearing severity and determine the onset temperature of hot tearing. The onset solid fraction of hot tearing was subsequently determined via thermodynamic software. The results suggest that hot tearing severity increased initially with addition of Zn (up to 5 wt%), but then decreased with further addition to 7 wt%. This was likely attributed to both the low onset solid fraction of hot tearing (i.e. 0.5) recorded for this alloy, which enabled enhanced feeding and opportunity to heal developing hot tears, as well as the divorced eutectic structure observed which may have facilitated late stage feeding of eutectic liquid and hence limit the alloy's susceptibility to hot tearing.

KW - Hot tearing

KW - Magnesium alloys

KW - Microstructure

KW - Solidification

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=84975091315&partnerID=8YFLogxK

U2 - 10.1002/9781119274803.ch26

DO - 10.1002/9781119274803.ch26

M3 - Article in conference proceedings

AN - SCOPUS:84975091315

T3 - Magnesium Technology

SP - 129

EP - 134

BT - Magnesium Technology 2016 - Held During TMS 2016

A2 - Singh, Alok

A2 - Solanki, Kiran

A2 - Manuel, Michele Viola

A2 - Neelameggham, Neale R.

PB - The Minerals, Metals & Materials Society

T2 - 145th Annual Meeting and Exhibition of Magnesium Technology - TMS 2016

Y2 - 14 February 2016 through 18 February 2016

ER -