Forming Process in Manufacturing

Forming is the one of manufacturing methods which is used to make some objectives. Metal forming is the metalworking process that is used to form metal parts for different shapes through deformation. The material piece is reshaped without adding or removing material.

Hot Forming

The hot hot-forming process is used very frequently to cast industrial products and parts. The raw materials are available form of sheets, tubes, bars or wire. In this process, heat is applied to the material to soften. Then, some of the required pressure is applied to get the desired shape of the metal. This process is also capable of forming a variety of complex parts and holds relatively tight tolerances.

Most hot-forming processes are complex due to the involvement of adiabatic heating, die chill and microstructural changes.

Hot hot-forming process is one of sheet forming processes of sheet metal. This process is also known as hot stamping or press hardening. All forming processes are run above the recrystallization temperature of the material. The material recovers and softness during the hot forming process of sheet metal. The hot sheet metal is brought into contact with the hot die and a hot punch is pressed into the die to form the shape and then apply forming pressure for a period.

A direct (one-stage) hot-forming process is commonly used due to forming and part hardening being done in one operation.

Advantages of hot forming	Disadvantages of hot forming
Accurate forming	Burr formation
Complex shapes	Furnaces cause high energy cost
Consistent thickness	The surface finish is poor
Higher surface profile tolerances	The component can wrapped in the worst-case
Resistance to cracking	The surface of the component slightly scaled due to the high working temperature
Good strength
Lower cost
Low spring back

The uses of the hot-forming process are as below, 

In the automobile industry: -

Side members, door reinforcements, sills, roof frames, roof rails, and bumper supports.

Cold Forming

The cold forming process is the metal forging process at bear room temperature or slightly above room temperature. Forming metal at cooler temperatures may retain or enhance the tensile strength of the material. This process is a high-speed process that allows the manufacture of large amounts of metal-based products in a fast, consistent and cost-effective way.  Cold-formed parts have greater yield, higher tensile strength and superior surface finish when compared to hot-formed parts.

The cold-forming process can be classified into four major groups, such as squeezing, bending, drawing, and shearing. However, higher loads are required to do the cold forming process and deformation is low compared hot forming process. Also, a high degree of manufacturing experience is required to achieve complex geometry parts.

Advantages of Cold-forming	Disadvantages of Cold forming
No heat is required, so low energy is required	Harder tools and dies are needed due to metal is harder
Better surface finish	Low deformation
Superior dimensional accuracy	Material with low ductility cannot be sold formed.
Improve strength properties	Metal surfaces must be clean and scale-free
Contamination problems are minimized	Residual stress may occur
Material savings & elimination of scrap	Higher forces required for deformation
Inexpensive
Big production rate and long life
Material savings & elimination of scrap

Application of the cold forming process,

Fasteners, screws, nuts, bolts, electrical contacts, and rivets

Warm Forming

Warm forming is the metal deform process in which metal is heated to a temperature that maximizes the material's malleability without allowing re-crystallization, grain growth, or metallurgical fracture. Warm forming aims to combine the strong points of hot and cold forming. Better surface finishes can be achieved than hot forming. Temperature control is difficult in this process. If more complex parts are formed, precision is low. The warm-forming process is suitable for medium-scale productions.

Advantages of Warm forming	Disadvantages of Warm forming
Reduce tooling loads compared to cold-forming	Lower precision than cold forming
Increased steel ductility	Strict temperature control
Lesser amount of heat energy requirement than hot forming	Greater press loads than hot forming
Lesser thermal shock on tooling than hot forming	Required skilled engineering to design appropriate tooling
Better dimensional control than hot forming
Better precision components than hot forming

In the automotive industry, warm-formed parts are used (Door panels, fenders). In such applications, warm forming of certain aluminium alloys may be cost-effective because of reduced vehicle weight and fuel consumption.