P. S. Sreejith

Bio: P. S. Sreejith is an academic researcher from Cochin University of Science and Technology. The author has contributed to research in topics: Machining & Tool wear. The author has an hindex of 11, co-authored 25 publications receiving 1244 citations. Previous affiliations of P. S. Sreejith include Indian Institute of Technology Madras & Nanyang Technological University.

Turning of Brasses Using Minimum Quantity of Lubricant (MQL) and Flooded Lubricant Conditions

Abstract: A lot of effort is being carried out to reduce the use of lubricants in metal machining operations from the viewpoint of cost, ecology and human health issues. Minimal quantity lubrication (MQL) is...

Material removal mechanisms in precision machining of new materials

Abstract: Modern-day products are characterised by high-precision components. A wide range of materials, including metals and their alloys, ceramics, glasses and semiconductors, are finished to a given geometry, finish, accuracy and surface integrity to meet the service requirements. For advanced technology systems, demands for higher fabrication precision are complicated by the use of brittle materials. For efficient and economical machining of these materials, an understanding of the material removal mechanism is essential. This paper focuses on the different material removal mechanisms involved in machining of brittle materials.

Magnesium and its alloys applications in automotive industry

Abstract: The objective of this study is to review and evaluate the applications of magnesium in the automotive industry that can significantly contribute to greater fuel economy and environmental conservation. In the study, the current advantages, limitations, technological barriers and future prospects of Mg alloys in the automotive industry are given. The usage of magnesium in automotive applications is also assessed for the impact on environmental conservation. Recent developments in coating and alloying of Mg improved the creep and corrosion resistance properties of magnesium alloys for elevated temperature and corrosive environments. The results of the study conclude that reasonable prices and improved properties of Mg and its alloys will lead to massive use of magnesium. Compared to using alternative materials, using Mg alloys results in a 22% to 70% weight reduction. Lastly, the use of magnesium in automotive components is increasing as knowledge of forming processes of Mg alloys increases.

Environmentally conscious machining of difficult-to-machine materials with regard to cutting fluids

Abstract: Machining difficult-to-machine materials such as alloys used in aerospace, nuclear and medical industries are usually accompanied with low productivity, poor surface quality and short tool life. Despite the broad use of the term difficult-to-machine or hard-to-cut materials, the area of these types of materials and their properties are not clear yet. On the other hand, using cutting fluids is a common technique for improving machinability and has been acknowledged since early 20th. However, the environmental and health hazards associated with the use of conventional cutting fluids together with developing governmental regulations have resulted in increasing machining costs. The aim of this paper is to review and identify the materials known as difficult-to-machine and their properties. In addition, different cutting fluids are reviewed and major health and environmental concerns about their usage in material cutting industries are defined. Finally, advances in reducing and/or eliminating the use of conventional cutting fluids are reviewed and discussed.

An Environmental Analysis of Machining

Abstract: This paper presents a system-level environmental analysis of machining. The analysis presented here considers not only the environmental impact of the material removal process itself, but also the impact of associated processes such as material preparation and cutting fluid preparation. This larger system view results in a more complete assessment of machining. Energy analyses show that the energy requirements of actual material removal can be quite small when compared to the total energy associated with machine tool operation. Also, depending on the energy intensity of the materials being machined, the energy of material production can, in some cases, far exceed the energy required for machine tool operation.Copyright © 2004 by ASME

Cooling techniques for improved productivity in turning

Abstract: The past century has witnessed significant advancements in turning process, cutting tools, machine controls and coolant/lubricant chemistry. These developments have particularly enhanced the machining of difficult-to-cut materials, which are used for aerospace, steam turbine, bearing industry, nuclear and automotive applications. In turning operation, friction and heat generation at the cutting zone are the frequent problems, which affect the tool life and surface finish apart from other machining results. This mechanism of heat generation plays quite a negative role during the turning of modern materials due to their peculiar characteristics such as poor thermal conductivity, high strength at elevated temperature, resistance to wear and chemical degradation. A good understanding of the methods of lubrication/cooling at the cutting zone, reduction of heat generation will lead to efficient and economic machining of these modern materials. This paper presents an overview of major advances in techniques as minimum quantity lubrication (MQL)/near dry machining (NDM), high pressure coolant (HPC), cryogenic cooling, compressed air cooling and use of solid lubricants/coolants. These techniques have resulted in reduction in friction and heat at the cutting zone, hence improved productivity of the process. A brief survey of modeling/FEA techniques is also performed.