Cast aluminium alloys are being employed increasingly in the automotive sector due to their light weight and excellent castability. This paper focuses on the strain hardening behaviour of Hipped and non-Hipped components of cast aluminium alloy 354 subjected to two-step ageing, as opposed to the routinely carried out single-step ageing. First step ageing (at 100°C) was carried out for 2 h and 5 h; ageing time at second step (at 170°C) was 1, 2 and 5 h. Mechanical properties and strain hardening behaviour were evaluated for different variants of two-step ageing treatment. Analysis of the results shows that the Hipped components have higher hardening capacity and generally higher strain hardening rate compared to the non-Hipped ones. Some of the two-step ageing treatments give mechanical properties comparable to the conventional T61 treatment, but with significantly higher strain hardening rate.

Nageswara Rao M

Department of Manufacturing Engineering

School of Mechanical Engineering

Vellore Campus

Gupta A

Eswar A

Babu G.D

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Advanced Materials Research

Strain Hardening Behaviour of Hipped and Non-Hipped Castings of Aluminium Alloy 354 Subjected to Two-Step Ageing Treatments

Cast aluminum alloy 354 is used extensively for production of critical automobile component, owing to its excellent castability and attractive combination of mechanical properties. With the advent of higher performance engines, there has been a steady demand to further improve the mechanical behavior of the alloy, among others, through improvements in processing. The present study explores the possibility of improving mechanical behavior and quality levels of the alloy by adopting certain non-conventional aging treatments. Quality indices Q and QC have been used for quality rating. The non-conventional treatments include aging cycles similar to T6I4 and T6I6 referred to in the published literature, artificial aging in two steps instead of in single step and artificial aging preceded by various natural aging times. The results show that none of the non-conventional treatments leads to improvement of all tensile properties compared to the standard T61 treatment. However, some specific treatments could be identified which lead to a comparable combination of tensile properties and a shade higher quality level. Increasing the time of preceding natural aging does not help in improving the tensile properties after artificial aging.

Effect of Non-Conventional Aging Treatments on the Tensile Properties and Quality Indices of Hipped Components Made of Cast Aluminum Alloy 354

Automotive industry makes wide scale use of cast aluminium alloy 354 in the production of crucial components, such as compressor wheels for turbochargers. The compressor wheels undergo T61 heat treatment, involving artificial ageing at 188°C. This study focuses on the possible improvement of the mechanical behaviour of the components by subjecting them to modified heat treatments involving usage of lower artificial ageing temperatures (160, 171 and 177°C). A comparative analysis of tensile properties and strain hardening behaviour has been carried out with different artificial ageing temperatures. Results showed that the heat treatment routinely employed by the industry (aged at 188°C) leads to overageing, thereby resulting in relatively inferior mechanical properties and lower strain hardening rates as compared to the samples heat treated at lower artificial ageing temperatures. It is concluded that lowering of the artificial ageing temperature can lead to a superior state of components with respect to mechanical behaviour.

Analysis of Strain Hardening Behaviour of Cast Aluminium Alloy 354 Subjected to Artificial Ageing at Various Temperatures

GSTF Journal of Engineering Technology

Effect of various non conventional aging treatments on the mechanical properties and quality indices of cast and heat treated components of aluminum alloy 354

Metallurgical and Materials Transactions A

Modeling of Strain Hardening in the Aluminum Alloy AA6061

Journal	Advanced Materials Research
Publisher	Trans Tech Publications, Ltd.
ISSN	10226680
Open Access	0