Sevda Albayrak, Hanifi Çinici, Recep Çalın, Canser Cömert

AZ91 magnezyum alaşımının sol-jel yöntemiyle hidroksiapatit kaplanması

Bu çalışmada amaç; biyomedikal uygulamalarda kullanılmak üzere mevcut biyomalzemelerden daha hafif, biyolojik saldırılara karşı dirençli ve kemik yapısına benzer, doku ile uyumlu bir malzeme üretebilmektir. Hafiflik biyomalzeme uygulamalarında son derece önemlidir, çünkü paslanmaz çelik ve bunun gibi ağır metalik alaşımlar vücutta kullanıldığında implant çevresindeki dokulara zarar vererek enfeksiyona sebep olabilmektedir. AZ91 Mg alaşımının hafifliği büyük bir avantaj olsa da vücutta kullanmak için yeterli mukavemete sahip değildir ve biyolojik ortamda bozunmaktadır. AZ91 Mg alaşım tozları 320 °C sıcaklık ve 275 MPa basınçta sıcak pres yöntemi ile preslendikten sonra, yeterli dayanımı sağlamak ve bozunmasını engellemek amacıyla sol-jel ve dip coating metoduyla yüzeyi farklı daldırma sayılarında hidroksiapatit ile kaplanmış ve 400 °C’de sinterlenmiştir. Kaplanan numunelerin yüzey morfolojileri SEM; faz yapıları ise XRD ile incelenmiştir.

Anahtar Kelimeler:

AZ91 magnezyum alaşımı, Hidroksiapatit, Sol-jel Yöntemi

Hydroxyapatite coating on AZ91 magnesium alloy via sol-gel method

Producing a material lighter than available biomaterials, having corrosion-resistance to biological attacks and histocompatible similar to the bone structure in order to use in biomedical applications is the purpose of this study. Lightness is extremely important in biomedical applications because stainless steel and many of the similar heavy metallic alloys can lead to infection by causing harm to tissues around the implant when it is used in the body. Although the lightness of AZ91 Mg alloy is an advantage, it is not strength enough to use in human body and it degrades in biological environment. After AZ91 Mg alloy powders were pressed with unidirectional hot pressing machine under 275 MPa pressure and 320 °C temperature, their surfaces were coated with hydroxyapatite to provide sufficient strength and prevent the degradation of specimens using sol-gel and dip coating method with different dipping number. Then the specimens were sintered at the temperature of 400 °C. The surface morphologies and phase structures of coated specimens were analyzed with SEM and XRD, respectively.

Keywords:

AZ91 magnesium alloy, Hydroxyapatite, Sol-gel Method,

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Wang H, Guan S, Wang X, Ren C, Wang L. "In vitro degradation and mechanical integrity of Mg-Zn-Ca alloy coated with ca-deficient hydroxyapatite by the pulse electrodeposition process". Acta Biomaterialia, 6, 1743-1748, 2010.
Razavi M, Fathi M, Savabi O, Vashaee D, Tayebi L. "In vivo assessments of bioabsorbable az91 magnesium implants coated with nanostructured fluoridated hydroxyapatite by MAO/EPD technique for biomedical applications". Materials Science and Engineering C, 48, 21-27, 2015.
Liu G, Hu J, Ding Z, Wang C. "Bioactive calcium phosphate coating formed on micro-arc oxidized magnesium by chemical deposition". Applied Surface Science, 257, 2051-2057, 2011.
Niu B, Shi P, Wei D, ES, Li Q, Chen Y. "Effects of sintering temperature on the corrosion behavior of AZ31 alloy with Ca-P Sol-gel Coating". Journal of Alloys and Compounds, 65, 435-442, 2016.
Ren Y, Zhou H, Nabiyouni M, Bhaduri S. "Rapid coating of az31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy". Materials Science and Engineering C, 49, 364-372, 2015.
Jamesh MI, Wu G, Zhao Y, McKenzie D, Bilek M, Chu P. "Electrochemical corrosion behavior of biodegradable Mg-Y-RE and Mg-Zn-Zr Alloys in Ringer’s solution and simulated body fluid". Corrosion Science, 91, 160-184, 2015.
Zhang S, Zhang X, Zhao C, Li J, Song Y, Xie C, Tao H, Zhang Y, He Y, Jiang Y, Bian Y. "Research on an Mg-Zn alloy as a degradable biomaterial". Acta Biomaterialia, 6, 626-640, 2010.
Xu L , Panc F, Yu G, Yang L, Zhang E, Yang K. "In vitro and in vivo evaluation of the surface bioactivity of a calcium phosphate coated magnesium alloy". Biomaterials, 30, 1512-1523, 2009.
Razavi M, Fathi M, Meratian M. "Microstructure, mechanical properties and bio-corrosion evaluation of biodegradable AZ91-FA nanocomposites for biomedical applications". Materials Science and Engineering A, 527, 6938-6944, 2010.
Wang H, Guan S, Wang Y, Liu H, Wang H, Wang L, Ren C, Zhu S, Chend K. "In vivo degradation behavior of ca-deficient hydroxyapatite coated Mg-Zn-Ca alloy for bone implant application". Colloids and Surfaces B: Biointerfaces, 88, 254-259, 2011.
Rojaee R, Fathi M, Raeissi K. "Comparing nanostructured hydroxyapatite coating on AZ91 alloy samples via sol-gel and electrophoretic deposition for biomedical applications". IEEE Transactions on NanoBioscience, 13, 409-414, 2014.
Hou DH, Liang SM, Chen RS, Dong C, Han EH. "Effects of Sb content on solidification pathways and grain size of AZ91 magnesium alloy". Acta Metallurgica Sinica, 28, 115121, 2015.
Razavi M, Fathi M, Savabi O, Beni BH, Razavi SM, Vashaee D, Tayebi L. "Coating of biodegradable magnesium alloy bone implants using nanostructured diopside (CaMgSi2O6)". Applied Surface Science, 288, 130-137, 2014.
Kabirian F, Mahmudi R. "Impression creep behavior of a cast az91 magnesium alloy". Metallurgical and Materials Transactions A, 40, 116-127, 2009.
Lee DSH, Pai Y, Chang S. "Effect of thermal treatment of the hydroxyapatite powders on the micropore and microstructure of porous biphasic calcium phosphate composite granules". Journal of Biomaterials and Nanobiotechnology, 4, 114-118, 2013.