Vibration Assisted Machining

Theory, Modelling and Applications

Lu Zheng, Wanqun Chen, Dehong Huo

• Publisher: Wiley-ASME Press Series
• Year: 2021
• Print ISBN: 9781119506355
• eBook ISBN: 9781119506362
• Edition: 1
• Topic: Physical Sciences
• Subtopic: Mechanics

The first book to comprehensively address the theory, kinematic modelling, numerical simulation and applications of vibration assisted machining

Vibration Assisted Machining: Theory, Modelling and Applications covers all key aspects of vibration assisted machining, including cutting kinematics and dynamics, the effect of workpiece materials and wear of cutting tools. It also addresses practical applications for these techniques. Case studies provide detailed guidance on the design, modeling and testing of VAM systems. Experimental machining methods are also included, alongside considerations of state-of-the-art research developments on cutting force modeling and surface texture generation.

Advances in computational modelling, surface metrology and manufacturing science over the past few decades have led to tremendous benefits for industry. This is the first comprehensive book dedicated to design, modelling, simulation and integration of vibration assisted machining system and processes, enabling wider industrial application of the technology. This book enables engineering students and professionals in manufacturing to understand and implement the latest vibration assisted machining techniques. Highlights include:

• Comprehensive coverage of the theory, kinematics modelling, numerical simulation and applications of vibration assisted machining (VAM)
• Case studies with detailed guidance on design, modelling and testing of VAM systems, as well as experimental machining methods
• Discussion of state-of-the-art research developments on cutting force modelling and surface texture generation
• Coverage of the history of VAM, its current applications and future directions for the technology

Vibration Assisted Machining: Theory, Modelling and Applications provides engineering students, researchers, manufacturing engineers, production supervisors, tooling engineers, planning and application engineers and machine tool designers with the fundamentals of vibration assisted machining, along with methodologies for developing and implementing the technology to solve practical industry problems.

1
Introduction to Vibration‐Assisted Machining Technology

1.1 Overview of Vibration‐Assisted Machining Technology

1.1.1 Background

Precision components are increasingly in demand in various engineering fields such as microelectromechanical systems (MEMS), electro‐optics, aerospace, automotive, biomedical engineering, and internet and communication technology (ICT) hardware. In addition to the aims of achieving tight tolerances and high‐quality surface finishes, many applications also require the use of hard and brittle materials such as optical glass and technical ceramics owing to their superior physical, mechanical, optical, and electronic properties. However, because of their high hardness and usually low fracture toughness, the processing and fabrication of these hard‐to‐machine materials have always been challenging. Furthermore, the delicate heat treatment required and composite materials in aeronautic or aerospace alloys have caused similar difficulties for precision machining.

It has been reported that excessive tool wear and fracture damage are the main failure modes during the processing of such materials, leading to low surface quality and machining accuracy. Efforts to optimize a conventional machining process to achieve better cutting performance with these materials have never been stopped, and these optimizations include the cutting parameters, tool materials and geometry, and cutting cooling systems in the past decades [1–6]. Generally, harder materials or wear‐resistant coatings are applied, and tool geometry is optimized to prevent tool cracking and to reduce wear on wearable positions such as the flank face [5, 7–10]. Cryogenic coolants are used in the machining process, and their input pressure has been optimized to achieve better cooling performance [2, 4, 11]. However, although cutting performance can be improved, the results are often still unsatisfactory.

Efforts to enhance machining performance have revealed that machining quality can be improved using the high‐frequency vibration of the tool or workpiece. Vibration‐assisted machining (VAM) was first introduced in the late 1950s and has been applied in various machining processes, including both traditional machining (turning, drilling, grinding, and more recently milling) and nontraditional machining (laser machining, electro‐discharge machining, and electrochemical machining), and it is now widely used in the precision manufacturing of components made of various materials. VAM adds external energy to the conventional machining process and generate high‐frequency, low‐amplitude vibration in the tool or workpiece, through which a periodic separation between the uncut workpiece and the tool can be achieved. This can decrease the average machining forces and generate thinner chips, which in turn leads to high processing efficiency, longer tool life, better surface quality and form accuracy, and reduced burr generation [12–17]. Moreover, when hard and brittle materials such as titanium alloy, ceramic, and optical glass are involved, the cutting depth in the ductile regime cutting mode can be increased [18]. As a result, the cutting performance can be improved and unnecessary post‐processing can be avoided, which allows the production of components with more complex shape features [14]. Nevertheless, there are still many opportunities for technological improvement, and ample scope exists for better scientific understanding and exploration.

