TY - CHAP

T1 - Hot forging behavior of Mg−8Al−4Ba−4Ca (ABaX844) alloy and validation of processing map

AU - Rao, K. P.

AU - Dharmendra, C.

AU - Prasad, Y. V.R.K.

AU - Dieringa, H.

AU - Hort, N.

PY - 2018

Y1 - 2018

N2 - Newly developed die-cast alloys based on Mg–Al−Ba–Ca (ABaX) system show promise for high temperature creep resistance. ABaX844 alloy is one of them and it has limited workability due to high alloy content. To identify the optimum processing conditions, processing map for this alloy was developed earlier, which exhibited two workability domains in the temperature and strain rate ranges: (1) 340–410 °C and 0.0003–0.005 s−1and (2) 425–500 °C and 0.0003–0.1 s−1Dynamic recrystallization (DRX) occurs in these domains. The map also exhibited extensive flow instability mainly at strain rates > 0.01 s−1up to a temperature of 400 °C and at strain rates >0.1 s−1beyond 400 °C. The aim of the present study is to validate the findings of processing map by performing forging tests in the temperature range 300–500 °C (at an interval of 40 °C) and forging speeds of 0.01, 0.1, 1 and 10 mm s−1to produce a rib-web (cup) shape component. Finite-element (FE) simulations were performed for obtaining the variations of strain and strain rate in the components during forging. The microstructures of forged specimens deformed under optimum process conditions derived from the processing map revealed the formation of dynamically recrystallized grains. The alloy specimens forged under the conditions of flow instability have fractured and/or exhibited flow localization. The results validated the predictions of the processing map and the load-stroke curves obtained by FE simulation correlated well with the experimental curves.

AB - Newly developed die-cast alloys based on Mg–Al−Ba–Ca (ABaX) system show promise for high temperature creep resistance. ABaX844 alloy is one of them and it has limited workability due to high alloy content. To identify the optimum processing conditions, processing map for this alloy was developed earlier, which exhibited two workability domains in the temperature and strain rate ranges: (1) 340–410 °C and 0.0003–0.005 s−1and (2) 425–500 °C and 0.0003–0.1 s−1Dynamic recrystallization (DRX) occurs in these domains. The map also exhibited extensive flow instability mainly at strain rates > 0.01 s−1up to a temperature of 400 °C and at strain rates >0.1 s−1beyond 400 °C. The aim of the present study is to validate the findings of processing map by performing forging tests in the temperature range 300–500 °C (at an interval of 40 °C) and forging speeds of 0.01, 0.1, 1 and 10 mm s−1to produce a rib-web (cup) shape component. Finite-element (FE) simulations were performed for obtaining the variations of strain and strain rate in the components during forging. The microstructures of forged specimens deformed under optimum process conditions derived from the processing map revealed the formation of dynamically recrystallized grains. The alloy specimens forged under the conditions of flow instability have fractured and/or exhibited flow localization. The results validated the predictions of the processing map and the load-stroke curves obtained by FE simulation correlated well with the experimental curves.

KW - Dynamic recrystallization

KW - Hot forging

KW - Magnesium alloy

KW - Simulation

KW - Engineering

UR - http://www.scopus.com/inward/record.url?scp=85042413679&partnerID=8YFLogxK

U2 - 10.1007/978-3-319-72332-7_45

DO - 10.1007/978-3-319-72332-7_45

M3 - Article in conference proceedings

AN - SCOPUS:85042413679

SN - 9783319723310

SN - 978-3-319-89171-2

T3 - Minerals, Metals and Materials Series

SP - 289

EP - 296

BT - Magnesium Technology 2018

A2 - Solanki, Kiran N.

A2 - Joshi, Vineet

A2 - Neelameggham, Neale R.

A2 - Orlov, Dmytro

PB - Springer International Publishing AG

T2 - International Symposium on Magnesium Technology 2018

Y2 - 11 March 2018 through 15 March 2018

ER -