Study For Preparation And Mechanical Properties Of Zirconia-Based Nano-hydroxyapatite Functional Gradient Materials

ObjectiveUse of functionally gradient materials technology,with middle 3Y-ZrO2/nHA gradient composite layer,the surface of porous n-HA,because of the gradient transition between the two materials,the internal interface is reduced or even disappeared,thus forming a solid organic combination.Case study of application of high temperature sintering technology to design the preparation of good sintered zirconia matrix nanometer hydroxyapatite functional gradient materials for biological ceramic,based on the 3Y-ZrO2/nHA FGM mechanics performance test,the optimum design for the screening of the FGM and the sintering temperature,the further research of this new type of bioceramics provides a preliminary experimental basis.Methods1.Sample design:the matrix is 100%3Y-ZrO2,the middle layer is 3Y-ZrO2/nHA composite gradient layer,and the surface layer is 100%nHA.According to the formula,nHA content(volume fraction)f(x)=(x/n)P ×f(s)in each layer gradient layer is calculated.According to the different thickness of zirconia layer in the substrate layer,the three groups of A,B and C were divided into groups of 1,2 and 3 according to the number of nHA volume fractions in the gradient layer.2.Powder preparation:lwt.%PVA powder was added in the 3 Y-ZrO2 and nHA powder,the surface is the addition of 10%vol nano carbon powder in the nano hydroxyapatite powder.This experiment set p=2.5,n=3,5 and 7,According to the formula,nHA in the gradient layer is calculated and the calculated nHA is added to 3Y-ZrO2 and the PVA of lwt.%is added and the ultrasonic vibrator is fully mixed.3.Specimens for grey system:For the convenience of mechanical performance testing,the specimen is designed as the component gradient layer along the thickness of the one direction,and the bottom layer is the substrate layer(middle layer).F irstly,3Y-ZrO2 powder was added,and the different mixing ratio 3Y-ZrO2/nHA powder gradient layer was added layer by layer.Finally,nHA surface layer powder was added,and the two powders were separated by PVA film.In more than 25 ℃(dissolved temperature)at room temperature to 150 Mpa pressure,speed of 1 mm/min single-sided vertical pressure.4.Specimen of sintering:set temperature from 1300℃to1550℃,50℃ difference between the two groups.Specimen to be included in the muffle furnace,heating up to 300℃ heat preservation 2h,further to set temperature insulation with furnace cooling to room temperature after 2h to take out the spare.5.Testing of mechanical properties:the cylindrical specimens with high temperature sintering are processed into rectangular samples of different sizes,and the surface of the material is polished for mechanical performance testing.(1)Flexural strength test:make 25mm X 15mm X 10mm specimen into the universal test machine,loading at room temperature environment,load of lOMpa,the speed is 1mm/min,until the specimen cracking,computer display fracture,crushing peak,record data and calculate the bending strength of FGM.(2)Shear strength test:make 20mmX 13mm×8mm specimen polished polishing in different parts of the specimen after applying load force lOMpa,the speed is lmm/min,until the specimen cracking,computer display crushing peak,FGM calculated using the formula of shear strength.6.Data processing:using the data with x±s,SPSS 17.0 software was used to conduct one-way anova analysis of the data,and the two groups were compared.Results1.Under normal temperature static pressure 150Mpa vertical pressure,can form the zirconia nano-hydroxyapatite gradient funtional materials raw material specimen.2.The intermediate gradient layer affects the mechanical properties of functionally graded materials.With the increase of the number of gradient layers,the difference in nHA content between adjacent layers gradually decreased,and the layer showed continuous gradient change,thus inproving its mechanical properties.3.The sintering temperature affects the flexural strength and shear strength of zirconia based nano hydroxyapatite FGM.from 1300℃Cto1550℃,as the temperature increases,the bending strength and shear strength increase.When 1550 ℃,the mechanical properties of the optimal,with significant difference compared with other groups of five.Conclusion1.Under the 150Mpa single-sided vertical pressure of the preparation of zirconium oxide nanometer hydroxyapatite functionally gradient material green specimen,can reach the design idea of functionally gradient materials and the requirements of the further experiments.2.The sintering temperature and gradient layer are the main factors affecting the mechanical properties of zirconia and nano hydroxyapatite.When the sintering temperature is 1550℃,the gradient layers for 7、zirconia matrix layer thickness for 40 mm、thickness of nHA gradient layer for10 mm,3 Y-ZrO2/nHA FGM can obtain the strongest resistance to bending strength and shear strength.3.3Y-ZrO2 and nHA powder as raw materials,according to the design of optimal gradient,the normal tenperature pressurized high temperature sintering technology of preparation of 3Y-ZrO2/nHA FGM ceramic specimen,has high mechanical properties,and the biocompatibility and biological properties of the in order to further the research laid the foundation.