V.E. Annamalai

Corrosion of Zirconium and its Alloys

Zirconium alloys are used in nuclear application due to good corrosion resistance, resistance to irradiation damage, adequate mechanical properties and transparency to thermal neutrons. Chemical process industry application arises from excellent resistance to a broad range of corrosives. In this paper, various zirconium alloys are discussed in terms of their physical and mechanical properties, microstructure, chemical properties, and corrosion properties. The effect of manufacturing processes like fabrication, handling, welding, heat treatment, and chemical cleaning etc., on the corrosion behavior of the zirconium alloys is discussed. Different kinds of corrosion of zirconium alloys in various environments are reported.

Corrosion of Titanium and Its Alloys

Titanium alloys are useful for aerospace applications due to their strength to weight ratio. They are useful in biomedical applications due to their biocompatibility and good corrosion resistance. This paper discusses on how these two different properties can be tailored by suitable additives. The effect of additives and the effect of the environment on the corrosion behavior of titanium alloys is discussed. Based on property enhancement, possible applications of titanium and its alloys are reported.

Managing knowledge in a process industry: some experiences and a framework

There are several studies on managing knowledge which focus on either a single approach like establishing a KM network or on a single objective like how to capture tacit knowledge. In reality, in any industry, it is observed that the knowledge creation and response to knowledge absorption vary with various departments, thereby adding complexity to the knowledge management practice. The objective of the present study is to highlight this variation in knowledge needs and to present an integrated approach to manage knowledge towards business gain. Ten major sources of knowledge creation are identified and various approaches of how to harvest knowledge from these sources are presented. The findings form a general practical framework for knowledge management in any industry for business gain.

Fabrication and performance evaluation of dissimilar magnesium–aluminium alloy multi-seam friction stir clad joints

Abstract This investigation is aimed to establish empirical relationships between continuous multi-seam friction stir cladding process parameters (i.e., rotational speed, welding speed and shoulder overlap ratio) and the quality characteristics (bond tensile strength, shear strength and corrosion) of dissimilar magnesium–aluminium alloy clad joints. The influence of considered process parameters on the clad properties was reported. Furthermore, multi-criterion optimization procedure was used to obtain ideal processing conditions, which can yield higher interface strength and lower corrosion rate of fabricated composite plate. Results indicate that, the aluminium-rich thin continuous layer, Mg-rich irregular shaped regions consists of Al3Mg2 and Al12Mg17 intermetallic compounds and nature of mechanical interlocking has great influence on the joint interface strength. On the other hand, the corrosion resistance of the clad joints is greatly affected by the amount of magnesium mixed with top aluminium sheet during friction stirring. Also, bend testing shows that, the cladded joints exhibit excellent ductility.

Enhancing the Properties of Ti6Al4V as a Biomedical Material: A Review

The alloy Ti 6 Al 4 V has evolved as a good biomedical material, by virtue of its bio-compatibility. In order to make implants out of this material, it has to be shaped and processed. Shaping this material by conventional manufacturing methods like machining, welding and brazing presents a huge challenge. This challenge has been met by various approaches like additive manufacturing, surface alloying and heat treatment. Additive manufacturing processes are used for shaping; coatings and surface alloying are used for property improvement; heat treatment is used for improving the machinability. The processing method has an impact on the final properties of the product. This review attempts to trace the development of methods and practices for converting Ti 6 Al 4 V into a useful material for biomedical applications.

Degradation of Glass and Glass Ceramics

Commercial glasses have good resistance to corrosion. Their inherent disadvantage is their low fracture toughness and inability to withstand impact loading. Also there is a limit on the size of object that can be fabricated using glass. This chapter discusses various classifications of glass, their structure–property correlation, and the development of properties. The thermal, chemical, and mechanical properties of vitreous silica and glass ceramics are discussed. Approaches to define durability of glass and several tests to measure durability are covered.

Effect of Aligning Internal Pores in a Grinding Wheel

Any grinding wheel has pores upto 20%. In a grinding situation, when the wheel contacts the workpiece material and grinds, it is literally difficult for the coolant to reach the grinding zone. An attempt is made to create capillary action in the grinding wheel by aligning the pore structure of the wheel and interconnecting the pores-to form a capillary like pore channel. This is done at the grinding wheel fabrication stage at the manufacturers end.

Development of an In-House Test for Nut Integrity in F-Type Wheels

Nut embedded disc grinding wheels, also known as disc grinding or F-Type wheels, are required for many production jobs. Nut pull-out is a common problem encountered in disc grinding wheels. The present work proposes a simple fixture, using which the integrity of the nut in the grinding wheel can be assessed. This method can be adopted by any grinding wheel manufacturer for a realistic estimate of nut pull out strength in double disc grinding wheels.

Optimum Welding Conditions for Dissimilar Spot Friction Joining of Aluminium - Interstitial Free Steel Joints

Design structures made of aluminium alloy and steel are useful to meet the needs of automotive industry such as light weight and higher strength. An effective joining technique to join light weight metals such as aluminium alloys with steel is required. Friction stir spot welding (FSSW) is relatively a new solid state process and it is a derivative of Friction Stir Welding. It creates a spot, lap joint weld without bulk melting. The FSSW parameters such as tool rotational speed, plunge depth, and dwell time plays a major role in determining the strength of the joints and need to be optimized to get quality joints. In this investigation, a central composite rotatable design with three factors and five levels was chosen to minimize the number of experimental conditions. Response surface methodology (RSM) was applied to optimize the FSSW parameters to attain maximum lap shear strength of the spot weld.

A performance simulator for grinding coolant evaluation

Purpose – The purpose of this paper is to simplify the testing of coolants for grinding in the automotive industry.Design/methodology/approach – A simple equipment is developed to test the coolant, by simulating the coolant‐grinding wheel‐workpiece interface and measuring in terms of grinding parameters.Findings – It was found that the simulator could indicate the performance trends that closely match the actual grinding conditions.Research limitations/implications – Since this is a general system, it has to be customised with individual settings of the machining parameters for a meaningful interpretation and for comparison between machines.Practical implications – This equipment will simplify the selection of coolants for grinding and serve as a pre‐qualifier before approving for trials in full‐scale shopfloor conditions.Originality/value – The design of the equipment is new and provides an alternate for the otherwise costly, full‐scale evaluation of coolants on the shopfloor.