 |
 |
 |
 |
 |
 |
Sains Malaysiana 44(8)(2015): 1175–1181 Effects of Vanadium Carbide on Sintered WC-10% Co Produced
by Micro-powder Injection Molding (Kesan Vanadium Karbida ke atas WC-10%
Co Bersinter dihasilkan
melalui Pengacuan Suntikan Serbuk
Mikro) WONG
YEE
NING,
NORHAMIDI
MUHAMAD,
ABU
BAKAR
SULONG*,
ABDOLALI
FAYYAZ
& MUHAMMAD RAFI RAZA
Department of Mechanical
& Materials Engineering, Faculty of Engineering & Built
Environment Universiti Kebangsaan Malaysia, 43600 Bangi,
Selangor, Malaysia Diserahkan: 17
Julai 2014/Diterima: 14 April 2015 ABSTRACT Ultrafine, cemented
tungsten carbide (WC) possesses exceptional hardness, wear
resistance and high strength in various applications. In this study,
WC
was produced through micro powder injection molding
(μPIM),
which is also applicable for metals and ceramics in producing complex
parts with high-dimensional accuracy. Different inhibitors, such
as VC, Cr2C3,
NbC, or TaC,
were added to improve the mechanical properties of WC and
control its grain growth. The effects of a grain growth inhibitor
were investigated by adding VC in WC–10%Co–nVC, where n = 0 to 1.2 wt. %. The mechanical properties
of the sintered part, such as hardness and flexural strength, were
determined. The morphology and elemental distribution of the samples
were studied by field emission scanning electron microscopy and
energy-dispersive X-ray spectroscopy. X-ray diffraction was employed
to study the phases of the obtained samples. The results showed
that the sample with 0.4 wt. % VC
(optimal amount) sintered at 1410°C exhibited the
highest theoretical density, hardness and flexural strength of 95.2%,
1973±31 HV and 2586±172 MPa,
respectively. The average grain size measured was 519±27 nm. VC
acted as a grain growth inhibitor during sintering, thereby improving
the mechanical properties. Keywords: Flexure strength;
grain growth inhibitor; microstructure; micro powder injection moulding; XRD ABSTRAK Ultra halus, tungsten karbida terikat (WC) memiliki ciri kekerasan yang tinggi, rintangan haus dan kekuatan
yang tinggi dalam
pelbagai aplikasi. Dalam kajian ini, WC
dihasilkan melalui
pengacuan suntikan
serbuk mikro
(μPIM) yang turut digunakan dalam bidang logam
dan seramik
untuk menghasilkan produk kompleks dengan ketepatan dimensi yang tinggi. Perencat lain seperti VC, Cr2C3,
NbC atau TaC telah
ditambah untuk
meningkatkan sifat mekanik WC dan mengawal pertumbuhan butirnya. Kesan perencat pertumbuhan
butir telah dikaji
dengan menambah
VC ke dalam WC-10%Co-nVC dengan n=0 - 1.2 wt. %. Sifat mekanik
pada bahagian
bersinter seperti kekerasan dan kekuatan
lenturan diukur.
Taburan morfologi dan unsur sampel
dikaji dengan
pancaran medan mikroskop imbasan elektron (FESEM) dan spektroskopi tenaga penyebar sinar-x. Pembelauan sinar-X digunakan
untuk mengkaji
fasa sampel yang diperoleh. Keputusan menunjukkan sampel dengan 0.4 wt. % VC (jumlah optimum)
yang disinter pada suhu
1410oC mencatatkan teori
ketumpatan tertinggi,
kekerasan dan kekuatan
lenturan masing-masing
pada 95.2%, 1973±31 HV
dan 2586±172
MPa. Purata saiz butir yang
dikira ialah
519±27 nm. VC berperanan
sebagai perencat
pertumbuhan butir semasa proses pensinteran, justeru memperbaiki sifat mekaniknya. Kata kunci: Kekuatan
lenturan; mikrostruktur;
pengacuan suntikan serbuk mikro; perencat
pertumbuhan butir;
XRD RUJUKAN Ani, S.M., Muchtar, A., Muhamad, N. &
Ghani, J.A. 2013. Characterisation of mixing uniformity
and rheological properties of alumina-zirconia powder for ceramic
injection moulding. Sains
Malaysiana 42: 1311-1317. Chua, M.I.H., Sulong, A.B., Abdullah, M.F.
& Muhamad, N. 2013. Optimization of injection
molding and solvent debinding parameters
of stainless steel powder (SS316L) based feedstock for metal injection.
Sains Malaysiana 42:
1743-1750. Fang, Z.Z., Wang, X., Ryu, T., Hwang, K.S.
& Sohn, H.Y. 2009. Synthesis, sintering, and mechanical properties of nanocrystalline cemented tungsten carbide - A review. International
Journal of Refractory Metals and Hard Materials 27: 288-299.
Fang, Z., Maheshwari, P., Wang, X., Sohn, H.Y., Griffo, A. & Riley,
R. 2005. An experimental study of the sintering
of nanocrystalline WC–Co powders. International Journal
of Refractory Metals and Hard Materials 23: 249-257. Fang, Z.Z. 2005. Correlation
of transverse rupture strength of WC-Co with hardness. International
Journal of Refractory Metals and Hard Materials 23: 119-127.
German, R.M. & Bose, A. 1997. Injection
molding of metals and ceramics Ed.: Metal Powder Industries Federation.
