Fabrication And Performance Study Of Zirconia Ceramic Surgical Scalpel

In this thesis,GNPs were introduced into 3Y-TZP/Al₂O₃ composites to overcome the shortcomings of traditional carbon steel scalpels,such as poor biocompatibility,easy rusting,poor sharpness,and charge.The 3Y-TZP/Al₂O₃/GNPs ceramic scalpel with excellent mechanical properties and good biocompatibility was successfully prepared,and its cutting force was tested.The influence of different cutting parameters on the cutting force of the scalpel was studied.The surface micro-texture was processed on the blade of the scalpel,and the effect of surface micro-texture on the cutting force of the scalpel was studied.The influence of femtosecond laser processing parameters on texture morphology was analyzed.3Y-TZP/Al₂O₃/GNPs ceramic scalpel materials were prepared by SPS-HF dual power plasma sintering.The effects of sintering temperature and GNPs content on the mechanical properties,relative density and microstructure of the composites were studied.The relationship between sintering displacement curve and mechanical properties was analyzed,and the effect of GNPs content on the grain size of the scalpel material was explained.The experimental results show that adding a small amount of GNPs can improve the flexural strength and fracture toughness of the tool material,but adding more GNPs will reduce the bending strength of the scalpel material.When the sintering temperature is 1400°C,the holding time is 5min,and the sintering pressure is 30Mpa,the scalpel material with 0.2wt%GNPs（YAG0.2）achieves the best mechanical property.The flexural strength and fracture toughness are 857±10Mpa and 12.70±0.16Mpa·m^1/2,respectively,and the relative density is 98.7±0.2%.At the same time,the addition of GNPs is beneficial to improve the density of the scalpel material,but it will reduce the Vickers hardness.With the gradual increase of GNPs content,the grain size of zirconia in the scalpel material gradually decreases,and the added GNPs can inhibit the growth of grains.The biocompatibility of the 3Y-TZP/Al₂O₃/GNPs ceramic scalpel material was tested.The cytotoxicity test was performed by using colon cancer cells（caco-2）,and the antibacterial test of the scalpel material was performed using staphylococcus aureus.The experimental results show that 3Y-TZP/Al₂O₃/GNPs scalpel material has no cytotoxicity and has no significant effect on the growth of caco-2 cells.As the content of GNPs in the composite matrix gradually increases,it can be observed that the cell growth state around the material remains good.Through the active staining fluorescence map of caco-2 cells,after long-term contact with the scalpel material,the number of dead caco-2 cell does not change significantly,and the cell death rate tends to be stable,indicating that the lower content of GNPs did not affect the proliferation and growth of caco-2 cells.The 3Y-TZP/Al₂O₃/GNPs composite ceramic material has a certain antibacterial effect,and the antibacterial rate of YAG0.2 is 47.35%,which is remarkable.The effects of femtosecond laser processing parameters on the surface micro-texture morphology of zirconia ceramic scalpel were studied.The effects of laser power,pulse duration and defocusing amount on the morphology were introduced in detail.The effects of cutting angle,cutting speed and surface texture on cutting force of the scalpel were investigated.The experimental results show that for YAG0.2 composite material,when the laser power ratio is 80%,the pulse duration is 2000 ms,and the defocusing amount is30μm,the morphology of the micropore is better,the edge is smooth,and the diameter of the processed micropore is about 30μm,which is consistent with the designed size.A larger power,a lower pulse duration or a lower defocusing amount for processing will cause a lot of melts to appear on the edge of the micropore.In the process of cutting silicone tissue,larger cutting angle and lower cutting speed are beneficial to reduce the breaking cutting force of the scalpel.When the cutting angle is 40°and the cutting speed is 100 mm/min,the breaking cutting force of the scalpel is the smallest,reaching 4.1 N.As the density of the micro-texture of the scalpel surface increases from 0%to 10%,the fracture cutting force of the scalpel shows a significant decreasing trend.However,with the further increase of the texture density,the fracture cutting of the scalpel shows a further increasing trend.When the texture density is 20%,the breaking force of the scalpel is the largest,and when the texture density is 10%,the breaking force of the scalpel reach the minimum value of 3.65 N.