Manufacturing processes

PRESENTED BY:

KUNAL BHASIN

Manufacturing processes are the steps through which raw materials

are transformed into a final product. The manufacturing process

begins with the creation of the materials from which the design is

made. These materials are then modified through manufacturing

processes to become the required part.

Forming, or metal forming, is the metalworking process of

fashioning metal parts and objects through mechanical

deformation; the work piece is reshaped without adding or

removing material, and its mass remains unchanged.

CHARACTERISTICS:

Large, heavy and expensive machinery is required.

Production runs with many parts and steps.

FORMING

COMPRESSIVE TENSILE BENDING SHEARING

It involves those processes where the primary means of metal

deformation is done. It includes the following processes:

ROLLING

EXTRUSION

The material is passed through a pair of rollers.

The material is forced through an orifice.

DIE FORMING

FORGING

Where the material is stamped by a press around or

onto a die.

Where the material is shaped by localized compressive

forces

Tensile forming involves those processes where raw material is

extended to a point till it fractures.

EXPANDING

STRETCHINGWhere the tensile load is applied along the longitudinal

axis of the work piece.

Where the circumference of a hollow body is

increased.

This category of forming processes involves those operations where it

involves both tensile stresses and compressive loads.

DEEP DRAWING

A flat sheet metal blank is formed into a

hollow body open on one side or a hollow

body is formed into a hollow body with a

smaller cross-section.

METAL SPINNING

FLANGE

Basically a metal disk or cylinder is rotated at

high speed by using specially designed tool

through which symmetric product are formed.

It is a process of producing protruding rim,

edge, rib, or collar, as on a wheel or a pipe

shaft, used to strengthen an object, hold it in

place, or attach it to another object.

Bending is a manufacturing

process that produces a V-

shape, U-shape, or channel

shape. Similar to other

forming processes it does not

cause any change in the

volume of the material.

Usually this sheet metal bending process can be carried out

cold but may require to heat the metal sometimes.

When a great enough shearing

force is applied, the tensile stress in

the material will exceed the ultimate

strength and the material will fail and

separate at the cut location.

Shearing is also known as die cutting and cuts the stock without

the formation of chips or the use of burning or melting. The

process can be performed manually or through electric power.

Gravity die casting Process

In this reusable metallic molds are used for creating the

mold cavity where molten metal are poured without

applying any force or pressure other than gravity.

Ideal applications- Suitable for producing aluminum alloy

and other similar light metal components.

Advantages:

Low cost set up

Quick cycle time

Waste can be recycled

Good surface finish compare

Disadvantages:

Chances of defects are high

Suitable for simple components

Squeeze casting Process

It requires pressure or force to be applied on the molten metal to

push the molten metal to be fill the heated metallic mold cavity.

Ideal applications- Small complex mass produced by

aluminum alloy or other similar metals.

Advantages:

Less porosity

Very less wastage

Good surface finish

Less post casting operation required

Good strength due to finer micro structure

Disadvantages:

High tooling and equipment cost

Centrifugal casting ProcessIn this, the tabular and axisymmetric components are

produced by revolving the mold at high speed(300-3000 rpm)

about its own axis while pouring the molten metal into the

mold cavity.

Ideal application- Suitable for making cylinders, flywheels

made of iron, steel etc.

Advantages:

Low tooling costs

Very less wastage

Disadvantages:

Lower mechanical strength

Sheet metal punching processIt is the process of removing part of the sheet metal by using

punching press and punching tool.

Ideal application- Suitable for making mass production of the

sheet metal components.

Advantages:

Same machine can be used for manufacturing different

components by changing the dies.

Disadvantages:

High equipment and tooling costs

What is MACHINING?1. MACHINING IS ANY OF VARIOUS PROCESSES IN WHICH A PIECE OF RAW MATERIAL IS

CUT INTO A DESIRED FINAL SHAPE AND SIZE BY A CONTROLLED MATERIAL-REMOVAL PROCESS.

2. MACHINING IS A PART OF THE MANUFACTURE OF MANY METAL PRODUCTS, BUT IT CAN ALSO BE USED ON MATERIALS SUCH AS WOOD, PLASTIC, CERAMIC, AND COMPOSITES.

Machining tools1. Boring tools: These are typically used as finishing equipment to enlarge holes previously cut

into the material.

2. Cutting tools: Devices such as saws and shears are typical examples of cutting implements.

They are often used to cut material with predetermined dimensions, such as sheet metal, into a

desired shape.

3. Drilling tools: This category consists of two-edged rotating devices that create round holes

parallel to the axis of rotation.

