Surface Roughness Of Stainless Steel Research Articles

Qualitative surface roughness of lithium disilicate endo-crown for pulpotomized primary molars

Rehabilitation of pulpotomized primary molars with an appropriate restoration is essential for recovering function and safeguarding the durability of the treatment. This study aimed to assess and compare the surface roughness of stainless steel (ST) crowns, zirconia (ZR) crowns, fiberglass (FG) crowns, and lithium disilicate (LD) endo-crowns as a restoration for pulpotomized primary molars also, evaluating the surface roughness of their antagonists. Sixty pulpotomized primary mandibular first molars were used for qualitative surface roughness evaluation and divided into four groups (n = 15/group) according to the crown type (group-ST, group-ZR, group-FG, group-LD). While the other sixty sound, unprepared primary maxillary first molars were used for evaluation of their surface roughness against the tested crowns. Specimens’ preparation and cementation were carried out according to each crown type and manufacturer’s instructions. The surface roughness was done using a two-body wear test. The data were statistically analyzed. All tested crowns showed an increased change in surface roughness, except group-ZR, which had the least change in surface roughness after mechanical wear with no statistically significant difference(P = 0.681). All crown types significantly increased the surface roughness of their antagonists after mechanical wear, except group-ST which showed insignificant affection (p ≥ 0.05). Zirconia crowns and lithium disilicate endo-crowns had the least change in surface roughness compared to other groups while SSCs showed the least tooth loss in the antagonist enamel.

Study on Measurement of Adsorption Capacity of Unsymmetrical Dimethylhydrazine Gas based on Stainless Steel

Unsymmetrical dimethylhydrazine (UDMH), as a high-energy liquid propellant, is widely used in aerospace, rocket, aircraft, and other fields. However, it also has certain toxicity, fire, and explosion risks, which will cause harm to the human liver, kidney, central nervous system, blood system, etc., especially the nervous system. UDMH is easy to be adsorbed on the surface of the human body or other substances, but there is a lack of research reports on the measurement of its adsorption capacity. In this paper, based on the principle of measuring gas adsorption capacity by the volumetric method, a set of UDMH gas adsorption capacity testing devices was built. In the experiment, 304 and 316L stainless steel materials were used as the adsorbent. Under the same experimental temperature and pressure conditions, the test bottle containing the adsorbent was filled with UDMH gas of different concentrations and fully adsorbed until saturation to explore the influence of 304 stainless steel surface roughness and 304 and 316L stainless steel materials on the adsorption capacity of UDMH gas under the same experimental conditions. The experimental results show that the adsorption capacity of 304 and 316L stainless steel materials to UDMH gas increases with the increase of UDMH gas concentration in the concentration range (0~100 ppm) studied in this paper. After polishing the surface of 304 stainless steel material, compared with the unpolished 304 stainless steel material under the same conditions, the adsorption capacity after polishing is significantly smaller, indicating that the larger the surface roughness of the adsorbent, the more adsorption capacity. Under the same conditions, the adsorption capacity of UDMH gas on 304 and 316L stainless steel materials is approximately equal. The experiment also proves that the adsorption of UDMH gas on stainless steel materials conforms to monolayer adsorption within the concentration range studied in this paper.

Optimization on Material Removal Rate and Surface Roughness of Stainless Steel 304 Wire Cut EDM by Response Surface Methodology

In this work, wire cut electrical discharge machining (WEDM) is used for the material removing processes; it is utilized for machining conductive parts where it is required to produce complicated shapes, new profiles, new geometry, new product development, and high-accuracy components. This machining process is best suitable for high-end applications such as aerospace, automations, automobile, and medical devices. At present, most of the industrial sectors choose the WEDM process because it is used to develop products in a very short development cycle and at a better economic rate. In this paper, the selected complex geometry of the metal sample was eroded away from the wire during the WEDM process, which eliminates mechanical tensions during machining. The effect of different WEDM operation variables set as wire speed, wire tension, discharge current, dielectric flow rate, and pulse on and off time on the parameter, stainless steel 304 material removing rate (MRR) using RSM, has been studied. The MRR will be maximized if the optimum sets of operational variations are used and also achieve a superior surface finish.

