The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method
The present study investigated the effect of the temperature, at which a new matrix material was produced via hot isostatic pressing (HIP) method by adding certain rate of Co and Ni elements into CuSn (85/15) bronze alloy, and Co and Ni elements wear resistance of the samples produced. One of major...
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Інститут надтвердих матеріалів ім. В.М. Бакуля НАН України
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Tülay Yıldız Süleyman Aba 2020-03-24T12:28:28Z 2020-03-24T12:28:28Z 2019 The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method / Tülay Yıldız, Süleyman Aba // Надтверді матеріали. — 2019. — № 3 (239). — С. 21-35. — Бібліогр.: 25 назв. — англ. 0203-3119 https://nasplib.isofts.kiev.ua/handle/123456789/167308 621.762.5:536.421.5 The present study investigated the effect of the temperature, at which a new matrix material was produced via hot isostatic pressing (HIP) method by adding certain rate of Co and Ni elements into CuSn (85/15) bronze alloy, and Co and Ni elements wear resistance of the samples produced. One of major advantages of HIP method is that heat and pressure are applied simultaneously during the sintering process. Thus, all or almost all of the pores are eliminated during the manufacturing and a denser material is obtained. Досліджено вплив температури, при якій новий матричний матеріал було отримано методом HIP (горячого ізостатичного пресування) при додаванні певного відсотка елементів Co і Ni до бронзового сплаву CuSn (85/15), а також елементів Co і Ni, на зносостійкість виготовлених зразків. Однією з головних переваг методу HIP є те, що нагрівання і тиск застосовуються одночасно у процесі спікання. Таким чином, всі або майже всі пори видаляються під час виготовлення і отримується більш щільний матеріал. Исследовано влияние температуры, при которой новый матричный материал был получен методом HIP (горячего изостатического прессования) путем добавления определенной доли элементов Co и Ni в бронзовый сплав CuSn (85/15), а также элементов Co и Ni, на износостойкость изготовленных образцов. Одним из основных преимуществ метода HIP является то, что нагревание и давление применяются одновременно во время процесса спекания. Таким образом, все или почти все поры удаляются во время изготовления, и получается более плотный материал. The research was supported by the Fırat University Scientific Research Projects Unit (Project No: TEKF.14.05). en Інститут надтвердих матеріалів ім. В.М. Бакуля НАН України Сверхтвердые материалы Одержання, структура, властивості The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method Article published earlier |
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The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
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The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method Tülay Yıldız Süleyman Aba Одержання, структура, властивості |
| title_short |
The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
| title_full |
The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
| title_fullStr |
The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
| title_full_unstemmed |
The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
| title_sort |
effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method |
| author |
Tülay Yıldız Süleyman Aba |
| author_facet |
Tülay Yıldız Süleyman Aba |
| topic |
Одержання, структура, властивості |
| topic_facet |
Одержання, структура, властивості |
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2019 |
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English |
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Сверхтвердые материалы |
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Інститут надтвердих матеріалів ім. В.М. Бакуля НАН України |
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Article |
| description |
The present study investigated the effect of the temperature, at which a new matrix material was produced via hot isostatic pressing (HIP) method by adding certain rate of Co and Ni elements into CuSn (85/15) bronze alloy, and Co and Ni elements wear resistance of the samples produced. One of major advantages of HIP method is that heat and pressure are applied simultaneously during the sintering process. Thus, all or almost all of the pores are eliminated during the manufacturing and a denser material is obtained.
Досліджено вплив температури, при якій новий матричний матеріал було отримано методом HIP (горячого ізостатичного пресування) при додаванні певного відсотка елементів Co і Ni до бронзового сплаву CuSn (85/15), а також елементів Co і Ni, на зносостійкість виготовлених зразків. Однією з головних переваг методу HIP є те, що нагрівання і тиск застосовуються одночасно у процесі спікання. Таким чином, всі або майже всі пори видаляються під час виготовлення і отримується більш щільний матеріал.
