ijitce sep 2014

INTERNATIONAL JOURNAL OF INNOVATIVE TECHNOLOGY AND CREATIVE ENGINEERING (ISSN:2045-8711) VOL.4 NO.9 SEPTEMBER 2014

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UK: Managing Editor

International Journal of Innovative Technology and Creative Engineering 1a park lane, Cranford London TW59WA UK E-Mail: [email protected] Phone: +44-773-043-0249

USA: Editor

International Journal of Innovative Technology and Creative Engineering Dr. Arumugam Department of Chemistry University of Georgia GA-30602, USA. Phone: 001-706-206-0812 Fax:001-706-542-2626

India: Editor

International Journal of Innovative Technology & Creative Engineering Dr. Arthanariee. A. M Finance Tracking Center India 66/2 East mada st, Thiruvanmiyur, Chennai -600041 Mobile: 91-7598208700

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IJITCE PUBLICATION

International Journal of Innovative Technology & Creative Engineering

Vol.4 No.9

Septembar 2014

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From Editor's Desk

Dear Researcher, Greetings! Research article in this issue discusses about motivational factor analysis. Let us review research around the world this month. Human brainpower has produced a computer chip reminiscent of the human brain. The new chip, reported in the Aug. 8 Science, scraps the design that formed the basis of decades of computers in favor of an architecture that resembles a bundle of 1 million neurons. Such technology could pinch hit to perform tasks that conventional computers struggle with to identifying objects in photos and videos. It’s an impressive piece of silicon says Stephen Furber, a computer engineer at the University of Manchester in England. “A million neurons on a single chip is a big number.” It has been an absolute pleasure to present you articles that you wish to read. We look forward to many more new technologies related research articles from you and your friends. We are anxiously awaiting the rich and thorough research papers that have been prepared by our authors for the next issue. Thanks, Editorial Team IJITCE


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Contents

Deformation and Fracture Mechanism during Forging of Sintered Preform by

Rajesh Rana…….……………………………………………………………….……………………….[231]


231

Deformation and fracture mechanism during forging of Sintered preform

Rajesh Rana Assistant Professor

Department of Mechanical Engineering RPS Group of Institutions Mahendergarh (Haryana)

E-Mail: [email protected]

Abstract--- Metal powder technology is currently arousing global interest as an economic method of producing components from metal powders. The process is attractive because it avoids large number of operations, high scrap losses and high-energy consumption associated with the conventional manufacturing processes such as casting, machining, etc. The properties of the metal powder products are comparable and in some cases even superior to those of cast and wrought products. The bulk processing of metal powder has therefore wide industrial applications because of good dimensional accuracy and surface finish with enhanced load bearing capacity of the component. So far this technology has been developed and employed without substantial theoretical background. A systematic approach is important to analyze and predict, the behavior of powder perform. Such as, the deforming loads necessary to deform the product plastically, or the density of the product, etc. In conventional wrought metal forming analysis, volumetric constancy is assumed for the deforming material, but this assumption cannot be made in the plastic deformation of porous metals where density does not remain constant and changes with load. The present work will help academician and the person associated with metal powder working in analyzing various properties. Sinter-forging has been commercially exploited in recent times for developing requisite product. Keywords-Sintered Preform, Compaction, Metal Forming, Deformed load, Porous Metal.

I . INTRODUCTION Powder Metallurgy is a process that has been utilized for

centuries, dating back to 2500 B.C. It has become one of the

most common, most efficient processing techniques. Powder

metallurgy components are being used in ever increasing

quantities in a wide variety of industries as the technology

combines unique technical features with cost effectiveness by

reducing quantity of scrape and at the same time cost of

machining is less. Among the various metalworking

technologies, powder metallurgy (P/M) is the most diverse

manufacturing approach. One attraction of P/M is the ability

to fabricate high quality, complex parts to close tolerances. In

essence, P/M takes a metal powder with specific attributes of

size, shape, and Packing, and then converts it into a strong,

precise, high performance shape by compression (1-4). Key

steps include the shaping or compaction of the powder and the

subsequent thermal bonding of the particles by sintering in the

furnace and cooling in the control environment. The cooling

rate also has effect on properties of metal components. The

solution developed in the present work may find a great

potential in automation and solving bulk-processing problems

of metal powder performs (5-7).

