Microstructure Induced Shear Instability Criterion During High-Speed Machining of Ti–6Al–4V
01 Oct 2020-Journal of Manufacturing Science and Engineering-transactions of The Asme (American Society of Mechanical Engineers Digital Collection)-Vol. 143, Iss: 6, pp 1-25
TL;DR: In this paper, a microstructure induced shear instability has been investigated using an analytical tool to unveil the deformation behavior in correlation with microstructural characteristics (grain sizes, phase fractions and microhardness) and process parameters; temperature, strain and strain rate.
Abstract:
The microstructure attributes are responsible for the deformation mechanism of material which induces shear instability primarily in difficult-to-machine material like Ti6Al4V. Consequently, the dynamic cutting force yields serrations in the chip morphology. Therefore, microstructure induced shear instability has been investigated in the present work using an analytical tool to unveiled the deformation behaviour in correlation with microstructural characteristics (grain sizes, phase fractions and microhardness) and process parameters; temperature, strain and strain rate. The combined effect of feed rate and high cutting speed was found to enhance the strain localization phenomena, which leads to a more pronounced cracking, inducing dynamic cutting force. Segmentation frequency and force-frequency correlation imply that there is a significant transition exhibit from static to dynamic nature of cutting force. The segmentation frequency of the equiaxed microstructure is lowest among the rest at lower cutting speed, which reveals the shear instability dependency on the microstructure. Grain size effect restricts the dislocation movement at the higher cutting speed which led to a larger strain in as-received microstructure followed by equiaxed and fully lamellar microstructure.
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TL;DR: In this paper, the effect of cutting dynamics on the machining process is discussed and a thorough review on pros and cons of HSMC can help to effectively utilize its advantages and circumvent its shortcomings.
Abstract: The research and application of high speed metal cutting (HSMC) is aimed at achieving higher productivity and improved surface quality. This paper reviews the advancements in HSMC with a focus on the material removal mechanism and machined surface integrity without considering the effect of cutting dynamics on the machining process. In addition, the variation of cutting force and cutting temperature as well as the tool wear behavior during HSMC are summarized. Through comparing with conventional machining (or called as normal speed machining), the advantages of HSMC are elaborated from the aspects of high material removal rate, good finished surface quality (except surface residual stress), low cutting force, and low cutting temperature. Meanwhile, the shortcomings of HSMC are presented from the aspects of high tool wear rate and tensile residual stress on finished surface. The variation of material dynamic properties at high cutting speeds is the underlying mechanism responsible for the transition of chip morphology and material removal mechanism. Less surface defects and lower surface roughness can be obtained at a specific range of high cutting speeds, which depends on the workpiece material and cutting conditions. The thorough review on pros and cons of HSMC can help to effectively utilize its advantages and circumvent its shortcomings. Furthermore, the challenges for advancing and future research directions of HSMC are highlighted. Particularly, to reveal the relationships among inherent attributes of workpiece materials, processing parameters during HSMC, and evolution of machined surface properties will be a potential breakthrough direction. Although the influence of cutting speed on the material removal mechanism and surface integrity has been studied extensively, it still requires more detailed investigations in the future with continuous increase in cutting speed and emergence of new engineering materials in industries.
78 citations
TL;DR: In this article , a novel lubricant has been extracted from mango (Mangifera indica L.) seeds using the soxhlet technique, and the obtained results were compared with edible and non-edible oils, such as sunflower oil (SFO) and mahua seed oil (MaSO) respectively.
Abstract:
In the present work, a novel lubricant has been extracted from mango (Mangifera indica L.) seeds using the soxhlet technique. Lubricants from agricultural waste can reduce the shortage of edible oils and eliminates the need to dispose them. Therefore, non-edible oils are economical comparable with edible oils. In order to validate the effectiveness of extracted lubricant, thermophysical characterization and tribology tests were performed. The obtained results were compared with edible and non-edible oils, such as sunflower oil (SFO) and mahua seed oil (MaSO) respectively. Friction tests were conducted using tribometer with pin-on-disk (WC-Co/Ti-3Al-2.5V) at different tribological conditions. Worn surface and wear mechanism of disks were examined using a scanning electron microscope (SEM) associated with energy-dispersive spectroscopy (EDS) in order to determine the quantitative comparison of elemental composition. These findings showed that mango seed oil (MSO) exhibited lowest coefficient of friction and wear volume followed by dry, SFO, and MaSO respectively. SEM analysis showed that no plowing was observed, however small pits and cracks were found on wear track under MSO.
4 citations
TL;DR: In this article, a novel approach is developed for measuring the resin shrinkage and strain evolution of an epoxy resin (EPON-862) in the composite manufacturing environment, where the resin is cured in a custom designed autoclave with borosilicate viewports, while digital image correlation (DIC) is used to analyze the strain evolution throughout the cure cycle.