Исследовано влияние температуры, при которой новый матричный материал был получен методом HIP (горячего изостатического прессования) путем добавления определенной доли элементов Co и Ni в бронзовый сплав CuSn (85/15), а также элементов Co и Ni, на износостойкость изготовленных образцов. Одним из основных преимуществ метода HIP является то, что нагревание и давление применяются одновременно во время процесса спекания. Таким образом, все или почти все поры удаляются во время изготовления, и получается более плотный материал.
|
| issn |
0203-3119 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/167308 |
| citation_txt |
The effect of sintering temperature on wear resistance of alloys produced by using hot isostatic pressing method / Tülay Yıldız, Süleyman Aba // Надтверді матеріали. — 2019. — № 3 (239). — С. 21-35. — Бібліогр.: 25 назв. — англ. |
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2025-11-25T23:10:30Z |
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2025-11-25T23:10:30Z |
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1850579061425831936 |
| fulltext |
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 21
UDC 621.762.5:536.421.5
Tülay Yıldız*, Süleyman Aba
Fırat University, Faculty of Technology, Department of Metallurgical
and Materials Engineering, Elazığ, Turkey
*tyildiz@firat.edu.tr
The effect of sintering temperature on wear
resistance of alloys produced by using hot
isostatic pressing method
The present study investigated the effect of the temperature, at which
a new matrix material was produced via hot isostatic pressing (HIP) method by adding
certain rate of Co and Ni elements into CuSn (85/15) bronze alloy, and Co and Ni
elements wear resistance of the samples produced. One of major advantages of HIP
method is that heat and pressure are applied simultaneously during the sintering
process. Thus, all or almost all of the pores are eliminated during the manufacturing
and a denser material is obtained. During the study, sintering pressure and sintering
time were kept constant as 15 min, and also sintering temperature was selected to be
700 and 800 °C as the variable parameter. Sintering process was carried out under
vacuum starting from the first burn. The produced samples were then prepared
metallographically and SEM and EDS analyses were performed for microstructure
examinations. Microhardness of the samples was taken to investigate mechanical
behaviors of the samples and they were subjected to wear test. Finally, density test was
applied to samples and their experimental and theoretical densities were calculated. In
conclusion, it was seen that more homogenous samples were obtained as sintering
temperature increased. As Co amount and temperature increased in the study, wear
resistance increased.
Keywords: hot ısostatic pressing, powder metallurgy, microhardness,
abrasive wear.
INTRODUCTION
New material technologies require the improvement of material characteristics
such as wear and corrosion resistance and strength properties. Powder metallurgy
(PM) has much to offer because sintering of powder materials produces materials
of extremely fine and uniform microstructure and enables the formulation of mate-
rials composed from different constituents yielding unique property combinations
[1–3].
The wear resistance of the composite was found to be much higher than that of
the matrix alloy. It expands with expanding the molecule content as the hard
particulates resist the wear action of abrasion and give protection to the surface,
meaning that; when the content increases, the wear resistance will be enhanced [4].
Powder metallurgy is a general name given to the technique of shaping pure
metal and alloy metal powders in a mold and bringing the strength to them with
heat treatment (sintering). In recent years, the number and variety of parts
produced by powder metallurgy method have increased. Main reasons for this are
affordability, their high strength as well as low densities and production for
specific uses [5]. Hot isostatic pressing (HIP), which is one of the production
© TÜLAY YILDIZ, SÜLEYMAN ABA, 2019
http://stmj.org.ua 22
methods of powder metallurgy, is a method containing high pressure gas in which
pressure is applied isostatically to one or more parts in order to produce completely
dense materials [6].
Co and Ni powders are used in an opposite amount to the Cu–Sn contribution as
diamond-binding phase in accordance with their good wetting properties. Cu–Sn
addition can be in the form of a mixture of Cu and Sn powders or in the form of
pure bronze powder. The manufacturer specifies the use mode with the pressure
sintering application characteristic [7]. The best result in bronze-based material
production and abrasion tests performed after the production with the powder
metallurgy method by adding ceramic powder in different types and rates was
obtained at 350 MPa pressing pressure and at 820 °C temperature. It was found
from the microstructure images that low-melting powders in the material formed
liquid phase sintering and accordingly the pores shrank. It was also observed that
some of the metal powders with low melting temperature evaporated during
sintering [8].
