Revealing the Effect of Local Connectivity of Rigid Phases during Deformation at High Temperature of Cast AlSi12Cu4Ni(2,3)Mg Alloys

The 3D microstructure and its effect on damage formation and accumulation during tensile deformation at 300 °C for cast, near eutectic AlSi12Cu4Ni2Mg and AlSi12Cu4Ni3Mg alloys has been investigated using in-situ synchrotron micro-tomography, complemented by conventional 2D characterization methods. An increase of Ni from 2 to 3 wt.% leads to a higher local connectivity, quantified by the Euler number χ, at constant global interconnectivity of rigid 3D networks formed by primary and eutectic Si and intermetallics owing to the formation of the plate-like Al-Ni-Cu-rich δ-phase. Damage initiates as micro-cracks through primary Si particles agglomerated in clusters and as voids at matrix/rigid phase interfaces. Coalescence of voids leads to final fracture with the main crack propagating along damaged rigid particles as well as through the matrix. The lower local connectivity of the rigid 3D network in the alloy with 2 wt.% Ni permits localized plastification of the matrix and helps accommodating more damage resulting in an increase of ductility with respect to AlSi12Cu4Ni3Mg. A simple load partition approach that considers the evolution of local connectivity of rigid networks as a function of strain is proposed based on in-situ experimental data.

[1]  J. Pang,et al.  Tensile Strength Evolution and Damage Mechanisms of Al–Si Piston Alloy at Different Temperatures , 2018 .

[2]  E. Boller,et al.  Influence of 3D connectivity of rigid phases on damage evolution during tensile deformation of an AlSi12Cu4Ni2 piston alloy , 2018 .

[3]  F. Mücklich,et al.  3D connectivity of eutectic Si as a key property defining strength of Al–Si alloys , 2016 .

[4]  A. Jarfors,et al.  High temperature tensile deformation behavior and failure mechanisms of an Al–Si–Cu–Mg cast alloy — The microstructural scale effect , 2015 .

[5]  Brian Y. Lattimer,et al.  Overview of aluminum alloy mechanical properties during and after fires , 2015 .

[6]  J. Hyttinen,et al.  Characterization of microstructures using contour tree connectivity for fluid flow analysis , 2014, Journal of The Royal Society Interface.

[7]  G. Requena,et al.  Effect of thermally stable Cu- and Mg-rich aluminides on the high temperature strength of an AlSi12CuMgNi alloy , 2014 .

[8]  C. Kok,et al.  Review: Effect of Alloying Element on Al-Si Alloys , 2013 .

[9]  G. Nicoletto,et al.  High Temperature Fatigue Strength and Quantitative Metallography of an Eutectic Al-Si Alloy for Piston Application , 2013 .

[10]  D. Larouche,et al.  Phase formation in as-solidified and heat-treated Al–Si–Cu–Mg–Ni alloys: Thermodynamic assessment and experimental investigation for alloy design , 2013 .

[11]  J. Dang,et al.  Effects of Si, Cu and Mg on the High-Temperature Mechanical Properties of Al-Si-Cu-Mg Alloy , 2013 .

[12]  F. Samuel,et al.  A Review on the Heat Treatment of Al-Si-Cu/Mg Casting Alloys , 2012 .

[13]  G. Requena,et al.  Three-Dimensional Architecture of Engineering Multiphase Metals , 2012 .

[14]  Johannes E. Schindelin,et al.  Fiji: an open-source platform for biological-image analysis , 2012, Nature Methods.

[15]  W. Cai,et al.  Characterization of tensile fracture in heavily alloyed Al-Si piston alloy , 2011 .

[16]  E. Boller,et al.  Three-dimensional rigid multiphase networks providing high-temperature strength to cast AlSi10Cu5Ni1-2 piston alloys , 2011, Acta materialia.

[17]  P. Cloetens,et al.  The Effect of the Connectivity of Rigid Phases on Strength of AlSi Alloys , 2011 .

[18]  F. Stadler,et al.  The Effect of Ni on the High-Temperature Strength of Al-Si Cast Alloys , 2011 .

[19]  J. Su,et al.  Characterization of fracture and debonding of Si particles in AlSi alloys , 2010 .

[20]  Xiangfa Liu,et al.  Quantitative comparison of three Ni-containing phases to the elevated-temperature properties of Al-Si piston alloys , 2010 .

[21]  G. Requena,et al.  The role of Ni and Fe aluminides on the elevated temperature strength of an AlSi12 alloy , 2010 .

[22]  R. Thomson,et al.  Investigation of mechanical properties of intermetallic phases in multi-component Al–Si alloys using hot-stage nanoindentation , 2010 .

[23]  L. Ceschini,et al.  Microstructure, tensile and fatigue properties of the Al–10%Si–2%Cu alloy with different Fe and Mn content cast under controlled conditions , 2009 .

[24]  P. Cloetens,et al.  Three-dimensional study of Ni aluminides in an AlSi12 alloy by means of light optical and synchrotron microtomography , 2009 .

[25]  E. Boller,et al.  Microtomographic study of the evolution of microstructure during creep of an AlSi12CuMgNi alloy reinforced with Al2O3 short fibres , 2008 .

[26]  Filipe S. Silva,et al.  Fatigue on engine pistons - A compendium of case studies , 2006 .

[27]  Muzaffer Zeren,et al.  Effect of copper and silicon content on mechanical properties in Al–Cu–Si–Mg alloys , 2005 .

[28]  D. Eskin,et al.  Constituent phase diagrams of the Al–Cu–Fe–Mg–Ni–Si system and their application to the analysis of aluminium piston alloys , 2005 .

[29]  S. Shabestari,et al.  Effect of copper and solidification conditions on the microstructure and mechanical properties of Al–Si–Mg alloys , 2004 .

[30]  P. Reed,et al.  Elevated temperature short crack fatigue behaviour in near eutectic Al–Si alloys , 2003 .

[31]  H. Lee,et al.  The Effect of Alloying Elements on the Microstructure and Mechanical Properties of Al-12Si Cast Alloys , 2003 .

[32]  J. Toriwaki,et al.  Euler Number and Connectivity Indexes of a Three Dimensional Digital Picture , 2002 .

[33]  David L. McDowell,et al.  Finite element analysis of the stress distributions near damaged Si particle clusters in cast Al–Si alloys , 2000 .

[34]  A. Deschamps,et al.  Influence of second-phase morphology and topology on mechanical and fracture properties of Al-Si alloys , 1997 .

[35]  Lorna J. Gibson,et al.  The effects of non-periodic microstructure and defects on the compressive strength of two-dimensional cellular solids , 1997 .

[36]  Roman Morgenstern,et al.  Transient microstructural thermomechanical fatigue and deformation characteristics under superimposed mechanical and thermal loading, in AlSi based automotive diesel pistons , 2016 .

[37]  G. Nicoletto,et al.  Fatigue Strength Degradation of AlSi12CuNiMg Alloy Due to High Temperature Exposure: A Structural Investigation☆ , 2014 .

[38]  C. Jeong.  Effect of Alloying Elements on High Temperature Mechanical Properties for Piston Alloy , 2012 .

[39]  E. Boller,et al.  Influence of Internal Architectures of Cast AlSi10Cu5Ni1-2 on High Temperature Strength , 2010 .