Zaw , Linn Htun (2016) Y2O3 And CaO Zirconia as Reinforcement for Hydroxyapatite Biocomposite. Masters thesis, Universiti Sains Malaysia.
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Abstract
Biokomposit hidroksiapatit diperkuat zirkonia (ZrO2/HAp) telah difabrik untuk menambahbaik kekuatan dan keliatan patah bioseramik HAp tunggal. Y2O3- ZrO2 dan CaO-ZrO2 komersial dipilih sebagai bahan penguat untuk matrik HAp. Sampel ZrO2/HAp telah dihasilkan dengan cara konvensional pemprosesan seramik, iaitu melibatkan pencampuran serbuk, pemadatar dan persinteran. Pemprosesan sampel dimulakan dengan pencampuran atau pengisaran-pencampuran untuk membandingkan kehasilan kedua-dua sistem ini. Hasil sifat fizikal dan mekanikal adalah lebih baik dengan penggunaan cara pengisaran-pencampuran. HAp yang diperkuatkan sebanyak 5 bt% Y2O3-ZrO2 komersial yang seterusnya ditambah dengan berlainan amaun CaF2 amaun (1, 3, 5, 7 and 9 bt%) sebagai pembantu sinter dalam biokomposit ZrO2/HAp. Sampel dipadat dengan mampatan ekapaksi sebanyak 90 MPa. Sampel kemudian disinter pade suhu 1050°C sehingga 1250°C dalam udara selama 5 jam. Semakin tinggi amaun CaF2 digunakan, semakin besar kemungkinan fasa HAp dikekalkan. Kekuatan lentur dan keliatan patah optima dicapai ialah 61.10 MPa dan 1.15 MPa.m1/2 selepas penambahan 3 bt% CaF2 (komposit 5YZH-3CF). Dengan ini, 3 dan 5 bt% CaF2 dipilih sebagai amaun optima. Dalam bahagian kedua, penambahan 5 dan 10 bt% CaO-ZrO2 dalam HAp dibanding dengan Y2O3-ZrO2 dari segi kesan kekuatan dan keliatan. Amaun CaF2 yang terpilih sebelum ini juga ditambah ke biokomposit CaO-ZrO2/HAp. Sifat mekanikal biokomposit CaO-ZrO2/HAp adalah lebih baik daripada optima HAp tunggal, iaitu kekuatan lentur dan ketahanan lentur ialah 54.77 MPa dan 1.33 MPa.m1/2 dengan ketumpatan 3.14 gcm-3. Bahagian terakhir adalah pengujian bioaktiviti biokomposit HAp diperkuat Y2O3 dan CaO-ZrO2. Pembentukan lapisan apatit dijumpai di atas permukaan sampel terpilih menandakan bioserasi dan potensi keupayaan pembentukan tulang. ________________________________________________________________________________________________________________________ Zirconia reinforced hydroxyapatite (ZrO2/HAp) biocomposites were fabricated to improve the strength and fracture toughness of monolithic HAp. Commercial Y2O3- ZrO2 and CaO-ZrO2 were selected as the reinforcement for the HAp matrix. The ZrO2/HAp samples were produced by conventional ceramic processing route. The samples were initially produced by pure mixing as well as milling-mixing system. Better physical and mechanical properties were observed from milling-mixing. 5 wt% of commercial Y2O3-ZrO2 was used to reinforce HAp and various amount of CaF2 (1, 3, 5, 7 and 9 wt%) were added to the ZrO2/HAp biocomposite as sintering aid. Samples were compacted with a uniaxial pressure of 90 MPa. The samples were then sintered from 1050°C to 1250°C for 5 hours. The optimum flexural strength of 61.10 MPa and fracture toughness of 1.15 MPa.m1/2 was achieved by 3 wt% of CaF2 addition. From this study, 3 and 5 wt% of CaF2 were selected as optimum addition. Subsequently, 5 and 10 wt% of CaO-ZrO2 were incorporated to HAp to improve the strength and toughness of the HAp as compared with Y2O3-ZrO2 addition. The selected amounts of CaF2 were also added to CaO-ZrO2/HAp biocomposites. The mechanical properties of CaO-ZrO2/HAp biocomposite were found to be better than the optimum properties of monolithic HAp. The biocomposite achieved better flexural strength of 54.77 MPa with higher density 3.14 gcm-3 and fracture toughness of 1.33 MPa.m1/2. The bioactivity test on both Y2O3 and CaO-ZrO2 reinforced HAp biocomposites revealed the formation of apatite layer on the surfaces, indicating the biocompatibility and potential bone forming ability.
| Item Type: | Thesis (Masters) |
|---|---|
| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=2083 |
| Subjects: | T Technology T Technology > TA Engineering (General). Civil engineering (General) > TA404 Composite materials |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Bahan & Sumber Mineral (School of Material & Mineral Resource Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 12 Jun 2018 03:07 |
| Last Modified: | 12 Jun 2018 03:07 |
| URI: | http://eprints.usm.my/id/eprint/40757 |
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