Park et al. joined FeCrAl and Zr alloys with HIP method for melting energy
applications. In the study, they chose the HIP temperatures between 700 °C and
1050 °C. They evaluated the mechanical properties of HIPped samples with four-
point bending and tensile tests. They obtained higher strengths from the samples
obtained with HIP at 700 °C. They stated that with increasing HIP temperature, the
diffusion layer forming in the interface and its thickness increased and intermetallic
compound and cavity were not observed at the interface up to 950 °C [9]. Tam et
al., investigated the effects of temperature on production of Cr and Si by hot
isostatic pressing. They examined the microstructures and porosity properties of
the samples. As a result of the study, they determined the optimum temperature as
1373 K [10]. Elrakayby et al., investigated the condensation behavior of nickel
alloy powder during the hot isostatic pressing by using the finite elements method
[11]. Chang et al., examined the effect of temperature on microstructure and tensile
properties by using hot isostatic pressing method in the compacting of Inconel 718
powder. They noted that the density of MC carbide particles decreased with
increasing temperature and a yield resistance of 0.2 % formed with increasing HIP
temperature [12]. Copper-based materials are generally used as plain bearing
material owing to their properties such as high corrosion resistance, high thermal
and electrical conductivity, self-lubrication, and high wear resistance [13]. Role of
tin having an anti-friction property among copper-based materials is important for
wearing. Copper-based tin bronzes containing tin are used as bearing material
because they display high resistance to wear [14]. Friction and wear properties of
these materials are proportionally positively influenced by the rate of tin in
manufactured parts [15, 16]. Amount of bronze compound used in cases where
intensive matrix wear is expected is increased by 70 % and the amount of bronze is
decreased only to quantity of filling stage (< 5 %) that is required to cover pores
when low wear is expected. Based on their well wetting property, powders of Co
and Ni are used in a reverse proportion to Cu–Sn addition as diamond bonding
stage. Cu–Sn addition can be in the form of a mixture of Cu and Sn powders or
pure bronze powder. Producer determines the way of use by characteristic of
pressure sintering [7]. In their study, Karagöz et al., changed the conditions of
sintering by keeping constant the matrix compound, consisting of powder grains
from Co, Ni and Cu + Sn. As a result of field studies and bending strength tests, the
best result was obtained at 730 °C with sintering time of 15 min [17]. In their
study, Boz and Kurt produced bronze-based brake pads by using powder
metallurgy method and tested friction-wear performances of the produced brake
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 23
pads. At the second stage, they produced by adding Zn powder of 0.5–0.4 % into
bronze-based pad powders and compared the two materials by applying the same
tests. While the optimum wear resistance was identified in the sample containing
0.5 % Zn, the optimum friction coefficient was identified in the sample containing
2 % Zn [18]. In their study, Ünlü et al., determined wear and mechanical properties
of copper-based CuSn10, Fe-based Fe–graphite, FeCu–graphite, and bronze–iron-
based CuSnFe–graphite bearings produced by P/M method and compared them
with each other. As a result of the experiments, it was revealed that cast bearings
had higher mechanical properties than bearings produced via P/M method [19].
The optimum result was obtained at 350 MPa of pressing pressure and at 820 °C in
the production of bronze-based material via powder metallurgy method by adding
various types and rates of ceramic powder and in the wear test made following the
production [8]. In the study by Lin D. et al. VN alloy/Co-based composite coatings
modified by Ti were prepared on a mild steel using laser cladding. The effect of Ti
addition on the microstructure and wear resistance of VN alloy/Co-based coatings
was investigated using optical microscopy, X ray diffraction, scanning electron
microscopy, energy dispersive spectroscopy, transmission electron microscopy,
microhardness tester and wear tester [20]. In the study by R. Ahmed et al., HIP-
consolidation of cobalt-based Stellite alloys offerred significant technological
advantages for components operating in aggressive wear environments. The aim of
this investigation was to ascertain the effect of re-HIPing on the HIPed alloy
properties for Stellite alloys 4, 6 and 20. Structure-property relationships are
discussed on the basis of microstructural and tribo-mechanical evaluations. Re-
HIPing results in coarsening of carbides and solid solution strengthening of the
matrix. The average indentation modulus improved, as did in the average hardness
at micro- and nano-scales. Re-HIPing showed improvement in wear properties the
extent of which was dependent on alloy composition [21]. By considering the
literature studies, the changes caused by cobalt and nickel elements at different
rates in the matrix structure were investigated and abrasive wear test was applied to
determine wear behaviors of the samples produced in the present study.
