Destruction of Epoxy Coatings under the Influence of Climatic Factors

2013 ◽  
Vol 199 ◽  
pp. 581-586 ◽  
Author(s):  
Danuta Kotnarowska
Keyword(s):  
Surface Roughness ◽  
Environmental Factors ◽  
Climatic Factors ◽  
Incidence Angle ◽  
Surface Layers ◽  
Coating Structure ◽  
Epoxy Coatings ◽  
Coating Surface ◽  
Light Incidence Angle ◽  
Structure Destruction

The paper presents investigation results of climatic as well as environmental factors influence on surface state of three-layer epoxy coatings. A three-year investigation documented substantial destruction of coating surface layers. In particular, a significant increase of aged coating surface roughness, evaluated on the basis of Ra and Rz parameters, was observed. Studies made with SEM corroborated a delamination as well as pigment and filler crumbling from surface layers of coatings. In the final period of ageing craters and superficial cracks appeared in the coating structure. Destruction of aged coating surfaces contributed to their gloss loss by over 98% (for light incidence angle α = 60o) decreasing in this way coating decorative properties.

Environmental influences on fish and shellfish production in the Northwest Atlantic

1994 ◽  
Vol 2 (1) ◽  
pp. 16-32 ◽  
Author(s):  
K.H. Mann ◽  
K.F. Drinkwater
Keyword(s):  
Environmental Factors ◽  
Gadus Morhua ◽  
Cold Water ◽  
Climatic Factors ◽  
Homarus Americanus ◽  
Fishing Mortality ◽  
Poor Growth ◽  
Northwest Atlantic ◽  
Grand Banks ◽  
Fish And Shellfish

Evidence is reviewed, linking physical oceanographic processes in the marine environment to changes in fish and shellfish stocks in the Northwest Atlantic. A case history study of the cod (Gadus morhua) stock of the northern Grand Banks and Labrador Shelf indicates a long slow amelioration of the environment between about 1945 and 1965, followed by a deterioration in the period 1965–1992. The most important environmental factors for the cod stocks appear to have been salinity and temperature. The trends can be traced back to climatic factors involving the Icelandic Low and the Azores–Bermuda High. When the atmospheric pressure difference in winter tended to be high, there was a progressive increase in the area of sea ice off Labrador and in the volume of cold water at depth. These factors have been shown to affect temperature and salinity conditions on the Grand Banks in spring and summer and are associated with poor growth and recruitment in the cod stocks. A similar case study of lobster (Homarus americanus) stocks indicates that temperature and river discharge are important environmental correlates, but neither can be shown to fully account for the recent trends in the stocks. Evidence is reviewed to show that physical environmental processes also influence recruitment and distribution of stocks of haddock, capelin, and squid. Some of the problems with correlational analysis are also discussed. It is recognized that factors other than the environment are influencing the stocks. Fishing mortality (detailed consideration of which is not included in this review) has clearly been important. Interactions between environmental factors and fishing mortality are probably of major importance.Key words: ocean environment, fish production, recruitment, northern cod, American lobster.

Hydrogen Ion Beam Processing of Single Crystal Diamond Chips

1994 ◽  
Vol 354 ◽  
Author(s):  
Shuji Kiyohara ◽  
Iwao Miyamoto
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Incidence Angle ◽  
Ion Beam ◽  
Etching Rate ◽  
Hydrogen Ion ◽  
Hydrogen Ions ◽  
Ion Beam Etching ◽  
Single Crystal Diamond ◽  
Before And After

AbstractIn order to apply ion beam etching with hydrogen ions to the ultra-precision processing of diamond tools, hydrogen ion beam etching characteristics of single crystal diamond chips with (100) face were investigated. The etching rate of diamond for 500 eV and 1000 eV hydrogen ions increases with the increase of the ion incidence angle, and eventually reaches a maximum at the ion incidence angle of approximately 50°, then may decrease with the increase of the ion incidence angle. The dependence of the etching rate on the ion incidence angle of hydrogen ions is fairly similar to that obtained with argon ions. Furthermore, the surface roughness of diamond chips before and after hydrogen ion beam etching was evaluated using an atomic force microscope. Consequently, the surface roughness after hydrogen ion beam etching decreases with the increase of the ion incidence angle within range of the ion incidence angle of 60°.