The process effectively uses automated operations with

low relative energy consumption, high material utilization,

and low capital costs. These characteristics make P/M well

aligned with current concerns about productivity, energy, and

raw materials. Consequently, the field is experiencing growth

and replacing traditional metal-forming operations. Further,

powder metallurgy is a flexible manufacturing process

capable of delivering a wide range of new materials,

microstructures, and properties (8-13). The formability of

porous metal powder preform has been discussed critically to

illustrate the various processing parameters involved and the

results are presented graphically.

II. Study and Design of Experimental Setup 2.1 Metal Powder Used

Basic experiments were conducted on Copper and

Aluminium metal powder preforms.

(a) Aluminium Powder:- Atomized Aluminium powder of purity 99.5% and finer

than 100 m was used throughout the experiments. The

physical and chemical property of Aluminium powder is given

in the Table-2.1 and Table-2.2 respectively.

Fig.2.1Aluminium powder used in experiment

Apparent Density 1.20 g/cc

Tap Density 2.1 g/cc

Maximum Limits of Impurities-

Iron Contents 0.17%

Copper 0.00159%

Silicon 0.1313%

Manganese 0.0023%

Magnesium 0.00160%

Zinc 0.0053%

Hydrogen Loss 0.4879%

Table 2.1: Physical Characteristics of Atomized

Aluminum Powder used


232

(b) Copper Powder:- Electrolytic Copper powder of greater than 99%

purity was used for preparation of test piece. The physical and

chemical property of Copper powder is given in the Table-2.3

and Table-2.4 respectively.

Apparent Density 2.60 g/cc

Tap Density 7.2 g/cc

Screen

Analysis

(micron)

+100

-100

+150

-150

+200

-200

+240

-240

+350

-350

Percentage

Weight

Retained

0

35.00

15.00

14.50

20.00

14.50

Table2.3: Physical Characteristics of Copper Powder

used

Maximum Limits of Impurities-

Copper 99.80%

Phosphorous 0.001%

Iron 0.006%

Silicon 0.002%

Table 2.4: Chemical Analysis of Sintered Copper

Powder (Weight Percentage)

2.2 Preparation of Specimens and Density Measurement.

In the preparation of metal powder compacts the

following steps are necessary:

1.Die preparation

2.Compaction

3.Sintering

4.Machining

2.2.1 Die preparation Firstly we made the five dies (circular, square,

rectangular, hexagonal) for filling the powder in these, so that

we can get the specimen as our required shape and size. For

this circular dies are made and then we prepare the head and

base for the die.

SPECIFICATION OF DIES

S.No. Die Internal

Diameter

Height

1. circular die 1 16 mm 70mm

2. circular die 2 25.4mm 85mm

S.No Die Side Widt

h

Outer

diameter

Length

1. Hexagonal

die

16m

m

----- 40mm 65mm

2. Square die 20.3

mm

----- ----- 75

3. Rectangula

r die

25.4

mm

20.3

mm

----- 65 mm

Extrusion die set

1. Circular cross-section

Cone angle -7


Cone angle -10


Cone angle -15

Fig.2.2 Circular & Hexagonal cross-section die

2.2.2 Compaction

For compaction firstly the powder material is filled in

the die as shown in the image, in which copper powder is

filled up in the die.

Fig.2.3 Filling of copper powder material

Aluminium and copper both powder was separately

compacted in a closed circular die using a hydraulic press at

various recoded pressures. The die wall was lubricated with

fine graphite powder. After that compaction is done as shown

in next figure. Compaction is done by the help of universal

testing machine (UTM), on which dies are placed and after

then pressure is applied as our requirement.


233

(1) (2) (3)

Fig.2.4 Compaction process on Hydraulic press and

UTM

Fig.2.5 Compacted billets of copper

Fig.-2.6 compacted billets of aluminium

2.2.3 Sintering The basic purpose of sintering is to develop

mechanical strength in the metal powder compacts. Sintering

of aluminium compacts was carried out at 4000C and 4500C

for two hours in an endothermic sand atmosphere and

sintering of copper compacts was carried out at 6000C and

7000C for two hours in an endothermic sand atmosphere. All

sintering operations were carried out in a muffle type silicon

carbide furnace capable of providing sintering temperature of

an accuracy of 50C.

