Development of biodegradable mg-znha composite via mechanical alloying
| dc.contributor.author | Emee Marina Salleh | |
| dc.date.accessioned | 2021-03-19T08:37:54Z | |
| dc.date.available | 2021-03-19T08:37:54Z | |
| dc.date.issued | 2016-05-01 | |
| dc.description.abstract | This work aims to develop biodegradable metallic material using mechanical alloying (MA). Magnesium (Mg) is the most highlighted candidate for biomedical applications because of its advantageous properties as compared with other biomaterials. But a rapid degradation rate in physiological environment limits its performance. Hence, Mg was alloyed with zinc (Zn) in order to improve its corrosion resistance and sustain its mechanical integrity. In achieving the target, Mg based biomaterials were fabricated using MA followed by compaction under 400 MPa and sintering at 350 °C. Four MA parameters namely milling time, milling speed, ball-to-powder-weight ratio (BPR) and Zn content were investigated. The density of 1.80 to 1.99 g/cm3 which is comparable to human bone and improved microhardness of 53.76 to 94.37 HV as compared to pure Mg (39.30 HV) were attained. By fractional factorial design (FFD), an optimized MA condition in producing Mg-Zn alloy was achieved by adding 6.5 wt% Zn and milled for 5 hours at 200 rpm with 7:1 BPR. A higher compressive strength (249.28 MPa) and lower corrosion rate (1.13x10-2 mm/y) than pure Mg (178.04 MPa and 13.77 x10-2 mm/y) were acquired. A further improvement of those properties was attained by incorporating 10 wt% HA into optimized Mg-6.5wt%Zn alloy. An enhanced compressive strength (292.33 MPa) and degradation rate (0.72 x10-2 mm/y) was attained. Mg-Zn/HA composite provided the highest bioactivity due to highest Ca:P ratio of 1:1.46 followed by Mg-Zn alloy of 1:1.29 which is in agreement with the required Ca:P ratio of 1:1 to 1:1.67 for initial bone mineralization. | en_US |
| dc.identifier.uri | http://hdl.handle.net/123456789/12354 | |
| dc.language.iso | en | en_US |
| dc.title | Development of biodegradable mg-znha composite via mechanical alloying | en_US |
| dc.type | Thesis | en_US |
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