Advancement in Centrifugal & Investment Casting

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ADVANCEMENT IN CENTRIFUGAL

& INVESTMENT CASTING

BE III(MET.& MTRLS ENGG.)

METALLURGICAL & MATERIALS ENGINEERING DEPARTMENT

FACULTY OF TECHNOLOGY AND ENGINEERING

M.S UNIVERSITY OF BARODA

VADODARA

MARCH 2011

SEMINAR TOPIC ON

905-BRAHMABHATT SAJAN 913-INAMDAR CHIRAYU

921-NASHIKKAR TRUSHIT 929-PATEL SANJAY

936-NIDHI SHAH 944-VANESHWARI VANKAR

952-PRATIK PATEL

PREPARED BY:



ADVANCEMENT IN

CENTRIFUGAL &

INVESTMENT CASTING



LAYOUT

Basic Process Principle

Process Mechanism

Detailing

Advantages

Disadvantages (defects) Application



CENTRIFUGAL CASTING



PROCESS:

Principle

Effect of centrifugal force on impurities

Uniqueness of the process

Gating system is not required.

A technology for material and energy

saving and high efficiency to somecasting with specific shape.

Types…



TRUE CENTRIFUGAL CASTING

300-3000 rpm speed

Casting without core

Solidification…

periphery towards thecenter

Withdrawal of pipe by pipe puller

Castings are cylindricalin shape, symmetrical tocentral axis like pipes,

tubes, etc…



SEMI-CENTRIFUGAL CASTING

The De Lavaud process & Moore casting system

An accurately machinedmetal mold with cooling

Machine is mounted on wheels, slightly incline

Liquid metal pouring

from far of the mold

The rate of pouring is thecontrolling factor



CENTRIFUGE CASTING

Castings which are notsymmetrical about any axis

Core and gates may beused

No special limitation

over shape of casting Products : valve bodies,

valve bonnets, yokes,

etc...



ADVANTAGES

Clean, Dense and fine grained metalcastings with good physical propertiescomparable with the forgings.

Proper directional solidification of thecasting.

No need of a central core and gatingsystem in true centrifugal casting.

Mass production and Rapid productionrate.

Ability to produce extremely large

cylindrical parts.



DISADVANTAGES:

True centrifugal casting is limited to few shapes.

Equipment costs are high.

Skilled workers are required for operation and

maintenance. Defects: #hot tear

# segregation

# banding (low melting point incl.)

Conventional casting defects like internalshrinkage, gas porosity & nonmetallic inclusion are

less likely to occur in centrifugal casting.



APPLICATIONS:

Figs : high chrome C.I. mill roll, steel pipes, bearings(cupro-nickel, bronze, gunmetal),carbon-steel and low alloy carbon-steel valves…



Figs : radiant tubes (Fe-Cr-Ni), bi-metalliccladding steel pipes, brass or copper or

bronze castings… Hot and cold rolled strip and plate mills,

power transmission industries, aerospace

industries etc…& conclusion…



INTRODUCTION

Also called “lost wax casting”

Castings with excellent surface finish and highdimensional accuracy.

200alloys are available with investment casting

Ferrous- s.s, tool steel, carbon-steel, ductile iron

Non-ferrous-aluminum, copper, brass etc…



PROCESS

Pattern & Mold making

Wax pattern made by wax injection machine

Attaching the metal delivery system



Wax assembly is INVESTED into ceramicsolution called slurry

Coating with fine zirconium sand and then

let it dry…



Again coarse sand is coated and repetition until

desired thickness…

Dewaxing in heating furnace

Heating of mould &purpose



Pouring of liquid metal

Solidification

Removal of ceramic mold coating



Cutting of metal delivery system

Surface polishing

Sizing & manufacturing



ADVANTAGES

Excellent detailing, smoother surface and closetolerance

Castings do not contain any disfiguring partingline.

Saving in machining operation cost

Intricate shapes, irregular parts which can not beproduced by any other process can also be cast with excellent mechanical properties



Sections as thin as 0.75 mm may be cast.

Sounder and denser castings.

With suitable heat treatment, the investmentcastings attain physical properties comparable toforged or rolled sections.

Castings produced are sound and free from usual

defects.



DISADVANTAGES

The process is relatively expensive Size limitation. Majority of castings less than 0.5

kg.

Pattern can be expendable; one wax pattern isrequired to make one investment casting.

Process is relatively slow.

The use of cores makes process more difficult.

The economic value of this process lies in its ability to produced intricate shapes in various alloys thatcould probably not be produced at all by any othercasting process.



DEFECTS

BUCKLING AIR BUBBLES IN SLURRY

LIFTING SHRINKAGE PITTING

SCABING, WORMING, ETC…



APPLICATION

highly complex

shapes such ashollow turbine blades

Parts for sewing

machines, locks,rifles and burnernozzles.

Aviation, power

industries Impellers and

other pump and valve components

Etc…



REFERENCE

FOUNDRY TECHNOLOGY by O.P.Khanna.

PRINCIPLES OF FOUNDRY TECHNOLOGY by P. L. Jain.

PRINCIPLES OF METAL CASTING by HEINE,

LOPER & ROSENTHAL.

Advancement in Centrifugal & Investment Casting

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