MATERIAL AND METHODS
In this study, a new matrix material was produced by adding Co and Ni
elements into 85/15 bronze alloy at certain rates. In the study, the metal powders
used were obtained in the grain size specified in Table 1.
Table 1. Grain sizes of the metal powders
Powder Bronze (85/15) Cobalt Nickel
Size, µm 70 35 5
Before the sintering process, the powders were prepared in groups at the rates
indicated in Table 2 in a powder weighing device (Fig. 1, a) with sensitivity of
1/1000. The proportionally prepared sample compositions were stirred for 20 min
in the mixing unit. In order for the powders to be processed at a certain size and
shape before sintering, the polyethylene glycol binder of 1 % was added to the
mixture In order to make the mixing process more homogeneous, iron beads and
chains at different diameters were left in the mixing cap. The samples were then
subjected to pre-pressing process in the dimensions of 10×20×40 mm in the cold
pressing machine (see Fig. 1, b). The pre-pressed samples were taken into pre-
prepared graphite molds and made ready for sintering. In order to make the
sintering process better, graphite mold was lubricated with a lubricant.
http://stmj.org.ua 24
a b
Fig. 1. Powder weighing device (a), cold press (b).
Table 2. Weight distribution of sample groups
Weight distribution of the sample groups, g
Group
bronze (85/15) cobalt nickel binder total
S1–S2 205 0 6 4 215
S3–S4 193 12 6 4 215
S5–S6 180 25 6 4 215
S7–S8 168 37 6 4 215
The matrix samples were produced in Çel-mak industry and Commerce ltd.
company. During the production of the samples, constant sintering pressure of
30 MPa, constant sintering time of 15 min and two sintering temperatures of 700
and 800 °C were used. While the sintering temperature is determined by taking 2/3
or 4/5 of the melting temperature of metal in single component systems, the
sintering temperature in the systems with more than one component is selected
below the melting temperature of the component with high melting temperature
and above the melting temperature of the component with low melting temperature
(Cu melting temperature was 1.085 °C and Sn melting temperature was 231.9 °C).
The sintering temperature in the study was determined by considering the Cu–Sn
dual balance diagram given in Fig. 2. The samples were produced with HIP
T
em
pe
ra
tu
re
, °
C
Tin, at % Cu Sn
0 10 20 30 40 50 60 70 80 90 100
100
200
300
400
500
600
700
800
900
1000
1100
1200
Fig. 2. Cu–Sn dual phase diagram [22].
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 25
method, a powder metallurgy production method. The sintering process was
carried out under vacuum after the first burn. The samples were produced in
dimensions of 10×10×40 mm (Fig. 3). Table 3 shows the amounts and the
production parameters of the metal powders used during the production.
Fig. 3. Samples produced by the HIP method.
Table 3. Production parameters of the samples
Group
Sintering
pressure, MPa
Sintering
temperature, °C
Sintering
time, min
Bronze,
%
Cobalt,
%
Nickel,
%
S1 30 700 15 97 0 3
S2 30 800 15 97 0 3
S3 30 700 15 92 5 3
S4 30 800 15 92 5 3
S5 30 700 15 87 10 3
S6 30 800 15 87 10 3
S7 30 700 15 82 15 3
S8 30 800 15 82 15 3
For the metallographic analysis of the produced samples, the surfaces of the
samples were cleaned with 200, 320, 500, 800, 1000 and 1200 mesh sandpaper,
respectively, and then polished with 3 μm diamond paste. Polished samples were
subjected to etching process with pre-prepared etchant and EDS analyses were
carried out to investigate the matrix material and to determine the compound of the
compositions in the produced samples.
