About: Tool wear is a(n) research topic. Over the lifetime, 10580 publication(s) have been published within this topic receiving 187761 citation(s). The topic is also known as: wear on cutting tools.
15 Aug 1997-Journal of Materials Processing Technology
Abstract: Although there have been great advances in the development of cutting tool materials which have significantly improved the machinability of a large number of metallic materials, including cast irons, steels and some high temperature alloys such as nickel-based alloys, no equivalent development has been made for cutting titanium alloys due primarily to their peculiar characteristics. This paper reviews the main problems associated with the machining of titanium as well as tool wear and the mechanisms responsible for tool failure. It was found that the straight tungsten carbide (WC/Co) cutting tools continue to maintain their superiority in almost all machining processes of titanium alloys, whilst CVD coated carbides and ceramics have not replaced cemented carbides due to their reactivity with titanium and their relatively low fracture toughness as well as the poor thermal conductivity of most ceramics. This paper also discusses special machining methods, such as rotary cutting and the use of ledge tools, which have shown some success in the machining of titanium alloys.
10 Mar 2003-Journal of Materials Processing Technology
Abstract: Advanced materials such as aeroengine alloys, structural ceramics and hardened steel provide a serious challenge for cutting tool materials during machining due to their unique combinations of properties such as high temperature strength, hardness and chemical wear resistance. Although these properties are desirable design requirements, they pose a greater challenge to manufacturing engineers due to the high temperatures and stresses generated during machining. The poor thermal conductivity of these alloys result in concentration of high temperatures at the tool–workpiece interface. This is worsened at higher cutting conditions because of the significant reduction in the strength and hardness of the cutting tool. This weakens the bonding strength of the tool substrate, thereby accelerating tool wear by mechanical (abrasion and attrition) and thermally related (diffusion and plastic deformation) mechanisms. Therefore, cutting tools used for machining aerospace materials must be able to maintain their hardness and other mechanical properties at higher cutting temperatures encountered in high speed machining. Tool materials with improved hardness like cemented carbides (including coated carbides), ceramics and cubic boron nitride (CBN) are the most frequently used for machining aeroengine alloys. Despite the superior hardness and cutting performance of CBN tools, ceramic tools are generally preferred for high speed continuous machining because of their much lower cost. Improvements in machining productivity can also be achieved with the latest machining techniques such as ramping or taper turning and rotary machining. These techniques often minimise or completely eliminate the predominant notching of the cutting tools, consequently resulting in catastrophic fracture of the entire cutting edge when machining aeroengine alloys.
Abstract: Titanium and nickel alloys represent a significant metal portion of the aircraft structural and engine components. When these critical structural components in aerospace industry are manufactured with the objective to reach high reliability levels, surface integrity is one of the most relevant parameters used for evaluating the quality of finish machined surfaces. The residual stresses and surface alteration (white etch layer and depth of work hardening) induced by machining of titanium alloys and nickel-based alloys are very critical due to safety and sustainability concerns. This review paper provides an overview of machining induced surface integrity in titanium and nickel alloys. There are many different types of surface integrity problems reported in literature, and among these, residual stresses, white layer and work hardening layers, as well as microstructural alterations can be studied in order to improve surface qualities of end products. Many parameters affect the surface quality of workpieces, and cutting speed, feed rate, depth of cut, tool geometry and preparation, tool wear, and workpiece properties are among the most important ones worth to investigate. Experimental and empirical studies as well as analytical and Finite Element modeling based approaches are offered in order to better understand machining induced surface integrity. In the current state-of-the-art however, a comprehensive and systematic modeling approach based on the process physics and applicable to the industrial processes is still missing. It is concluded that further modeling studies are needed to create predictive physics-based models that is in good agreement with reliable experiments, while explaining the effects of many parameters, for machining of titanium alloys and nickel-based alloys.
