TY - JOUR
T1 - Numerical and experimental studies of AlSi coating microstructure and its fracture at high temperatures
AU - bin Zaman, Shakil
AU - Hazrati, Javad
AU - de Rooij, Matthijn
AU - van den Boogaard, Ton
N1 - Funding Information:
This research was carried out under project number S22.1.15583 in the framework of the Partnership Program of the Materials innovation institute M2i ( www.m2i.nl ) and the Technology Foundation TTW ( www.stw.nl ), which is part of the Netherlands Organization for Scientific Research ( www.nwo.nl ). The authors would like to thank TATA Steel for their scientific feedback.
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/10/19
Y1 - 2021/10/19
N2 - As AlSi-coated press hardening steel is heated to austenitization temperatures, various FeAl intermetallic compounds (e.g. FeAl, Fe2Al5 etc.) and voids are generated throughout the coating, increasing also the surface roughness. The goal of this study is to investigate the effects of coating surface roughness, voids and intermetallic distribution on AlSi coating fracture during its deformation at elevated temperatures. For this purpose, hot tensile experiments and finite element (FE) analyses are conducted to understand crack initiation and propagation in the coating. The coatingsubstrate FE model is built, taking the realistic distributions of intermetallics, voids and surface profile into account. The FE model is calibrated to experiments and the sensitivity of coating fracture to the distributions of intermetallics, voids and surface profile is analyzed. According to FE simulation results, coating fracture is minimized either by increasing the content of FeAl intermetallic or by reducing the void fraction in AlSi coating. Furthermore, to validate the aforementioned numerical prediction, the heating stage parameters are modified to reproduce coating micro-structure from the FE model. Hot tensile experiments on the samples with modified heating parameters confirm the FE simulation results, showing a similar decline in coating crack density. In conclusion, the AlSi coating fracture during hot tensile deformation depends on its micro-structure, which is mainly generated during the heating stage. Furthermore, the results also suggest that coatingsubstrate FE simulations can be utilized as a tool to achieve a suitable coating micro-structure which minimizes coating fracture.
AB - As AlSi-coated press hardening steel is heated to austenitization temperatures, various FeAl intermetallic compounds (e.g. FeAl, Fe2Al5 etc.) and voids are generated throughout the coating, increasing also the surface roughness. The goal of this study is to investigate the effects of coating surface roughness, voids and intermetallic distribution on AlSi coating fracture during its deformation at elevated temperatures. For this purpose, hot tensile experiments and finite element (FE) analyses are conducted to understand crack initiation and propagation in the coating. The coatingsubstrate FE model is built, taking the realistic distributions of intermetallics, voids and surface profile into account. The FE model is calibrated to experiments and the sensitivity of coating fracture to the distributions of intermetallics, voids and surface profile is analyzed. According to FE simulation results, coating fracture is minimized either by increasing the content of FeAl intermetallic or by reducing the void fraction in AlSi coating. Furthermore, to validate the aforementioned numerical prediction, the heating stage parameters are modified to reproduce coating micro-structure from the FE model. Hot tensile experiments on the samples with modified heating parameters confirm the FE simulation results, showing a similar decline in coating crack density. In conclusion, the AlSi coating fracture during hot tensile deformation depends on its micro-structure, which is mainly generated during the heating stage. Furthermore, the results also suggest that coatingsubstrate FE simulations can be utilized as a tool to achieve a suitable coating micro-structure which minimizes coating fracture.
KW - Fe-Al intermetallics
KW - Surface roughness
KW - Void fraction
KW - Coating fracture
KW - Hot stamping
U2 - 10.1016/j.msea.2021.142067
DO - 10.1016/j.msea.2021.142067
M3 - Article
SN - 0921-5093
VL - 827
JO - Materials Science & Engineering A
JF - Materials Science & Engineering A
M1 - 142067
ER -
