Laser Composite Surfacing of a Magnesium Alloy with TiO2 Nanoparticles

2012 ◽  
Vol 549 ◽  
pp. 643-646 ◽  
Author(s):  
Min Zhang ◽  
Chang Jun Chen ◽  
Qun Xing Fei

In the study, ZM5 Mg alloy was laser melted by dispersion of TiO2nanoparticles on its surface. The microstructure of the composite surfaced layer (both the top surface and the cross section) was characterized by optical and scanning electron microscope. A detailed analysis of the composition of the composite layer was carried out by energy dispersive spectroscopy. The microhardness of the composite layer was measured and the wear of the composite surfaced ZM5 was studied. Experimental results showed that composite surface layer consists of TiO2particles in grain refined ZM5 matrix, but the nanoparticles was agglomerated. And there was degradation of TiO2particles or interfacial reaction at the particle-matrix interface. Microhardness and wear resistance of the composite surfaced zone was improved compared to ZM5 substrate.

2012 ◽  
Vol 557-559 ◽  
pp. 534-537 ◽  
Author(s):  
Yong Ping Niu ◽  
Sa Li ◽  
Jun Kai Zhang ◽  
Li Hua Cai ◽  
Yong Zhen Zhang

Polytetrafluoroethylene (PTFE) nanocomposites filled with alumina nanoparticles were prepared by compression molding and follow-up sintering. The tribological behaviors of PTFE nanocomposites sliding against GCr15 steel were evaluated using ball-on-disk tribology test rig. The worn surfaces of the unfilled and filled PTFE nanocomposite were investigated using a scanning electron microscope (SEM). The wear behavior of the PTFE nanocomposites was explained in terms of the topography of worn surfaces. It was found that the addition of alumina nanoparticles was effective in enhancing the wear resistance of the PTFE nanocomposite.


Author(s):  
E. O. Fadeeva

Conducted electron microscopic investigation of the primary remex fine structure of thirteen species of Owls (Strigiformes), using a scanning electron microscope (SEM). It is shown that Owls (Strigiformes) have a number of specific primary remex microstructural characteristics. First of all, these are the features of the structure of the pennaceous barb: a cross section configuration, a pith architectonics on the cross section and longitudinal sections, a cuticular structur of the barb. A number of the unique features in the microstructure of the vanules of the pennaceous barb have been found for the first time (at the scanning electron microscope level, at a large SEM magnification). First of all, these are the structural features of the distal barbules and the structure of the apical portion of the barb with the elongated proximal barbules and the distal barbules tightly contiguous to the ramus and closed with each other. Mentioned characteristics make for the thick velvet-like dorsal surface of the vane and the presence of a complex of peculiar “bunches” (fringes) forming the cleft edge (a fringed edge) of the inner vane – exceptionally specific adaptive characteristics in Strigiformes. Рresentenced original research results suggest that Owls (Strigiformes) have a number specific microstructural characteristics of the primary remex and also a number of the unique features in the microstructure of the primary remex which reflecting the ecological and morphological adaptations conditioned by the flight specificity.


2013 ◽  
Vol 20 (05) ◽  
pp. 1350048 ◽  
Author(s):  
Xiaodong Hu ◽  
Yajiang Li

Effect of the tempering on the microstructures and tribological properties of the laser alloying coatings is investigated. Laser alloying of the T - Co 50/ TiC mixed powders on a 45 steel substrate can form a hard composite coating, which increased the micro-hardness and wear resistance of the substrate greatly. Such laser alloying coating was investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). Experimental results indicate that the tempering is able to remove the accumulation of the residual stress in a certain extent, improving the plastic and toughness properties of such coating; moreover, tempering also improves greatly the formation mechanism, making the coating have enough ability of the intensity transfer, which is beneficial in preventing the crack propagation of the interface in such coating, leading to an improvement of the wear resistance.


2021 ◽  
Author(s):  
RAJA KALIYAPERUMAL ◽  
T.KASILINGAM

Abstract Inhibition action of 4-Chloro-N(3,4,5-trimethoxybenzilidene) benzohydrazide on the corrosion of magnesium alloy in alkaline medium was investigated by weight-loss technique, Nyquist spectra, Tafel plot, scanning electron microscope and energy dispersive x-ray analysis. Tafel curves of magnesium alloy showed both anodic and cathodic process suppressed. Nyquist plots, scanning electron microscope and energy dispersive x-ray analysis studies provide the confirmatory evidence for the protection of magnesium alloy by the studied inhibitor.


2010 ◽  
Vol 165 ◽  
pp. 306-309 ◽  
Author(s):  
Beata Majkowska ◽  
Waldemar Serbiński

The purpose of this paper is to demonstrate the method of laser remelting at cryogenic conditions of the SUPERSTON alloy and its influence on microstructure and cavitation wearing. The cavitation test was performed using the rotating disc facility in IPM PAN Gdansk. During the cavitation test, the mass loss of the material with different parameters of laser remelting was determined. Surface and cross-section microstructure of the SUPERSTON alloy after laser treatment and cavitation test were observed by scanning electron microscope. The cavitation resistance of the remelted SUPERSTON alloy was approximately 40% higher in comparison to the base material.


2011 ◽  
Vol 18 (03n04) ◽  
pp. 103-108 ◽  
Author(s):  
JIANING LI ◽  
CHUANZHONG CHEN ◽  
CUIFANG ZHANG

Laser cladding of the Fe3Al + B4C/TiN + Al2O3 pre-placed powders on the Ti-6Al-4V alloy can form the Ti3Al/Fe3Al + TiN/TiB2 composite coating, which improved the wear resistance of the Ti-6Al-4V alloy surface. In this study, the Ti3Al/Fe3Al + TiN/TiB2 composite coating has been researched by means of X-ray diffraction and scanning electron microscope. It was found that during the laser cladding process, Al2O3 can react with TiB2 , leading to the formations of Ti3Al and B . This principle can be used to improve the Fe3Al + B4C/TiN laser-cladded coating on the Ti-6Al-4V alloy. Furthermore, during the cladding process, C consumed the oxygen in Fe3Al + B4C /TiN + Al2O3 molten pool, which retarded the productions of the redundant metal oxides.


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