Milton C. Shaw

Bio: Milton C. Shaw is an academic researcher from Arizona State University. The author has contributed to research in topics: Grinding & Brittleness. The author has an hindex of 19, co-authored 40 publications receiving 3594 citations.

Metal cutting principles

Abstract: Table of Contents Preface Symbols Introduction Typical Cutting Operations Mechanics of Steady State Elastic Behaviour Plastic Behaviour Fracture Dynamometry Shear Strain in Cutting Shear Stress in Cutting Friction Wear and Tool Life Cutting Temperatures Cutting Fields Tool Materials Work Material Considerations Complex Tools Surface Integrity Chip Control Optimisation Modeling of Chip Formation Precision Engineering Unusual Applications of the Metal Cutting Process

The size effect in metal cutting

Abstract: When metal is removed by machining there is substantial increase in the specific energy required with decrease in chip size. It is generally believed this is due to the fact that all metals contain defects (grain boundaries, missing and impurity atoms, etc.), and when the size of the material removed decreases, the probability of encountering a stress-reducing defect decreases. Since the shear stress and strain in metal cutting is unusually high, discontinuous microcracks usually form on the metal-cutting shear plane. If the material being cut is very brittle, or the compressive stress on the shear plane is relatively low, microcracks grow into gross cracks giving rise to discontinuous chip formation. When discontinuous microcracks form on the shear plane they weld and reform as strain proceeds, thus joining the transport of dislocations in accounting for the total slip of the shear plane. In the presence of a contaminant, such as CCI4 vapour at a low cutting speed, the rewelding of microcracks decreases, resulting in decrease in the cutting force required for chip formation. A number of special experiments are described in the paper that support the transport of microcracks across the shear plane, and the important role compressive stress plays on the shear plane. Relatively recently, an alternative explanation for the size effect in cutting was provided based on the premise that shear stress increases with increase in strain rate. When an attempt is made to apply this to metal cutting by Dineshet al (2001) it is assumed in the analysis that the von Mises criterion pertains to the shear plane. This is inconsistent with the experimental findings of Merchant. Until this difficulty is taken care of, together with the promised experimental verification of the strain rate approach, it should be assumed that the strain rate effect may be responsible for some notion of the size effect in metal cutting. However, based on the many experiments discussed here, it is very unlikely that it is totally responsible for the size effect in metal cutting as inferred in Dineshet al (2001).

The Mechanism of Chip Formation with Hard Turning Steel

Abstract: Steels having a hardness of HRC 60 or greater are presently being finished by turning instead of grinding. This is usually done using a polycrystalline cubic boron nitride insert having a rather large nose radius on a very rigid machine at a relatively high cutting speed. In order to understand this process it is important that the sequence of events occurring in the formation of the unique type of chip involved be correctly identified. Experimental evidence to this end is presented and discussed in fundamental terms.

Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and CNC Design

Abstract: Metal cutting is a widely used method of producing manufactured products. The technology of metal cutting has advanced considerably along with new materials, computers, and sensors. This new edition treats the scientific principles of metal cutting and their practical application to manufacturing problems. It begins with metal cutting mechanics, principles of vibration, and experimental modal analysis applied to solving shop floor problems. Notable is the in-depth coverage of chatter vibrations, a problem experienced daily by manufacturing engineers. The essential topics of programming, design, and automation of CNC (computer numerical control) machine tools, NC (numerical control) programming, and CAD/CAM technology are discussed. The text also covers the selection of drive actuators, feedback sensors, modeling and control of feed drives, the design of real time trajectory generation and interpolation algorithms, and CNC-oriented error analysis in detail. Each chapter includes examples drawn from industry, design projects, and homework problems. This book is ideal for advanced undergraduate and graduate students, as well as practicing engineers.

Design optimization of cutting parameters for turning operations based on the Taguchi method

Abstract: In this study, the Taguchi method, a powerful tool to design optimization for quality, is used to find the optimal cutting parameters for turning operations. An orthogonal array, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) are employed to investigate the cutting characteristics of S45C steel bars using tungsten carbide cutting tools. Through this study, not only can the optimal cutting parameters for turning operations be obtained, but also the main cutting parameters that affect the cutting performance in turning operations can be found. Experimental results are provided to confirm the effectiveness of this approach.

Dry Machining and Minimum Quantity Lubrication

Abstract: Modern machining processes face continuous cost pressures and high quality expectations. To remain competitive a company must continually identify cost reduction opportunities in production, exploit economic opportunities, and continuously improve production processes. A key technology that represents cost saving opportunities related to cooling lubrication, and simultaneously improves the overall performance of cutting operations, is dry machining. The elimination of, or significant reduction in, cooling lubricants affects all components of a production system. A detailed analysis and adaptation of cutting parameters, cutting tools, machine tools and the production environment is mandatory to ensure an efficient process and successfully enable dry machining.

Sustainable manufacturing: Modeling and optimization challenges at the product, process and system levels

Abstract: Achieving sustainability in manufacturing requires a holistic view spanning not just the product, and the manufacturing processes involved in its fabrication, but also the entire supply chain, including the manufacturing systems across multiple product life-cycles. This requires improved models, metrics for sustainability evaluation, and optimization techniques at the product, process, and system levels. This paper presents an overview of recent trends and new concepts in the development of sustainable products, processes and systems. In particular, recent trends in developing improved sustainability scoring methods for products and processes, and predictive models and optimization techniques for sustainable manufacturing processes, focusing on dry, near-dry and cryogenic machining as examples, are presented.

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.