scholarly journals Effect of Surface Roughness on Pitting Corrosion of AZ31 Mg Alloy

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 651 ◽  
Author(s):  
Jeffrey Mitchell ◽  
Natalie Crow ◽  
Andy Nieto
Keyword(s):  
Surface Roughness ◽  
Pitting Corrosion ◽  
Weight Ratio ◽  
High Strength ◽  
Az31 Alloy ◽  
Initial Surface ◽  
X Ray Diffraction ◽  
Three Samples ◽  
Salt Fog ◽  
Effect Of Surface

Magnesium is a highly desired material for multiple applications including automotive, aircraft, and biomedical components due to its high strength to weight ratio, non-toxicity, and its good machinability. The main drawback of magnesium use is its poor resistance to corrosion. The goal of this experiment was to determine the effect of surface roughening treatments on the rate of corrosion and to characterize the resultant magnesium oxide (MgO) and brucite (Mg(OH)2) corrosion products. Three samples of AZ31 alloy with varying initial surface roughness were exposed to simulated marine conditions using a salt fog chamber for 672 h. The salt fog experiments used a 3.5 wt.% NaCl solution and were conducted in accordance with the ASTM B117 test protocols. One sample was tested in an as-received state, served as the control, another sample was roughened using a grit blaster, and another was polished to a mirror finish. Formed oxide scales were characterized using scanning electron microscopy, X-ray diffraction, and energy dispersive spectroscopy. The samples with a higher roughness underwent the severest corrosion and ensuing formation of the thickest oxide layers. The results indicate that the initial surface roughness has a profound effect on the resulting severity of pitting corrosion in Mg alloys and that mechanical polishing can substantially reduce the propensity for uniform and pitting corrosion to occur.

ADDITIVE MANUFACTURING PARAMETERS OPTIMIZATION OF Ti6AL4V ELI FOR MEDICAL IMPLANTS

2022 ◽  
Author(s):  
VIJAY KUMAR MEENA ◽  
PARVEEN KALRA ◽  
RAVINDRA KUMAR SINHA
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
Weight Ratio ◽  
High Strength ◽  
Surface Characteristics ◽  
Parameters Optimization ◽  
Medical Implants ◽  
Scan Speed ◽  
Grey Relational ◽  
Manufacturing Parameters

Additive manufacturing (AM) of titanium (Ti) alloys has always fascinated researchers owing to its high strength to weight ratio, biocompatibility, and anticorrosive properties, making Ti alloy an ideal candidate for medical applications. The aim of this paper is to optimize the AM parameters, such as Laser Power (LP), Laser Scan Speed (LSS), and Hatch Space (HS), using Analysis of Variance (ANOVA) and Grey Relational analysis (GRA) for mechanical and surface characteristics like hardness, surface roughness, and contact angle, of Ti6Al4V ELI considering medical implant applications. The input parameters are optimized to have optimum hardness, surface roughness and hydrophilicity required for medical implants.

scholarly journals Effect of Surface Roughness on Step-Wise S-N Curve in High Strength Steel

2002 ◽  
Vol 2002.51 (0) ◽  
pp. 299-300
Author(s):  
Hisatake ITOGA ◽  
Keiro TOKAJI ◽  
Masaki NAKAJIMA ◽  
Haeng Nam KO
Keyword(s):  
Surface Roughness ◽  
High Strength Steel ◽  
High Strength ◽  
Effect Of Surface

THE EFFECTS OF DEBULKING ON THE MICROSTRUCTURE OF CARBON FIBER REINFORCED COMPOSITES

2021 ◽  
Author(s):  
MATHEW SCHEY ◽  
SCOTT STAPLETON ◽  
TIBOR BEKE
Keyword(s):  
Carbon Fiber ◽  
Volume Fraction ◽  
Weight Ratio ◽  
High Strength ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Three Samples ◽  
The Matrix ◽  
Carbon Fiber Reinforced Composites ◽  
Carbon Fiber Reinforced

Carbon fiber reinforced plastics (CFRPs) are widely used due to their high strength to weight ratios. A common process manufacturers use to increase the strength to weight ratio is debulking. Debulking is the process of transversely compacting a dry fibrous reinforcement prior to wet out with the matrix resin, in order to induce fiber nesting, effectively increasing the volume fraction of the sample. While this process is widely understood macroscopically its effects on fibrous microstructures have not yet been well characterized. The aim of this work is to compare the microstructures of three CFRPs, varying only the debulking step in the manufacturing process. The microstructural effects of debulking on three unidirectional CFRPs made from three different levels of debulking were studied. High resolution serial sections of all three samples were taken using the UES ROBO-MET at the NASA Glenn Research Center in Cleveland, Ohio. Using these scans, the fiber positions were measured and connected to make fiber paths. Statistical descriptors such as local fiber and void volume fractions, and void distribution and morphology were then generated for each sample and compared. Using these descriptors, the effects of debulking on the composite microstructure can be measured.

scholarly journals Experimental Study on Steel to FRP Bonded Lap Joints in Marine Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Çiçek Özes ◽  
Nurhan Neşer
Keyword(s):  
Surface Roughness ◽  
Adhesive Bonding ◽  
Weight Ratio ◽  
Steel Structures ◽  
High Strength ◽  
Lap Joints ◽  
Bonded Joints ◽  
Bonding Performance ◽  
Marine Industry ◽  
Marine Applications

Steel structures coated with fiber-reinforced polymer (FRP) composites have gained wide acceptance in marine industry due to their high strength-to-weight ratio, good protection from environmental degradation, and impact loads. In this study, adhesive bonding performance of single-lap bonded joints composed of steel coated with FRP has been investigated experimentally for three different surface roughness and two epoxy types. Single-lap bonded joints have been tested under tensile loading. The adhesive bonding performance has been evaluated by calculating the strain energy values. The results reveal that the surface roughness of steel has a significant effect on the bonding performance of steel to FRP combinations and the performance of the resin can be improved by using the primer in an economical way.