Abstract: Cure shrinkage of the polymer matrix during the composite manufacturing process leads to residual stresses, which can adversely affect the structural integrity and dimensional stability of composite structures. In this paper, a novel approach is developed for measuring the resin shrinkage and strain evolution of an epoxy resin (EPON-862) in the composite manufacturing environment. The resin is cured in a custom designed autoclave with borosilicate viewports, while digital image correlation (DIC) is used to analyze the strain evolution throughout the cure cycle. These processing induced strains are correlated to the cure-state using differential scanning calorimetery (DSC). The different mechanisms involved in the polymer strain evolution during composite processing are discussed.
2 citations
TL;DR: In this article , the machinability of SLMed stainless steel 316 L in hard turning processes through comparison with the machining of wrought 316 L parts has been investigated, and the authors have also revealed how cutting depth affects the plastic deformation in machining SLMed 316 L.
1 citations
References
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28 Jan 2005
TL;DR: Peters et al. as discussed by the authors discussed the structure and properties of Titanium and Titanium Aluminides, and proposed a continuous fiber reinforced Titanium matrix composites (C.Leyens, et al.).
Abstract: Foreword.List of Contributors.1. Structure and Properties of Titanium and Titanium Alloys (M. Peters, et al.).2. Beta Titanium Alloys (G. Terlinde and G. Fischer).3. Orthorhombic Titanium Aluminides: Intermetallic with Improved Damage Tolerance (J. Kumpfert and C. Leyens).4. gamma-Titanium Aluminide Alloys: Alloy Design and Properties (F. Appel and M. Oehring).5. Fatigue of Titanium Alloys (L. Wagner and J.K. Bigoney).6. Oxidation and Protection of Titanium Alloys and Titanium Aluminides (C. Leyens).7. Titanium and Titanium Alloys - From Raw material to Semi-finished Products (H. Sibum).8. Fabrication of Titanium Alloys (M. Peters and C. Leyens).9. Investment Casting of Titanium (H.-P. Nicolai and Chr. Liesner).10. Superplastic Forming and Diffusion Bonding of Titanium and Titanium Alloys (W. Beck).11. Forging of Titanium (G. Terlinde, et al.).12. Continuous Fiber Reinforced Titanium matrix Composites: Fabrication, Properties and Applications (C. Leyens, et al.).13. Titanium Alloys for Aerospace Applications (M. Peters, et al.).14. Production, Processing and Application of gamma(TiAl)-Based Alloys (H. Kestler and H. Clemens).15. Non-Aerospace Applications of Titanium and Titanium Alloys (M. Peters and C. Leyens).16. Titanium and its Alloys for Medical Applications (J. Breme, et al.).17. Titanium in Dentistry (J. Lindigkeit).18. Titanium in Automotive Production (O. Schauerte).19. Offshore Applications for Titanium Alloys (L. Lunde and M. Seiersten).Subject Index.
2,278 citations
Book•
15 Mar 1960
TL;DR: In this paper, the authors describe typical cutting operations, including: 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
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
2,229 citations
TL;DR: In this article, the main problems associated with the machining of titanium as well as tool wear and the mechanisms responsible for tool failure are discussed. But no equivalent development has been made for cutting titanium alloys due primarily to their peculiar characteristics.
1,417 citations
15 Mar 1998-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, the relationship between processing, microstructure, and mechanical properties of two-phase (α+β) titanium alloys is summarized and the advantages of a bi-modal (duplex) type of micro-structure usable for most applications are discussed.
Abstract: The present paper tries to summarize the relationship between processing, microstructure, and mechanical properties of two-phase (α+β) titanium alloys. Although for most structural applications of titanium alloys a variety of important mechanical properties (yield stress, ductility, HCF, LCF, da/dN of micro- and macrocracks, KIC, and creep) have to be optimized or balanced, and although both processing as well as microstructure contain many variables, it can be shown that from the numerous correlation possibilities only a few underlying basic principles are really important. One of them is the relationship between cooling rate, colony size, and slip length leading directly to the advantages of a bi-modal (duplex) type of microstructure usable for most applications and involving a reproducible and insensitive processing route.
1,200 citations
TL;DR: An analysis of the chip geometry and the force system found in the case of orthogonal cutting accompanied by a type 2 chip has yielded a collection of useful equations which make possible the study of actual machining operations in terms of basic mechanical quantities as mentioned in this paper.
Abstract: An analysis of the chip geometry and the force system found in the case of orthogonal cutting accompanied by a type 2 chip has yielded a collection of useful equations which make possible the study of actual machining operations in terms of basic mechanical quantities. The shearing strain undergone by the metal during chip formation, and the velocities of shear and of chip flow are among the geometrical quantities which can be quantitatively determined. The force relationships permit calculation of such quantities as the various significant force components, stresses, the coefficient of friction between chip and cutting tool, and the work done in shearing the metal and in overcoming friction on the tool face. The experimental methods by which such analyses can be readily made are described. Observed and calculated values from typical tests are presented.
1,152 citations