Dependence of LPBF Surface Roughness on Laser Incidence Angle and Component Build Orientation

2021 ◽  
Author(s):  
Ramesh Subramanian ◽  
David Rule ◽  
Onur Nazik
Keyword(s):  
Surface Roughness ◽  
Gas Turbine ◽  
High Efficiency ◽  
Surface Defects ◽  
Incidence Angle ◽  
Turbine Component ◽  
Potential Applicability ◽  
Process Qualification ◽  
Process Signature ◽  
Manufacturing Technologies

Abstract Laser Powder Bed Fusion (LPBF) of metallic components is unlocking new design options for high efficiency gas turbine component designs not possible by conventional manufacturing technologies. Surface roughness is a key characteristic of LPBF components that impacts heat transfer correlations and crack initiation from co-located surface defects — both are critical for gas turbine component durability and performance. However, even for a single material, there is an increasing diversity in laser machines (single vs multi-laser), layer thicknesses (∼20–80 microns) and orientations to the build plate (upskin, vertical and downskin) that result in significant variability in surface roughness. This study systematically compares the surface roughness across the above-mentioned variables to further develop a repeatable correlation of surface roughness to the angle between the substrate normal and laser incidence direction. This presented data will be discussed in detail, to show potential applicability of this process signature curve across materials, machines, and substrate orientations. Future steps to a rapid process qualification standard for surface roughness, across Siemens Energy’s global manufacturing footprint will also be discussed.

scholarly journals REDUCING THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE BENDING DEFORMATION OF CURED CARBON FIBER BY MICROWAVE PROCESSING

2021 ◽  
pp. 56-58
Author(s):  
I. V. Zlobina
Keyword(s):  
Electromagnetic Field ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Environmental Factors ◽  
Flux Density ◽  
Environmental Conditions ◽  
Climatic Factors ◽  
Transverse Load ◽  
Bending Deformation ◽  
Energy Flux Density

The article discusses the results of a study of bending deformation and creep under transverse load of cured polymer composite materials (PCM), which were located for 8 months in full-scale environmental conditions in Saratov. It was found that being under the influence of natural climatic factors for the specified time leads to an increase in the bending deformation of samples from 13,5 to 25,4%, depending on the load. Processing in a microwave electromagnetic field with a frequency of 2450 MHz with an energy flux density of (17-18) x10 mW / cm for 2 minutes reduces bending deformation by (9-18)%, and creep - up to 4 times.

scholarly journals Effects of Surface Roughness, Freestream Turbulence, and Incidence Angle on the Performance of a 2-D Compressor Cascade

1990 ◽  
Author(s):  
W. C. Elrod ◽  
P. I. King ◽  
E. M. Poniatowski
Keyword(s):  
Surface Roughness ◽  
Total Pressure ◽  
Incidence Angle ◽  
Two Dimensional ◽  
Freestream Turbulence ◽  
Compressor Cascade ◽  
Suction Surface ◽  
Linear Cascade ◽  
Pressure Loss Coefficient ◽  
Total Pressure Loss Coefficient

The effects of surface roughness, freestream turbulence, and incidence angle on the performance of a two-dimensional compressor cascade were investigated. The test section consisted of seven NACA 65-A506 airfoils arranged in a linear cascade. Four different surface roughness conditions were applied to the first 25 percent chord on the suction surface of each of the five middle blades in the cascade. Freestream turbulence levels of approximately one and seven percent were used. Incidence angles of −3, zero and +3 degrees were investigated. Of the three parameters tested, freestream turbulence exerted the largest influence on blade performance. The total pressure loss coefficient increased with increased roughness and was reduced for large turbulence. Changes in flow incidence had a lesser effect on the performance of the blade.

AN INVESTIGATION OF THE INFLUENCE OF CLIMATIC FACTORS ON THE EROSIVE WEAR KINETICS OF POLYMER COATINGS

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 115-125
Author(s):  
Danuta KOTNAROWSKA ◽  
Andrzej KOTNAROWSKI
Keyword(s):  
Grain Size ◽  
Climatic Factors ◽  
High Surface ◽  
Surface Hardness ◽  
Surface Profile ◽  
Erosive Wear ◽  
Epoxy Coatings ◽  
Mean Grain Size ◽  
Resistance Decrease ◽  
20 Nm

The paper presents investigation results concerning the influence of the modification with nanoparticles of silica (of mean grain size 12 nm or 20 nm) or aluminium trioxide (20 nm) of the structure of epoxy coatings on their resistance to climatic factors and the action of erosive particles. Epoxy coatings aged in natural climatic conditions showed an erosive resistance decrease with ageing. The erosive resistance decrease was accompanied by a hardness decrease as well as surface roughness increase. The highest resistance to erosive wear after 3 years of ageing revealed coatings modified with aluminium trioxide nanoparticles, while the lowest one showed coatings modified with silica nanoparticles of 12 nm mean grain size. Nanocoatings modified with aluminium trioxide nanoparticles also had the highest resistance to ageing; which was proven by the lowest increase of Ra and Rz surface profile parameter values with time, as well as by a high surface hardness, which was higher than hardness of new unmodified coatings.

Influence of the light incidence angle on the precision of generalized magneto-optical ellipsometry

2015 ◽  
Vol 386 ◽  
pp. 150-154 ◽  
Author(s):  
C. Gonzalez-Fuentes ◽  
J.B. Gonzalez-Diaz ◽  
L. Fallarino ◽  
J.A. Arregi ◽  
A. Berger
Keyword(s):  
Incidence Angle ◽  
Light Incidence Angle ◽  
Optical Ellipsometry
Sign in / Sign up

Export Citation Format

Share Document