In order to minimize the non-uniformity of density

distribution, the sintered compacts were re-pressed at the same

compaction pressure in the same die. The specimens were

resintered at the same temperature and time.

Fig.-2.7 Sintered billets of copper power

Fig.-2.8 Sintered billets of aluminium powder

Fig.- 2.9 Hexagonal Sintered billets of copper &

aluminium powder

Fig.-2.10 Rectangular Sintered billets of copper &

aluminium powder

2.2.4 Experimental Procedure and Measurements Experiments were conducted on a Universal Testing

Machine and hydraulic press using appropriate dies. The

Aluminium and Copper powder preform of known relative

density was placed between flat dies and was compressed at

room temperature by applying the load. The compression was

carried out in dry and lubricated conditions. Fine graphite

powder was applied as lubricant. The following important

measurements were made:

(i) Increase in relative density of the preform with

increase in compressive load.

(ii) Increase in relative density of the preform with

decrease in height.

In order to evaluate the formability (limit reduction)

the sintered Aluminium and Copper powder preforms of

known initial relative densities were deformed at room

temperature between flat dies. The compressive load was

gradually increased until cracks were observed on the

equatorial free surface of the Aluminium and Copper powder

preform. The percentage compression and the corresponding

compressive load value just at the time of the appearance of

cracks were recorded for all specimens. The experimental

procedure was repeated for five compacts under the similar

processing conditions and an average reading was recorded.


234

repeated for five compacts under the similar processing

conditions and an average reading was recorded.

2.3 Metallographic Test Preparation

Preparation of metallographic specimens generally

requires five major operations: sectioning, mounting (which is

optional), grinding, polishing and etching. A well-prepared

metallographic specimen is sectioned, ground and polished so

as to minimize disturbed or flowed surface metal caused by

mechanical deformation, and thus to allow the true

microstructure to be revealed by etching.

Sectioning

Important uses of metallography other then process

control include: examination of defects that appear in finished

or partly finished products and studies of parts that have failed

in service. Investigations for these purposes usually require

that the specimen be broken from a large mass of material,

and often involve more than one sectioning operation.

2.3.1 Mounting of Specimen

Compression mounting, the most common mounting

method, involves molding around the specimen by heat and

pressure such molding materials as Bakelite diallyl phthalate

resins, and acrylic resins. Bakelite and diallylic resins are

thermosetting, and acrlyic resins are thermoplastic. Both

thermosetting and thermoplastic materials require heat and

pressure during the molding cycle, but after curing, mounts

made of thermosetting materials may be ejected from the

mold at maximum temperature. Thermoplastic materials

remain molten at the maximum molding temperature and must

cool under pressure before ejection.

Mounting presses equipped with molding tools and a

heater is necessary for compression mounting. Readily

available molding tools for mounts having diameters of 1 inch

are used for mounting of specimen. Consist of a hollow

cylinder of hardened steel, a base plug, and a plunger.

Fig.-2.11 Specimen mounting machine mounted

specimen

A specimen to be mounted is placed on the base

plug, which is inserted in one end of the cylinder. The

cylinder is nearly filled with molding material in powder

form, and the plunger is inserted into open end of the cylinder.

A cylindrical heater is placed around the mold assembly,

which has been positioned between the platens of the

mounting press. After the prescribed pressure has been

exerted and maintained on the plunger to compress the

molding material until it and the mold assembly has been

heated to the proper temperature nearly for 10 minute, the

finished mount may be ejected from the mould by forcing the

plunger entirely through the mold cylinder.

2.3.2 Finishing Process

Grinding is accomplished by abrading the specimen

surface through a sequence of operations using progressively

finer abrasive grit. Grit sizes from 40 mesh through 150 mesh

are usually regarded as coarse abrasives and grit sizes from

180 mesh through 600 mesh as fine abrasives.

Grinding should commence with coarse grit size that will

establish an initial flat surface and remove the effects of

sectioning within a few minutes. An abrasive grit size 150 or

180 mesh is coarse enough to use on specimen surfaces

sectioned by an abrasive cutoff wheels. Hacksawed, band

sawed or other rough surfaces usually require abrasive grit

sizes in the range 80 to 150 mesh. The abrasive used for each

succeeding grinding operation should be one or two grit size

smaller than that used in the preceding operation. A

satisfactory grinding sequence might involve grit sizes of 180,

240, 400, 600, 800, 1000 and 1200 meshes.

