1. Ravinder Pal Singh, Pankaj Sharma Attri, Upinder Kumar Yadav, Sandeep Kumar /
International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622
www.ijera.com Vol. 3, Issue 1, January-February 2013, pp.308-311
Development of self lubricating Cutting tool material for
machining polymer matrix material
Ravinder Pal Singh, Pankaj Sharma Attri, Upinder Kumar Yadav, Sandeep
Kumar
(Department of Mechanical Engineering, M.M.University, Mullana - Ambala, Haryana (India))
ABSTRACT
Dry machining i.e. without use of cutting spacecraft bearings. Evans and Senior [3] reported
fluid has been accepted as most preferred option the performance in plain bearing applications of
for clean manufacturing environment and commercially available self-lubricating materials,
precision machining in space, electronics and including PTFE and other plastics and metals
medical applications. In dry machining, there will containing solid lubricants. Todd [4] reported the
be more friction and adhesion between the tool performance of three specific lubricants, which
and work piece. In this work, an attempt has account for the majority of applications: PTFE-
been made to develop self lubricating cutting tool composite, RF-sputtered MoS2 and ion plated lead
material for machining polymeric composites. film, and then compared in terms of durability and
Powder metallurgy technique is chosen for torque characteristics.
manufacturing the self lubricating cutting tool
material. With the tungsten carbide as base Paxton [5] investigated the operating limits,
material and cobalt as binder material, solid physical properties of carbon, graphite and metal-
lubricant material, molybdenum di-sulphide bonded molybdenum disulphide solid lubricant
(MoS2) material is added during milling. Milling bearings and recommended design practices and life
as well as compaction characterization is carried expectancy. He et at. [6] developed
out to understand the influence of material and polyoxymethylene/molybdenum disulphide
amount of solid lubricant material. Addition of composite and investigated tribological behaviour to
solid lubricant material found to improve the utilize as self lubricating bearing material. Self-
compaction characteristics. Load deflection curve lubrication bearing materials with MoS2 nano-balls
of compaction and powder morphology showed better tribological properties under selected
confirmed this behavior. Compacted specimens testing conditions than those with micro-MoS2
were sintered at controlled atmosphere and platelets. Du et al. [7] developed a coating of
sintering characterization is done. When the tungsten carbide, cobalt and molybdenum disulphide
amount of cobalt is less than a particular amount mixture and investigated the friction and wear
visible cracks were found. Micro structure of behaviour under sliding condition. It is found that
sintered part confirmed the improvement of theMoS2 composition disperses homogeneously in
sintering due to the presence of solid lubricant the coating, which results in the decreasing hardness
material. and fracture toughness for the coating.
Dhanasekaran and Gnanamoorthy attempted to
Keywords: Cutting fluid, Dry machining, Milling, develop sintered steel with self lubricating
Polymeric composite, Powder metallurgy, Self characteristics [8-10]. Iron-copper-carbon sintered
lubrication, Solid lubricants. steels with MoS2 are prepared through powder
metallurgy route, wherein microstructure,
I. INTRODUCTION: mechanical strength is reported. Addition of MoS2
In the recent years, many works has been found to improve compressibility and part density
attempted to develop self lubricating material for the [8]. Sintered steel containing 3 % MoS2 exhibited
various applications such as bearings, gears, cutting reduction in coefficient of friction whereas at
tool and coating [1-10]. sintered steel containing 5 % MoS2 material causes
severe three body contact due to the excessive
Agostino et al. [1] reported the tribological formation of brittle phases [9]. The abrasive wear
properties of sintered iron bearings self-lubricated behavior of sintered steel with MoS2 at different
with perfluoropolyethers under severe operating normal loads is reported [10]. MoS2 added material
conditions [1] .The performance of the PFPE- exhibited high coefficient of friction and good wear
lubricated bearings was found to be superior to that resistance compared to the base composition.
bearings lubricated with mineral oil. Hopple and
Loewenthal [2] reviewed the development and In the present work, attempt has been made
problems encountered in applying recently to develop tungsten carbide cutting tool material
developed sputtered MoS2 films to precision with self lubrication characteristics by powder
308 | P a g e

