scholarly journals Characterization of Flow Properties of Powder Coatings Used in the Automotive Industry

2004 ◽  
Vol 22 (0) ◽  
pp. 94-106 ◽  
Author(s):  
Cyril Conesa ◽  
Khashayar Saleh ◽  
Aline Thomas ◽  
Pierre Guigon ◽  
Nicolas Guillot
Author(s):  
S Bair

A thorough characterization of all viscous flow properties relevant to steady simple shear was carried out for five liquid lubricants of current interest to tribology. Shear stresses were generated to values significant to concentrated contact lubrication. Two types of non-Newtonian response were observed: shear-thinning as a power-law fluid and near rate-independence. Functions and parameters were obtained for the temperature and pressure dependence of the viscosity and of the time constant for the Carreau-Yasuda equation. Results are consistent with free volume and kinetic theory, but directly contradict many assumptions currently utilized for numerical simulation and for extracting rheological properties from contact measurements.


2021 ◽  
Vol 40 (11) ◽  
pp. 823-830
Author(s):  
Nikita Bondarenko ◽  
Sherilyn Williams-Stroud ◽  
Jared Freiburg ◽  
Roman Makhnenko

Carbon sequestration activities are increasing in a global effort to mitigate the effects of greenhouse gas emissions on the climate. Injection of wastewater and oil-field fluids is known to induce seismic activity. This makes it important to understand how that risk relates to CO2 injection. Injection of supercritical CO2 into the Cambrian Mt. Simon sandstone in Illinois Basin induced microseismicity that was observed below the reservoir, primarily in the Precambrian crystalline basement. Geomechanical and flow properties of rock samples from the involved formations were measured in the laboratory and compared with geophysical log data and petrographic analysis. The controlling factors for induced microseismicity in the basement seem to be the hydraulic connection between the reservoir and basement rock and reactivation of pre-existing faults or fractures in the basement. Additionally, the presence of a laterally continuous low-permeability layer between reservoir and basement may have prevented downward migration of pore pressure and reactivation of critically stressed planes of weakness in the basement. Results of the geomechanical characterization of this intermediate layer indicate that it may act as an effective barrier for fluid penetration into the basement and that induced microseismicity is likely to be controlled by the pre-existing system of faults. This is because the intact material is not expected to fail under the reservoir stress conditions.


2021 ◽  
Vol 20 (1) ◽  
pp. 31-39
Author(s):  
Oluyemisi Adebowale Bamiro ◽  
Aishat Oyinkansola Salisu ◽  
Ese Mary Iyere ◽  
Olatundun Atoyegbe ◽  
Olutayo Ademola Adeleye ◽  
...  

The aim of the work was to characterize chitosan extracted from snail shell and evaluate its use as a disintegrant and binder in metronidazole tablet formulation in comparison with standard chitosan (SC). The mechanical properties were assessed using crushing strength and friability, while the release properties were assessed using disintegration and dissolution times. The extracted chitosan (EC) was crystalline in nature and the scanning electron microscopy (SEM) showed polygonal particles with rough surface. The moisture and swelling capacity was 1.80% and 15.00%, respectively. The densities and flow properties were significantly (p<0.05) higher than those of the SC. As a binder, the crushing strength of formulations containing EC was higher than SC, but both formulation failed friability test. There was significant difference between the disintegration times of the metronidazole formulations containing EC and SC as a disintegrant. The result showed that EC is more effective as a binder in tablet formulations. Dhaka Univ. J. Pharm. Sci. 20(1): 31-39, 2021 (June)


2017 ◽  
Vol 17 (4) ◽  
pp. 73-78 ◽  
Author(s):  
F. Kahrıman ◽  
M. Zeren

Abstract In this study, Al-0.80Mg-0.85Si alloy was modified with the addition of 0.3 wt.-% zirconium and the variation of microstructural features and mechanical properties were investigated. In order to produce the billets, vertical direct chill casting method was used and billets were homogenized at 580 °C for 6 h. Homogenized billets were subjected to aging practice following three stages: (i) solution annealing at 550 °C for 3 h, (ii) quenching in water, (iii) aging at 180 °C between 0 and 20 h. The hardness measurements were performed for the alloys following the aging process. It was observed that peak hardness value of Al-0.80Mg-0.85Si alloy increased with the addition of zirconium. This finding was very useful to obtain aging parameters for the extruded hollow profiles which are commonly used in automotive industry. Standard tensile tests were applied to aged profiles at room temperature and the results showed that modified alloy had higher mechanical properties compared to the non-modified alloy.


2010 ◽  
Vol 638-642 ◽  
pp. 769-774 ◽  
Author(s):  
Waldemar Alfredo Monteiro ◽  
E.M.R. Silva ◽  
L.V. Silva ◽  
W. de Rossi ◽  
S.J. Buso

A localized source of heat, such as that of laser beam, can provide a convenient means of producing a surface layer of altered microstructure. By using surface hardening treatment, wear resistance can be increased. Experiments were performed using a Nd:YAG pulsed laser under different processing conditions. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray mapping (SEM) were employed to observe the effect of laser melting treatment on the microstructural properties of the samples. Depending on the selected laser treatment working conditions, different microstructures characteristics of surface melting can be achieved in the treated zone. Higher microhardness values were found at the treated area showing a superficial hardening of the sample and, consequently, an improvement of the wear resistance of these automotive alloys. The aim of this work is to find the optimal process parameters and to evaluate the characteristics of the laser superficial hardening (LSH) in a pearlitic gray iron and Al-Si alloy used in an automobile industry (bearing and piston materials in automotive industry).


2008 ◽  
Vol 254 (22) ◽  
pp. 7198-7214 ◽  
Author(s):  
M. Barletta ◽  
A. Gisario ◽  
L. Lusvarghi ◽  
G. Bolelli ◽  
G. Rubino

2012 ◽  
Vol 1481 ◽  
pp. 83-88
Author(s):  
J. A. Garabito ◽  
H. Granados ◽  
V. H. López ◽  
A. R. Kennedy ◽  
J. E. Bedolla

ABSTRACTIn this study, scrap from the automotive industry was used to produce aluminium foams under vacuum. Chips of an aluminium alloy LM26 were melted and 1wt. % of Mg was added for creating a viscous casting with uniform distribution of oxides. An ingot was obtained of this alloy after casting and solidification. Trials for foaming this alloy were performed by re-melting pieces under vacuum at different temperatures. A window in the vacuum chamber allowed observation of the foaming and collapse of the porous structures was observed during cooling. Characterization of the aluminum foams revealed different levels of expansion, porous structures and degrees of drainage. The best foams were obtained at 680 °C with a density of 0.78 g/cm3. This technique appears to be a feasible low cost route for producing Al foams based on scrap material.


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