Magnesium-based biomaterials have recently gained great attention as promising candidates for the new generation of biodegradable implants.This study investigated the mechanical performance and biodegradation behaviou...Magnesium-based biomaterials have recently gained great attention as promising candidates for the new generation of biodegradable implants.This study investigated the mechanical performance and biodegradation behaviour of magnesium-zinc/hydroxyapatite(Mg-Zn/HA)composites fabricated by different powder mixing techniques.A single step mixing process involved mechanical alloying or mechanical milling techniques,while double step processing involved a combination of both mechanical alloying and mechanical milling.Optimum mechanical properties of the composite were observed when the powders were prepared using single step processing via mechanical alloying technique.However,Mg-Zn/HA composite fabricated through single step processing via mechanical milling technique was found to have the most desirable low degradation rate coupled with highest bioactivity.The composite achieved the lowest degradation rate of 0.039×10^−3 mm/year as measured by immersion test and 0.0230 mm/year as measured by electrochemical polarization.Ca:P ratio of the composite also slightly more than enough to aid the initial bone mineralization,that is 1:1.76,as the required Ca:P ratio for initial bone mineralization is between 1:1 and 1:1.67.展开更多
Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in...Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in Al 1100 alloy has been studied in detail.Before subjecting to 50%cryorolling,samples were pre-annealed at 250℃ for 2 h and pre-solution treated at 540℃ for 1 h.X-ray diffraction and HRTEM techniques were used to understand the crystallite size,lattice strain and dislocation configuration in the processed alloy.The results indicate that the pre-annealed sample has the highest grain aspect ratio(4.43),the smallest crystallite size(37.53 nm),the highest lattice strain(9.12×10^(−3))and the highest dislocation density(45.16×10^(13) m^(−2))among the tested sample.The pre-annealed sample shows a significant improvement of 43.44%,24.64%and 20.33%in hardness,ultimate tensile strength and yield strength.Both pre-annealed and pre-solution treated samples show improved corrosion resistance when compared to cryorolled samples without any pre-treatment,with the pre-annealed sample showing the best corrosion resistance.展开更多
基金The authors would like thank to Universiti Sains Malaysia for FRGS Grant No.203/PBAHAN/6071386 and financial scholarship from Ministry of Higher Education of Malaysia.
文摘Magnesium-based biomaterials have recently gained great attention as promising candidates for the new generation of biodegradable implants.This study investigated the mechanical performance and biodegradation behaviour of magnesium-zinc/hydroxyapatite(Mg-Zn/HA)composites fabricated by different powder mixing techniques.A single step mixing process involved mechanical alloying or mechanical milling techniques,while double step processing involved a combination of both mechanical alloying and mechanical milling.Optimum mechanical properties of the composite were observed when the powders were prepared using single step processing via mechanical alloying technique.However,Mg-Zn/HA composite fabricated through single step processing via mechanical milling technique was found to have the most desirable low degradation rate coupled with highest bioactivity.The composite achieved the lowest degradation rate of 0.039×10^−3 mm/year as measured by immersion test and 0.0230 mm/year as measured by electrochemical polarization.Ca:P ratio of the composite also slightly more than enough to aid the initial bone mineralization,that is 1:1.76,as the required Ca:P ratio for initial bone mineralization is between 1:1 and 1:1.67.
基金Universiti Sains Malaysia for providing the fund for this study under RU grant No.1001/PBahan/8014105.
文摘Effect of annealing and solution treatment prior to cryorolling on the formation of initial structure influencing microstructure formation from nano to micron scale and resultant mechanical and corrosion properties in Al 1100 alloy has been studied in detail.Before subjecting to 50%cryorolling,samples were pre-annealed at 250℃ for 2 h and pre-solution treated at 540℃ for 1 h.X-ray diffraction and HRTEM techniques were used to understand the crystallite size,lattice strain and dislocation configuration in the processed alloy.The results indicate that the pre-annealed sample has the highest grain aspect ratio(4.43),the smallest crystallite size(37.53 nm),the highest lattice strain(9.12×10^(−3))and the highest dislocation density(45.16×10^(13) m^(−2))among the tested sample.The pre-annealed sample shows a significant improvement of 43.44%,24.64%and 20.33%in hardness,ultimate tensile strength and yield strength.Both pre-annealed and pre-solution treated samples show improved corrosion resistance when compared to cryorolled samples without any pre-treatment,with the pre-annealed sample showing the best corrosion resistance.
