http://nopr.niscpr.res.in/handle/123456789/57647 2026-10-10T09:34:02Z http://nopr.niscpr.res.in/handle/123456789/57663 Title: Retrospective investigation on emergence and development of additive manufacturing Authors: Khan, Shahroz Akhtar; Kumar, Harish; Arora, Pawan Kumar Abstract: The ability to obtained personalized and complex-shaped products with lower cost of development, less energy consumed during manufacturing, less material waste while facilitating in making the products on-demand are the unique benefits associated with additive manufacturing (AM). This work is a review comprising of the details on the early development of AM including key developments over the years, followed by discussion on the advantages offered by AM in relation to the traditional manufacturing methods. The purpose of this work is to help the researchers in the area to have an idea of emergence of the AM technology and gather the information associated since the creation of first three-dimensional (3D) object till the advancement in the field in recent years. Discussion on some recent research developments therefore are made part of this study work in order to clearly have an idea of currently conducted work by the researchers in the development of materials, enhancement of material properties and study of effect of various factors, additives, orientation, machining parameters, etc. on the behavior of additively manufactured material. Page(s): 115-124 2021-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/57660 Title: Experiences from the implementation of last planner system® in construction project Authors: Venkatesh, Prasad Kudrekodlu; Venkatesan, Vasugi Abstract: Lean practices have shown their potential in reducing environmental, economic, and social impacts during the construction phase, with an increase in the parameters of sustainability in the development of projects. Last planner system® (LPS) has gained prominence in recent times for its ability to increase the possibility of timely construction project delivery. However, LPS is yet to gain sufficient confidence from industry for wide spread implementation. The present paper intends to present the benefits, critical success factors, barriers and drawbacks of the LPS with the intent of promoting the applications in industry. An extensive review of literature published over last two decades has been done. The study has identified that improvement in the reliability of planning, visualization of future and planning transparency, reduction in project time as the major benefits, commitment from top management, training of the participants as the critical success factors, resistance to implement LPS, involvement of many parties in the project as the most significant barriers of implementation. The study has also presented the difficulties faced during LPS implementation which if addressed shall be able to improve the process of implementation, translate to project success, and instil confidence in the industry practitioners to implement the system widely. Page(s): 125-141 2021-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/57659 Title: Cu-Cu thermo compression wafer bonding techniques for micro-system integration Authors: Agrawal, Megha; Manohar, Bottumanchi Morish; Nagarajaiah, Kusuma Abstract: Copper (Cu) is used as an interconnect material in many applications owing to its high thermal, electrical conductivity and excellent electromigration resistance. Though this material has many advantages, the main drawback is that it gets oxidized on exposure to air. Thermo-compression bonding is a wafer bonding technique that uses metal layers for heaping wafers, which aids in attaining outstanding electrical conductivity without weakening the mechanical properties. The adsorbed oxide layer hurdles the proper bonding to happen between the wafers. In order to enhance the diffusion between the metal layers, the copper oxide layer should be removed which necessitates the requirement of high temperature, pressure, long bonding time and the inert gas atmosphere throughout the Cu-Cu thermo compression wafer bonding process. Simultaneous application of high temperature and pressure for a long time leads to the deterioration of the underlying sensitive components. This paper aims to present several techniques such as surface treatment, chemical pretreatment, surface passivation, crystal orientation modification, stress gradient in the thin film and formic acid vapour treatment which are used in order to avoid the deterioration of underlying sensitive devices and to obtain a proper bonding between the wafers at low temperature and pressure. Page(s): 142-151 2021-04-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/57657 Title: Influence of cutting conditions in drilling of CFRP/Al stacked composites Authors: Koyyagura, Lakshmi Kala; Karanam, Prahlada Rao Abstract: Composite laminates are gorgeous for several applications such as aerospace and aircraft structural components due to their excellent properties. Typically, mechanical drilling has been important machining operation for components made of composite laminates. Nevertheless, laminated composites are considered as hard-to-machine material which results in low drilling efficiency and drilling-induced delamination which is undesirable. This paper reviews the experiments during drilling of CFRP/Al stacked and sandwich composites. The machinability facets of these material stacks has been generally used in aerospace applications, it has been studied based on impact of drill material, drill geometries, and drilling process parameters such as speed and feed. Composite material requires high spindle speed and low feed rate, whereas drilling aluminum requires stability between speedsto feed rate. The review reports essential results and gap in the collected literature for CFRP/Al stacked and sandwich composites. A compromise between several parameters is required during drilling of multi-material stacks. The problems and solutions allied to drilling of multi-material stacks are deliberated and the directions in which the research on drilling of multi-materials may be carried out are suggested in this paper. It is intended to assist readers to acquire a thorough view on mechanical drilling of laminated composite. Page(s): 152-164 2021-04-01T00:00:00Z