2 Marks Questions and Answers

TWO MARK QUESTIONS AND ANSWERS

1. What is incremental forming?

Incremental forming, also known as incremental sheet forming, is a dieless metalworking process that is suitable for small lot productions of a wide variety of complex parts. The desired shape is obtained by applying localized pressure with a deforming tool that moves along a metal sheet. A sheet is shaped into the final part shape by progressively applying small increments of deformations using a round-tipped or hemispherical head tool, typically 5 to 20 mm in diameter.

2. Write classifications of incremental forming.

Incremental forming can be classified into the following categories:

(a) Conventional Incremental Sheet Forming (CISF)

(i) Single-point incremental forming or Negative dieless forming

(ii) Two-point incremental forming or Positive dieless forming

(b) Hybrid Incremental Sheet Forming (HISF)

(i) Single-point incremental hydro-forming

(ii) Two-point incremental forming with partial die

(iii) Two-point incremental forming with full die

3. Explain briefly the conventional incremental forming operation.

In this process, generally a sheet of metal is deformed by progressive and localized plastic deformation using a simple hemispherical/ballpoint tool, and this path of the forming tool is controlled by a CNC machine. The forming tool moves over the surface of the sheet and results the final shape. There is no other tool or external pressure applied for deforming the sheets into the desired shape.

4. Write brief description about hybrid incremental forming.

This process is the modified forms of conventional incremental forming. In this process, forming tool moves over the surface of sheet metals, while the another side of surface of sheet metals is supported by pressurized hydraulic fluid, partial die or full die to get the desire shape and size.

5. List the advantages of incremental forming.

1. Useable parts can be formed directly from CAD data with a minimum of specialized tooling. A conventional CNC milling machine or lathe can be used for this process.

2. The process does not require either positive or negative dies; hence, it is dieless.

3. Changes in part design sizes can be easily and quickly accommodated, giving a high degree of flexibility.

4. Making metal rapid prototypes is normally difficult, but easy with this process.

5. The small plastic zone and incremental nature of the process contribute to increased formability, making it easier to deform low formability sheet.

6. Mention the limitations of incremental forming.

1. Forming time is much longer than competitive processes such as deep drawing.

2. This process is limited to small-size batch production.

3. The forming of right angles cannot be done in one step, but requires a multi-step process.

7. List down the applications of incremental forming.

There are a number of areas, where high precision of the products is required for the accuracy of the performance. Areas of products can manufacture by incremental forming are as follows:

(a) Aerospace industry: Instrument panel, body panel, passenger seat cover, etc.

(b) Automobile: Door inner/outer panel, hood panel, engine cover, etc.

(c) High customized products: Denture plate, ankle support, metal helmet, etc.