Tool wear monitoring in machining of stainless steel

monitoring systems for automated machines must be capable of operating on-line and interpret the working condition of machining process at a given point in time because it is an automated and unmanned system. But this has posed a challenge that lead to this research study. Generally, optimization of machining process can be categorized as minimization of tool wear, minimization of operating cost, maximization of process output and optimization of machine parameter. Tool wear is a complex phenomenon, capable of reducing surface quality, increases power consumption and increased reflection rate of machined parts. Tool wear has a direct effect on the quality of the surface finish for any given work-piece, dimensional precision and ultimately the cost of parts produced. Tool wear usually occur in combination with the principal wear mode which depends on cutting conditions, tool insert geometry, work piece and tool material. Therefore, there is a need to develop a continuous tool monitoring systems that would notify operator the state of tool to avoid tool failure or undesirable circumstances. Tool wear monitoring system for macro-milling has been studied using design and analysis of experiment (DOE) approach. Regression analysis, analysis of variance (ANOVA), Box Behnken and Response Surface Methodology (RSM). These analysis tools were used to model the tool wear. Hence, further investigations were carried out on the data acquired using signal processing and Neural networks frame work to validate the model. The effects of cutting parameters are evaluated and the optimal cutting conditions are determined. The interaction of cutting parameters is established to illustrate the intrinsic relationship between cutting parameters, tool wear and material removal rate. It was observed that when working with stainless steel 316, a maximum tool wear value of 0.29mm was achieved through optimization at low values of feed about 0.06mm/rev, speed of 4050mm/min and depth of cut about 2mm

Energy: A continuing bibliography with indexes, issue 19

A bibliographical list of 1339 reports, articles, and other documents introduced into the NASA scientific and technical information system from July 1, 1978 through September 30, 1978 are presented

Engineering Principles

Over the last decade, there has been substantial development of welding technologies for joining advanced alloys and composites demanded by the evolving global manufacturing sector. The evolution of these welding technologies has been substantial and finds numerous applications in engineering industries. It is driven by our desire to reverse the impact of climate change and fuel consumption in several vital sectors. This book reviews the most recent developments in welding. It is organized into three sections: “Principles of Welding and Joining Technology,” “Microstructural Evolution and Residual Stress,” and “Applications of Welding and Joining.” Chapters address such topics as stresses in welding, tribology, thin-film metallurgical manufacturing processes, and mechanical manufacturing processes, as well as recent advances in welding and novel applications of these technologies for joining different materials such as titanium, aluminum, and magnesium alloys, ceramics, and plastics

Energy: A continuing bibliography with indexes, issue 32

This bibliography lists 1316 reports, articles, and other documents introduced into the NASA scientific and technical information system from October 1, 1981 through December 31, 1981

Energy: A continuing bibliography with indexes

This bibliography lists 1920 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System from July 1, 1980 through September 30, 1980

Energy: A continuing bibliography with indexes (Issue 29)

This bibliography lists 1360 reports, articles, and other documents introduced into the NASA scientific and technical information system from January 1, 1981 through March 31, 1981

Ultra-high precision machining of rapidly solidified aluminium (RSA) alloys for optics

The advancement of ultra-precision is one of the most adaptable machining processes in the manufacturing of very complex and high-quality surface structures for optics, industrial, medical, aerospace and communication applications. Studies have shown that single-point diamond turning has an outstanding ability to machine high-quality optical components at a nanometric scale. However, in a responsive cutting process, the nanometric machinability of these optical components can easily be affected by several factors. The call for increasing needs of optical systems has recently led to the development of newly modified aluminium grades of non-ferrous alloys characterized by finer microstructures, defined mechanical and physical properties. To date, there has been a lack of sufficient research into these new aluminium alloys. In modern ultra-precision machining, the high demands for smart and inexpensive cutting tools are becoming more relevant in recent precision machines. In monitoring and predicting high-quality surface, cutting forces in single point diamond turning are believed to be as critical as other machining processes due to their potential effects on the quality of surface roughness. Undermining such an important factor is a compromise between the machining process's efficiency and the increased cost of production. Therefore, a comprehensive scientific understanding of the Nano-cutting mechanics is critical, particularly on modelling and analysis of cutting force, surface roughness, chip vii formation, acoustic emission, material removal rates, and molecular dynamic simulation of the rapidly solidified aluminium alloys to bridge the gap between fundamentals and industrial-scale application. The study is divided into three essential sections. First, the development of a force sensor. Secondly, investigation of the effect of cutting parameters (i.e., cutting speed, feed rate, and cutting depth) on cutting force, acoustic emission (AE), material removal rate (MRR), chip formation, Nose radius, and surface roughness (Ra), which play a leading role in the determination of machine productivity and efficiency of single-point diamond turning of rapidly solidified aluminium alloys. Thirdly, a 3-D molecular dynamic (MD) simulation of RSA 6061 is also carried out to further understand the nanometric mechanism and characterization of the alloy. The experiment was mainly conducted using Precitech Nanoform ultra-grind 250 lathe machines on three different advanced optical aluminium alloys materials; these are RSA 443, RSA 905, and RSA 6061.Thesis (PhD) -- Faculty of Engineering, the Built Environment and Information Technology, School of Engineering, 202

