Search Results for sheet

This chapter describes the equipment and processes used to form titanium alloy parts. It discusses the advantages and disadvantages of hot and cold forming, the factors that influence formability, and the effect of forming temperature and lubricants. It describes common processes, including brake forming, stretch forming, deep drawing, and spin forming as well as roll forming, drop-hammer forming, tube bulging and bending, and superplastic forming. It also discusses dimpling and joggling and the use of hot sizing to correct springback.

This chapter describes a sheet metal forming method, called hydroforming, that uses pressurized liquid and a shaped punch or die. It discusses the advantages and disadvantages of the two approaches, the effect of process variations, and tooling modifications intended to reduce sheet bulging. It identifies the factors that influence part quality and explains how finite-element analysis can be used to optimize hydroforming operations. It also discusses the economics of sheet hydroforming and presents several application examples.

This chapter describes incremental sheet forming processes, including single-point, two-point, and kinematic (two tool) techniques. It provides information on the tooling and equipment used, work flow and forming parameters, process mechanics and forming limits. It also discusses multistage forming strategies, process modeling and simulation, and advanced hybrid forming processes.

This chapter discusses the types of sensors used in sheet forming operations and the information they provide. It explains how force sensors protect equipment from overloads due to tool wear, friction, and misfeeds, how displacement and proximity sensors help to prevent die crashes, how acoustic emission, ultrasonic, and eddy current sensors detect tool breakage and part defects such as cracks, and how roller ball and optical sensors measure material flow. It also discusses the role of draw-in, wrinkle, oil-monitoring, and vision sensors and explains how material properties can be derived in real time from various sensor outputs.

Sheet metal forming operations consist of a large family of processes, ranging from simple bending to stamping and deep drawing of complex shapes. Because sheet forming operations are so diverse in type, extent, and rate, no single test provides an accurate indication of the formability of a material in all situations. However, as discussed in this chapter, the uniaxial tensile test is one of the most widely used tests for determining sheet metal formability. This chapter describes the effect of material properties and temperature on sheet metal formability. Information on the types of formability tests is also provided. The chapter discusses the processes involved in uniaxial and plane-strain tensile testing. Examples include the uniaxial tensile test and the plane-strain tensile test which are subsequently described.

This chapter provides a concise, design-oriented summary of more than 30 sheet forming processes within the categories of bending and flanging, stretch forming, deep drawing, blank preparation, and incremental and hybrid forming. Each summary includes a description and diagram of the process and a bullet-point list identifying relevant equipment, materials, variations, and applications. The chapter also discusses critical process variables, interactions, and components and the classification of sheet metal parts based on geometry.

This chapter describes the formability and forming characteristics of low-carbon sheet steels, coated sheet steels, stainless steels, and aluminum and magnesium alloys. It provides property data as well as flow stress curves for numerous grades of each material and explains how composition, microstructure, and processing methods influence forming behaviors.

This chapter discusses the design and application of sheet forming presses. The discussion covers critical variables and design parameters, key components, basic machine configurations, and energy and load requirements. The chapter also discusses time-dependent characteristics, dimensional accuracy, and stiffness as well as die change procedures.

This chapter describes the various types of cushion systems used in forming presses and their effect on part quality. It begins with a review of the deep drawing process, explaining that wrinkling, tearing, and fracture are the result of excess or insufficient material flow, which can be prevented by maintaining the correct amount of holding force on the periphery of the blank. It then describes how blank holding force is generated in double-action presses and the extent to which displacement profiles can be adjusted on both the inner and outer slides. The discussion then turns to single-action presses that incorporate some type of cushion system. The chapters describes the many ways that cushion systems are implemented in forming presses and the force and displacement characteristics achievable with each method. It also explains how multipoint cushion systems are designed and how they facilitate uniform metal flow into the die cavity of large deep-drawn parts.

This chapter covers the mechanics and tribology of sheet metalworking processes, including shearing, bending, spinning, stretching, deep drawing, ironing, and hydroforming. It explains how to determine friction, wear, and lubrication needs based on process forces, temperatures, and strains and the effects of strain hardening on workpiece materials. It presents test methods for evaluating process tribology, describes lubrication and wear control approaches, and discusses the factors, such as surface roughness, lubricant breakdown, and adhesion, that can lead to galling and other forms of wear. It also provides best practices for selecting, evaluating, and applying lubricants for specific materials, including steels, stainless steels, and aluminum and magnesium alloys.