DESIGN AND FABRICATION OF DIE FOR BLOW FORMING

Guided by Mr. VIJAY ANANTH Asst prof.

Submitted by

A.RAMASUNDARESAN :31008114043

A.VIGNESH :31008114304

V.VIJAYABASHKAR :31008114306

E.S.VINOTHKUMAR :31008114307

ABSTRACT:

A stiff competition in the automobile and aerospace industries in recent

times has forced to innovate newer and better technologies for the fast paced

world. Aluminum automotive components made using a hot blow forming

process are reducing vehicle weight and increasing the fuel efficiency of today’s

cars

Al 6063 disks of a super plastic forming grade gas-pressure formed to

hemispheres at constant forming pressures with back pressure. The forming

operation was performed using an in-house designed forming apparatus. The

temporal change of dome heights of the hemispheres were measured for the

different forming and back pressure applied. Forming test with dies were

performed at 5800 C.

INTRODUCTION:

Recent interest in lightweight and inexpensive alloys for transportation

systems has attracted attentions to aluminum – magnesium alloys. Al 6063

alloy , because of its good weld ability , reasonably high corrosion resistance

and high strength with reasonable ductility , has been one of such alloys. Large

ductility required in forming engineering parts with contoured geometry has to

development of superplastic grade of the alloy. Deformation behavior and

microstructural evolution of the superplastic Al 6063 has been extensively

investigated for tensile deformation . the purpose of the present study is to

investigate the deformation behavior of Al6063 alloy using hemispherical dies.

Superplasticity

• Superplasticity in materials is characterized by large neck free elongation under low flow stress when they are formed at temperature exceeding about one half of the melting point.

• Superplastic forming is carried out essentially under isothermal conditions with very low strain rates.

SUPERPLASTIC BLOW FORMING PROCESS:

• It is metal working process for forming sheet metal. It works upon the

theory of superplasticity which means that a material can elongate beyond

100% of its original size.

• It is manufacturing method used for making aluminum automotive

components . Parison is a tube like pipe which is used to pass the argon

gas . The parison is then clamped into the Die and gas pumped into the

mould. Aluminum is heated one third of its melting point and argon

pressure gas is passed and aluminum forms the mould shape.

Superplastic Blow Forming Process

FORMULAσ = k έ m

where,• ‘σ’ is effective flow stress, • ‘έ’ is strain rate,• ‘k’ is constant depends upon temperature and

grain size ‘m’ is strain rate sensitivity index .

LAYOUT OF THE DIE

DESIGN CALCULATION

For the analysis of the superplastic forming behaviour, the disk specimens were

assumed to bulge to spherical membranes of uniform thickness.

An applied pressure, P, In a hemispherical die of results Ro would deform a disk

specimen of the initial thickness T0 Into a spherical membrance of radius p.

By measuring the dome height HD of the membrane, and assuming the volume

constancy of the material, one can calculate the radius p, thickness t, strain e, and shell

stress , of the membrane.

SPECIFICTION

Applied pressure : 25 N/mm2

Initial thickness of Al 6063: 2 mm

Operating temperature: 5800C

Diameter of the hemispherical cavity: 30 mm

Hemispherical die of radius (Ro): 15 mm

Dome Height (HD): 25 mm

1) P =

P =

P = 25 N/mm2

2) t =

t =

t = 1 mm3) = ln = ln

= 0.693 (Compressive in nature)

=312.5 N/mm^2

=

DESIGN CALCUATION

MATERIALS DIMENSIONS QUANTITY

MALE DIE MILD STEEL

DIAMTER=100 mm THICKNESS=25 mm

1

FEMALE DIE MILD STEEL

DIAMETER=100mm THICKNESS=100 mm

1

PARISON TUBE DIAMETER =20 mm 1

ALIGN BOLT 4

BILL OF MATERIALS:

BENEFITS:

Weight saving of 40% on a typical mid size automobile

which reduces green house gas emission and increase fuel

economy.

No color and fit issues on the auto assembly where two

piece construction as become one piece.

simply of auto assembly process.

completive advantage for US industry in manufacturing

light weight automotive components.

Low-cost tooling

Low environmental impacts –non-lead die tubes, low noise

Reduced weight for high fuel efficiency

Improved structural performance

PHOTOGRAPHS:

COMPONENT PRODUCED:

Cost of the project

MATERIALS COST

MALE DIE 400 FEMALE DIE 800

MACHINING 900 BOLT 100

PARISON TUBE WITH 300REDUSER

TOTAL COST 2500

CONCULSION

Thus we have successfully design and fabricated a

die for conducting blow forming tests. Blow forming tests has

been conducted for different pressure and temperatures.

REFERENCES

Super plastic flow phenomenology and mechanics by

kuppuswamyananthapadhmanabhan, R.A. Vasin, F.V.

ENIKEEV.

Super plasticity in metals and ceramics by T.G. Nieh, wads

worth, oleg D . Sherby

psg design data book.