VAM may be classified in two ways. The first classification is according to the dimensions in which vibration occurs: 1D, 2D, or 3D VAM. The other classification is based on the vibration frequency range, for example, in ultrasonic VAM and non‐ultrasonic VAM. Ultrasonic VAM is the most common type of VAM. It works at a high vibration frequency (usually above 20 kHz), and a resonance vibration device maintains the desired vibration amplitude. Most of its applications are concentrated in the machining of hard and brittle materials because of the fact that high vibration frequency dramatically improves the cutting performance of difficult‐to‐machine materials. Meanwhile non‐ultrasonic VAM uses a mechanical linkage to transmit power to make the device expand and contract, and this can obtain lower but variable vibration frequencies (usually less than 10 kHz). It is easier to achieve closed‐loop control because of the low range of operating frequency, which makes it uniquely advantageous in applications such as the generation of textured surface.

1.1.2 History and Development of Vibration‐Assisted Machining

The history of vibration technology in VAM can be traced back to the 1940s. During the period of World War II, the high demand for the electrically controlled four‐way spool valves mainly used in the control of aircraft and gunnery circuits stimulated the development of servo valve technology [19]. Because of their wide frequency response and high flow capacity, electrohydraulic vibrators were successfully developed and applied in VAM in the 1960s with positive effects in enhanced processing quality and efficiency [20]. With the further development of technology, electromagnetic vibrators featuring higher accuracy and a wide range of frequency and amplitude generation were developed based on electromagnetic technology, and these were successfully applied to various VAM processes [21]. The need for complex hydraulic lines was eliminated, and greater tolerance for the application environment was allowed, which also leads to smaller devices. As a result, a transmission line or connecting body can be attached to the vibrator to achieve a wide range of vibration frequencies and amplitude adjustments [22]. In the 1980s, the maturity of piezoelectric transducer (PZT) piezoelectric ceramic technology had brought a new choice for the vibrator. A piezoelectric ceramic stack could be sandwiched under compressive strain between metal plates, and this has advantages including compactness, high precision and resolution, high frequency response, and large output force [23]. Various shapes of piezoelectric ceramic elements can be used to make different types of vibration actuators, which indicate that the limitations of traditional vibrators were overcome and the application of VAM technology for precision machining was broadened. In addition, it helped in the development of multidimensional VAM equipment. Elliptical VAM has received extensive attention since it was first proposed in the 1990s. Although this process has many advantages compared to its 1D counterpart in terms of reductions in cutting force and prolongation of tool life, it requires higher performance in the vibrator, producing a more accurate tool tip trajectory [24–28]. Piezoelectric actuators with high sensitivity can fulfill the requirements of vibration devices and promote the development of elliptical VAM technology.

1.2 Vibration‐Assisted Machining Process

This section briefly introduces commonly used VAM processes, including milling, drilling, turning, grinding, and polishing. Different vibration device layouts are required to implement these vibration‐assisted processes and to achieve advantages over the corresponding conventional machining processes.

1.2.1 Vibration‐Assisted Milling

Milling is one of the most common machining processes and is capable of fabricating parts with complex 3D geometry. However, uncontrollable vibration problems during the cutting process are quite serious and can affect processing stability, especially in the micro‐milling process, leading to excessive tolerance, increased surface roughness, and higher cost. Vibration‐assisted millin...

Table of contents

• Cover
• Table of Contents
• Preface
• 1 Introduction to Vibration‐Assisted Machining Technology
• 2 Review of Vibration Systems
• 3 Vibration System Design and Implementation
• 4 Kinematics Analysis of Vibration‐Assisted Machining
• 5 Tool Wear and Burr Formation Analysis in Vibration‐Assisted Machining
• 6 Modeling of Cutting Force in Vibration‐Assisted Machining
• 7 Finite Element Modeling and Analysis of Vibration‐Assisted Machining
• 8 Surface Topography Simulation Technology for Vibration‐Assisted Machining
• Index
• End User License Agreement