Two-Step Chemical Mechanical Polishing of Stainless Steel

Stainless steel with high surface quality is required in many industries and chemical mechanical polishing can achieve both local and global planarization of the substrate surface. However, it is difficult to realize both high material removal rate and high surface quality by a single step polishing. In this regard, a two-step polishing process, coarse polishing with α-Al2O3 abrasives first and then fine polishing with silica abrasives, was proposed to solve the trade-off between material removal and surface quality. The effects of pH (1 ∼ 12) and H2O2 (0 ∼ 0.5 wt%) on the polishing of 304 stainless steel disk (area ∼ 6.7 cm2) were systematically studied and CMP mechanism of stainless steel was discussed. The results indicated that, at pH 4, with the addition of 0.01 wt% H2O2, the surface roughness of stainless steel was successfully reduced from 0.702 μm to 44.6 nm (the first step using α-Al2O3 abrasives) and 1.61 nm (the second step using silica abrasives). Finally, an ultra-smooth surface was obtained with decent material removal rate.

Antibacterial Effect of Stainless Steel Surfaces Treated with a Nanotechnological Coating Approved for Food Contact.

Stainless steel, widely present in the food industry, is frequently exposed to bacterial colonization with possible consequences on consumers’ health. 288 stainless steel disks with different roughness (0.25, 0.5 and 1 μm) were challenged with four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive bacteria (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) and underwent three different sanitizing treatments (UVC, alcohol 70% v/v and Gold lotion). Moreover, the same procedure was carried out onto the same surfaces after a nanotechnological surface coating (nanoXHAM® D). A significant bactericidal effect was exerted by all of the sanitizing treatments against all bacterial strains regardless of roughness and surface coating. The nanoXHAM® D coating itself induced an overall bactericidal effect as well as in synergy with all sanitizing treatments regardless of roughness. Stainless steel surface roughness is poorly correlated with bacterial adhesion and only sanitizing treatments can exert significant bactericidal effects. Most of sanitizing treatments are toxic and corrosive causing the onset of crevices that are able to facilitate bacterial nesting and growth. This nanotechnological coating can reduce surface adhesion with consequent reduction of bacterial adhesion, nesting, and growth.

Experimental Investigation on Material Removal Rate, Surface Roughness of Stainless Steel 306 by EDM

Experimental Investigation on Material Removal Rate, Surface Roughness of Stainless Steel 306 by EDM

Ocena parametrów chropowatości powierzchni po laserowym wspomaganiu skrawania stali nierdzewnej

The paper presents the analysis of the influence of laser assisted machining (LAM) on various parameters of surface roughness of stainless steel. The tests were carried out for cemented carbide inserts with varying cutting parameters. In most cases, a significant reduction in the roughness parameters was observed using LAM.

Layer-by-layer films based on catechol-modified polysaccharides produced by dip- and spin-coating onto different substrates.

Layer-by-layer films based on chitosan and hyaluronic acid were produced by dip- and spin-coating techniques onto glass, 316L stainless steel and titanium. These natural polymers were modified with catechol groups, in order to build coatings with improved adhesive properties. Polymeric coatings were exclusively composed by both modified polymers whereas the multifunctional coatings combined an inorganic phase of bioactive glass nanoparticles with the polymeric layers to confer bioactivity. Ultraviolet-visible spectroscopy demonstrated that both polymers were successfully synthesized. Fourier transform infrared imaging was used as an innovative way to analyze the layer interdiffusion in these coatings. Their morphology was analyzed by scanning electron microscopy and atomic force microscopy, and their wettability was evaluated by water contact angle measurements. Major differences were found in the structure and surface properties of the coatings assembled either by dip- or spin-coating. The spin-coated films onto glass were smoother, with a more homogeneous structure and lower interdiffusion of polyelectrolytes layers, when compared with the dip-coated ones. Furthermore, it was concluded that the intrinsic surface roughness of stainless steel and titanium substrates had great influence on the surface morphology and wettability of the coatings obtained from both layer-by-layer methodologies.

