Microstructure and Mechanical Properties of Cast Al-Si-Cu-Mg-Ni-Cr Alloys: Effects of Time and Temperature on Two-Stage Solution Treatment and Ageing

Ameliorating the high-temperature performance of cast Al-Si alloys used as engine components is essential. The effects of different T6 heat-treatment processes on the microstructure and mechanical properties of cast Al-Si-Cu-Mg-Ni-Cr alloys were investigated in the present study. The results demonstrate that, under the optimal solution treatment conditions of 500 °C for 2 h and 540 °C for 4 h, the T-Al9FeNi phase was present in the alloy, and the roundness of primary Si and the aspect ratio of eutectic Si in the alloy reached valley values of 1.46 and 2.56, respectively. With increasing ageing time at 180 °C, the tensile strength significantly improved, while the microhardness first increased and then decreased. When the ageing time was 4 h, microhardness reached a peak value of 155.82 HV. The fracture characteristics changed from quasi-cleavage to the coexistence of quasi-cleavage and dimples. After heat treatment, the high-temperature tensile properties of the alloy improved, which is a significant advantage compared to the as-cast alloy. The stable Al3Ni and Al9FeNi phases inhibited the cracking of the alloy at 350 °C.

[1]  G. Winter,et al.  Influence of T6 Heat-Treating and Over-Ageing on Out-of-Phase Thermo-Mechanical Fatigue Behaviors of Al-Si-Cu Alloy , 2022, Social Science Research Network.

[2]  Chuandong Wu,et al.  Influence of Annealing Time on Microstructure and Mechanical Properties of Al-14.5Si Alloy Prepared by Super-Gravity Solidification and Cold-Rolling , 2022, Materials.

[3]  Zhen Jia,et al.  Effect of Cd on Mechanical Properties of Al-Si-Cu-Mg Alloys under Different Multi-Stage Solution Heat Treatment , 2022, Materials.

[4]  Xufeng Yang,et al.  Towards strength-ductility synergy through an optimized two-stage solution treatment in Al–7Si–3Cu-0.5Mg alloys , 2022, Materials Science and Engineering: A.

[5]  Weiweng Zhang,et al.  Effect of Initial Fe Content on Microstructure and Mechanical Properties of Recycled Al-7.0Si-Fe-Mn Alloys with Constant Mn/Fe Ratio , 2022, Materials.

[6]  A. Samuel,et al.  Intermetallics Formation during Solidification of Al-Si-Cu-Mg Cast Alloys , 2022, Materials.

[7]  J. Pezda.  Optimization of Heat Treatment Parameters of AlSi7Mg Alloy , 2022, Materials.

[8]  Yongchang Liu,et al.  The effect of solution temperature on the precipitates evolution and aging hardening response of Al-15%Mg2Si(-1%Cu) alloys , 2022, Journal of Materials Research and Technology.

[9]  Y. Choi,et al.  Effects of solution treatment temperature and time on the porosities and mechanical properties of vacuum die-casted and T6 heat-treated Al–Si–Mg alloy , 2021 .

[10]  J. Pang,et al.  Effect of temperature on the mechanical properties of Al–Si–Cu–Mg–Ni–Ce alloy , 2021 .

[11]  Chunde Ma,et al.  In-situ study of effects of heat treatments and loading methods on fracture behaviors of a cast Al–Si alloy , 2021 .

[12]  Hao-wei Wang,et al.  Morphological Evolutions of Ni-Rich Phases in Al-Si Piston Alloys during 250–400 °C Thermal Exposure Processes , 2020, Materials.

[13]  Z. Yang,et al.  Effect of thermal exposure on microstructure and high-temperature fatigue life of Al-Si piston alloys , 2020, Journal of Materials Research and Technology.

[14]  G. Sha,et al.  On the strengthening effect of Al-Cr-Si dispersoid in an Al-Si-Mg-Cu casting alloy with Cr addition , 2020 .