Sr.

No.

Metal

Powder

Used

Sintering Temp. &

Time

Shape/Size of the Preform

1. Copper

6000C

6300C

6500C

For 3

hours

1.Cylindrical

16mm X 12mm

2. Square

20mm X 20mm X 11mm

3.Hexagonal

side-15mm

height-12mm

4.cilinderical

16mm X 12mm

16mm X 12mm

2.

Alumini

um

4000 C

4500C

For 3

hours

1.Cylindrical

16mm X 15mm

16mm X18mm c. 19mm X 26mm

2. Cylindrical

25.4mm X 16mm

25.4m X18mm

16mm X 20mm

3.Hexagonal

side-20.3mm

height-13mm

4.cilinderical

16mm X 22mm


235

Fig.2.12 Amery paper used for primary finishing

Grinding Mediums

The grinding abrasives commonly used in the

preparation of specimens are silicon carbide (SiC), aluminium

oxide (Al2O3), emery (Al2O3 - Fe3O4), diamond particles,

etc. Usually are generally bonded to paper or cloth.

Aluminium oxide abrasive material has a trigonal crystal

structure and a hardness of 9.1 on the Morhs scale and is

synthetic corundum.

Lapping

Is a grinding technique similar to disk grinding. The

grinding surface (lap) is a rotating disk whose working surface

is charged with a small amount of a hard abrasive material.

Laps are made of wood, lead, nylon, paraffin, paper, leather,

cast iron and laminated plastics. The abrasive charge may be

pressed into lap material by means of a steel block, or the lap

may be charged directly with a mixture of abrasive and

distilled water during lapping. A groove in the form of a spiral

is a direction counter to the lap rotation is often cut in the

surface of laps, particularly of lead and paraffin laps. The

spiral groove aids retention of cooling water and abrasive.

2.3.3 Polishing

Polishing is the final step in production a surface that

is flat, scratch free, and mirror like in appearance. Such a

surface is necessary for subsequent accurate metallographic

interpretation, both qualitative and quantitative.

Polishing Cloths

A cloth without nap or with a very low nap is

preferred for the preliminary or rough polishing operation.

The absence of nap ensures maximum contact with the

polishing abrasive, and results in fast cutting with minimum of

relief. The cloths most frequently used are canvas, low-nap,

cotton, nylon and silk. After installation, the cloths are

charged with the appropriate abrasive (usually in sizes from

15 microns down to 1 micron) and carrier. Rough polishing is

usually done with the laps rotating at 500 to 600 rpm.

Fig.-2.13 Polishing machine polishing process

Polishing Abrasives

Polishing usually involves the use one or more of

five types of abrasive: aluminium oxide (Al2O3), magnesium

oxide (MgO), chromic oxide (Cr2O3), iron oxide (Fe2O3),

and diamond compound. With the exception of diamond

compound these abrasives are normally used in a distilled

water suspension. Aluminium oxide (alumina) is the polishing

abrasive most widely used for general metallographic

polishing. The alpha grade aluminium oxide is used in a range

of particle sizes from 15 microns to 0.3 micron. For some hard

materials the 0.3 micron size is sufficient for a final polish.

The gamma grade of aluminium oxide is available in a 0.05

micron particle size for final polishing.

Fig.2.14 Aluminium Oxide (polishing abrasive)

2.3.4 Etching

Although certain information may be obtained from

as-polished specimens, the microstructure is usually visible

only after etching. Only features which exhibit a significant

difference in reflectivity (10% or greater) can be viewed

without etching.

Chemical Etching

Chemical etching is based on the application of

certain illumination methods, all of which use the Kohler

illumination principle. This principle also underlies common

bright-filed illumination. These illumination modes are dark

field, polarized light, phase contrast and interference contrast.

They are available in many commercially produced

microscopes, and in most cases, the mode may be put into

operation with few simple manipulations.

Fig.-2.15 Etching Agent (methanol)

Cleaning

Cleanliness is an important requirement for

successful sample preparation. Specimens must be cleaned

after each step; all grains from one grinding and polishing step

must be completely removed from the specimen to avoid

contamination, which would reduce the efficiency of the next

preparation step. Through cleaning is particularly critical after

fine grinding and before rough polishing and all subsequent

steps.