Microhardness measurement was made under a load of 500 g, at waiting period
of 10 s, and at a distance of 1 mm to determine hardness of the samples produced
via HIP method. The samples were then subjected to abrasive wear test to
determine wear resistance of the samples. Abrasive wear samples were worn once
they were prepared in the sizes of 10×10×10 mm. Figure 4 shows abrasive wear
apparatus and its parts. Abrasive wear test was performed by abrasion of surface of
the sample. The tests were carried out using abrasion apparatus with pin-on disc
system. Abrasive wear tests were applied using 120 mesh SiC sanding cylinder and
applying two different loads, 5 and 15 N. Wear test was applied individually under
every load at 10, 20, 30 m distances. In the abrasive wear tests carried out on
turning lathe rotation speed and feed rate were chosen as 16 rpm and 2.8 mm,
respectively. By taking the diameter of abrasive sanding cylinder into account, total
distance was determined by calculating circumference of the cylinder. Operation of
http://stmj.org.ua 26
turning lathe was based on 16 rpm. In the system, sample works by applying a load
to abrasive from the top with a straight angle of 90°.
A�Cross section
Sample
Sample socket
Ball bearing
Weared surface
Load Table
Balance load
Abrasive
wear
Fig. 4. Wearing device and parts [23].
DENSITY CALCULATION
The density measurements of the samples produced with the HIP method were
calculated according to Archimedes’ principle. The density measurements were
performed with the AD-1653 brand
density measurement kit in Fig. 5.
Firstly, the weight of the samples in
air and then their weight in water
were measured and their expe-
rimental densities were determined
with the help of the formula used for
determining the density with the
density measurement kit:
ρ = Rho
G
W
, g/cm3, (1)
where ρ – density, g/cm3; W –
weight of the samples in air, g; G –
weight of the samples in water, g;
Rho – value taken from the catalog
according to the water temperature,
g/cm3.
The theoretical densities of these
samples whose experimental
densities were determined were
calculated with the help of the
formula shown in equation
Fig. 5. Precision scale and density measurement kit
[24].
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 27
Theoretical density = (mbronze ρbronze) + (mCo ρCo) +
+ (mNi ρNi) + (mbinder ρpolyethyleneglycol), (2)
where mbronze, mCo, mNi, mbinder – the components’ percentage by weight; ρbronze –
8.9 g/cm3; ρCo = 8.9 g/cm3; ρNi = 8.9 g/cm3; ρpolyethyleneglycol = 1.1239 g/cm3.
RESULTS
Microstructure results
Figure 6 shows SEM images of S1 and S2 samples produced with no Co and
3 % nickel addition at 700 and 800 °C sintering temperature at 30 MPa sintering
pressure and the EDS points taken from these samples. When these images were
examined, it was observed that the grain boundaries became more apparent with
increasing sintering temperature.
S1 S2
Fig. 6. SEM images of S1 and S2 samples.
Figure 7 shows SEM images of S3 and S4 samples produced with 5 % Co, 3 %
nickel addition at 700 and 800 °C sintering temperatures at 30 MPa sintering
pressure and the EDS points taken from these samples.
S3 S4
Fig. 7. SEM images of S3 and S4 samples.
Figure 8 shows SEM images of S5 and S6 samples produced with 10 % cobalt
and 3 % nickel addition at 700 and 800 °C sintering temperatures at 30 MPa
sintering pressure and the EDS points taken from these samples.
Figure 9 shows SEM images of S7 and S8 samples produced with 18 % cobalt
and 3 % nickel addition at 700 and 800 °C sintering temperatures at 30 MPa
http://stmj.org.ua 28
sintering pressure and the EDS points taken from these samples. It is seen that
cobalt accumulated more in the grain boundaries in these samples and a more
homogeneous distribution was observed with increasing temperature.
S5 S6
Fig. 8. SEM images of S5 and S6 samples.
S7 S8
Fig. 9. SEM images of S7 and S8 samples.
