Transactions of The Indian Institute of Metals 

About: Transactions of The Indian Institute of Metals is an academic journal. The journal publishes majorly in the area(s): Microstructure & Alloy. It has an ISSN identifier of 0019-493X. Over the lifetime, 3055 publications have been published receiving 15067 citations.

Selection of materials for prototype fast breeder reactor

Abstract: This paper discusses the rationale behind the selection of materials for the different components of the 500 MWe sodium cooled Prototype Fast Breeder Reactor (PFBR). The major factors considered in the selection of materials include operating conditions, availability of design data in nuclear codes, ease of fabrication, international experience and cost. Attempt has been made to minimise the number of materials and welding consumables in order to avoid mix up of materials during fabrication, and to reduce the cost of Research and Development on materials development and characterisation. From consideration of radiation damage, 20% cold worked Alloy D9 (15Cr-15Ni-Mo- Ti-Si) has been chosen for the initial core of the PFBR. Type 316L(N) stainless steel (SS) has been chosen for structural components of reactor assembly, other than the core components, operating at temperatures above 700 K while 304L(N) SS is the choice for components operating at lower temperatures. Modified 9Cr-1Mo steel is the choice for steam generator while carbon steel has been chosen for top shield components of the reactor assembly. Stringent specifications for chemical compositions and other mechanical properties have been drawn for PFBR materials with the view to improve reliability of components.

Mechanical Properties and Tribological Behavior of Al6061–SiC–Gr Self-Lubricating Hybrid Nanocomposites

Abstract: In the present investigation, a newly fabricated Al6061 reinforced with various quantity (0.4–1.6 wt%) of nano SiC in steps of 0.4 and fixed quantity (0.5 wt%) of micro graphite particle’s hybrid nanocomposites were prepared by ultrasonic assisted stir casting method. The influence of nano SiC and graphite content on the mechanical and tribological properties of Al6061 hybrid nanocomposites were studied. The pin-on-disc equipment was used to carry out experiment at 10–40 N applied load, 0.5 m/s sliding speed and 1000 m sliding distance. The Al/SiC/Gr hybrid nano-composite and matrix alloy wear surfaces were characterized by FESEM equipped with an EDS, 3D profilometer to understand the wear mechanisms. The results of Al/SiC/Gr self-lubricating hybrid nano-composites showed improved wear resistance than the Al6061 matrix alloy. The co-efficient of friction of Al/SiC/Gr hybrid nano-composites were lower than those of the unreinforced alloy at various applied load. Compared to matrix alloy, the surface roughness of Al/SiC/Gr hybrid nano-composites had significantly reduced to 66% at low load and 75% at high load. Self-lubricating Al/SiC/Gr hybrid nanocomposites showed superior surface smoothness compared to matrix alloy.

Review of Microstructure Evolution in Hypereutectic Al–Si Alloys and its Effect on Wear Properties

Abstract: Al–Si alloys with silicon content more than 13 % are termed as hypereutectic alloys. In recent years, these alloys have drawn the attention of researchers due to their ability to replace cast iron parts in the transportation industry. The properties of the hypereutectic alloy are greatly dependent on the morphology, size and distribution of primary silicon crystals in the alloy. Mechanical properties of the hypereutectic Al–Si alloy can be improved by the simultaneous refinement and modification of the primary and eutectic silicon and by controlling the solidification parameters. In this paper, the effect of solidification rate and melt treatment on the evolution of microstructure in hypereutectic Al–Si alloys are reviewed. Different types of primary silicon morphology and the conditions for its nucleation and growth are explained. The paper discusses the effect of refinement/modification treatments on the microstructure and properties of the hypereutectic Al-Si alloy. The importance and effect of processing variables and phosphorus refinement on the silicon morphology and wear properties of the alloy is highlighted.

Determination of Silica Activity Index and XRD, SEM and EDS Studies of Amorphous SiO 2 Extracted from Rice Husk Ash

Abstract: Rice husk ash (RHA) contains 20% SiO2 in hydrated amorphous form (Si–OH). On thermal treatment, the SiO2 converts to cristobalite, the crystalline form which is not reactive. However under controlled conditions, amorphous SiO2 with high reactivity is produced. Therefore rice husk has been one of the useful bio-mass. The silica activity index was determined to be equal to 97.73 which was used to determine the percentage of amorphous SiO2 in RHA. The values of the soluble fraction and silica activity index were also stated. Comparative study of amorphous and crystalline SiO2 done by X-ray diffraction revealed the total amorphous nature of SiO2. The scanning electron microscopy (SEM) images displayed the comparative morphological features of the rice husk and RHA. The energy dispersive spectroscopy analysis of rice husk was done to determine the presence of SiO2 on the upper portion of rice husk and to determine the percentage of SiO2 in RHA. The SiO2 particles in an agglomerated form was found to be of micron size when observed under SEM.

Oxidation of Aluminium Alloy Melts and Inoculation by Oxide Particles

Abstract: One of the main concerns in recycling aluminium alloy scrap is the removal of oxide inclusions. Understanding the nature and behaviour of oxide films in the alloy melts is an important step for developing efficient recycling technologies. In this work, characterisation of oxides formed in pure Al and Al–Mg alloy melts was carried out. In commercially pure Al melt, γ-Al2O3 platelets and α-Al2O3 particles were found to form at 750 and 920 °C, respectively. The oxides were in the form of liquid-like films consisting of numerous individual particles. The addition of 0.49 and 0.70 wt% Mg resulted in the formation of MgAl2O4, and the MgAl2O4 particles were {1 1 1} faceted and had a cube-on-cube orientation relationship with α-Al. The MgAl2O4 films were also liquid-like in which large numbers of the particles were held by the melt. Grain refinement was achieved by intensive shearing of the melts prior to solidification. It is believed that intensive melt shearing broke up the oxide films and dispersed the potent oxide particles which in turn enhanced the heterogeneous nucleation, resulting in grain refinement. The potency of the oxide particles and the mechanism of the inoculation by the oxides were discussed on the basis of the TEM results and theoretical analysis of the lattice misfits at the interfaces along specific orientation relationships.