4. Grinding tools: These instruments apply a rotating wheel to achieve a fine finish or to make

light cuts on a work piece.

5. Milling tools: A milling tool employs a rotating cutting surface with several blades to create

non-circular holes or cut unique designs out of the material.

6. Turning tools: These tools rotate a work piece on its axis while a cutting tool shapes it

to form. Lathes are the most common type of turning equipment

1. Boring 2. Drilling

3. Thread Cutting

4. Grooving

What is CNC

Machining ?Computer numerical control Machining it is a automated

process.

It requires software and

programming, usually in the G-

code language, to guide a

machining tool in shaping the

workpiece according to preset

parameters.

Advantages1. High production cycles: Once the CNC machine has been properly coded, it

usually needs minimal maintenance or downtime, allowing for a faster production rate.

2. Low manufacturing costs: Due to its turnover speed and low manual labor

requirements, CNC machining can be a cost-efficient process, particularly for high-volume

production runs.

3. Uniform production: CNC machining is typically precise and yields a high level of

design consistency among its products.

CASTING

What is Casting?

Casting is a manufacturing process by which a liquid material is

usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also

known as a casting, which is ejected or broken out of the mold to

complete the process. Casting materials are usually metals or

various cold setting materials that cure after mixing two or more

components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for

making complex shapes that would be otherwise difficult or

uneconomical to make by other methods.

Types of Casting

Casting ProcessIt is the oldest

manufacturing process in

which liquid molten metal is poured into a perforated

casting cavity of refractory

material. Allow liquid metal

to solidify, after solidification

the casting metal can be

taken out by breaking the

mould. Casting process is

used to produce

components such as

pistons, mill rolls, wheels, cylinder blocks, liners,

machine tool beds.

AdvantagesAdvantages of casting process:

• Molten metal flows into ant small section in molten cavity, hence any complex

shape can be easily produced.

• Practically any type of material can be casted.

• Ideal method is by producing small quantities

• Due to small cooling rate from all directions, the properties of casting are same in

all directions.

• Any size of casting can be produced like up to 200 tonnes.

• Casting is the often cheapest and most direct way of producing a shape with

certain desired mechanical properties.

• Certain metals and alloys such as highly creep resistant metal-based alloys for gas

turbines cannot be worked mechanically and can be cast only.

• Heavy equipment like machine leads, ship’s propeller etc. can be cast easily in the

required size rather than fabricating them by joining several small pieces.

• Casting is best suited for composite components requiring different properties in

different direction. These are made by incorporating preferable inserts in a casting.

For example, aluminium conductors into slots in iron armature for electric motors,

wear resistant skins onto shock resistant components.

Limitations

• With normal casting process

the dimensional accuracies

and surface finish is less.

• Defects are unavoidable.

• It is labor intensive.

Joining:-

Why do we need joining?

To restrict some degrees of freedom of motion for components (i.e. to make

mechanisms).

(a) A complex shaped component may be impossible/expensive to

manufacture, but it may be possible/cheaper to make it in several parts and

then join them.

(b) Some products are better made as assemblies, since they can be

disassembled for maintenance.

(c) Transporting a disassembled product is sometimes easier/feasible

compared to transporting the entire product. A good example of this is the

beautiful TsingMa bridge of Hong Kong; individual sections were fabricated,

raised to the correct position, and then welded/riveted together to construct

the structure.

Joining

Process

Welding Brazing and

Soldering

Adhesive

bonding

Welding:-

In the welding process, two or more parts are heated and

melted or forced together causing the joined parts to

function as one.

Brazing:-

During the brazing process a filler metal is melted and distributed in

between multiple solid metal components after they have been

heated to the proper temperature. The filler metal must have a

melting point that is above 840 degrees Fahrenheit but below the

melting point of the base metals and the metal must also have high

fluidity and wettability. No melting of the base metals occurs during

brazing.

Adhesive bonding:-

Adhesive bonding is a low cost process that normally has

100% material utilization. In adhesive bonding a filler

material called an adhesive is used to hold multiple

closely spaced parts together through surface

attachment. The adhesive is a nonmetallic substance

often it is a polymer.

PROCESS OF GIVING SHAPE TO THE SOFT RAW MATERIALS BY

PASSING IT THROUGH A SET OF ROLLERS WITHOUT APPLYING HEAT.

ADVANTAGES:

GOOD SURFACE FINISH

GOOD DIMENSIONAL

COST EFFECTIVE PROCESS

DISADVANTAGES:

CANNOT CHANGE THE SHAPE DRASTICALLY

REQUIRE ANNEALING BEFORE ROLLING

COLD ROLLING PROCESS

If the temperature of the metal is above its recrystallization

temperature then the process is known as Hot rolling .

