Mohd Sabri, Nurul Shafyra (2013) Design of Experiment (Doe) Study Of Hydroxyapatite (Ha) For Load Bearing Application Via 2k Factorial Design. Masters thesis, Universiti Sains Malaysia.
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Abstract
Tujuan kajian ini adalah untuk menghasilkan biokomposit hidroksiapatit (HA)/alumina (Al2O3) dengan menggunakan kaedah percampuran kering bagi mengkaji faktor eksperimen dan kesannya (kesan utama dan kesan interaksi) terhadap sifat akhir biokomposit (kekerasan, ketumpatan dan keliangan). Kesan-kesan ini diukur menggunakan rekabentuk eksperimen (DOE) bagi membentuk model matematik. Kajian ini merangkumi dua bahagian di mana bahagian I adalah berkaitan dengan cara-cara penyediaan sampel yang bermula dengan pencirian sifat fizikal, struktur (fasa) dan sifat kimia bagi bahan mentah. Prosedur ini diikuti dengan fabrikasi biokomposit HA/Al2O3 berdasarkan parameter yang berbeza (suhu pensinteran ;1100 ºC dan 1250 ºC, masa pencampuran ; 3 jam dan 9 jam dan komposisi Al2O3; 0wt% dan 30 wt%). Eksperimen ini dijalankan mengikut turutan yang dicadangkan oleh perisian DOE (Minitab 16) semasa proses perawakan. Setelah itu, sifat fizikal dicirikan melalui ujian ketumpatan dan keliangan manakala morfologi sampel dilihat dengan menggunakan mikroskop imbasan elektron (SEM). Bagi analisis fasa,sampel dicirikan menggunakan analisis pembelauan sinaran-X (XRD) dan ujian kekerasan Vickers digunakan untuk mengkaji kekerasan sampel. Dalam bahagian II, kaedah DOE faktoran dua aras (2k) digunakan untuk mengkaji faktor-faktor yang memberi kesan dalam proses penghasilan biokomposit HA/Al2O3 berkekuatan tinggi. Faktor-faktor ini dianalisis dan faktor yang memberi kesan besar ditentukan menerusi model regresi dan analisis variasi (ANOVA). Model disahkan menerusi ANOVA bagi mengkaji kepadanan antara model dan data yang diperoleh secara eksperimen. Seterusnya, ralat eksperimen dan interaksi antara parameter dikaji untuk mengenalpasti perbezaan antara nilai data ramalan dan data eksperimen. Keputusan menunjukkan komposisi Al2O3 dan suhu pensinteran telah memberi kesan yang besar ke atas respon manakala masa pencampuran tidak memberikan sebarang pengaruh. Untuk respon kekerasan, analisis telah menunjukkan bahawa untuk mendapatkan kekerasan yang tinggi, suhu pensinteran haruslah ditetapkan di atas suhu 1240 ºC dan komposisi Al2O3 haruslah berada di bawah 3 wt%. Syarat yang sama juga diperlukan bagi respon keliangan di mana suhu pensinteran haruslah ditingkatkan melebihi 1188 oC dan komposisi Al2O3 haruslah berada di bawah 7 wt% untuk mendapatkan keliangan antara 5-10 %. Bagi respon ketumpatan, ketumpatan yang hampir menyamai ketumpatan tulang manusia (lelaki : 3.88 g/cm3 ; wanita : 2.90 g/cm3) boleh diperolehi dengan menetapkan suhu pensinteran masing-masing pada 1180 oC ke atas dan komposisi Al2O3 dibawah 30 wt% atau suhu pensinteran pada 1200 oC ke atas dan komposisi Al2O3 melebihi 10 wt%. . Secara keseluruhan, parameter yang memberi kesan besar terhadap respon-respon adalah komposisi Al2O3 dan suhu pensinteran. _______________________________________________________________________________________________________ The present study aims to fabricate hydroxyapatite (HA)/alumina (Al2O3) biocomposite via dry mixing process, in order to evaluate the experimental factors and their effects (main effects and interaction effects) on the response or final biocomposite characteristics (hardness, density, and porosity). These effects were quantified using Design of Experiments (DOE) to develop mathematical models. This study covered two parts where the part I deals with the sample preparation procedures which was started with the characterization of raw materials in term of physical, structural (phases) and chemical properties. This procedure was followed by the fabrication of HA/Al2O3 biocomposite with different parameter setting (sintering temperature; 1100 ºC and 1250 ºC, mixing time; 3 hours and 9 hours and Al2O3 composition; 0wt% and 30 wt%). The experiment was run by following the run order suggested by DOE software (Minitab 16) through randomization stage. Next, the physical properties was characterized using density and porosity testing while the morphology of the sample was studied using Scanning Electron Microscopy (SEM). For phase analysis, the sample was characterized through X-ray Diffraction analysis and Vickers hardness testing was employed to study its hardness. In part II, two-level (2k) factorial method of DOE was employed to determine the suitable or significant factors in producing high strength HA/Al2O3 biocomposite. The experimental factors were analyzed and the significant factors were determined through regression model and Analysis of Variance (ANOVA). The model was then validated through ANOVA in order to study how fit is the model with the experimentally obtained data. Experimental errors and interactions between factors were investigated to verify the significant between predicted and experimental data. Results shows that Al2O3 composition and sintering temperature has given a significant effects on the responses while mixing time has given no influence. For hardness response, it shows that, in order to obtained a high hardness, the sintering temperature must be set above 1240 ºC with Al2O3 composition lower than 3 wt%. The same requirement goes to porosity response where sintering temperature must be above 1188 oC with Al2O3 composition below 7 wt% in order to obtained 5-10 % porosity. For density response, acceptable density that mimicking the natural dense male and female bone density (3.88 g/cm3 for male; 2.90 g/cm3 for female) can be obtained by setting the sintering temperature above 1180 oC and Al2O3 composition below 30 wt% or sintering temperature above 1200 oC and Al2O3 composition above 10wt % respectively. The most significant parameters that effecting all the response are Al2O3 composition and sintering temperature
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=1895 |
| Subjects: | T Technology T Technology > TA Engineering (General). Civil engineering (General) |
| 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: | 04 Jun 2018 03:51 |
| Last Modified: | 04 Jun 2018 06:23 |
| URI: | http://eprints.usm.my/id/eprint/40673 |
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