I.S. Jawahir

Present Situation and Future Trends in Modelling of Machining Operations Progress Report of the CIRP Working Group ‘Modelling of Machining Operations’

Abstract In 1995 CIRP STC “Cutting” started a working group “Modelling of Machining Operations” with the aim of stimulating the development of models capable of predicting quantitatively the performance of metal cutting operations which will be better adapted to the needs of the metal cutting industry in the future. This paper has the character of a progress report. It presents the aims of the working group and the results obtained up to now. The aim is not to review extensively what has been done in the past. It is basically a critical assessment of the present state-of-the-art of the wide and complex field of modelling and simulation of metal cutting operations based on information obtained from the members of the working group, from consultation in industry, study of relevant literature and discussions at meetings of the working group whit the aim to stimulate and pilot future developments. For this purpose much attention is given to a discussion of desirable and possible future developments and planned new activities.

Recent Developments in Chip Control Research and Applications

Summary During the 1990 CIRP General Assembly in Berlin a working group on Chip Control was formed within the STC -“Cutting”, with a view to evaluating and sharing the present knowledge on chip formation and chip control and promoting new research in this area. To date, about 40 researchers have made more than 60 contributions at six chip control working group meetings. Among these presentations, several contributions really provided fresh insights dealing with new and innovative research methods. The working group also provided a framework for international cooperative work, enabling exchange of information and coordinated research collaboration. The group placed a greater emphasis on the practical value of knowledge on chip control for industrial applications. This paper presents the major results of this cooperative work covering modeling of the chip formation process for chip flow; curl and breaking; means of chip breaking, including experimental as well as the knowledge-based systems approach; and a summary of future directions in research and applications.

A Review of Engineering Research in Sustainable Manufacturing

Karl R. Haapala 1 School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, 204 Rogers Hall, Corvallis, OR 97331 e-mail: Karl.Haapala@oregonstate.edu Fu Zhao School of Mechanical Engineering, Division of Environmental and Ecological Engineering, Purdue University, 585 Purdue Mall, West Lafayette, IN 47907 e-mail: fzhao@purdue.edu Jaime Camelio Department of Industrial and Systems Engineering, Virginia Polytechnic Institute and State University, 235 Durham Hall, Blacksburg, VA 24061 e-mail: jcamelio@vt.edu John W. Sutherland Division of Environmental and Ecological Engineering, Purdue University, 322 Potter Engineering Center, West Lafayette, IN 47907 e-mail: jwsuther@purdue.edu Steven J. Skerlos Department of Mechanical Engineering, University of Michigan, 2250 GG Brown Building, Ann Arbor, MI 48105 e-mail: skerlos@umich.edu David A. Dornfeld Department of Mechanical Engineering, University of California, 6143 Etcheverry Hall, Berkeley, CA 94720 e-mail: dornfeld@berkeley.edu I. S. Jawahir Department of Mechanical Engineering, University of Kentucky, 414C UK Center for Manufacturing, Lexington, KY 40506 e-mail: jawahir@engr.uky.edu A Review of Engineering Research in Sustainable Manufacturing Sustainable manufacturing requires simultaneous consideration of economic, environmen- tal, and social implications associated with the production and delivery of goods. Funda- mentally, sustainable manufacturing relies on descriptive metrics, advanced decision- making, and public policy for implementation, evaluation, and feedback. In this paper, recent research into concepts, methods, and tools for sustainable manufacturing is explored. At the manufacturing process level, engineering research has addressed issues related to planning, development, analysis, and improvement of processes. At a manufac- turing systems level, engineering research has addressed challenges relating to facility operation, production planning and scheduling, and supply chain design. Though economi- cally vital, manufacturing processes and systems have retained the negative image of being inefficient, polluting, and dangerous. Industrial and academic researchers are re- imagining manufacturing as a source of innovation to meet society’s future needs by under- taking strategic activities focused on sustainable processes and systems. Despite recent developments in decision making and process- and systems-level research, many chal- lenges and opportunities remain. Several of these challenges relevant to manufacturing process and system research, development, implementation, and education are highlighted. [DOI: 10.1115/1.4024040] Andres F. Clarens Department of Civil and Environmental Engineering, University of Virginia, D220 Thornton Hall, Charlottesville, VA 22904 e-mail: aclarens@virginia.edu Jeremy L. Rickli Department of Industrial and Systems Engineering, Virginia Polytechnic Institute and State University, 217 Durham Hall, Blacksburg, VA 24061 e-mail: jlrickli@vt.edu Corresponding author. Contributed by the Manufacturing Engineering Division of ASME for publication in the J OURNAL OF M ANUFACTURING S CIENCE AND E NGINEERING . Manuscript received July 11, 2012; final manuscript received March 4, 2013; published online July 17, 2013. Editor: Y. Lawrence Yao. Manufacturing and Sustainability The concept of sustainability emerged from a series of meetings and reports in the 1970s and 1980s, and was largely motivated by environmental incidents and disasters as well as fears about Journal of Manufacturing Science and Engineering C 2013 by ASME Copyright V AUGUST 2013, Vol. 135 / 041013-1 Downloaded From: http://manufacturingscience.asmedigitalcollection.asme.org/ on 07/09/2014 Terms of Use: http://asme.org/terms

