Sains Malaysiana 46(9)(2017): 1635–1640

http://dx.doi.org/10.17576/jsm-2017-4609-36

 

Sinteran Hidroksiapatit dalam Atmosfera Nitrogen untuk Peningkatan Sifat Mikrokekerasan

(Sintering of Hydroxyapatite under Nitrogen Atmosphere for Improved Microhardness)

 

LEONG CHEE HUAN^1*, ANDANASTUTI MUCHTAR¹, TAN CHOU YONG², MASFUEH RAZALI³ & CHIN CHUIN HAO¹

 

¹Department of Mechanical and Materials Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan

Malaysia

 

²Department of Mechanical Engineering, Faculty of Engineering, Universiti Malaya, 50603 Kuala Lumpur, Wilayah Persekutuan, Malaysia

 

³Periodontology Department, Faculty of Dentistry, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300 Kuala Lumpur, Wilayah Persekutuan, Malaysia

 

Diserahkan: 17 November 2016/Diterima: 10 Jun 2017

 

ABSTRAK

Hidroksiapatit (HA) adalah sejenis kalsium fosfat yang merupakan komposisi kepada kebanyakan fasa mineral tulang dan enamel gigi. HA bersifat bioserasi dan berkonduksi osteo selain mempunyai afiniti biologi dan kimia yang bagus untuk tisu tulang. Dengan ciri tersebut, HA diguna secara luas sebagai graf tulang dan bahan salut bagi implan tisu keras manusia. Walau bagaimanapun, kerapuhan dan keliatan patah yang rendah HA tersinter menghadkan penggunaannya dalam aplikasi bebanan yang tinggi. Kajian ini tertumpu kepada mengenal pasti kesan atmosfera sinteran dengan gas nitrogen (N₂) ke atas sifat mekanik HA untuk aplikasi pergigian. Serbuk nano HA dicirikan dengan menggunakan mikroskop elektron pancaran. Cakera silinder HA dihasilkan dengan kaedah penekanan ekapaksi. Kemudian, cakera silinder HA dikenakan tekanan isostatik sejuk dan disinter dalam dua atmosfera sinteran yang berbeza iaitu sinteran dalam gas N₂ dan sinteran dalam udara pada suhu 1300°C. Ketumpatan, mikrostruktur, kestabilan fasa dan mikrokekerasan HA tersinter dicirikan. Secara keseluruhan, sinteran dengan menggunakan gas N₂ menyebabkan pertumbuhan saiz butiran yang lebih besar dengan ketumpatan relatif dan mikrokekerasan yang lebih tinggi jika dibandingkan dengan atmosfera sinteran dalam udara. Dalam kajian ini, HA yang disinter dengan menggunakan gas N₂ pada suhu 1300°C menunjukkan mikrostruktur yang lebih tumpat, ketumpatan relatif (94%) dan mikrokekerasan (4.07 GPa) yang lebih tinggi jika berbanding dengan sinteran dalam udara tanpa penguraian HA. Kesimpulannya, penggunaan atmosfera sinteran dengan menggunakan gas N₂ pada suhu 1300°C dapat meningkatkan sifat kekerasan Vickers nanokomposit HA dengan mikrostruktur yang padat.

 

Kata kunci: Atmosfera sinteran; hidroksiapatit; sinteran dengan gas nitrogen

 

ABSTRACT

Hydroxyapatite (HA) is a type of calcium phosphate which constitutes most of the mineral phase of bones and tooth enamel. HA is biocompatible and osteoconductive; it also exhibits excellent chemical and biological affinity with bone tissues. With these characteristics, HA has been widely used as bone graft and coating material for human hard tissue implants. However, the brittleness and low fracture toughness of sintered HA limit its capability in load-bearing applications. This study focuses on determining the effect of sintering in nitrogen gas (N₂) atmosphere on the mechanical properties of HA. HA nanopowders were characterised using a transmission electron microscope. Next, HA powders were uniaxially pressed into pellets. The pellets were then isostatically cold-pressed and sintered in two types of atmospheres, namely, sintering in N₂ and sintering in air at 1300°C. The density, microstructure, phase stability and microhardness of sintered HA were characterised. Overall, sintering in N₂ led to the formation of larger grains with higher relative density and microhardness than sintering in air. In this study, HA sintered in N₂ at 1300°C exhibited more compact microstructure with higher relative density (94%) and microhardness (4.07 GPa) without decomposition in comparison to sintering in air. In conclusion, N₂ sintering at 1300°C improves the Vickers hardness of HA by yielding a more compact microstructure.