236

After cleaning, specimens may be dried rapidly by

rinsing in alcohol, benzene, or other low-boiling-point liquids,

then placed und a hot-air drier for sufficient time to vaporize

liquids remaining in cracks and pores. Rinsing is most

frequently used and consists of holding specimen under a

stream of running water and wiping the surface with a soft

brush or cotton swab.

Fig.2.16 Prepared specimen for metallography

Fig. 2.17 Metallurgical Microscope

3. Experimental Results And Discussion Densification

Densification of Aluminium and Copper powder

preform before and after deformation is governed by several

factors, which interact with each other in a complex manner.

Some of the important factors considered here are as follows:

(a) Powder Particle Size-

Powder particle size has a remarkable effect on the

relative density which in turn affects deformation

characteristics and fracture mechanisms of the metal powder

preforms. The influence of powder particle size on the relative

density of the copper powder preforms compacted at 30

kg/mm2 and sintered at 6500C and the influence of powder

particle size on the relative density of the aluminium powder

preforms compacted at 10 kg/mm2 and sintered at 4500C and.

The decrease in grain size of powder, however, results in more

densification and improvement in formability of the powder

preforms. Poor flow rate for finer particles are also observed.

(b) Compacting Pressure-

Figure 3.1.1 & fig 3.1.2 shows the relative density

variation with increase in compacting pressure. It is seen that

the relative density of the Aluminium and Copper powder

preform increases gradually with increase in compacting

pressure. The formability of Aluminium and Copper powder

preforms improves at higher compacting pressure.

Combine figure and table for various compacting pressure and different temperature range (600˚C -

650˚C) for copper Table.3.1.1

At Temp- 620˚C 630˚C 640˚C 650˚C

LOAD REL. DEN. REL. DEN. REL. DEN. REL. DEN.

1.5 0.574588 0.61553 0.62821 0.6351683

2 0.613005 0.64388 0.6541 0.65117385

2.5 0.676908 0.67877 0.70448 0.71921792

3 0.696438 0.6979 0.71242 0.74385264

3.5 0.705491 0.72734 0.75162 0.763821478

1.5 2.0 2.5 3.0 3.5

0.56

0.58

0.60

0.62

0.64

0.66

0.68

0.70

0.72

0.74

0.76

0.78

Rel

ati

ve

Den

sity

Load (P)

At Temp = 6200

At Temp =6300

At Temp = 6400

At Temp =6500Load Vs. Relative Density

Fig.-3.1.1

Fig. 3.11 shows load Vs. relative density for various sintering

temperature, considerable pattern for increase in relative

density. In Fig: 3.1.1 relative density increases with rapid rate

from load 0 - 2.5 tone. After that rate of increase in relative

density decrease in the range of load from 2.5 – 3 tone.

Further increase in load shows an increased rate of increase in

relative density. So we can conclude that compacting pressure

range for copper components is 3 tones to 4.5 tones per inch

square for better quality and for obtaining relative density near

to unity i.e. density of copper powder components approaches

to the density of solid copper .

Combine figure and table for various compacting

pressure and different temperature range (400˚C-

450˚C) for aluminium Table.-3.1.2

At Temp 410˚C 420˚C 430˚C 440˚C

LOAD Rel.

Density Rel.

Density Rel.

Density Rel. Density

1.5 0.707582 0.70397 0.71835 0.71081079

2 0.757399 0.76256 0.76758 0.8302024

2.5 0.775723 0.78334 0.79867 0.83108403

3 0.819335 0.82335 0.82836 0.84860878

3.5 0.853088 0.86611 0.87309 0.88458159

Fig: 3.1.2 load Vs. relative density for various

sintering temperature shows a considerable pattern for

increase in relative density. In Fig: 3.1.2 relative density

increases with rapid rate from load 0 – 2 tone. After that rate

of increase in relative density decrease in the range of load


237

from 2 -2.5 tone. Further increase in load shows an increased

rate of increase in relative density. So we can

1.5 2.0 2.5 3.0 3.5

0.70

0.72

0.74

0.76

0.78

0.80

0.82

0.84

0.86

0.88

0.90

Rel

ativ

e D

ensi

ty

Load (P)

Load Vs. Relative Density

At Temp = 4200

At Temp =4300

At Temp = 4100

At Temp = 4400

Fig.- 3.1.2 Variation between load in tone and

relative density conclude that compacting pressure range for aluminium

components is 3 tones to 4 tones per inch square for better

quality and for obtaining relative density near to 1. i.e. density

of aluminium powder components approaches to the density

of solid aluminium.

