Study On Preparation And Mechanical Properties Of Purple Ceramics

With the rapid development of the intelligent age,colored ceramics are more and more widely used in all walks of life.Because the color of colored ceramics bright color,with low signal interference and other characteristics,colored ceramics began to be widely used in mobile phone back panel,watch ring and other smart wear.This paper was prepared in order to meet the requirement for smart wear purple ceramic,selected only zirconate neodymium can satisfy the requirements of the color,but zirconate neodymium purple ceramic mechanical performance is not good,especially the fracture toughness is extremely low,thus to improve the fracture toughness of purple neodymium zirconate ceramics has become a top priority,this is also a hotspot in the research of the scholars at home and abroad.This paper mainly studies the mechanical and optical properties of multiphase ceramics prepared by adding 3YSZ to neodymium zirconate.In this paper,neodymium zirconate,yttrium stabilized zirconia(3YSZ)as raw materials,with a certain proportion of ingredients,through solid phase ball milling method to prepare neodymium zirconate multiphase ceramics,the mass fraction of yttrium stabilized zirconia added is:20wt%3YSZ,40wt%3YSZ,50wt%3YSZ,60wt%3YSZ,70wt%3YSZ,80wt%3YSZ,preparation of the duplex ceramic,at the same time for the preparation of ceramic chip specimen,phase structure,microstructure and optical properties and mechanical properties test,respectively using X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM),Raman spectroscopy(Raman),automatic vickers microhardness tester,uv spectral reflectance,chromameter.According to the X-ray diffraction(XRD)and Raman spectroscopy analysis of the phase structure,it can be seen that the ceramic chip prepared by pyrochloritic phase and zirconia tetragalic phase coexist,through the field emission scanning electron microscopy(FE-SEM)can be seen that the ceramic chip sample prepared uniform compact,small grain size.According to the test of its optical properties,it can be seen from the ultraviolet spectrum test that: for all sintering temperatures and all components,the trend of the change law is roughly the same.For the same component,the reflectivity of all sintering temperatures at the same wavelength does not change much,indicating that the temperature has little effect on it.For the same sintering temperature,in the range of violet wavelength 400-435 nm,with the decrease of 3YSZ content,its reflectivity gradually increases,indicating that the violet light reflection increases and the purple degree deepens.By chroma meter test shows: for the same sintering temperature,with 3 mass fraction of ysz decreases,namely zirconate nd the increase of mass fraction,the brightness values of all ceramic chip sample(L*)reduced gradually,the purple deepened,the temperature effect on the brightness values,show that temperature on the color shade shadow can think big,this is consistent with the actual ceramic piece of the color of the sample.The mechanical properties of 3YSZ were tested by vickers hardness tester.It was found that when 3YSZ was added,the vickers hardness of 3YSZ was improved compared with that of pure neodymium zirconate no matter whether the mass fraction was more or less.When the content of 3YSZ is 80% and the sintering temperature is 1400 o C,the maximum vickers hardness is 12.93 GPa,which is nearly 88.48% higher than that of pure neodymium zirconate 6.86 GPa,for the same sintering temperature,with the decrease of3 YSZ mass fraction,the vickers hardness value decreases gradually;For the same 3YSZ content,the vickers hardness value decreases with the decrease of sintering temperature,which is caused by the change of grain size after adding 3YSZ.When 3YSZ content is 80%and sintering temperature is 1400 o C,the fracture toughness of pure neodymium zirconate increases to 8.15 MPa m1/2,which is 217.12% higher than that of pure neodymium zirconate 2.57 MPa m1/2.For the study of its toughening mechanism,this paper carried out the micro-crack Raman test,using Raman spectroscopy on the sensitivity of phase composition,Raman spectroscopy was used to test the crack root of each sample after microhardness test,to see whether there is a phase transition from tetragonal zirconia to monoclinic zirconia.It is found that there is m-t Zr O2 phase transition,and the toughening is increased by stress-induced phase transition.Phase transformation toughening is to improve the fracture toughness of ceramic materials by martensitic transformation of tetragonal zirconia to monoclinic zirconia.The monoclinic phase(m-Zr O2)of zirconia was observed in all of the Raman spectra,indicating a martensitic transformation.In conclusion,this paper prepared purple multiphase ceramics by adding yttrium stabilized zirconia(3YSZ)into neodymium zirconate,and its color met the requirements of smart wear,and its vickers hardness and fracture toughness were significantly improved.