Effects of cyclonic plasma deposited organosilicon nano‐coating on 316 stainless steel and its surface characterization

Cyclonic atmospheric pressure plasma is developed to synthesize the organosilicon nano‐coating on 316 L stainless steel surface with hexamethyldisilazane (HMDSN) and HMDSN/N2 monomers. The modified 316 L stainless steel surface characteristics of cyclonic plasma deposited organosilicon nano‐coating were evaluated by the static contact angle measurement, FTIR, SEM, AFM, and XPS detections. The chemical analysis with FTIR and XPS depicts that cyclonic plasma deposited nano‐coating obtains the relatively inorganic characteristics. The surface morphological determination with SEM and AFM refers cyclonic plasma deposited 316 L stainless steel surface roughness alteration with switching monomer inputs. This study shows the potential of chamber‐less deposition to create the plasma deposited organosilicon nano‐coating for 316 L stainless.

STUDY OF THE INFLUENCE OF SAVINASE®EVITY16L ENZYME ON BIOFILMS FORMATION OF STAPHYLOCOCCUS AUREUS ON STAINLESS STEEL WITH DIFFERENT ROUGHNESS

Microbial films formation on the dairy equipment creates a serious problem, because they are difficult to eliminate by washing and disinfecting means that results in contaminating dairy products by microorganisms. The aim of the work was to study the influence of Savinase®Evity 16L proteolytic enzyme on the process of destructing biofilms, formed by Staphylococcus aureus on stainless steel with different surface roughness. It has been established, that surface roughness of stainless steel influences the process of Savinase®Evity 16L enzyme penetration in a hollow and prevents the destruction of the biofilm matrix, created by Staphylococcus aureus. It has been revealed, that after the influence of a proteolytic enzyme on Staphylococcus aureus biofilms, created on steel with roughness 0,16±0,018 mcm, the density decreased in 4,0 times (р≤0,05), comparing with a condition before processing. At roughness 0,63±0,087 mcm the density of formed biofilms decreased at the effect of Savinase®Evity 16L in 3,3times (р≤0,05) and the biofilm was characterized as a weak one. At the same time at stainless steel surfaces with roughness 2,68–0,95mcm, the density of biofilms decreased in 2,3–2,1times (р≤0,05), comparing with a condition before processing, and they were characterized as ones of the middle density. It has been also revealed, that the degradation intensity of biofilms under the influence of Savinase®Evity 16L enzyme at roughness 2,68–0,95 mcm was 1,7–1,9 times (р≤0,05) lower than at the surface with roughness 0,16±0,018 mcm. So, the revealed degradation features of a biofilm, created by Staphylococcus aureus at surfaces of stainless steel of different roughness at the influence of Savinase®Evity 16L proteolytic enzyme give a possibility to substantiate the addition of proteolytic enzymes to the composition of washing means for dairy production. It is also offered to process the surface to the roughness no more than 0,63 mcm for producing food steel for raising the effectiveness of biofilms destruction by enzymes and for the sanitary processing.

Influence of Wire Electrical Discharge Machining (WEDM) process parameters on surface roughness

In obtaining the best quality of engineering components, the quality of machined parts surface plays an important role. It improves the fatigue strength, wear resistance, and corrosion of workpiece. This paper investigates the effects of wire electrical discharge machining (WEDM) process parameters on surface roughness of stainless steel using distilled water as dielectric fluid and brass wire as tool electrode. The parameters selected are voltage open, wire speed, wire tension, voltage gap, and off time. Empirical model was developed for the estimation of surface roughness. The analysis revealed that off time has a major influence on surface roughness. The optimum machining parameters for minimum surface roughness were found to be at a 10 V open voltage, 2.84 μs off time, 12 m/min wire speed, 6.3 N wire tension, and 54.91 V voltage gap.

BONN Technique: Tribological Properties Predictor for Plasma Nitrided 316L Stainless Steel

Plasma nitriding is the most encouraging process to harden the surface roughness of stainless steel. Stainless steels has broad application in various fields, especially biomedical. The 316L stainless steel is the most recommended material for biomedical application. In this paper a novel predictor for the tribological properties of plasma nitride 316L stainless steel. The proposed predictor combines an optimization technique with an artificial intelligence technique such as Bat optimization and neural network respectively. Initially the data obtained from plasma nitriding of gas mixture of 50% H2, 50% N2 at three different time and temperature. Then the BONN is trained and the performance is compared with the actual value. The performance analysis shows the effectiveness of the proposed technique.