(c) Sintering Temperature The basic purpose of sintering is to improve the

strength of green compacts. Fig: 3.3.1 & Fig: 3.3.2 shows the

variation of relative density with the sintering temperature for

preforms compacted at various compacting pressure. It is

observed that the relative density of the Aluminium and

Copper powder preform increases with both the sintering

temperature and compacting pressure.

3.3 Relation Between Temperature And Relative Density At Different Load

Table.-3.3.1

3.3.1 For Aluminium

410 415 420 425 430 435 440

0.5

0.6

0.7

0.8

0.9

Temp Vs Relative Density

Rel

ativ

e D

ensi

ty p

/po

Temp

AT 1.5 load

AT 3.5 load

AT 2.5 load

AT 2.0 load

AT 3.0 load

Fig .-3.3.1

As shown in the Fig: 3.3.1 relative density increases with the

increase in sintering temperature. It is experimentally found

that the pieces held at greater sintering temp. have the high

density as compared to the pieces held at relatively low

sintering temp. This difference in the density occurs due to the

bonding formation between the powder particles. At relatively

high temp. Crystallization takes place and bonding starts

between the particles as a result void reduced in the metal

preform hence density increases. Crystallization Temp. for

aluminium is 450˚C.

3.3.2 For Copper

Relation between Temperature and Relative density at

different Load

Table.-3.3.2

1.5

load 2.0 load 2.5 load 3.0 load 3.5 load

Temp Rel.

Den

Rel.

Den Rel. Den Rel. Den Rel. Den

620 0.574

588

0.61300

5 0.676908

0.6964382

3 0.705491

630 0.615

528

0.63388

2 0.678769

0.6978995

4 0.727345

640

0.62

8212

0.6540

97

0.70447

8

0.712417

93

0.75161

7

650 0.63

5168

0.6511

74

0.71921

8

0.743852

64

0.76382

1

620 625 630 635 640 645 650

0.56

0.58

0.60

0.62

0.64

0.66

0.68

0.70

0.72

0.74

0.76

Temp Vs Relative Density At Load 3.5 T

At Load 3.0 T

At Load 2.5T

At Load 1.5 T

At Load 2.0 T

Rel

ati

ve

Den

sity

p/p

o

Temp

Fig:-3.3.2

As shown in the Fig: 3.3.2 relative density increases with the

increase in sintering temperature. It is experimentally found

that the pieces held at greater sintering temp. have the high

density as compared to the pieces held at relatively low

sintering temp. This difference in the density occurs due to the

bonding formation between the powder particles. At relatively

high temp. Crystallization takes place and bonding starts

between the particles as a result void reduced in the metal

preform hence density increases.

1.5 load 2.0 load 2.5 load 3.0 load 3.5 load

Temp. Rel. Den Rel. Den Rel. Den Rel. Den Rel. Den

410 0.707582 0.757399 0.775723 0.819335 0.853088

420 0.70397 0.76256 0.80334 0.82335 0.86611

430 0.71835 0.76758 0.77786 0.82836 0.87309

440

0.71081 0.8302 0.83108 0.84861 0.88458


238

(d) Compression

The influence of compression is to increase the

relative density of the metal powder preform. The relative

density of the preform increases with increase in compressive

load as shown in Fig: 3.1.1 and Fig: 3.1.2. The relative

density of the preform increases very sharply at the beginning

of loading and then increases slowly with increase in load.

After attaining 1 the preform starts yielding significantly.

For simple compression, the pressure distribution at

the die-work piece interface decreases from the center towards

the edge. The decrease in adhesion friction results in a further

decrease in the pressure distribution which in turn affects the

relative density. Therefore, the relative density is a function of

pressure and flow stress of the metal powder preform.

3.4 Result and discussion of matelography test

Effect of sintering temperature on microstructure of copper preform

Fig: 3.4.1 Copper (sintering temp=600˚C) & Copper

(sintering temp=620˚C)

Fig: 3.4.2 Copper (sintering temp=640˚C) & Copper

(sintering temp=650˚C) The above photograph of microstructure shows the

effect of sintering temperature on bonding of metal powder.

