Publication: Hidroksiapatit ve MgO kompozitlerine ; ZnO, La2O3 ve SiO2 bileşenlerinin ilavesi ve mikroyapısal, mekanik ve biyouyumluluk özelliklerinin incelenmesi
Abstract
Bu çalışmada hidroksiapatit (HA) - ağırlıkça %1 magnezya (MgO) ikili kompozitinin sinterlenebilme, mikroyapısal ve mekanik özelliklerine (boyca kısalma, yoğunluk, sertlik ve kırılma tokluğu) farklı oranlarda ZnO, La2O3 ve SiO2 ağırlıkça % 0.25, 0.50 ve 1 ilavesinin etkisi incelenmiştir. Saf HA’ in kırılma tokluğu dışındaki bütün özelliklerinin artan sinterleme sıcaklığı ile arttığı (boyca kısalmasının %13.53’ ten %18.20’ ye, yoğunluğunun 2.31 g/ cm’ den 3.06 g/ cm’ e, sertliğinin ise 1.51 GPa’ dan 4.87 GPa’ a), kırılma tokluğundaki azalmanın (0.96’ dan 0.71 MPa.m1/ 2) ise HA’ in dekompoze olması ve aşırı tane büyümesinden dolayı olduğu tespit edildi. Ağırlıkça %1 MgO takviyeli HA’ in, saf HA’ e oranla tüm sinterleme sıcaklıkları için daha iyi özelliklere (en yüksek boyca kısalmasının %18.45, yoğunluğun 3.064 g/ cm, sertliğin 5.03 GPa ve kırılma tokluğunun 1.47 MPa.m1/ 2) sahip olduğu belirlendi. Ağırlıkça %1 La2O3’ nın ağırlıkça %1 MgO-HA ikili kompozitine eklenmesi, yaklaşık %10 (183.2 ile 202,0 MPa) basma mukavemetinde yaklaşık %69 (1.37 ila 2,32 MPa·m1/ 2), kırılma tokluğu ve ayrıca kırılganlık indeksinin 3.24 ile 2.18 μm-1/ 2'lik azalmasına katkıda bulunmuştur. 1300 °C 'de sinterleme sonrasında en iyi performans, ağırlıkça %0.25 La2O3'e sahip MgO-HA numunesi için elde edilmiştir. Biyomedikal uygulamaların ihtiyaçları göz önüne alındığında 1200 °C 'de sinterlenmiş olan ağırlıkça %1 La2O3 ilaveli 1MgO - HA kompoziti uygun olduğu gözlemlenmiştir. Yapılan incelemeler neticesinde HA - 1 MgO kompozitine %0.5 oranında ZnO ilave edilmesi ile HA-%1MgO’ e ait sertlik (447.6’ dan 495 HV’ ye), kırılma tokluğu (1.80’ den 2.15 MPam1/ 2’ ye) ve basma mukavemeti (183’ den 198.17 MPa’ ya) özelliklerinde artışın sağlanabildiği ve belirtilen bu özelliklerin elde edilmesinde tane boyutunda azalmanın ve oluşan Zn-P-O elementlerini içeren ZnP2O6 ve ZnP4O11 fazlarının etkili olduğu belirlendi. Ancak ZnO ilaveli numunelerin 1300 oC sinterlenmesinin aşırı tane büyümesi nedeniyle azaldığı belirlendi. HA-1MgO ikili kompozitine ağırlıkça % 0.5 oranında SiO2 ilavesinin, diğer oranlardaki SiO2’ lere oranla daha optimum özelliklere sahip olduğu (En yüksek boyca kısalmasının %19.58, yoğunluğun 2.97 g/ cm, sertliğin 4.28 GPa ve kırılma tokluğunun 1.78 MPam1/ 2), bunun ise ortalama tane boyutu değerlerinin daha az ve içerdiği fazlardan kaynaklandığı belirlenmiştir.