Tool-wear mechanisms in hard turning with polycrystalline cubic boron nitride tools

Hard turning is a turning operation performed on high strength alloy steels (45 < HRC < 65) in order to reach surface roughness close to those obtained in grinding (R ∼ 0.1 μm). Extensive research being conducted on hard turning has so far addressed several fundamental questions concerning chip formation mechanisms, tool-wear, surface integrity and geometric accuracy of the machined components. The major consideration for the user of this relatively newer technology is the quality of the parts produced. A notable observation from this research is that flank wear of the cutting tool has a large impact on the quality of the machined parts (surface finish, geometric accuracy and surface integrity). For components with surface, dimensional and geometric requirements (e.g. bearing surfaces), hard turning technology is often not economical compared with grinding because tool-life is limited by the tolerances required (i.e. high flank wear rate). The aim of this paper is to present the various modes of wear and damage of the polycrystalline cubic boron nitrides (PCBN) cutting tool under different loading conditions, in order to establish a reliable wear modeling. Flank wear has a large impact on the quality of the parts produced and the wear mechanisms have to be understood to improve the performance of the tool material, namely by reducing the flank wear rate. The wear mechanisms depend not only on the chemical composition of the PCBN, and the nature of the binder phase, but also on the hardness value and above all on the microstructure (percentage of martensite, type, size, composition of the hard phases, etc.) of the machining work material. The proposed modeling is in a generalized form of the extended Taylors law allowing to prediction of the tool-life as a function of the cutting parameters and of the workpiece hardness The effects of these factors on tool-wear, tool-life and cutting forces are discussed in the paper.

SURFACE INTEGRITY CHARACTERIZATION AND PREDICTION IN MACHINING OF HARDENED AND DIFFICULT-TO-MACHINE ALLOYS: A STATE-OF-ART RESEARCH REVIEW AND ANALYSIS

This paper presents a review of the state-of-art research on surface integrity characterization, especially the characteristics of residual stresses produced in machining of hardened steels, titanium and nickel-based superalloys using the geometrically defined tools. The interrelationships among residual stresses, microstructures, and tool-wear have been discussed. Current research on residual stress modeling and simulation using finite element method has been critically assessed. Also, the rationale for developing multi-scale simulation models for predicting residual stresses in machining has been presented. At the end, possible future work has been proposed.

A universal slip-line model with non-unique solutions for machining with curled chip formation and a restricted contact tool