In general, when the microstructure results were examined, all microstructure
images obviously showed that since the sintering temperature was selected as 700
and 800 °C, the melting temperatures of Co element (1455 °C) and Ni element
(1495 °C) could not be reached so these elements accumulated in grain boundaries
without being dissolved. When the Cu–Sn balance diagram in Fig. 2 was
examined, it was observed that the bronze liquefied at about 800 °C.
As is seen from Figs. 6–9, EDS analysis was applied to all of the samples
without Co and with 5, 10, and 15 % Co addition from the marked points. Table 4
shows results of the analysis. When examining the table, it was seen that Ni
element was dense at points where EDS was taken on the Co-free samples S1 and
S2, the point, where EDS was measured, in the sample S3 with 5 % Co addition
was the point where Co element condensed at 3.21 %, and Ni element condensed at
2.1 %. In the sample S4, EDS was measured from the point with 0.29 % Ni and
1.21 % Co element. EDS was measured from the point where Co element
condensed (6.3 %) in the sample S5 and Ni element condensed (3.2 %) in the
sample S6. Evaluation of EDS results of the samples S7 and S8 revealed that Co
element (10.3 %) condensed without dissolving particularly in the grain boundaries
in the sample S7. The point where EDS was measured was seen to contain 2.3 % Ni
and 3.8 % Co element in the sample S8.
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 29
Table 4. EDS results
Weight of element, %
Sample No
Ni Cu Sn Co
S1 3.1 82.7 12.7 –
S2 2.8 78.1 21.2 –
S3 2.1 81.2 14.8 3.21
S4 0.29 85.3 13.7 1.21
S5 2.3 73.1 15.3 6.3
S6 3.2 79.3 14.7 2.8
S7 2.8 72.3 14.8 10.3
S8 2.3 81.8 12.1 3.8
Microhardness results
Figure 10 shows microhardness graph of the samples S1, S3, S5 and S7
produced at 700 °C of sintering temperature. When examining this graph, it
was observed that there was an increase in microhardness results as the rate of
Co increased. While microhardness value of the sample S1 without Co addition
produced at 700 °C of sintering temperature was 201 HV, it was 213 HV in the
sample S7 with 15 % Co addition produced with sintering temperature of
700 °C.
S1 S3 S5 S7
200
202
204
206
208
210
212
214
A
ve
ra
ge
h
ar
dn
es
s
va
lu
e,
H
V
Samples
Fig. 10. Microhardness results of samples produced at 700 °C in different composition.
Figure 11 shows microhardness graph of the samples S2, S4, S6 and S8
produced at 800 °C of sintering temperature. When examining this graph, it was
observed that there was an increase in microhardness values as the ratio of Co
increased. While microhardness value of the sample S2 without Co produced at
800 °C of sintering temperature was 210 HV, it was 216 HV in the sample S8 with
15 % Co addition produced with sintering temperature of 800 °C.
Wear test results
Figure 12 and Table 5 show results of wear tests samples manufactured at
700 °C under 5 and 15 N loads.
http://stmj.org.ua 30
S2 S4 S6 S8
206
208
210
212
214
216
A
ve
ra
ge
h
ar
dn
es
s
va
lu
e,
H
V
Samples
Fig. 11. Microhardness results of samples produced at 800 °C in different compositions.
10 20 30
0.004
0.006
0.008
0.010
0.012
0.014
Distance, mm
M
as
s
lo
ss
, g
10 20 30
0.004
0.006
0.008
0.010
0.012
0.014
Distance, mm
M
as
s
lo
ss
, g
a b
Fig. 12. Wear graphs of samples manufactured at 700 °C under 5 (a) and 15 (b) N loads: S1 (�),
S3 (�), S5 (�), S7 (�).