 

Keywords: Hydroxyapatite; sintering atmosphere; sintering in nitrogen gas

RUJUKAN

 

Akbari, B., Pirhadi Tavandashti, M. & Zandrahimi, M. 2011. Particle size characterization of nanoparticles - a practical approach. Butirannian Journal of Materials Science & Engineering 8(2): 48-56.

Aminzare, M., Eskandari, A., Baroonian, M.H., Berenov, A., Razavi Hesabi, Z., Taheri, M. & Sadrnezhaad, S.K. 2013. Hydroxyapatite nanocomposites: Synthesis, sintering and mechanical properties. Ceramics International 39(3): 2197- 2206.

Angelo, P.C. & Subramaniam, R. 2008. Powder Metallurgy. New Delhi: Prentice Hall of India Private Limited.

Antonio Nanci. 2003. Ten Cate’s Oral Histology: Development, Structure, and Function. Elsevier: St Louis.

Anusavice, K.J., Shen, C. & Rawls, H.R. 2013. Phillips’ Science of Dental Materials. 12. Haryana: Elsevier.

Asif, M., Zhengyi, F., Weimin, W., Hao, W., Tiening, T. & Shahzad Ahmad Khan. 2014. Fluoridation and sintering of hydroxyapatite material and their mechanical properties. Journal of Wuhan University of Technology 29: 190-196.

Badica, P., Borodianska, H., Xie, S., Zhao, T., Demirskyi, D., Li, P., Tok, A.I.Y., Sakka, Y. & Vasylkiv, O. 2014. Toughness control of boron carbide obtained by spark plasma sintering in nitrogen atmosphere. Ceramics International 40(2): 3053-3061.

Chun, K.J & Lee, J.Y. 2014. Comparative study of mechanical properties of dental restorative materials and dental hard tissues in compressive loads. Journal of Dental Biomechanics 5: 1-6.

Curran, D., Fleming, T., Towler, M. & Hampshire, S. 2010. Mechanical properties of hydroxyapatite-zirconia compacts sintered by two different sintering methods. Journal of Materials Science: Materials in Medicine 21(4): 1109-1120.

Delgado, J.A., Morejón, L., Martínez, S., Ginebra, M.P., Carlsson, N., Fernández, E., Planell, J.A., Clavaguera-Mora, M.T. & Rodríguez-Viejo, J. 1999. Zirconia-toughened hydroxyapatite ceramic obtained by wet sintering. Journal of Materials Science: Materials in Medicine 10(12): 715-719.

Dorozhkin, S.V. 2010. Calcium orthophosphates as bioceramics: State of the art. J. Funct. Biomater. 1(1): 22-107.

Ergun, C. 2011. Enhanced phase stability in hydroxylapatite/ zirconia composites with hot isostatic pressing. Ceramics International 37(3): 935-942.

Evis, Z. & Doremus, R.H. 2007. Effect of Yf3 on hot-pressed hydroxyapatite and monoclinic zirconia composites. Materials Chemistry and Physics 105(1): 76-79.

Fahami, A., Nasiri-Tabrizi, B. & Ebrahimi-Kahrizsangi, R. 2012. Synthesis of calcium phosphate-based composite nanopowders by mechanochemical process and subsequent thermal treatment. Ceramics International 38(8): 6729-6738.

Fang, Z.Z. 2010. Sintering of Advanced Materials Fundamentals and Processes. Philadelphia: Elsevier.

Feng, P., Niu, M., Gao, C., Peng, S. & Shuai, C. 2014. A novel two-step sintering for nano-hydroxyapatite scaffolds for bone tissue engineering. Scientific Reports 4: 5599.

