Study of the Composition and Properties of Coatings being Formed during Combustion of Al + B2O3 Mixtures on Steel Substrates

2021 ◽  
Vol 1022 ◽  
pp. 87-96
Author(s):  
Alexandr Shegolev ◽  
Alexey Ishkov ◽  
Vladimir N. Malikov

Within the scope of this work, the methods of the experimental research of SHS processes during HFC-heating, particularly of hardening coatings applied on samples by HFC-heating have been developed. A study of the composition and properties of the products formed during the SHS process in the basic mixture on the surface of S355 steel parts during HFC-heating has been made, and it has been shown that aluminum oxide, aluminum nitride (by-product), and amorphous boron are formed under these conditions, and composite porous inhomogeneous coatings up to 250 microns thick, based on aluminum oxide, SHS products in the basic mixture and traces of high-speed HFC-boriding products are formed on the workpiece surface.

1996 ◽  
Vol 11 (7) ◽  
pp. 1810-1818 ◽  
Author(s):  
V. P. Godbole ◽  
J. Narayan

The role of aluminum nitride (AlN) as a buffer layer on the nucleation and growth of diamond on silicon and steel substrates during hot filament chemical vapor deposition (HF-CVD) has been investigated systematically. The scanning Auger electron microscopy (AES) is employed to study chemistry and content of carbon on the surface and in subsurface regions of AlN as a function of HF-CVD parameters. It is found that AlN offers an excellent diffusion barrier for carbon over a wide range of temperature and hydrocarbon content of CVD gas environment, with simultaneous inhibition of graphitization. It also facilitates nucleation of diamond phase. The surface reactions between AlN and carbon are discussed in terms of hydrogen-assisted phase transformations. We have developed a two-step procedure to obtain a continuous diamond film on steel substrates. The characteristic features of AlN have been exploited to obtain adherent and graphite-free diamond deposits on various types of steels, including low carbon steel, tool steel, high speed steel, and bearing steel.


1993 ◽  
Vol 20 (5) ◽  
pp. 352-356 ◽  
Author(s):  
Z. Naeem ◽  
A. B. Smith ◽  
M. Lamsehchi ◽  
G. W. Critchlow

2013 ◽  
Vol 420 ◽  
pp. 74-77
Author(s):  
Ying Yang ◽  
Jing Hua Dai ◽  
Xu Li

Under high and super high speed, the oil film of a journal bearing is easy to crack and then becomes cavitation. The existence of cavitation has a great effect on the work performance of the bearing. The cavitation mechanism of a spiral oil wedge journal bearing was investigated on the experimental rig. The effects of rotating speed and supply pressure on the cavitation shape of oil film and the number of cavitation strip in the rupture zone were analyzed. The results show that the cavitation shape of oil film is a long strip. The number of cavitation strip increases when supply pressure has been improved, and the location of oil outlet must be designed optimally.


Author(s):  
C.J. Swindeman ◽  
R.D. Seals ◽  
W.P. Murray ◽  
M.H. Cooper ◽  
R.L. White

Abstract Electrical properties of plasma-sprayed aluminum oxide coatings were measured at temperatures up to 600 °C. High purity (>99.5 wt% pure Al2O3) alumina powders were plasma-sprayed on stainless steel substrates over a range of power levels, using two gun configurations designed to attain different spray velocities. Key electrical properties were measured to evaluate the resultant coatings as potential insulating materials for electrostatic chucks (ESCs) being developed for semiconductor manufacturing. Electrical resistivity of all coatings was measured under vacuum upon heating and cooling over a temperature range of 20 to 600 °C. Dielectric constants were also measured under the same test conditions. X-ray diffraction was performed to examine phase formation in the coatings. Results show the importance of powder composition and careful selection and control of spray conditions for optimizing electrical behavior in plasma-sprayed aluminum oxide, and point to the need for further studies to characterize the relationship between high temperature electrical properties, measured plasma-spray variables, and specific microstructural and compositional coating features.


2011 ◽  
Vol 239-242 ◽  
pp. 2331-2335 ◽  
Author(s):  
Fang Mei ◽  
Guang Zhou Sui ◽  
Man Feng Gong

TiN coatings were deposited on AISI M2 high-speed-steel (HSS) substrates by multi-arc ion plating technique. The thickness of substrate was 1.0 mm and five thicknesses of TiN coatings were 3.0, 5.0, 7.0, 9.0 and 11.0 μm, respectively. X-ray diffraction (XRD) has been used for measuring residual stresses. The stresses along five different directions (Ψ=0°, 20.7°, 30°, 37.8° and 45°) have been measured by recording the peak positions of TiN (220) reflection for each 2θ at different tilt angles Ψ. Residual compressive stresses present in the TiN coatings. Furthermore, the results revealed that the value of the residual stresses in TiN coatings was high. While the coatings thickness changed from 3 to 11 μm, the residual stresses varied from -3.22 to -2.04 GPa, the intrinsic stresses -1.32 to -0.14 GPa, the thermal stresses -1.86 to -1.75 GPa. The residual stresses in TiN coatings showed a nonlinear change. When the coatings thickness was about 8 μm, the residual stresses in TiN coatings reached to the maximum value.


2010 ◽  
Vol 97-101 ◽  
pp. 2044-2048 ◽  
Author(s):  
Yuan Ling Chen ◽  
Bao Lei Zhang ◽  
Wei Ren Long ◽  
Hua Xu

As the factors influencing the workpiece surface roughness is complexity and uncertainty, according to orthogonal experimental results, the paper established Empirical regression prediction model and generalized regression neural networks (GRNN) for prediction of surface roughness when machining inclined plane of hardened steel in high speed , moreover, compared their prediction errors. The results show that GRNN model has better prediction accuracy than empirical regression prediction model and can be better used to control the surface roughness dynamically.


2013 ◽  
Vol 295-298 ◽  
pp. 1529-1534
Author(s):  
Long Lin Sun ◽  
Wen Wei Huang ◽  
Mou Rong Gao

The taxies’ emission experiments on urban roads are carried out with a high-precision mobile emission analyzer. Then the emission characteristics are analyzed. The experiment data show that the high speed, the low acceleration and the low VSP will be helpful to decrease the emission and the long mileage will worsen the emission.


2012 ◽  
Vol 433-440 ◽  
pp. 116-122
Author(s):  
Chang Yuan Wang ◽  
Fu Shui Liu ◽  
Xiang Rong Li

A series of experimental research results on the characteristic of diesel elastic-plate impingement spray using High Speed Photography camera are presented in this paper. The experiments were carried out in a constant volume chamber specially designed, which can hold a high ambiance pressure. The special fixed device was designed so that the elastic-plate can be fixed on the spray path, meanwhile the spray incident angle and height can be changed. The free jet spray and elastic-plate impingement spray was compared under the same experimental condition including different injection pressure and different background pressure. Experimental research showed that impingement spray droplets diffuse more quickly than free jet spray.


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