| Exploring the preparation process of biomaterials has become a research hotspot with the wide application of biomaterials in the medical field.Wherein,bioglass is an vitial branch in the field of biomaterials research,and is often used to repair damaged bones in human bone tissue engineering.However,the poor mechanical properties of bioglass limit its application range.The biological glass-ceramic obtained by crystallization heat treatment can improve the glass structure and enhance the mechanical properties of the material.Therefore,the research on the mechanical properties of biological glass-ceramics is a key factor to expand the application space of materials.Bioactive glass was based on the Na2O-Ca O-Si O2-P2O5system in this research.The sintering process of bio-ceramics was explored,and a novel preparation method was provided for the preparation of high-performance bio-ceramics.Differential thermal analysis（DSC）,X-ray diffraction（XRD）,Raman spectroscopy（Raman）and scanning electron microscopy（SEM）were used to characterize the thermodynamics and phase structure of the samples prepared by different sintering processes.Vickers hardness tester and atomic force microscope（AFM）were used to characterize the mechanical properties of the samples for the physical property test of biological glass-ceramics,and the changing trends of the hardness and Young’s modulus of the materials were obtained.From the test results of differential thermal analysis,the sintering system of biological glass-ceramic was designed,and the sintering temperature was determined as 750℃,850℃,950℃,1050℃.Based on this heat treatment system,bio-ceramics were prepared by three sintering techniques:conventional sintering,microwave sintering and spark plasma sintering（SPS）.The effects of the three sintering processes on the structure and properties of the material were mainly discussed,and the relationship between the sintering temperature and the structure and properties of the material was deeply analyzed.The research conclusions are as follows:1.Conventional sintering and microwave sintering can successfully prepare combeite phase biological glass-ceramics.The analysis of the phase structure of the biological glass-ceramic displays that the increase of the sintering temperature is favourable to improve the crystallinity of the glass-ceramic.However,the samples sintered at 750°C prepared by conventional sintering method appeared the low temperature phase of combeite crystal with unstable structure,and the samples sintered at 750°C,850°C and950°C all formed the second phase Si O2.Contrarily,the samples prepared by microwave sintering method all formed a single stable combeite crystal phase.The microtopography of conventional sintered and microwave sintered samples was obtained by SEM.The samples prepared by the two sintering processes can promote the growth of microcrystalline phase grains as the increase of heat treatment temperature.Compared with conventional sintering,the samples prepared by microwave sintering were prepared at the same heat treatment temperature,and the athermal effect of microwave had obvious effect of grain refinement.2.Using Raman spectroscopy to study the structure of biological glass-ceramic prepared by different sintering processes,and explore the influence of heat and mass transfer on the structure of biological glass-ceramic.Through the analysis of the structural units in the glass-ceramics,the typical Q3Raman peaks of the silicon-oxygen tetrahedral structure appear in the glass-ceramics prepared by the two sintering processes.And the intensity of the Q3peaks gradually increases with the increase of the heat treatment temperature,which means the growth in temperature is more conducive to the depolymerization of the glass.However,in the conventional sintered samples,the Raman frequency shift peak corresponding to the P-O-P bond is gradually enhanced,which provides nucleation particles for the crystallization of the combeite phase and promotes the crystallization of the glass.There is no obvious change in the structural unit of P-O-P bonds in the microwave sintered samples.Because the microwave athermal effect makes the microwave sintered samples have perfect crystallization ability,hence,there is no obvious change in the relative content of P-O-P bonds.3.The mechanical properties of biological glass-ceramic samples prepared under different process conditions was tested.From the AFM test results that the crystallinity is the main factor affecting the Young’s modulus.The higher the crystallinity,the higher the Young’s modulus of the sample.The overall Young’s modulus of the microwave sintered sample is higher than that of conventional sintering.The higher Young’s modulus will lead to a decrease in the strain energy rate（G）,increase the damage resistance of the glass-ceramic,and improve the fracture toughness of the glass-ceramic. |
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