![HIGH ENERGY RATE FORMING
PROCESS [HERF ]
It is a process that form products at very high
velocities and extremely high pressure](https://image.slidesharecdn.com/highenergyrateformingprocess-160825082634/85/High-energy-rate-forming-process-2-320.jpg)
High energy rate forming process
- 1. UNIT IV SHEET METAL FORMING & UNCONVENTIONAL FORMING PROCESS
- 2. HIGH ENERGY RATE FORMING PROCESS [HERF ] It is a process that form products at very high velocities and extremely high pressure
- 3. Large amount of energy is applied for a very short interval of time. High particle velocities are produced in contrast with conventional forming process. The velocity of deformation is also very large and hence these are also called High Velocity Forming (HVF) processes. HERF process used short burst of energy that is transmitted to the part surface through a medium (water/air). The resulting force or shockwave acts to force the part into a die cavity that has the desired shape of finished product. Materials being formed beyond their usual limits
- 4. High energy required for small interval time. Many metals tend to deform more rapidly under extra fast application of load which make these processes useful to form large size parts out of these most metals including those which are difficult to form. Material that are difficult to form in conventional methods due to spring back effect will undergo large plastic deformation with almost no spring back effect when HERF is used.
- 5. Advantages of HERF Processes Production rates are higher, as parts are made at a rapid rate and thus these process are also called high velocity forming process. Die costs are relatively lower. it is possible to form most metals including difficult to form metals. No or minimum spring back effect on the material after the process. Production cost is low as power hammer (or press) is eliminated in the process. Complex shapes / profiles can be made much easily, as compared to conventional forming.
- 6. Suitable for a range of production volume such as small numbers, batches or mass production. Limitations: Not suitable to highly brittle materials. Source of energy (chemical explosive or electrical) must be handled carefully. Highly skilled personnel are required from design to execution. Dies need to be much bigger to withstand high energy rates and shocks and to prevent cracking.
- 7. Applications: In ship building – to form large plates / parts (up to 25 mm thick). Bending thick tubes/ pipes (up to 25 mm thick). Radar dish space applications
- 8. TYPES OF HERF PROCESSES 1. EXPLOSIVE FORMING 2. ELECTRO HYDRAULIC FORMING 3. MAGNETIC PULSE FORMING