Permeability Study of Austenitic Stainless Steel Surfaces Produced by Selective Laser Melting

Selective laser melting (SLM) is emerging as a versatile process for fabricating different metal components with acceptable mechanical properties and geometrical accuracy. The process has been used in the manufacturing of several parts (e.g., aerospace or biomedical components), and offers the capability to tailor the performance of several surface and mechanical properties. In this work, permeability properties and surface roughness of stainless steel (SS316L) surfaces were evaluated through experimentation with three different laser scanning patterns (chessboard, meander, and stripe), and different sloping angles between the fabricated surface and the laser beam incident on the process. Results showed that for each scanning pattern, the roughness decreased as the sloping angle increased consistently in all experimental trials. Furthermore, in the case of the permeability evaluation, the manufactured surfaces showed changes in properties for each series of experiments performed with different scanning patterns. The chessboard pattern showed a change of 67° to 107° in contact angle, while the meander and stripe patterns showed a variation in contact angle in a range of 65° to 85°. The different scanning strategies in the SLM process resulted in an alternative method for surface enhancement with different hydrophobicity properties, valuable for designing the most appropriate permeability characteristics for specific applications.

Experimental investigation on influence of ECM process parameters on responses using full factorial design

Stainless steel 310 is having excellent high temperature properties with good weldability and ductility and is designed for high temperature service. Electro chemical machining is a non-traditional machining process belongs to electrochemical category. In this study, the effect of the input parameters on the material removal and surface roughness of stainless steel 310 was investigated using full factorial design (32) of experiments. Flow rate was the parameter with the larger influence on responses.

Impact of roughness, wettability and hydrodynamic conditions on the incrustation on stainless steel surfaces

The goal of this work was to investigate the influence of the stainless steel surface roughness and wettability on incrustation of MgSO4·7H2O from aqueous solutions and resulting heat transfer resistance. The experiments were done for laminar flow (Re=59–178) which is characteristic for regions of apparatus where fouling usually begin. A series of steel plates (X5CrNi18-10) were prepared and used as a heat transfer surfaces. Their properties, i.e. roughness, wettability and elementary composition of surfaces were determined. The experiments were done using specially designed flow cell equipped with Peltier element. Each incrustation measurement lasted for two hours, during which heat transfer resistance was measured as a function of time. After the experiments the mass of crystalline deposit was weighted. It was proved that wettability as well as surface roughness cannot be considered separately in the case of incrustation phenomenon. The knowledge of surface roughness is insufficient due to the fact, that it is possible to obtain surfaces with similar roughness but substantially different wettability for the same material.

Effect of Surface Roughness on Contact Angle Measurement of Nanofluid on Surface of Stainless Steel 304 by Sessile Drop Method

Contact angles play an important role in the mass and heat transfer. Stainless steel 304 has been used for nuclear power plan structure material until now. An experiment to measure contact angle of demineralized aqua and nanofluid containing nano particle of zirconia on metal surface of stainless steel 304 with sessile drop method was conducted. The measurement to measure the static contact angle and drop of nano fluid containing nano particle zirconia on stainless steel with different surface roughness was carried out. It was observed that stainless steel 304 was good hydrophylic properties with decreasing surface roughness of stainless steel during drop of aqua demineralized and nano fluid respectively. As a result the contact angle of demineralized aqua is decreased from 97.39 to 78.42 and contact angle of nano fluid from 94.3 to 67.50, respectively with decreasing surface roughness of stainless stee 304. Wettability of nanofluid on surface stainless steel 304 is better than aqua demineralized.

Study of Water Droplet Removal on Etched-Metal Surfaces for Proton Exchange Membrane Fuel Cell Flow Channel

Within a proton exchange membrane fuel cell (PEMFC), the transport route of liquid water begins at the cathode catalyst layer, and then progresses into the gas diffusion layer (GDL) where it then goes into the flow channel. At times, significant accumulation of liquid droplets can be seen on either side of the membrane on the surface of the flow channel. In this work, liquid water and the flow dynamics within the transport channel were examined experimentally, with the channel acting as an optical window. Ex situ interpretations of the liquid water and flow patterns inside the channel were established. Liquid water droplet movements were analyzed by considering the change of the contact angle with different flow rates. Also, various surface roughness of stainless steel was used to determine the relationships between flow rate and the contact angles. When liquid water is found within the gas channels of PEMFCs, the channels' characteristic changes become more dominant and it becomes more of a necessity to monitor the effects. Physical motion of water droplets in the flow channels of PEMFCs is important. The surface roughness properties were used to describe the contact angle and the droplet removal force on the stainless steel flow channel.