23 Oct 1996-
Abstract: INTRODUCTION Scope of the Subject Historical Development Types of Production References METAL CUTTING OPERATIONS Introduction Turning Boring Drilling Reaming Milling Planing and Shaping Broaching Tapping and Threading Grinding and Related Abrasive Processes Roller Burnishing Deburring Examples Problems References MACHINE TOOLS Introduction Production Machine Tools CNC Machine Tools and Cellular Manufacturing Systems Machine Tool Structures Slides and Guideways Axis Drives Spindles Coolant Systems Tool Changing Systems Examples References CUTTING TOOLS Introduction Cutting Tool Materials Tool Coatings Basic Types of Cutting Tools Turning Tools Boring Tools Milling Tools Drilling Tools Reamers Threading Tools Grinding Wheels Microsizing and Honing Tools Burnishing Tools Examples Problems References TOOLHOLDERS AND WORKHOLDERS Introduction Toolholding Systems Toolholder/Spindle Connections Cutting Tool Clamping Systems Balancing Requirements for Toolholders Fixtures Examples Problems References MECHANICS OF CUTTING Introduction Measurement of Cutting Forces and Chip Thickness Force Components Empirical Force Models Specific Cutting Power Chip Formation and Primary Plastic Deformation Tool-Chip Friction and Secondary Deformation Shear Plane and Slip Line Theories for Continuous Chip Formation Shear Plane Models for Oblique Cutting Shear Zone Models Minimum Work and Uniqueness Assumptions Finite Element Models Discontinuous Chip Formation Built-up Edge Formation Examples Problems References CUTTING TEMPERATURES Introduction Measurement of Cutting Temperatures Factors Affecting Cutting Temperatures Analytical Models for Steady-State Temperatures Finite Element and Other Numerical Models Temperatures in Interrupted Cutting Temperatures in Drilling Thermal Expansion Examples Problems References MACHINING PROCESS ANALYSIS Introduction Turning Boring Milling Drilling Force Equations and Baseline Data Process Simulation Examples Finite Element Analysis for Clamping, Fixturing, and Workpiece Distortion Applications Finite Element Application Examples Examples Problems References TOOL WEAR AND TOOL LIFE Introduction Types of Tool Wear Measurement of Tool Wear Tool Wear Mechanisms Tool Wear--Material Considerations Tool Life Testing Tool Life Equations Prediction of Tool Wear Rates Tool Fracture and Edge Chipping Drill Wear and Breakage Thermal Cracking and Tool Fracture in Milling Tool Wear Monitoring Examples Problems References SURFACE FINISH AND INTEGRITY Introduction Measurement of Surface Finish Surface Finish in Turning and Boring Surface Finish in Milling Surface Finish in Drilling and Reaming Surface Finish in Grinding Residual Stresses in Machined Surfaces White Layer Formation Surface Burn in Grinding Examples Problems References MACHINABILITY OF MATERIALS Introduction Machinability Criteria, Tests, and Indices Chip Control Burr Formation and Control Machinability of Engineering Materials References MACHINING DYNAMICS Introduction Vibration Analysis Methods Vibration of Discrete (Lumped Mass) Systems Types of Machine Tool Vibration Forced Vibration Self-Excited Vibrations (Chatter) Chatter Prediction Vibration Control Active Vibration Control Examples References MACHINING ECONOMICS AND OPTIMIZATION Introduction Role of a Computerized Optimization System Economic Considerations Optimization of Manufacturing Systems--Basic Factors Optimization of Machining Conditions Formulation of the Optimization Problem Optimization Techniques Numerical Examples Problems References CUTTING FLUIDS Introduction Types of Cutting Fluids Coolant Application Filtering Condition Monitoring and Waste Treatment Health and Safety Concerns Dry and Near-Dry Machining Methods Test Procedure for Cutting Fluid Evaluation References HIGH THROUGHPUT AND AGILE MACHINING Introduction High Throughput Machining Agile Machining Systems Tooling and Fixturing Materials Handling Systems References DESIGN FOR MACHINING Introduction Machining Costs General Design for Machining Rules Special Considerations for Specific Types of Equipment and Operations CAPP and DFM Programs Examples References INDEX
Abstract: In this paper, a concept of delamination factor F d (i.e. the ratio of the maximum diameter D max in the damage zone to the hole diameter D ) is proposed to analyze and compare easily the delamination degree in the drilling of carbon fiber-reinforced plastic (CFRP) composite laminates. Experiments were performed to investigate the variations of cutting forces with or without onset of delamination during the drilling operations. The effects of tool geometry and drilling parameters on cutting force variations in CFRP composite materials drilling were also experimentally examined. The experimental results show that the delamination-free drilling processes may be obtained by the proper selections of tool geometry and drilling parameters. The effects of drilling parameters and tool wear on delamination factor are also presented and discussed. Cutting temperature has long been recognized as an important factor influencing the tool wear rate and tool life. An experimental investigation of flank surface temperatures is also presented in this paper. Experimental results indicated that the flank surface temperatures increase with increasing cutting speed but decreasing feed rate. Optimal cutting conditions are proposed to avoid damage from burning during the drilling processes.