[15]  W. Ding,et al.  Effect of thermal exposure on microstructure and mechanical properties of Al−Si−Cu−Ni−Mg alloy produced by different casting technologies , 2020, Transactions of Nonferrous Metals Society of China.

[16]  R. Guan,et al.  Microstructure evolution of eutectic Si in Al-7Si binary alloy by heat treatment and its effect on enhancing thermal conductivity , 2020 .

[17]  A. Samuel,et al.  Effect of morphological changes of eutectic Si particles on the ambient and high temperature tensile properties of Zr containing Al–Si alloys , 2020 .

[18]  X. Kong,et al.  Effect of ε-Al3Ni phase on mechanical properties of Al–Si–Cu–Mg–Ni alloys at elevated temperature , 2020 .

[19]  S. Ji,et al.  Effect of Zr on the high cycle fatigue and mechanical properties of Al–Si–Cu–Mg alloys at elevated temperatures , 2019, Journal of Alloys and Compounds.

[20]  S. Bera,et al.  Improvement in dry sliding wear resistance of Al-17Si-5Cu alloy after an enhanced heat treatment process , 2018, Transactions of Nonferrous Metals Society of China.

[21]  Bin-hao Hu,et al.  Analyzing the microstructural evolution and hardening response of an Al-Si-Mg casting alloy with Cr addition , 2018, Materials Characterization.

[22]  Z. Zhang,et al.  Thermo-mechanical fatigue behavior and life prediction of the Al-Si piston alloy , 2018 .

[23]  Qudong Wang,et al.  Effects of Ni content on low cycle fatigue and mechanical properties of Al-12Si-0.9Cu-0.8Mg-xNi at 350 °C , 2017 .

[24]  Hong Yan,et al.  Evolution of second phases and mechanical properties of 7075 Al alloy processed by solution heat treatment , 2017 .

[25]  W. Ding,et al.  Effect of Q-Al5Cu2Mg8Si6 phase on mechanical properties of Al-Si-Cu-Mg alloy at elevated temperature , 2017 .

[26]  Lina Han,et al.  Effects of Nd on microstructure and mechanical properties of cast Al-Si-Cu-Ni-Mg piston alloys , 2017 .

[27]  I. Estrada-Guel,et al.  Effect of Nickel addition and solution treatment time on microstructure and hardness of Al-Si-Cu aged alloys , 2016 .

[28]  S. K. Shaha,et al.  Ageing characteristics and high-temperature tensile properties of Al–Si–Cu–Mg alloys with micro-additions of Cr, Ti, V and Zr , 2016 .

[29]  Hao-wei Wang,et al.  Effect of Cr content and heat-treatment on the high temperature strength of eutectic Al–Si alloys , 2015 .

[30]  M. Pekguleryuz,et al.  The effects of manganese on the Τ-phase and creep resistance in Al–Si–Cu–Mg–Ni alloys , 2013 .

[31]  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 .

[32]  M. Román,et al.  Improvement of the tensile properties of an Al–Si–Cu–Mg aluminum industrial alloy by using multi stage solution heat treatments , 2013 .

[33]  Xiangfa Liu,et al.  Supportive strengthening role of Cr-rich phase on Al–Si multicomponent piston alloy at elevated temperature , 2011 .

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

[35]  E. Sjölander,et al.  The heat treatment of Al–Si–Cu–Mg casting alloys , 2010 .

[36]  F. Nový,et al.  Microstructure changes in a 2618 aluminium alloy during ageing and creep , 2009 .

[37]  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 .

[38]  Z. Fan,et al.  Effect of heat treatment on microstructure and tensile properties of die-cast Al-Cu-Si-Mg alloys , 2021 .

[39]  Xiangfa Liu,et al.  Evolution of nickel-rich phases in Al–Si–Cu–Ni–Mg piston alloys with different Cu additions , 2012 .