2. Ravinder Pal Singh, Pankaj Sharma Attri, Upinder Kumar Yadav, Sandeep Kumar /
International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622
www.ijera.com Vol. 3, Issue 1, January-February 2013, pp.308-311
metallurgy technique, wherein compaction and
sintering characteristics of the proposed mixture is
reported 40 0 % MoS2
II. MATERIALS AND PROCESSING: 3 % MoS2
Tungsten carbide (WC) of 1-6µm size with 30
Load (kN)
99.8% purity (Rapicut carbides) as base material,
Cobalt (Co) of 1-6µm of size with 99.5% purity 5 % MoS2
(Loba Chemie) as binder material , molybdenum 20
disulphide(MoS2 ) of 10µm with 98% of purity 7 % MoS2
(Loba Chemie), as lubricant materials are chosen for
the proposed cutting tool material. To understand the 10
effect of binder and solid lubricant on the proposed 10 % MoS2
material over mechanical properties of the proposed
cutting tool material, three different proportion of 0
cobalt and five different proportions of molybdenum 0 1 2 3 4 5 6
disulphide mixtures are chosen. Weight percentage Ram displacement(mm)
of cobalt is chosen as 5 and 10 and weight
percentage of molybdenum di sulphide is chosen as Figure 1: Load and displacement plot of
0, 3, 5, 7 and 10 %. compaction test compacted at 40 KN
Process control agent, stearic acid of 4gms The presence of MoS2 in the test material
is added to the mixture to avoid cold welding during alters the compaction behaviour, from the slope of
milling. The proposed powders are milled in the the second and third stage of load deflection curve, it
planetary ball mill (Insmart system) under nitrogen is apparent that presence of MoS2 found to improve
(0.5kg/cm²) atmosphere, with plate and bowl speed compaction, higher amount of MoS2 contribute to
90 and 207 rpm for 40 hrs and the powder to ball improve compaction further. Presence of MoS2 in
ratio is fixed as 1:5.Plate speed and powder ball ratio the mixture found to reduce the particle size and
is decided to avoid iron pickup during milling reported elsewhere (PFAM Conference Ref).
(PFAM Conference Ref). Effect of milling time and Rigidity of compacted specimen also confirms that
distribution of powder is investigated and reported test material without MoS2 and test material with
with the aid of powder morphology, XRD and SEM small amount of MoS2 (3%) is found to be poor.
and reported elsewhere (PFAM Conference Ref).
.After completion of milling the powder is heated to Hence there is a need to mill these materials beyond
remove the PCA agent stearic acid in the powder in 40 hours so that they can be compacted into rigid
the in house dewaxing unit up to 300°C in a vacuum specimens.
atmosphere with a holding time of 30 min.
IV. SINTERING CHARACTERISTICS:
III. COMPACTION CHARACTERISTICS: The compacted rigid test specimens are
Dewaxed test powders are uniaxially sintered (Okay, Bysakh) in the controlled
compressed (UTE 20) into rectangular transverse environment. The heating and cooling cycle of test
rupture strength specimen of 40 X 16 X 5mm size as specimen is shown in figure 2. Heating rate is
per the ASTM B331-95 at different loads, 40, 44, maintained at 3.2°C/min and sintering is carried out
and 48 kN with displacement rate of 1mm/min. in the nitrogen (0.5kg/cm²) atmosphere to avoid the
Figure 1 shows the load displacement curve of test oxidation. Test specimens with 5 % cobalt exhibits
specimen compaction. From the figure it is infer that mild to severe cracks whereas specimens with 10 %
the compaction take place in three stages. In the first cobalt doesn’t show any cracks as shown in figure 3
stage, particle arrangement, take place which is
significantly influenced by the particle size and
shape. In the second stage, elastic and plastic
deformation takes place which is influenced by the
nature and purity of particles. In the third stage cold
working of the bulk material take place and is
significantly affected by deformation and work
hardening of the particles.
309 | P a g e

3. Ravinder Pal Singh, Pankaj Sharma Attri, Upinder Kumar Yadav, Sandeep Kumar /
International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622
www.ijera.com Vol. 3, Issue 1, January-February 2013, pp.308-311
800
5 % MoS2
600 7 % MoS2
Load (N)
400
200
3 % MoS2
0
0 0.1 0.2 0.3 0.4
Deflection (mm)
Figure 2: View of sintered specimens (a) 5 % Co, Figure 3: Transverse rupture strength of test
5 % MoS2, (b) 5 % Co, 7 % MoS2, (c, d) 10 material
%Co, 5 and 7% MoS2
Green and sintered density of test specimens was
TRANSVERSE RUPTURE STRENGTH, measured by the Archimedean principle. From the
HARDNESS AND MICROSTRUCTURE OF results it is further confirmed that amount of MoS2
SINTERED SPECIMENS significantly contributes to the compaction as well as
density. When the amount of MoS2 increases in the
Transverse rupture strength (TRS) of the
test mixture, density as well as hardness is found to
test material is evaluated as per the ASTM B406-96,
be increased. At lower percentage of MoS2 the
since the proposed material is meant for the cutting
formation of agglomerates is more by which the
tool application using following equation
bonding of particles are not even as with fine
powders. As the percentage of MoS2 increase the
3 P  L compaction of powders is good with fine density by
TRS 
2t2  w which the liquid phase sintering of specimen is also
performed well. Hardness of the sintered specimens
was measured with the micro hardness tester
where P is the force requires to rupture the
(Micromet 2101. Buehler) with indented load of 50
specimen (N), L is the length of the specimen span
of fixture (mm), W is width of the specimen (mm), gms as per the ASTM 3384
T is thickness of specimen (mm) and TRS is 14
transverse rupture strength (MPa).The sintered test
specimens of 3, 5and 7 % MoS2, were tested for 12
transverse rupture strength (TRS) with loading rate
Density( g/mm)-
of 0.25mm/min. Test specimen with 7% MoS2 10
3
exhibited superior strength 85.7MPa; followed by
75.3MPa by 5% MoS2and 10MPa by 8
3%MoS2.These magnitude of strength reflects the Green
role of MoS2in sintering. Figure 5 shows the 6 Sintered
microstructure of fractured sintered specimens,
wherein the role of MoS2 is clearly exhibited 4
2
0
5 6 7 8 9 10 11
Amount of MoS2( %)
310 | P a g e

4. Ravinder Pal Singh, Pankaj Sharma Attri, Upinder Kumar Yadav, Sandeep Kumar /
International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622
www.ijera.com Vol. 3, Issue 1, January-February 2013, pp.308-311
The addition of solid lubricant MoS2 in the tungsten
100 carbide material for the self lubrication purpose is
found to improve compaction as well as sintering
Vickers Hardness (HV)-
characteristics of the proposed material.
80
REFERENCES
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V. CONCLUSIONS: 2007, 617-623.
Development of self lubricating cutting tool
material for dry machining of polymer matrix
material is attempted.
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