The Effect Of Silica Film Made By Sol-gel Method On Anticorrosion Properties Of Pure Titanium

Objectives To raise the corrosion resistance of pure titanium specimen, making a layerof silicon dioxide film on the surface of pure titanium by sol-gel method, measuring thecorrosion potential, the corrosion current density and the polarization resistance of puretitanium specimen with different thickness of silicon dioxide thin film in artificial salivawith fluoride, to evaluate the influence of different thickness of silicon dioxide thin filmon the corrosion resistance of pure titanium specimen, to provide reference for anti-corrosion treatment of pure titanium metal full crown, pure titanium stents and others.Methods The preparation of specimens:28pieces pure titanium plates were casted,with length of side1cm, and thickness of1mm, and10cylindrical test specimens ofdiameter6mm and height13mm were casted, cleaning them with ultrasonic in turn withacetone, ethanol, distilled water, drying and setting aside. The28pieces of specimenswere divided into A, B, C, D four groups, respectively made silicon dioxide thin film by0,1,2,4times sol-gel method. Measuring the thickness of silicon dioxide thin films, andobserving the surface morphology under the electron microscope. Putting the specimensinto the artificial saliva with fluoride, drying after24hours, scanning their polarizationcurves with electricity chemistry workstation, getting the corrosion current density（Icorr）and corrosion potential （Ecorr）of each specimen by observing the curve.Cleaning them with ultrasonic in distilled water for5minutes after the measurement, dry,observing the surface morphology under electron microscope.10cylinder of puretitanium specimen were divided into two groups, each group of five pieces, randomlyselected one of the group, make the test surface of silicon dioxide coating with two-timeway. All of10specimens were tested on friction and wear tester. Recording their’s wearweight. Using SPSS13.0software to make an analysis of S-N-K test, Dunnett T3test anda t-test analysis of the data.Results1Observing the surface of the specimens with different thickness of silicondioxide thin film by scanning electron microscopy, we finded that coating films haddifferent degrees of cracks. After the electrochemical test specimens’ surface haddifferent degrees of corrosion pit.2The results of the electrochemical analysis: TheEcoor, Icoor of experimental groups（B, C, D group） and control group（group A） were statistically significant difference（P <0.05）, while the three experimental groups（B, C, D） differences between groups were statistically significant （P <0.05）.Thecorrosion resistance of B, C, D groups was better than A group, and C group was betterthan D group, D group was better than A group.3Compared the amount of wear ofexperimental group and control group, there was statistically significant （P<0.05）.Conclusions In these experimental conditions:1The silica coating in the surface ofpure titanium specimen were prepared by sol-gel method. The distribution of the coatingwas uniform, the surface crack was less.2The silica coating in the surface of puretitanium specimen prepared by sol-gel method can increase the corrosion resistance ofpure titanium specimen, the effect of double coating was best.3The wear resistance ofsilica coating in the surface of pure titanium specimen was insufficient, which meanscoating preparation process needed to be improved.4The silica coating in the surface ofpure titanium specimen prepared by sol-gel method had good corrosion, providing a newreference for corrosion resistance of casted pure titanium denture material. But its wearresistance was insufficient, affecting its next clinical application, so it is necessary todevelop a new preparation technology in order to enhance its wear resistance.