Gille, G.,
Szesny, B., Dreyer, K., van den Berg,
H., Schmidt, J., Gestrich, T. & Leitner,
G. 2002. Submicron and ultrafine grained
hardmetals for microdrills
and metal cutting inserts.
International Journal of Refractory Metals and Hard Materials
20: 3-22. Heng,
S.Y., Raza, M.R., Muhamad, N., Sulong,
A.B. & Fayyaz, A. 2014. Micro-powder injection molding (μPIM)
of tungsten carbide. International Journal of Refractory
Metals and Hard Materials 45: 189-195. Heng,
S.Y., Muhamad, N., Sulong, A.B., Fayyaz,
A. & Amin, S.M. 2013. Effect of sintering
temperature on the mechanical and physical properties of WC–10%
Co through micro-powder injection molding (μPIM).
Ceramics International 39: 4457-4464. Huang,
S.G., Liu, R.L., Li, L., Van der Biest,
O. & Vleugels, J. 2008. NbC as grain growth
inhibitor and carbide in WC–Co hardmetals.
International Journal of Refractory Metals and Hard Materials
26: 389-395. Huang,
S.G., Li, L., Vanmeensel, K., Van der
Biest, O. & Vleugels, J. 2007.
VC, Cr3C2 and NbC
doped WC–Co cemented carbides prepared by pulsed electric current
sintering. International Journal of Refractory Metals and Hard
Materials 25: 417-422. Jamaludin,
K.R., Muhamad, N., Rahman, M.N.A.B., Amin, S.Y.M., Ahmad, S., Ibrahim,
M.H.I. & Murtadhahadi 2009. Performance of solvent debinding using design
of experiment method. Sains
Malaysiana 38: 883-888. Janisch, D.S.,
Lengauer, W., Rödiger,
K., Dreyer, K. & Berg, H.V.D. 2010. Cobalt capping: Why is sintered
hardmetal sometimes covered with binder? International
Journal of Refractory Metals and Hard Materials 28: 466-471.
Lei,
Y. & Wu, E. 2009. Sintering characteristics
and microstructure of WC-Co-VC/Cr3C2 ultrafine
cemented carbides. Rare Metals 28: 482-486. Li,
A., Zhao, J., Wang, D., Gao, X. & Tang,
H. 2013. Three-point bending fatigue behavior of WC–Co cemented
carbides. Materials & Design 45: 271-278. Mahmoodan,
M., Aliakbarzadeh, H. & Gholamipour,
R. 2011. Sintering of WC-10%Co nano
powders containing TaC
and VC grain growth inhibitors. Transactions of Nonferrous Metals
Society of China 21: 1080-1084. Morton,
C.W., Wills, D.J. & Stjernberg, K.
2005. The temperature ranges for maximum effectiveness of grain
growth inhibitors in WC–Co alloys. International Journal of Refractory
Metals and Hard Materials 23: 287-293. Ouyang,
C., Zhu, S. & Qu, H. 2012. VC and Cr3C2
doped WC– MgO compacts prepared by hot-pressing
sintering. Materials & Design 40: 550-555. Petersson,
A. & Ågren, J. 2005. Rearrangement
and pore size evolution during WC–Co sintering below the eutectic
temperature. Acta Materialia
53: 1673-1683. Piotter,
V., Zeep, B., Norajitra,
P., Ruprecht, R., von der Weth,
A. & Hausselt, J. 2008. Development of a powder metallurgy process for tungsten components.
Fusion Engineering and Design 83: 1517-1520. Sun,
L., Yang, T.E., Jia, C. & Xiong,
J. 2011. VC, Cr3C2 doped ultrafine WC–Co
cemented carbides prepared by spark plasma sintering. International
Journal of Refractory Metals and Hard Materials 29: 147-152.
Sun,
L., Jia, C., Cao, R. & Lin, C. 2008. Effects
of Cr3C2 additions on the densification, grain
growth and properties of ultrafine WC–11Co composites by spark plasma
sintering. International Journal of Refractory Metals and Hard
Materials 26: 357-361. Sun,
L., Jia, C.C., Lin, C.G. & Cao, R.J.
2007. VC
addition prepared ultrafine WC-11Co composites by spark plasma sintering.
International Journal of Iron and Steel Research 14: 85-89.
Tsai,
K.M. 2011. The effect of consolidation parameters
on the mechanical properties of binderless
tungsten carbide. International Journal of Refractory
Metals and Hard Materials 29: 188-201. Xiao,
D.H., He, Y.H., Luo, W.H. & Song, M. 2009. Effect of VC and
NbC additions on microstructure and properties
of ultrafine WC-10Co cemented carbides. Transactions of Nonferrous
Metals Society of China 19: 1520-1525. Xiong, Z.,
Shao, G., Shi, X., Duan, X. & Yan,
L. 2008. Ultrafine hardmetals prepared
by WC–10 wt.%Co composite powder. International
Journal of Refractory Metals and Hard Materials 26: 242-250.
Zakaria,
H., Muhamad, N., Abu Bakar Sulong, Ibrahim,
M.H.I. & Foudzi, F. 2014. Moldability characteristics of 3 mol%
Yttria stabilized Zirconia feedstock for
micro-powder injection molding process. Sains
Malaysiana 42: 129-136. *Pengarang
untuk surat-menyurat;
email: abubakar@ukm.edu.my
|
|||
|
