Two mark Questions and Answers

TWO MARK QUESTIONS AND ANSWERS

1. Write brief description on cold forging.

Cold forging is an impact forming process that plastically deforms a piece of raw material, under high compressive force, between a punch and a die within suitable equipment such as a machine press. Cold forging deforms metal while it is below its recrystallization point. Cold forging process takes place near room temperature, rather than at higher temperatures like warm and hot forging. It is done by placing the workpiece in-between two dies, and pounding the dies until the metal assumes their shape.

2. What are the advantages of cold forging?

1. It is often more economical than other processes, as the final product doesn't require much finishing if any at all.

2. The dies used in cold forging last longer than in hot forging which reduces die cost.

3. Yield and tensile strength of the cold forged metals increase greatly.

4. It is easier to impart directional properties.

5. Improved reproducibility is possible.

3. Mention the limitations of cold forging.

1. The metal surfaces must be clean and free of scale before forging occurs.

2. The ductility of metal reduces.

3. Residual stresses may occur.

4. Heavier and more powerful equipment is needed.

5. Stronger tooling is required.

4. List down the applications of cold forging.

1. Cold forging is being used in a wide variety of industries including fastener, automotive, pole-line hardware, truck-trailers, outboard engine controls, bicycle pedal cranks, constant velocity joints, universal joint crosses, and military projectile hardware.

2. Shapes generally have been limited to rotationally symmetrical and axisymmetric, including long shafts and struts.

3. It is used to weld titanium, zirconium and beryllium metals and its alloy.

5. Define shaping operation.

Shaping operations take raw materials and modify their form to make the intermediate and final product shapes. The component or product can be created from a solid, granular, particle state or liquid state based on the state of the work material in the shaping phase.

6. How the shaping operations are classified?

In general, the shaping operations are classified into two main types: primary and secondary.

Primary shaping operations form the overall shape of the product or the component such as sheet, bar, plate, or some other preliminary form.

Secondary shaping operations take the preliminary form and alters its shape further to a final, precisely shaped version of the product that will meet the product requirements. Secondary operations further improve the properties, surface quality, dimensional accuracy, tolerance, etc. These operations are primarily used to remove metal to develop a specific form from the unfinished piece.

7. List various categories of shaping operation.

There are four broad categories of primary shaping operations for metals as follows:

(a) Casting and moulding

(b) Particulate processing (powder metallurgy)

(c) Deformation processes

(d) Material removal processes