Table 5. Wear results of samples produced at 700 °C
Group
No
Load,
N
Distance,
m
Sintering
pressure,
MPa
Sintering
temparature,
°C
Bronz,
%
Kobalt,
%
Nikel,
%
Difference,
g
10 30 700 97 0 3 0,0083
20 30 700 97 0 3 0,0101
5
30 30 700 97 0 3 0,0127
10 30 700 97 0 3 0,0095
20 30 700 97 0 3 0,0128
S1
15
30 30 700 97 0 3 0,0143
10 30 700 92 5 3 0,0073
20 30 700 92 5 3 0,0081
5
30 30 700 92 5 3 0,0095
10 30 700 92 5 3 0,0082
20 30 700 92 5 3 0,0124
S3
15
30 30 700 92 5 3 0,0136
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 31
Table 5. (Contd)
10 30 700 87 10 3 0,0041
20 30 700 87 10 3 0,0063
5
30 30 700 87 10 3 0,0076
10 30 700 87 10 3 0,0069
20 30 700 87 10 3 0,0082
S5
15
30 30 700 87 10 3 0,0133
10 30 700 82 15 3 0,0034
20 30 700 82 15 3 0.0045
5
30 30 700 82 15 3 0,0065
10 30 700 82 15 3 0,0052
20 30 700 82 15 3 0,0071
S7
15
30 30 700 82 15 3 0,0097
Figure 13 and Table 6 show results of wear tests samples manufactured at
800 °C under 5 and 15 N loads. Wear tests was carried out with abrasive wear by
using mass loss method under loads of 5 and 15 N at 10, 20, and 30 m distances.
Results of wear tests were transferred into graphs by establishing the relationship
between mass loss and distance loss. As is seen from the graphs, resistance to wear
was generally determined to increase based on increased cobalt rate in all groups.
Graphs of wear test results revealed that the samples S7 and S8 had the highest
wear resistance. The lowest mass loss namely the highest wear resistance was
determined in the sample S8 produced at 800 °C and under 30 MPa.
10 20 30
0.002
0.004
0.006
0.008
0.010
0.012
M
as
s
lo
ss
, g
Distance, mm
10 15 20 25 30
0.004
0.006
0.008
0.010
0.012
0.014
M
as
s
lo
ss
, g
Distance, mm
a b
Fig. 13. Wear graphs of samples manufactured at 800 °C under 5 (a) and 15 (b) N loads: S2 (�),
S4 (�), S6 (�), S8 (�).
Density measurement results
In order to get an idea about compressibility and condensation, density
measurements of the samples produced by using HIP method were made. Table 7
shows the experimental and theoretical densities of the samples, whose weights are
present in Table 2, produced at 30 MPa sintering pressure and with two different
sintering temparature. Since densities of elements like Co (8.9 g/cm3), Ni
(8.9 g/cm3) were not significantly different from each other, no significant
difference occurred in the density values of the samples. It was found in the
http://stmj.org.ua 32
literature that the closer the value of the experimental density to the theoretical
density value, the less the amount of cavities in the samples [25].
Table 6. Wear results of samples produced at 800 °C
Group
No
Load,
N
Distance,
m
Sintering
pressure,
MPa
Sintering
temparature,
°C
Bronz,
%
Kobalt,
%
Nikel,
%
Difference,
g
10 30 800 97 0 3 0,0081
20 30 800 97 0 3 0,0106
5
30 30 800 97 0 3 0,0121
10 30 800 97 0 3 0,0097
20 30 800 97 0 3 0,0132
S2
15
30 30 800 97 0 3 0,0141
10 30 800 92 5 3 0,0067
20 30 800 92 5 3 0,0083
5
30 30 800 92 5 3 0,0097
10 30 800 92 5 3 0,0085
20 30 800 92 5 3 0,0127
S4
15
30 30 800 92 5 3 0,0134
10 30 800 87 10 3 0,0033
20 30 800 87 10 3 0,0063
5
30 30 800 87 10 3 0,0079
10 30 800 87 10 3 0,0071
20 30 800 87 10 3 0,0091
S6
15
30 30 800 87 10 3 0,0122
10 30 800 82 15 3 0,0028
20 30 800 82 15 3 0,0041
5
30 30 800 82 15 3 0,0059
10 30 800 82 15 3 0,0043
20 30 800 82 15 3 0,0068
S8
15
30 30 800 82 15 3 0,0091
Table 7. Experimental and theoretical densities of the samples
Sample
No
Sintering temperature,
°C
Experimental density,
g/cm3
Theoretical density,
g/cm3
S1 700 8,798 8,878
S2 800 8,801 8,878
S3 700 8,881 8,931
S4 800 8,887 8,931
S5 700 8,891 8,911
S6 800 8,898 8,911
S7 700 8,701 8,747
S8 800 8,731 8,747
ISSN 0203-3119. Надтверді матеріали, 2019, № 3 33
CONCLUSIONS
In this study, the production of a new matrix material was successfully carried
out by using the constant sintering pressure, constant sintering time and different
sintering temperatures by HIP method by adding Co into CuSn (85/15) bronze
alloy at certain ratios.