Advantages:

Drastic shape change is possible

Good microstructure & good strength

Disadvantages:

Less dimensional tolerance compared to cold rolling

Poor surface finish

HOT ROLLING PROCESS

Given shape by applying high force(hammer) with the presence of

heat.

Advantages:

Good strength

Versatility in design

Disadvantages:

Equipment & tooling cost is high

Forging is skillful job

FORGING PROCESS

Process of making components by pumping the liquid materials into

the mold.

Advantages:

Good surface finish

High production rate

Fully automated(less manpower)

Disadvantage:

High tooling and equipment cost

INJECTION MODELLING

PROCESS

Air is pumped after pumping the molten materials into the two piece

mold cavity, the combine effect produce walled components.

Advantages:

Lower manufacturing cost per item

Variety of designs

Disadvantages:

Only hollow parts can be produced

BLOW MOLDING

PROCESS

Single point cutting tool used for removing materials from a fast

rotating work piece by using a machine called lathe.

Advantages:

Lead time is shorter

Tight tolerance cannot be achieved

Disadvantages:

Large scrap wastage

Equipment cost is quite high

TURNING PROCESS

Making hole in a work piece by removing materials from it by means of

a rotating cutting tool called drill bit.

Advantages:

Variety of materials can be chosen


Disadvantages:

Large scrap wastage

DRILLING PROCESS

Layer by layer materials removing process from the work piece.

Advantages:



Disadvantages:

Large scrap wastage

Equipment cost is high

MILLING PROCESS

Use grinding wheel as cutting tool to make surface smoother.

Advantages:

Good surface finish


Disadvantages:

Large scrap wastage

GRINDING PROCESS

Moving the work piece slowly against some sort of abrasives. Can be

performed manually or by machine.

Advantages:

Great surface finish


Disadvantages:

Slow process

LAPPING PROCESS

Mechanically rubbing the honing stone against the work piece

surface along the controlled path.

Advantages:

Good surface finish


Disadvantages:

Equipment cost is high

HONING PROCESS

Abrasive jet machining

Abrasive jet machining (AJM), also known as abrasive micro-blasting, pencil blasting and micro-abrasive blasting, is anabrasive blasting machining process that uses abrasives propelled by a high velocity gas to erode material from the work piece. Common uses include cutting heat-sensitive, brittle, thin, or hard materials. Specifically it is used to cut intricate shapes or form specific edge shapes.

Advantage:

1. Hard Materials can be Machined.2. Complex Profile can be Created.3. Very Good Surface can be Achieved.

Fusion Welding

Fusion welding is a generic term for welding processes that rely upon melting to join materials of similar compositions and melting points. Due to the high-temperature phase transitions inherent to these processes, a heat-affected zone is created in the material (although some techniques, like beam welding, often minimize this effect by introducing comparatively little heat into the workpiece.

Advantage:

Variety of materials can be chosenVariety of welding design can be Chosen

Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding in the U.S.) and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903. Pure oxygen, instead of air, is used to increase the flame temperature to allow localized melting of the work piece material (e.g. steel) in a room environment. A common propane/air flame burns at about 2,000 °C (3,630 °F), a propane/oxygen flame burns at about 2,500 °C (4,530 °F), and an acetylene/oxygen flame burns at about 3,500 °C (6,330 °F).

Oxy-fuel welding

Advantages:

1.Less equipment Cost.2.Portable equipment.3.Easy to Operate.

Powder metallurgy is the process of blending fine powdered materials, pressing them into a desired shape or form (compacting), and then heating the compressed material in a controlled atmosphere to bond the material sintering. The powder metallurgy process generally consists of four basic steps: powder manufacture, powder blending, compacting, and sintering. Compacting is generally performed at room temperature, and the elevated-temperature process of sintering is usually conducted at atmospheric pressure. Optional secondary processing often follows to obtain special properties or enhanced precision. The use of powder metal technology bypasses the need to manufacture the resulting products by metal removal processes, thereby reducing costs.Powder metallurgy is also used in "3D printing" of metals.

Powder Metallurgy

Advantage:

Very less Machining operation required after the Components are Produced

Rate of Production is very high.

Scrap wastage is very less.

Complex 3D objects can be Created

Rapid prototyping is a group of techniques used to quickly fabricate a scale model of a physical part or assembly using three-dimensional computer aided design (CAD) data. Construction of the part or assembly is usually done using 3D printing or "additive layer manufacturing" technology.

Rapid prototyping

Manufacturing processes

Engineering

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