Microscopic study of surface roughness of four orthodontic arch wires

Aim/purpose Comparative evaluation of surface roughness of stainless steel (SS), nitinol (NiTi), titanium molybdenum alloy (TMA) and copper nitinol (Cu NiTi) orthodontic arch wires before and after clinical use to find the smoothest wire surface best used in orthodontic sliding mechanics. Materials and methods Surface roughness of 40 arch wires divided into four groups (group 1: 10 SS arch wires, group 2: 10 NiTi arch wires, group 3: 10 TMA arch wires and group 4: 10 Cu NiTi arch wires) were measured at five different points for each wire before and after its clinical use in oral cavity for 4 weeks using atomic force microscope and optical digital microscope. All obtained data was statistically tested. Results SS arch wires had the smoothest surface (average roughness: 17.38 μm for new wires and 104.1 μm for used wires) and Cu NiTi arch wires had the roughest surface (average roughness: 221.12 μm for new wires and 499 μm for used wires) with high significant differences between both groups either new or used arch wires (P < 0.001). High significant difference was found between new and used wires for all groups. NiTi wires had greater surface roughness (average roughness: 211.8 μm for new wires and 313.8 for used wires) than TMA wires (average roughness: 138.5 μm for new wires and 221.2 μm for used wires). Conclusion SS orthodontic arch wires exhibited the least amount of surface roughness and advocated to be used in sliding mechanics to minimize the friction during orthodontic tooth movements.

ВНЕДРЕНИЕ ТЕХНОЛОГИИ ЭЛЕКТРОЛИТНО-ПЛАЗМЕННОГО ПОЛИРОВАНИЯ МЕТАЛЛИЧЕСКИХ ИЗДЕЛИЙ

Modern methods of final polishing of complex-surface goods are labor-consuming and unsustainable. Nowadays, the method of electrolytic-plasma polishing is developed intensively. This method is the high-efficiency process of conductive goods treatment in the environmentally safe aqueous solutions of inorganic salts of weak concentration. Commercial application of electrolytic-plasma polishing method is impeded in engineering due to its poor exploration. The authors studied the influence of multistep polishing and electrolyte composition on the process technological parameters and surface roughness of plate specimens of 08H18N10T austenitic stainless steel processed using laboratory machine. The authors carried out the comparing study of surface roughness of specimens processed according to the suggested modes and the specimens processed according to the known modes of polishing in the widely used aqueous solutions of ammonium sulfate-based (4 % (NH4)2SO4) and sodium carbonate-based (12 % Na2CO) electrolytes. The study showed that the introduction of 0,05–0,45 % chlorine hydride to the electrolyte containing 4–5 % of ammonium sulfate reduces twofold the temperature of working electrolyte. It is established that the multistep polishing allows decreasing the stainless steel surface roughness by 20–25 % in comparison with traditional polishing methods. Basing on the results obtained, the authors suggested technological modes of final treatment of austenitic stainless steels with the use of electrolytic-plasma polishing method, developed and produced the machine for electrolytic-plasma polishing of goods (MEPPG-1). This machine is universal and allows carrying out the final polishing of various conductive materials up to 250 cm2 in area used in manufacturing industry (copper, aluminum, steel, titanium and others) by means of the electrolyte composition and processing modes changes.

Surface Roughness Optimization in Turning Operation Using Hybrid Algorithm of Artificial Bee Colony with RSM

For cost reduction and quality improvement of machining products, optimum output machining parameters such as material removal rate, tool wear ratio and surface roughness is very essential. Moreover, these output parameters are strongly depends on the precision of the machine tool as well as the input machining parameters. In this paper, a hybrid model of Artificial Bee Colony (ABC), which is motivated by the intelligent behavior of honey bees with Response Surface Methodology (RSM), has been developed for optimizing the surface roughness of stainless steel during turning operation. The predicted optimal value of surface roughness of stainless steel is further confirmed by conducting supplementary experiments. Finally, the performance of this algorithm is evaluated in comparison with desirability analysis. The performance of ABC is at par with that of desirability analysis for different parametric conditions.