This study aims to examine the effect of clay micro particles addition on the microstructure,wear and corrosion behavior of PEO coatings on AM 50 magnesium alloy.PEO coatings were prepared using an aluminate-based ele...This study aims to examine the effect of clay micro particles addition on the microstructure,wear and corrosion behavior of PEO coatings on AM 50 magnesium alloy.PEO coatings were prepared using an aluminate-based electrolyte with and without the presence of 5 g/L clay particles.The structure and composition of the coatings were evaluated using SEM,EDS and XRD.The wear investigations were conducted using a ball-on-disk tribometer at 2,5 and 10 N loads.The corrosion behavior of the coatings was examined using polarization and EIS tests in 0.5 wt.%NaCl.The results revealed that the addition of clay particles deteriorated the wear resistance of the coatings under the loads of 5 and 10 N.The SEM examinations of the worn surfaces indicated that a combination of adhesive and abrasive wear mechanisms was activated for the coating with clay particles.The poor wear performance of the clay-incorporated coating was related to its lower adhesion strength and higher roughness.The potentiodynamic polarization examinations revealed that the addition of clay particles slightly decreased the corrosion rate of the coatings.Corrosion resistance of the clay-containing coating was attributed to its compactness,as indicated by the results of EIS tests.展开更多
Duplex NiP/TiN coatings consisting of the electroless intermediate layers and the physical vapor deposition(PVD) top layers were fabricated on the AA6061 aluminum alloy in order to enhance the load bearing capacity. T...Duplex NiP/TiN coatings consisting of the electroless intermediate layers and the physical vapor deposition(PVD) top layers were fabricated on the AA6061 aluminum alloy in order to enhance the load bearing capacity. The main objective of this study was to model the load bearing based on the thickness, adhesion and elastic modulus of the coatings. For this purpose, partial least square(PLS) and support vector regression(SVR) approaches were employed.The results showed that both models had an acceptable performance;however, the PLS model outperformed SVR. The correlation coefficients between thickness, adhesion and elastic modulus with load bearing were 0.841, 0.8092 and 0.7657, respectively;so, thickness had the greatest effect on the load bearing capacity. The composition and structure of the samples were evaluated using XRD and SEM. The load capacity of the coated samples was also discussed based on the wear and adhesion evaluations. Dry sliding wear tests, under a load of 2 N and a sliding distance of 100 m,demonstrated the complete destruction of the coated specimens with low load capacity. The samples with high load capacity showed not only a superior tribological performance, but also a remarkable adhesion according to the Rockwell superficial hardness test.展开更多
文摘This study aims to examine the effect of clay micro particles addition on the microstructure,wear and corrosion behavior of PEO coatings on AM 50 magnesium alloy.PEO coatings were prepared using an aluminate-based electrolyte with and without the presence of 5 g/L clay particles.The structure and composition of the coatings were evaluated using SEM,EDS and XRD.The wear investigations were conducted using a ball-on-disk tribometer at 2,5 and 10 N loads.The corrosion behavior of the coatings was examined using polarization and EIS tests in 0.5 wt.%NaCl.The results revealed that the addition of clay particles deteriorated the wear resistance of the coatings under the loads of 5 and 10 N.The SEM examinations of the worn surfaces indicated that a combination of adhesive and abrasive wear mechanisms was activated for the coating with clay particles.The poor wear performance of the clay-incorporated coating was related to its lower adhesion strength and higher roughness.The potentiodynamic polarization examinations revealed that the addition of clay particles slightly decreased the corrosion rate of the coatings.Corrosion resistance of the clay-containing coating was attributed to its compactness,as indicated by the results of EIS tests.
文摘Duplex NiP/TiN coatings consisting of the electroless intermediate layers and the physical vapor deposition(PVD) top layers were fabricated on the AA6061 aluminum alloy in order to enhance the load bearing capacity. The main objective of this study was to model the load bearing based on the thickness, adhesion and elastic modulus of the coatings. For this purpose, partial least square(PLS) and support vector regression(SVR) approaches were employed.The results showed that both models had an acceptable performance;however, the PLS model outperformed SVR. The correlation coefficients between thickness, adhesion and elastic modulus with load bearing were 0.841, 0.8092 and 0.7657, respectively;so, thickness had the greatest effect on the load bearing capacity. The composition and structure of the samples were evaluated using XRD and SEM. The load capacity of the coated samples was also discussed based on the wear and adhesion evaluations. Dry sliding wear tests, under a load of 2 N and a sliding distance of 100 m,demonstrated the complete destruction of the coated specimens with low load capacity. The samples with high load capacity showed not only a superior tribological performance, but also a remarkable adhesion according to the Rockwell superficial hardness test.