Abstract A universal slip-line model and the corresponding hodograph for two-dimensional machining which can account for chip curl and chip back-flow when machining with a restricted contact tool are presented in this paper. Six major slip-line models previously developed for machining are briefly reviewed. It is shown that all the six models are special cases of the universal slip-line model presented in this paper. Dewhurst and Collinss matrix technique for numerically solving slip-line problems is employed in the mathematical modeling of the universal slip-line field. A key equation is given to determine the shape of the initial slip-line. A non-unique solution for machining processes when using restricted contact tools is obtained. The influence of four major input parameters, i.e. (a) hydrostatic pressure (PA) at a point on the intersection line of the shear plane and the work surface to be machined; (b) ratio of the frictional shear stress on the tool rake face to the material shear yield stress (τ/k); (c) ratio of the undeformed chip thickness to the length of the tool land (t1/h); and (d) tool primary rake angle (γ1), upon five major output parameters, i.e. (a) four slip-line field angles ( θ, η 1 , η 2 , ψ ); (b) non-dimensionalized cutting forces (Fc/kt1w and Ft/kt1w); (c) chip thickness (t2); (d) chip up-curl radius (Ru); and (e) chip back-flow angle (ηb), is theoretically established. The issue of the “built-up-edge” produced under certain conditions in machining processes is also studied. It is hoped that the research work of this paper will help in the understanding of the nature and the basic characteristics of machining processes.

Predicting total machining performance in finish turning using integrated fuzzy-set models of the machinability parameters

Abstract Due to the numerous interacting machining variables involved in finish turning, it is extremely difficult to assess the total machining performance (TMP) encompassing surface finish, tool-wear rate, dimensional accuracy, cutting power and chip breakability. This paper presents the development of a new methodology for assessing each aspect of the TMP in finish turning of steels as follows. First, a machining reference database is established from the representative machining experiments to provide a primary quantitative standard. Second, a knowledge poo) is developed based on the extended experiments and the present knowledge of the major influencing factors on the TMP. Then, a fuzzy-set method is introduced to quantify the effects of these factors. Finally, a series of fuzzy-set models are developed to give quantitative assessments of the TMP for any given set of input conditions, including work material properties, tool geometries, chip-breaker types and cutting conditions.

Extending total life-cycle thinking to sustainable supply chain design

Conventional supply chain management (SCM) practices have focused only on three life-cycle stages: pre-manufacturing, manufacturing and use. The fourth stage, post-use, probably the most important from a sustainability perspective, is often addressed on a piece-meal basis, only when such practices deliver economic benefits. This paper introduces a total life-cycle-based approach to sustainable SCM (SSCM) that extends beyond the 3Rs of reduce, reuse and recycle to 6Rs that includes recover, redesign and remanufacture. A new definition for SSCM that adopts the total life-cycle approach and triple bottom-line (TBL) is presented. Two existing supply chain frameworks: supply chain operations reference (SCOR) model and the global supply chain forum (GSCF) framework, are evaluated in the context of SSCM to improve economic growth while ensuring environmental protection and societal well-being. The review finds that neither framework explicitly captures the non-economic aspects of SSCM, but the broader view of the GSCF framework offers much promise.

The Tool Restricted Contact Effect as a Major Influencing Factor in Chip Breaking: An Experimental Analysis

Summary Chip breaking performances of six commercially available chip forming tool inserts have been assessed. The tool restricted contact effect determining the chip streaming (i.e. chip backflow) has been found to be a major influencing factor in chip breaking. No commercial chip former fully utilises the restricted contact effect. Chip up and side curling mechanisms have been investigated. Deforming the chip laterally across the chip-section contributes to the chip breaking. Commercial chip formers have been found to lie in an intermediary level between flat-faced conventional tools and restricted contact tools in terms of cutting power consumed.

The influence of the microstructure of hardened tool steel workpiece on the wear of PCBN cutting tools

Abstract Due to the recent developments of advanced cutting tool materials in the superbarasive family, such as cubic boron nitride (CBN) tools, the interest in cutting hardened steels has increased significantly. High flexibility and ability to manufacture complex workpiece geometry in one set up is the main advantage of hard turning compared to grinding. The focus of this study is to investigate the performance and wear behavior of CBN tools in finish, dry turning of four different hardened steels, treated to the same hardness Rc = 54. The following four materials were machined: X155CrMoV 12 cold work steel (AISI D2), X38CrMoV5 (AISI H11) hot work steel, 35NiCrMo16 hot work steel and 100Cr6 bearing steel (AISI 52100). A large variation in tool wear rate was observed in the machining of these steels. The tool flank grooves have been correlated to the microstructure of these steels, namely the presence of various carbides. The chip study reveals that there is presence of different amounts of white layers in machining these steels.