چكيده به لاتين
Bone defections and related diseases among the elderly, and recently the youth, have led to noticeable increase in the amount of effort in researches concerning one specific field of biomedical engineering. In the past three decades, bone cements have attracted so much attention and there have been numerous experiments and researches in order to enter the biomaterials, mostly ceramics and composites, from in-vitro to in-vivo uses. Among these materials, PMMAs and CPCs are considered the most popular ones; however, their potential have been limited due to their specific shortages. For instance the disappointing bioactivity and biocompatibility of PMMAs and substantial lack of toughness and strength of CPCs in relevant applications. This issue was addressed by further searching for better bioceramics, a material without those flaws, showing more overall potential than the previous options. One of the most recent ceramics with its notable capabilities is forsterite. In this research, the required amount of pure, nanocrystalline forsterite was synthesized. Then the powder underwent the processes needed to prepare the SCB samples out of it, including cold pressing and sintering. Consequently doing fracture tests under mode-I, mode-II and mixed-mode loading, the fracture toughness was calculated and the crack growth behavior was investigated. In the end, by comparing the test results with two of the common criteria in fracture mechanics, naming MTS and GMTS, the overall results were reported in a figure. The fracture toughness was 1.68 MPa√m and the two criteria, there was a harmony in comparing the average test results' curve and the calculations of GMTS. The MTS results, though, went far behind concerning the accuracy while moving from pure mode-I towards mode-II.
Keywords: mixed-mode, fracture toughness, bioceramic synthesis, nanocrystalline forsterite, bone-dental implants