Ultra-high precision machining of rapidly solidified aluminium (RSA) alloys for optics

The advancement of ultra-precision is one of the most adaptable machining processes in the manufacturing of very complex and high-quality surface structures for optics, industrial, medical, aerospace and communication applications. Studies have shown that single-point diamond turning has an outstanding ability to machine high-quality optical components at a nanometric scale. However, in a responsive cutting process, the nanometric machinability of these optical components can easily be affected by several factors. The call for increasing needs of optical systems has recently led to the development of newly modified aluminium grades of non-ferrous alloys characterized by finer microstructures, defined mechanical and physical properties. To date, there has been a lack of sufficient research into these new aluminium alloys. In modern ultra-precision machining, the high demands for smart and inexpensive cutting tools are becoming more relevant in recent precision machines. In monitoring and predicting high-quality surface, cutting forces in single point diamond turning are believed to be as critical as other machining processes due to their potential effects on the quality of surface roughness. Undermining such an important factor is a compromise between the machining process's efficiency and the increased cost of production. Therefore, a comprehensive scientific understanding of the Nano-cutting mechanics is critical, particularly on modelling and analysis of cutting force, surface roughness, chip vii formation, acoustic emission, material removal rates, and molecular dynamic simulation of the rapidly solidified aluminium alloys to bridge the gap between fundamentals and industrial-scale application. The study is divided into three essential sections. First, the development of a force sensor. Secondly, investigation of the effect of cutting parameters (i.e., cutting speed, feed rate, and cutting depth) on cutting force, acoustic emission (AE), material removal rate (MRR), chip formation, Nose radius, and surface roughness (Ra), which play a leading role in the determination of machine productivity and efficiency of single-point diamond turning of rapidly solidified aluminium alloys. Thirdly, a 3-D molecular dynamic (MD) simulation of RSA 6061 is also carried out to further understand the nanometric mechanism and characterization of the alloy. The experiment was mainly conducted using Precitech Nanoform ultra-grind 250 lathe machines on three different advanced optical aluminium alloys materials; these are RSA 443, RSA 905, and RSA 6061.Thesis (PhD) -- Faculty of Engineering, the Built Environment and Information Technology, School of Engineering, 202

Mortars in old buildings and masonry conservation: a historical and practical treatise

This thesis examines the subject of mortar, with the aim of presenting information that will assist in the repair of historic masonry structures. A historical examination of two primary mortar ingredients, lime and cement, together with a discussion of other ingredients, establishes a basis for further scientific study. Analysis of observed case studies yields hypotheses on mortar behavior. A survey of published literature discloses much information about creep, a vital element of mortar behavior. However, because in most of the previous research the creep measurements were made on brickwork or blockwork piers, an experimental program was devised, to measure the shrinkage and creep in mortars alone, using a range of seven mortar mixes. Some of the findings of D. Lenczner and A. M. Neville have been confirmed, and considerable additional information concerning creep and shrinkage in mortars has been obtained. Results indicate that-the, quantity of, lime in a mortar is related to shrinkage and creep «*the richer the mortar is in lime, the higher the values for creep and the lower the values for shrinkage. The laboratory data can aid in the future selection of the proper mortar for repairs to masonry buildings

Energy, a continuing bibliography with indexes. Issue 33

This bibliography lists 1211 reports, articles, and other documents introduced into the NASA scientific and technical information system from January 1, 1981 through March 31, 1981