These micrograph shows that the grain size was enlarged

approximately 2 times (from about 0.4µm at 600c to about

0.75 µm at 650˚C after 120 min.). Grain size increases with

increase in sintering temperature. At low temperature bonding

between the particle does not take place. When there is

increase in the sintering temp. , crystallization stage reached

where bonding between particles takes place which result in

the uniform micrograph as shown in above fig for sintering

temp. 650˚C. A densification of about 12% and relative

density of approximately 65% to 77% of the pore-free value

were obtained during the solid state sintering of Cu. From

temp.600˚C to 650˚C.

Fig: 3.4.3 Void between the bonded particles of

powder The above micrograph shows the formation of void due to

interruption of air between the metal powders during

compaction process. Air does not release from the preform

and filled between the interstitial sites which result in the

formation of void as shown in the above micrograph. These

void are formed due to compacting pressure simultaneously

void can be reduced by increasing the compacting pressure

and by using suitable die design.

Effect of sintering temperature on microstructure of aluminium perform

Fig: 3.4.4 Aluminium (sintering temp=400˚C);

Aluminium (sintering temp=420˚C) &Aluminium (sintering temp=430˚C)

Fig: 3.4.5 Aluminium (sintering temp=440˚C) &

Aluminium (sintering temp=450˚C) The above photograph of microstructure shows the effect

of sintering temperature on bonding of metal powder. These

micrograph shows that the grain size was enlarged

approximately 2 times (from about 0.1μm at400˚C to about

1.75 μm at 450˚C after 150 min.). Grain size increases with

increase in sintering temperature. At low temperature bonding

between the particles does not take place. A densification of

about 5% and relative density of approximately 84% to 89%

of the pore-free value were obtained during the solid state

sintering of Cu. From temp.400˚C to 450˚C. When there is

increase in the sintering temp. , crystallization stage reached

where bonding between particles takes place which result in

the uniform micrograph as shown in above fig for sintering

temp. 450˚C.

V. CONCLUSION

On the basis of above experiments some basic rules are

established and these rules will be very much helpful for

analysis of the deformation characteristics of the metal

powder performs for evaluating the various parameters such

as die load, internal power of deformation, relative density

distribution etc. These rules are also used for verifying the

experimental results with theoretical mathematical solutions.

REFERENCES

[1].A.K Jha and S.Kumar: Int. J.Mach. Tool Des.Res.,1983,

23,201-210.

[2].A.K.Jha and S.Kumar: Adv. Tech Plast., 1984, 1, 353-357.

[3].A.K Jha and S. Kumar: J. Inst. Eng. Ind.,1985,65,169-174.

[4]. B. V. Deryagin, “What is Friction”, IZD, AKAD, NAUK,

USSR, 1952.

[5]. A. W. Rooks,”The Effect of Die Temperature on Metal

Flow & Die Wear During High speed Hot Forging”, Proc.

15th Int MTDH Conference, Birmingham, p487, sept. 1974.

[6]. H. A. Kuhn & C. L. Downey, “Deformation

Characteristics & Plasticity Theory of Sintered Powder

materials”, Int. J. of Powder Metallurgy, Vol. 7, p15, 1971.

[7]. R. J. Green, Int. J. of Mech. Sci., Vol. 14, p215, 1972.


239

[8].M. Oyane, S. Shima & Y. Kono, “Bull. Japan Soc. Mech.

Engrs., 16-99, p 1254, 1973.

[9].M.Oyane & T.Tabata, J.Soc.Technol.Plasticity,155-156, p

43,1974.

[10] P. Ramakrishna: Proc.Int.Seminar on Metal Working

Technology Today & Tomorrow,Ranchi,India,1980,43-46.

[11] T. Tabata & S. Masaki, “A Yield Criterion for Porous

Metals Analyses of Axial Compression of Pours Disks”,

Memoirs of The Osaka Institute of Technology, Series A:

science & Technology, Vol. 22, No. 2, 1972.

[12] T. Wonklin, “Friction at High Normal Pressure”, Proc.

First Wcit, Paper No. F-7,1972.

[13] T.Tabata.,S.Masaki and K. Hosokawa: Int. J. Powder

Metallurgy Powder Tech., 1980, 16, 149-161.


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