In this study, the effects of the addition of wt. % 0.25, 0.5, 1 ZnO, La2O3 and SiO2 reinforcements were examined of the sinterability, microstructural and mechanical properties of the HA-1MgO composite (neck shortening, density, stiffness and fracture toughness). All the characteristics of pure HA, except for the fracture toughness, have increased with increasing sintering temperature (from 13.53% to 18.20% of neck shortening, from 2.31 g/ cm to 3.06 g/ cm to 0.71 GPA of stiffness), from 1.51 GPA to 4.87 GPA of fracture toughness (0.96 to MPa.M1/ 2) However, it was determined that the HA was decompensed and caused by excessive grain growth. The wt. 1% MgO addition HA has better properties for all sintering temperatures (18.45% of maximum height shortening, 3,064 g/ cm density, 5.03 GPA of hardness and 1.47 MPa.m1/ 2) compared to pure HA. With the addition of wt. 1% La2O3 to HA-1MgO composites, it has contributed to a reduction of compression strength approximately 10% (183.2 to 202.0 MPa), 69% (1.37 to 2.32 MPa·m1/ 2), fracture toughness and also the vulnerability index by 3.24 to 2.18 μm-1/ 2. Best performance after sintering at 1300 °C was obtained for MgO-HA sample with wt. 0.25% La2O3. Given the needs of biomedical applications, the wt. 1% La2O3 addition 1MgO-HA composites that were sintered at 1200 °C were observed to be appropriate. With wt. 0.5% ZnO added to the HA-1MgO composites as a result of the inspections carried out, harshness of HA-1MgO (from 447.6 to 495 HV), fracture toughness (from 1.80 to 2.15 MPa.m1/ 2) and the compression strength (183 to 198.17 MPa). The ZnP2O6 and ZnP4O11 phases, which include grain size reduction and Zn-P-O elements, were determined to be effective in achieving these characteristics. However, it was determined that the sinteration of ZnO additive samples of 1300 oC was reduced due to excessive grain growth. The addition of SiO2 wt. 0.5% to the HA-1MgO composites has been determined to have more optimal properties than SiO2 in other ratios (19.58% of the highest height reduction, 2.97 g/ cm density, 4.28 GPA of hardness and 1.78 MPa.m1/ 2 of the fracture toughness), which is due to the phases in which the average grain size values are less and included.
In this study, the effects of the addition of wt. % 0.25, 0.5, 1 ZnO, La2O3 and SiO2 reinforcements were examined of the sinterability, microstructural and mechanical properties of the HA-1MgO composite (neck shortening, density, stiffness and fracture toughness). All the characteristics of pure HA, except for the fracture toughness, have increased with increasing sintering temperature (from 13.53% to 18.20% of neck shortening, from 2.31 g/ cm to 3.06 g/ cm to 0.71 GPA of stiffness), from 1.51 GPA to 4.87 GPA of fracture toughness (0.96 to MPa.M1/ 2) However, it was determined that the HA was decompensed and caused by excessive grain growth. The wt. 1% MgO addition HA has better properties for all sintering temperatures (18.45% of maximum height shortening, 3,064 g/ cm density, 5.03 GPA of hardness and 1.47 MPa.m1/ 2) compared to pure HA. With the addition of wt. 1% La2O3 to HA-1MgO composites, it has contributed to a reduction of compression strength approximately 10% (183.2 to 202.0 MPa), 69% (1.37 to 2.32 MPa·m1/ 2), fracture toughness and also the vulnerability index by 3.24 to 2.18 μm-1/ 2. Best performance after sintering at 1300 °C was obtained for MgO-HA sample with wt. 0.25% La2O3. Given the needs of biomedical applications, the wt. 1% La2O3 addition 1MgO-HA composites that were sintered at 1200 °C were observed to be appropriate. With wt. 0.5% ZnO added to the HA-1MgO composites as a result of the inspections carried out, harshness of HA-1MgO (from 447.6 to 495 HV), fracture toughness (from 1.80 to 2.15 MPa.m1/ 2) and the compression strength (183 to 198.17 MPa). The ZnP2O6 and ZnP4O11 phases, which include grain size reduction and Zn-P-O elements, were determined to be effective in achieving these characteristics. However, it was determined that the sinteration of ZnO additive samples of 1300 oC was reduced due to excessive grain growth. The addition of SiO2 wt. 0.5% to the HA-1MgO composites has been determined to have more optimal properties than SiO2 in other ratios (19.58% of the highest height reduction, 2.97 g/ cm density, 4.28 GPA of hardness and 1.78 MPa.m1/ 2 of the fracture toughness), which is due to the phases in which the average grain size values are less and included.