High Fugacity Hydrogen Effects in Beta-21S Titanium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 1355-1360
Author(s):  
Dan Eliezer ◽  
E. Tal-Gutelmacher ◽  
Lothar Wagner
Keyword(s):  
Titanium Alloy ◽  
Weight Ratio ◽  
Thermal Desorption Spectroscopy ◽  
High Strength ◽  
Advanced Materials ◽  
X Ray Diffraction ◽  
Hydrogen Induced Cracking ◽  
Second Phases ◽  
Rolled Condition ◽  
Hot Rolled

Beta-21S titanium alloy is ranked among the most important advanced materials for a variety of technological applications, due to its combination of a high strength/weight ratio, good corrosion behavior and oxidation resistance. However, in many of these technological applications, this alloy is exposed to environments which can act as sources of hydrogen, and consequently, severe problems may arise. The objective of this paper is to investigate the influence of high fugacity hydrogen on Beta-21S alloy in as-received (mill-annealed and hot-rolled) condition. Hydrogen effects on the microstructure are studied using X-ray diffraction and electron microscopy, while the absorption and desorption characteristics are determined respectively by means of a hydrogen determinator and thermal desorption spectroscopy. Preliminary results at room temperature revealed hydrogen-induced straining and expansion of the lattice parameters. However, neither second phases formation (hydrides), nor hydrogen-induced cracking, were observed after hydrogenation. The main characteristics of hydrogen absorption/desorption behavior, as well as hydrogen-induced microstructural changes in both microstructures are discussed in detail.

Surface Roughness Study of Milled Carbon Fiber Reinforced Polymer (CFRP) Composite Using 4 mm 2-Flute Titanium Aluminum Nitride (TiAlN) Coated Carbide End Mills

2014 ◽  
Vol 887-888 ◽  
pp. 1101-1106 ◽  
Author(s):  
Mohamed Konneh ◽  
Sudin Izman ◽  
Mirza Emmil Dzahi Padil ◽  
Rosniza Roszat
Keyword(s):  
Surface Roughness ◽  
Weight Ratio ◽  
High Strength ◽  
Milling Process ◽  
Machining Parameters ◽  
Inherent Anisotropy ◽  
Pull Out ◽  
Cfrp Composite ◽  
End Mills ◽  
Coated Carbide

As the goal for aircraft weight reduction and low fuel consumption becomes a dire concern in aerospace industries, there is driving desire for the increasing use of advanced exotic materials such as composites, titanium and Inconels in the aerospace industry because of their high strength to weight ratio. Nevertheless the inherent anisotropy, inhomogeneous properties of CFRP and low bonding strength within the laminates make machining of these composite materials results in several undesirable effects such as delamination, micro-cracking, burr, fiber pull out and breakage. This paper discusses an experimental investigation into the influence of machining parameters on surface roughness when milling CFRP using 4 mm-diameter 2-fluted carbide end-mill coated with Titanium Aluminium Nitride (TiAlN). Relationship between the machining variables and the output variables is established and a mathematical model is predicted for the surface roughness produced during the milling process for the machining conditions investigated.

Method to Measure Effects of Surface Roughness on High-frequency Transmission Lines

2013 ◽  
Vol 2013 (1) ◽  
pp. 000496-000499
Author(s):  
Toshiki Iwai ◽  
Daisuke Mizutani ◽  
Motoaki Tani
Keyword(s):  
Surface Roughness ◽  
Transmission Lines ◽  
Printed Circuit Boards ◽  
Skin Depth ◽  
Capacitive Coupling ◽  
Strip Line ◽  
Circuit Boards ◽  
Three Samples ◽  
Novel Method ◽  
Effect Of Surface

In recent years, the transmission losses induced by surface roughness of conductors in printed circuit boards (PCB) have become important from the standpoint of signal integrity. To clarify this effect, current measurement methods use a microstrip line or a strip line in the PCB, which is fabricated for different values of surface roughness. However, since errors are induced in each sample because of the presence of dispersion in the manufacturing process, it is difficult to extract the effect of surface roughness from the measured data. In this paper, we propose a novel method to measure the effect by means of using capacitive coupling in which the dispersion errors can be eliminated. The results have been verified using electromagnetic simulation. This method was performed on three samples having differing values of surface roughness. It was concluded that the transmission characteristics are influenced by surface roughness at higher frequencies when the skin depth becomes comparable to the surface roughness.

Mechanical Properties Investigation of HIP and As-Built EBM Parts

2012 ◽  
Vol 576 ◽  
pp. 216-219 ◽  
Author(s):  
Afshin Mohammad Hosseini ◽  
S.H. Masood ◽  
Darren Fraser ◽  
Mahnaz Jahedi
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Electron Beam Melting ◽  
Vickers Microhardness ◽  
Hot Isostatic Pressing ◽  
Weight Ratio ◽  
High Strength ◽  
Biomedical Implants ◽  
Titanium Alloy Ti6al4v ◽  
Metal Additive

Electron beam melting (EBM) is a direct metal additive manufacturing technique which has been recently utilized for fabrication of biomedical implants. This paper represents an investigation into the mechanical properties of both as-built and hot isostatic pressing (HIP) processed samples manufactured in EBM process. The titanium alloy, Ti6Al4V was used, which is one of the most common materials for biomedical implants due to its high strength to weight ratio, corrosion resistance, and its biocompatibility features. Tensile properties, surface roughness, and Vickers microhardness have been investigated.

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