Surface Topography Of Stainless Steel Research Articles

Assessment of the influence of metal ions released from the fixed orthodontic appliances on the static friction and surface topography of stainless steel and I archwires: An in-vitro study.

Static friction force between the orthodontic brackets and wire impacts the sliding mechanics that affect teeth movements and treatment duration. This sliding media is jam-packed with released metal ions from the fixed appliances. This study aimed to assess the static frictional force and surface topography of stainless steel (SS) and I archwires in dry conditions and in media fully with metal ions that were released from fixed appliances. In this research study, a set of 60 as-received straight archwires specimens (5 cm wire) were employed and categorized into two groups based on the material type [30 super elastics new I archwires gauge (0.018 × 0.014 inch) and 30 SS archwires 0.018 × 0.022" as a control]. The archwires' static friction force was measured while sliding a loaded Roth SS brackets (0.018") on the archwire using a universal tensile testing machine in dry and metal ions released media, while the surface topography was assessed using a noncontact AFM machine. The static friction of I archwire was significantly lower than the SS wire in dry condition. Metal ions media released from fixed appliances significantly reduced the Static friction compared to dry and wet conditions with deionized water for both wires. An Atomic Force Microscope machine surface roughness reports revealed that the highest mean of all three roughness parameters was found in the SS group, followed by I archwires in descending order. Additionally, metal ions media significantly reduce all roughness parameters.

Investigating and understanding the effects of multiple femtosecond laser scans on the surface topography of stainless steel 304 and titanium

The majority of studies performed on the formation of surface features by femtosecond laser radiation focuses on single scan procedures, i.e. manipulating the laser beam once over the target area to fabricate different surface topographies. In this work, the effect of scanning stainless steel 304 multiple times with femtosecond laser pulses is thoroughly investigated over a wide range of fluences. The resultant laser-induced surface topographies can be categorized into two different regimes. In the low fluence regime (FΣline,max<130J/cm2), ellipsoidal cones (randomly distributed surface protrusions covered by several layers of nanoparticles) are formed. Based on chemical, crystallographic, and topographical analyses, we conclude that these ellipsoidal cones are composed of unablated steel whose conical geometry offers a significant degree of fluence reduction (35–52%). Therefore, the rest of the irradiated area is preferentially ablated at a higher rate than the ellipsoidal cones. The second, or high fluence regime (FΣline,max>130J/cm2) consists of laser-induced surface patterns such as columnar and chaotic structures. Here, the surface topography showed little to no change even when the target was scanned repeatedly. This is in contrast to the ellipsoidal cones, which evolve and grow continuously as more laser passes are applied.

Chemical mechanical polishing of stainless steel foil as flexible substrate

Stainless steel foils as thin as 120μm are polished to meet the requirement of low roughness for fabricating flexible thin-film transistors on them used in display or sensor. Using the colloidal silica as abrasives in the chemical mechanical polishing (CMP) procedure, different slurries are evaluated in terms of material removal rates (MRRs). Preliminary CMP tests show that the slurries containing oxidant with the pH less than 2.0 produce the greatest removal rate, and accordingly the mechanism of material removal is proposed. The surface topography of stainless steel before and after polishing is characterized by optical image, scanning electron microscopy and atomic force microscopy image. The surface roughness can be reduced from the unpolished 13.6nm to the polished 0.7nm. However, it's found that the microscopic defects of 1–2μm in size are always present within the polished surface, and the electrochemical cause of their occurrence is suggested according to elementary mapping analysis.

Effect of Machining Parameters on Surface Roughness During Wet and DryWire-EDM of Stainless Steel

Surface integrity of Machined parts is one of the major machining characteristics that play an important role in determining the quality of engineering components. It is well-known fact that good quality surfaces improve the fatigue strength, corrosion and wear resistance of workpiece. The purpose of this study was to investigate the effects of Wire-Electrical Discharge Machining (WEDM) variables on surface topography of stainless steel. In the present work, the effects of pulse current and gap voltage on surface topography during wet and dry WEDM of stainless steel were investigated. It was evident that as the two process parameters increase the surface topography of workpiece becomes worse. The effect of both dry and wet machining conditions on surface topography is also reported in this paper.

Influence of the Surface Topography of Stainless Steel on Bacterial Adhesion

Bacterial adhesion on stainless steel may cause problems such as microbially induced corrosion or represent a chronic source of microbial contamination. The investigation focussed on how the extent and patterns of four bacterial species comprising three different phyla and a broad variety of physicochemical characteristics was influenced by the surface topography of AISI 304 stainless steel. Five types of surface finish corresponding to roughness values R a between 0.03 and 0.89 w m were produced. Adhesion of all four bacteria was minimal at R a =0.16 w m, whereas smoother and rougher surfaces gave rise to more adhesion. This surface exhibited parallel scratches of 0.7 w m, in which a high proportion of bacteria of three of the strains aligned. Reduced overall adhesion was attributed to unfavorable interactions between this surface and bacteria oriented other than parallel to the scratches. Interaction energy calculations and considerations of micro-geometry confirmed this mechanism. Rougher surfaces exhibiting wider scratches allowed a higher fraction of bacteria to adhere in other orientations, whereas the orientation of cells adhered to the smoothest surface was completely random.