Hoffmann, M.J., Fünfschilling, S. & Kahraman, D. 2013. Hot isostatic pressing and gas-pressure sintering. Dlm. Ceramics Science and Technology, disunting oleh Riedel, R. & Chen, I.W. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA. hlm. 171-187.

Kamalanathan, P., Ramesh, S., Bang, L.T., Niakan, A., Tan, C.Y., Purbolaksono, J., Hari Chandran & Teng, W.D. 2014. Synthesis and sintering of hydroxyapatite derived from eggshells as a calcium precursor. Ceramics International 40: 16349-16359.

Kang, S.J.L. 2005. Sintering, Densification, Grain Growth and Microstructure. Oxford: Butterworth-Heinemann.

Karimzadeh, A., Majid, R., Ayatollahi, Bushroa, A.R. & Herliansya, M.K. 2014. Effect of sintering temperature on mechanical and tribological properties of hydroxyapatite measured by nanoindentation and nanoscratch experiments. Ceramics International 40: 9159-9164.

Khoo, W., Nor, F.M., Ardhyananta, H. & Kurniawan, D. 2015. Preparation of natural hydroxyapatite from bovine femur bones using calcination at various temperatures. Procedia Manufacturing 2: 196-201.

Leong, C.H., Muchtar, A., Tan, C.Y., Razali, M. & Noor Faeizah Amat. 2014a. Sintering of hydroxyapatite/yttria stabilized zirconia nanocomposites under nitrogen gas for dental materials. Advances in Materials Science and Engineering 2014: Article ID. 367267.

Leong, C.H., Muchtar, A., Tan, C.Y. & Razali, M. 2014b. A review: Effect of sintering method on the decomposition of hydroxyapatite and density of hydroxyapatite zirconia composites. Applied Mechanics and Materials 465-466: 843-846.

Lim, K.F., Andanastuti Muchtar, Rusnah Mustaffa & Chou Yong Tan. 2014. Synthesis and characterization of hydroxyapatite-zirconia composites for dental applications. Asian Journal of Scientific Research 7(4): 609-615.

Lim, N.H., Kassim, A. & Huang, N.M. 2010. Preparation and characterization of calcium phosphate nanorods using reverse microemulsion and hydrothermal processing routes. Sains Malaysiana 39(2): 267-273.

Lin, K. & Chang, J. 2015. Structure and properties of hydroxyapatite for biomedical applications. Dlm. Hydroxyapatite (Hap) for Biomedical Applications, disunting oleh Mucalo, M. Sawston, Cambridge: Woodhead Publishing. hlm. 3-19.

Mohd Reusmaazran Yusof, Roslinda Shamsudin, Syafiq Baharuddin & Idris Besar. 2008. Fabrication of porous hydroxyapatite for bone graft substitutes via gas technique. Sains Malaysiana 37(4): 395-399.

Montoya, C., Arola, D. & Ossa, E.A. 2016. Importance of tubule density to the fracture toughness of dentin. Archives of Oral Biology 67: 9-14.

Rahaman, M.N. 2003. Ceramic Processing and Sintering. London: Taylor & Francis.

Tan, C.Y., Singh, R., The, Y.C. & Tan, Y.M. 2014. The effects of calcium-to-phosphorus ratio on the densification and mechanical properties of hydroxyapatite ceramic. Int. J. Appl. Ceram. Technol. 12(1): 223-227.

Wang, L.I., Wang, X.F., Yu, C.L. & Zhao, Y.Q. 2015. Effect of titanium addition on thermal stability of hydroxyapatite/ zirconia nanocomposite. Science of Sintering 47: 107-112.

Wu, Shih-Ching, Hsueh-Chuan Hsu, Shih-Kuang Hsu, Ya-Chu Chang & Wen-Fu Ho. 2016. Synthesis of hydroxyapatite from eggshell powders through ballmilling and heat treatment. Journal of Asian Ceramic Societies 4: 85-90.

 

 

*Pengarang untuk surat-menyurat; email: cheehuan@hotmail.my