316L表面激光熔覆复合微弧氧化制备陶瓷涂层

Ceramic Coating Prepared by Laser Cladding and Composite Micro-arc Oxidation on 316L Surface

目的提高316L不锈钢表面的耐蚀性和生物活性。方法首先采用激光熔覆技术在316L不锈钢表面制备钛层,然后对钛层表面进行微弧氧化处理,从而在316L不锈钢表面制备出含有Ca、P元素的多孔状陶瓷涂层。利用扫描电子显微镜(Scanning Electron Microscope,SEM)、能谱仪(Energy Dispersive Spectrometer,EDS)、X射线衍射仪(X-Ray Diffraction,XRD)分析了钛层厚度对陶瓷涂层的表面显微形貌、元素含量及物相组成的影响。利用电化学实验、浸泡实验分别测试了涂层在1.5倍SBF溶液中的耐蚀性能和生物活性。结果通过激光熔覆复合微弧氧化能够在316L不锈钢表面制备出多孔状陶瓷涂层。随着钛层厚度的增加,微弧氧化原位生成的陶瓷涂层致密度、厚度也增加。当钛层厚度达到0.4 mm时,微弧氧化后得到的陶瓷涂层完整致密,厚度达到20μm。涂层主要由锐钛矿相Ti O2、金红石相Ti O2组成。极化曲线分析可知,腐蚀电位Ecorr为-0.162 V,腐蚀电流密度降至5.11×10-7 A/cm2。陶瓷涂层在1.5倍SBF中浸泡3天后表面即有羟基磷灰石沉积。结论通过激光熔覆复合微弧氧化在316L不锈钢表面制备的陶瓷涂层在模拟体液环境下具有较好的耐蚀性能,同时也具备良好的生物活性。

The work aims to improve the corrosion resistance and bioactivity of 316L stainless steel surface.The titanium coating was prepared on 316L by laser cladding,and then the micro-arc oxidation was carried out on the surface of the titanium layer.Therefore,porous ceramic coating containing Ca and P was prepared on the surface of 316L.The influence of the thickness of titanium layer on the surface morphology,element content and phase composition of ceramic coating was analyzed by SEM(Scanning Electron Microscope),EDS(Energy Dispersive Spectrometer)and XRD(X-Ray Diffraction).The corrosion resistance and bioactivity of the coating in 1.5×SBF solution were tested by electrochemical tests and immersion tests.Porous ceramic coating was prepared on 316L stainless steel by laser cladding and composite micro arc oxidation.The density and thickness of ceramic coating in situ formed by micro-arc oxidation increased with increase of the thickness of titanium layer.When the thickness of titanium layer reached 0.4 mm,the ceramic coating prepared by micro-arc oxidation was dense and the thickness of the dense coating reached 20μm.The coating mainly consisted of anatase phase and rutile phase.From the polarization curve,the corrosion potential Ecorr was-0.162 V and the corrosion current density decreased to 5.11×10^-7 A/cm2.After immersion in 1.5 times of SBF for 3 days,hydroxyapatite was observed on the surface of the ceramic coating.The ceramic coating prepared by laser cladding combined with micro-arc oxidation on 316L surface has excellent corrosion resistance in simulated body fluid,and can effectively improve the bioactivity of 316L stainless steel.