In process design, many factors affect the determination of process design space and the identification of the best process solution. In the next section, different types of flexible-die forming processes are introduced. In those years, new rolling mills were developed and industrially implemented, and a great deal of theoretical and experimental research was conducted to better understand CWR process regularities (1). It is agreed that the first fully industrial application of CWR took place in 1949, when, at the Gorky Automobile Plant in Russia, the method was implemented to form connecting rods. Generally a desirable property for metals is a large plastic deformation In this type of forming, a flexible medium such as rubber, fluid or highly-viscous semi-solid material is replaced with conventional rigid tools, to form a component into its final shape. Additionally, a strategy for the evaluation of the sub-topography on single asperities is presented leading to an improved understanding of the tribological behaviour in micro forming processes. Deep Drawing Sheet Metal At the asperity contacts, pick-up of workpiece material on the tool surface is typically prevented by a thin boundary lubricant film (Fig. According to the mechanical-rheological model these fractions are mainly the real contact area (RCA) and the so-called closed lubricant pockets (CLP). They are deformed part design, process determination, tooling design, and product quality assurance and control [1]. Curling is a sheet metal forming process that’s used to smooth out the otherwise sharp and … There are two main types of filling-related defect: Figure 7.2. Sheet forming: Sheet metal forming involves forming and cutting operations performed on metal sheets, strips, and coils. Grains will Sheet Metal Ironing Recrystallization of the metal in hot working involves atomic diffusion, which is a time-dependent process. Therefore, some of the sheet metal Electrohydraulic forming is a high-velocity forming process that deforms sheet metals with velocities above 100 m/s and strain rates more than 100 s −1. Some of these parameters influence each other directly. As early as 4500 BC, copper was subjected to metal forming, originally with hammers made of durable stones. Metal Rolling Rolling, forging, extrusion, and drawing are bulk forming processes. direction. There are four categories of design activities as shown in Fig. Given that the method requires high technological capabilities, its factual development came later. At that time, hand-operated rolling mills were also introduced and they were used to work easily deformable metals like lead or tin. Anisotropy is the In such a case, the term stamping is used in order to distinguish between the deep drawing (radial tension-tangential compression) and stretch-and-bend (along the straight sides) components. 7.2A gives the flow defects of metal-formed parts in the automotive industry. Tube hydroforming is an unconventional metal forming process that uses the internal hydraulic pressure and tube end axial load to avoid rupture of the blank. The factory often USES the pressure riveting stud, riveting nut, riveting screw, etc. An inappropriate fill sequence may result in trapped gas, which prevents the material from flowing into the space occupied by the trapped air, as shown in Fig. It is a common flow defect in the metal-forming process due to uneven or poor lubrication, insufficient deformation pressure, excessive die chill in hot working process, inappropriate fill sequence of material, trapped gas in the die cavity, etc. By this process, tubes are formed into different shapes using internal pressure and axial compressive loads simultaneously to force a tubular blank to conform to the shape of a given die cavity.3. The Middle Ages witnessed a development of forging owing to a widespread use of the water wheel, which was used in hammer forges of the time to power hammers for open die forging. The grid and circles will deform with the metal. This process requires a blank, blank-holder, punch, and die. Metal forming processes are used to produce structural parts and components that have widespread applications in many industries including automobile, aerospace, appliances. The main difference between conventional and unconventional forming is the type of tools used in the process. To demonstrate the validity of the proposed integrated micro-mechanics forming simulation system, CPFE analysis had been carried out to simulate the typical forming process of a micro-pin. Furthermore, additive manufacturing processes are not yet as accurate as desired regarding surface quality, which means that producing a net-shape is often not possible. sheet metal products. Z. Pater, in Comprehensive Materials Processing, 2014. Tekkaya, in Laser Additive Manufacturing, 2017. Sheet metal refers Bulk Forming Processes – One is bulk-forming and the other is sheet metal forming. for sheet metal manufacturers. Sheet metal is metal formed by an industrial process into thin, flat pieces. Velocity-related flow defects are usually formed by an excessive material flow velocity gradient. Hydroforming allows to overcome some of the limitations of conventional deep drawing increasing the drawing ratio and minimizing the thickness reduction of the formed parts. also be neglected in most cases. Examples of the studied parameters are the blank shape, sheet dimensions, blank holding force or pressure, feed, lubrication and punch/die design need to be controlled and optimized. 7.6 as an example, when the upper die moves downward, the central material will move up with a higher velocity than the outer materials, pulling the trapped material away from the lower die surface and finally leading to a suck-in flow defect in the bottom part of the workpiece. The main difference between conventional and unconventional forming is the type of tools used in the process. Tools include punch, die that are used to deform the sheets. Bending is a flexible process by which a wide variety of shapes can be fabricated. In unconventional forming processes, flexible tools are used to punch the workpiece. The material properties can be evaluated by means of standard material characteristics such as tensile yield strength, ultimate elongation and tensile strength obtained from testing. Lap in titanium-alloy forging: (A) 3.5×; (B) 50× [7]. The effects of regularity and grain size upon local deformation had been demonstrated by a three-dimensional micro-pillar compression simulation [31]. Many sheet metal operations will create a complex distribution of forces. The cup shaped part thus produced has the depth greater than half of its diameter. The defects are formed in the inner and outer parts of the flanged features in the multiflanged parts. Curling. depending upon their location within the work. The earliest rolling mills powered by the water wheel were used in the seventeenth century to produce lead sheets that were probably used to cover bottoms of ship hulls. Usually, the initial shape is a simple one. Deep drawing: The sheet metal is clamped down by the blank-holder over the die, which has a cavity in the external shape of the part. Generally for sheet metal applications there is Taking the case presented in Fig. A few case studies will be given to illustrate how FE modeling and simulation helps reveal and avoid flow defects in the forming process. This book discussed the latter case and presented different metal forming processes where friction between the elastic tools and the workpiece can be used as a beneficial factor. Grain size, structure Effective ways to avoid folding or lapping defects include smoothening the critical die corner radius, controlling metal-flow direction, and pre-forming the geometrical features or the pre-filling the space where the fold and lap defects originally exist.