Search Results for tool force

Fundamental to the machining process, is the metal-cutting operation, which involves extensive plastic deformation of the work piece ahead of the tool tip, high temperatures, and severe frictional conditions at the interfaces of the tool, chip, and work piece. This article explains that the basic mechanism of chip formation is shear deformation, which is controlled by work material properties such as yield strength, shear strength, friction behavior, hardness, and ductility. It describes various chip types, as well as the cutting parameters that influence chip formation. It also demonstrates how the service life of cutting tools is determined by a number of wear processes, including tool wear, machining parameters, and tool force and power requirements. It concludes by presenting a comprehensive collection of formulas for turning, milling, drilling, and broaching, and its average unit power requirement.

Probability of detection (POD) assesses the performance of a non-destructive evaluation (NDE)-based inspection, which is a method used to determine the capability of an inspection as a function of defect type and defect size. This article provides an overview of the concept of POD, why it is needed, the history behind the development of POD, how POD assessments are performed, and how modeling and simulation can be integrated into the execution of a POD assessment. It describes the methods by which POD is determined. This includes detail on the experimental process to acquire the needed data, the mathematical methods to obtain a POD curve, and techniques to assess uncertainty in the POD curve as it is obtained from a limited data set. The concept of model-assisted POD (MAPOD) is introduced, with additional details and representative examples of MAPOD.

Machining of cast iron involves removing metal from the cast part, usually by cutting with a power-driven machine tool. This article discusses the factors that influence machinability, the methods used to evaluate machinability of cast irons, the effects of cast iron microstructure on cutting tool life, and the importance of as-cast surface integrity on the machining variation. It presents examples of cutting tool materials selection for different cast iron grades, and describes the effects of coolants on the machining of cast irons. A chart showing different cutting materials and cutting speed ranges for selected iron-carbon alloys is also presented. Different types of cutting tool wear observed during turning are schematically illustrated.

Many shearing, blanking, and piercing operations are based on the same underlying principles of shear mechanisms. This article provides information on the various operations associated with die cutting and describes three phases involved in the shear cutting or punching action. These phases include deformation, penetration and fracture. The article also explains the effect of clearance on tool life and force and power requirements. It reviews the forces involved in the punching process and describes the diameter of a hole or blank in relation to material thickness. The limitations of punching are also discussed. The article describes the relationship of the die clearance to stress-strain curves and explains the procedure of interpreting the stress-strain curves. The article concludes with information on the dynamic stripping forces in blanking.

This article describes friction force as a function of normal force in dry forming. It focuses on metal forming operations usually classified as cold working and hot working based on metallurgical considerations. The article discusses surface flattening and roughening of workpiece asperities in metal forming. It presents advanced tribology models and results for friction in isothermal forging operations in which the tooling is maintained at a temperature close to that of the workpiece. The article provides information on heat transfer models. It discusses the effect of wear in manufacturing processes. The article concludes with information on the main categories of tool and die materials used for a variety of manufacturing application.

The designer of die casting tooling must balance the functional requirements of the part being cast with the cost, speed, and quality requirements of the process. In addition, attention must also be paid to the capacity and operating parameters of the casting machines being used and the need and economics of postprocessing. This article examines how design and materials selection address these diverse requirements of conventional die casting tooling. It focuses on the tooling for high-volume processes where the liquid or semisolid metal is forced into the die with high pressure and speed. The article also describes the functions of the tooling which involves supplying of molten alloy to the casting machine and injecting it into the die.

This article discusses the installation of the most commonly used force-monitoring devices, namely, load cells and piezoelectric force sensors. It describes the purpose and operation of commonly used displacement sensors, such as linear variable differential transformers, proximity sensors, photoelectric sensors, and ultrasonic sensors. The article provides information on the sensors used for detecting tool breakages and flaws in parts, the measurement of material flow during sheet metal forming, and lubrication. It also describes the operating stages of machine vision systems used for automated quality-control purposes. The theory of eddy-current-based material properties evaluation is also discussed.

Machining tribology poses a significant challenge due to the multiple parameters that must be simultaneously considered to arrive at a cost-minimized solution in production. This article provides information required to make informed decisions about machining parameters. It describes the relationships between machining parameters, workpiece material properties, cutting forces, and the corresponding temperature field in the chip. The article provides information on tool life, with an empirical model, common wear features, and the relationship between tool life and machining cost. The cutting fluids and their effect on tool life are also discussed. The article discusses machining process dynamics and corresponding vibrations. It contains a table that provides a summary of high-pressure coolant research.

This article begins with a discussion on the classification of aluminum alloys and the selection of alloy and temper based on machinability. It provides an overview of cutting force and power, tool design and material, and general machining conditions. In addition, the article discusses distortion and dimensional variation and machining problems during the machining of high-silicon aluminum alloy. It also provides information on tool design and material, speed and feed, and the cutting fluid used for various machining processes, namely, turning, boring, planing and shaping, broaching, reaming, tapping, milling, sawing, grinding, honing, and lapping. The article concludes with a discussion on drilling operations in automatic bar and chucking machines and drill presses.