The SEM images of the samples and the element distribution maps were
examined. As a result of these investigations, it was observed that with the increase
of sintering temperature, the grains accumulated and formed larger grains, and
smooth and homogeneous structures formed. Additionally, it was observed Co was
distributed on grain boundaries in Co added samples and they accumulated on
grain boundaries as the amount increased.
When the microhardness results of the samples were evaluated, an increase was
observed in the hardness values of all samples with both the increased sintering
temperature and increased amount of Co.
When examining wear values of the samples, it was found that as amount of Co
and sintering temperature increased, wear resistance increased.
When the theoretical and experimental densities of the samples were examined,
it was seen that the difference was very small. Thus, it was concluded that the
sample was produced in the minimum pore.
FUNDING
The research was supported by the Fırat University Scientific Research Projects
Unit (Project No: TEKF.14.05)
Досліджено вплив температури, при якій новий матричний матеріал
було отримано методом HIP (горячого ізостатичного пресування) при додаванні певного
відсотка елементів Co і Ni до бронзового сплаву CuSn (85/15), а також елементів Co і Ni,
на зносостійкість виготовлених зразків. Однією з головних переваг методу HIP є те, що
нагрівання і тиск застосовуються одночасно у процесі спікання. Таким чином, всі або
майже всі пори видаляються під час виготовлення і отримується більш щільний
матеріал. При дослідженні тиск і час спікання були постійними протягом 15 хв, а також
температуру спікання вибирали рівною 700 і 800 °C як змінний параметр. Процес
спікання проводили під вакуумом, починаючи з першого відпалювання. Потім отримані
зразки готували для металографічних досліджень, для мікроструктурних досліджень
проводили SEM і EDS аналізи. Мікротвердість зразків вивчали для дослідження
механічної поведінки, також випробували їх на знос. Було досліджено густину зразків,
обчислено її експериментальні та теоретичні значення. Було виявлено, що більш
гомогенні зразки отримано при збільшенні температури спікання, також при збільшенні
кількості Co і значення температури підвищувалась їхня зносостійкість.
Ключові слова: HIP, горяче изостатичне пресування, порошкова
металургія, мікротвердість, абразивний знос.
Исследовано влияние температуры, при которой новый матричный
материал был получен методом HIP (горячего изостатического прессования) путем
добавления определенной доли элементов Co и Ni в бронзовый сплав CuSn (85/15), а
также элементов Co и Ni, на износостойкость изготовленных образцов. Одним из
основных преимуществ метода HIP является то, что нагревание и давление
применяются одновременно во время процесса спекания. Таким образом, все или почти
все поры удаляются во время изготовления, и получается более плотный материал. Во
время исследования давление и время спекания поддерживали постоянными в течение
15 мин, а также температура спекания была выбрана равной 700 и 800 °C как
переменный параметр. Процесс спекания проводили в вакууме, начиная с первого
обжига. Полученные образцы затем были подготовлены для металлографических
исследований, для микроструктурных исследований были выполнены SEM и EDS
анализы. Микротвердость образцов изучали для исследования механического поведения
http://stmj.org.ua 34
образцов, также их испытывали на износ. Исследовали плотность образцов, были
рассчитаны ее экспериментальные и теоретические значения. Было виявлено, что
более однородные образцы получены при повышении температуры спекания, также по
мере увеличения количества Co и значения температуры повышается их
износостойкость.
Ключевые слова: HIP, горячее изостатическое прессование, порошко-
вая металлургия, микротвердость, абразивный износ.
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Received January 04.04.18
Revised January 02.07.18
Accepted April 03.07.18
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