Investigation of Adhesion and Tribological Behavior of Borided AISI 310 Stainless Steel

In the present study, the effects of the boriding process on adhesion and tribological properties of AISI 310 steel were investigated. Boriding was performed in a solid medium consisting of Ekabor-II powders at 1123 and 1323K for 2 and 6 h. The boride layer was characterized by optical microscopy, the X-ray diffraction technique and the micro-Vickers hardness tester. The X-ray diffraction analysis of the boride layers on the surface of the steels revealed the existence of FexBy, CrxBy and NixBy compounds. Depending on the chemical composition of substrates, the boride layer thickness on the surface of the AISI 310 steel was found to be 56.74 μm. The hardness of the boride compounds formed on the surface of the AISI 310 steel ranged from 1658 to 2284 HV0,1, whereas the Vickers hardness value of the untreated steel AISI 310 was 276 HV0,1. The wear tests were carried out in a ball-disc arrangement under a dry friction condition at room temperature with an applied load of 10N and with a sliding speed of 0.3 m/s, at a sliding distance of 1000m. The wear surfaces of the steel were analyzed using an SEM microscopy and X-ray energy dispersive spectroscopy EDS. It was observed that the wear rate of unborided and borided AISI 310 steel ranged from 4.57 to 71.42 mm3/Nm

Diffusivity, solubility and permeability of water vapor in flexible PVC/silica composite membranes

WOS: A1996UR18100011Flexible PVC/silica composite membranes having a porous structure have been produced using plastisol-plastigel technology. Equilibrium and rate studies related to water vapor adsorption on membranes have been studied using a Cahn 2000, gravimetric adsorption system. For the solubility and diffusivity of water vapor in membranes 4.23-7.74 cm(3)/(cm(3) cmHg) and 2.0-3.5 x 10(-13) m(2)/s values have been determined respectively. The measured permeability of water vapor through membranes 1.6-7.3 x 10(-6) ((cm(2)/s)/(cm(2) cmHg))cm, were much higher than predicted permeabilities 0.85-2.73 x 10(-8) ((cm(2)/s)/(cm(2) cmHg))cm. from solubility diffusion data, indicated the membranes had a porous structure. The membranes are suggested as a leather substitute since the permeability through membranes is comparable to that of leather and is at least 100 times higher than that of plasticized PVC film obtained by conventional processing techniques

Empirical Modeling of Residual Stress Profile in Machining Nickel-based Superalloys Using the Sinusoidal Decay Function

After machining nickel-based superalloys, tensile surface residual stresses can cause end-product issues such as fatigue failure. Modeling the residual stress profile is currently tedious and inaccurate. This study introduces a new method of understanding the residual stress profile in terms of quantifiable key measures: peak tensile stress at the surface, magnitude and depth of peak compressive stress, and depth at which residual stress becomes near-zero. Experiments in turning IN-100 and milling GTD-111 have been conducted and subsequent X-ray Diffraction measurements have been utilized to obtain residual stress profiles. Using a sinusoidal decay function fitted to measured residual stress profiles, these four key profile measures are extracted and then the effects of process parameters such as cutting speed, feed, cutting edge radius, and tool coating on these measures are investigated

Empirical Modeling of Residual Stress Profile in Machining Nickel-based Superalloys Using the Sinusoidal Decay Function

After machining nickel-based superalloys, tensile surface residual stresses can cause end-product issues such as fatigue failure. Modeling the residual stress profile is currently tedious and inaccurate. This study introduces a new method of understanding the residual stress profile in terms of quantifiable key measures: peak tensile stress at the surface, magnitude and depth of peak compressive stress, and depth at which residual stress becomes near-zero. Experiments in turning IN-100 and milling GTD-111 have been conducted and subsequent X-ray Diffraction measurements have been utilized to obtain residual stress profiles. Using a sinusoidal decay function fitted to measured residual stress profiles, these four key profile measures are extracted and then the effects of process parameters such as cutting speed, feed, cutting edge radius, and tool coating on these measures are investigated

Water vapour adsorption on organic and inorganic polymers

29th International Vacuum Microbalance Techniques Conference -- SEP 05-07, 2001 -- TEESSIDE UNIV, MIDDLESBROUGH, ENGLANDWOS: 000180782200014Water vapour adsorption on polymers affects their processing behaviour and useful properties. Water vapour adsorption on organic polymers, silk, Nylon 6 fibres in undrawn and permanent set forms, polyester micro fibres, plasticised PVC films with 60 phr dioctylphthalate (DOP) and inorganic polymer sepiolite particles were investigated in this study. The materials were examined using the BET equation. The surface areas of silk, cast Nylon 6 and muss Nylon 6 were determined as 108, 46 and 23 m(2) g(-1), respectively. Sepiolite did not fit BET equation. Polyester and PVC adsorbed very small amounts of moisture

Dynamics of water vapor adsorption on humidity-indicating silica gel

WOS: 000075851300005Well-defined CoCl2-containing silica gels were prepared by impregnation of the aqueous solution of the salt to silica hydrogel, drying and aging methods. Silica gels having 392-437 m(2) g(-1) surface area and 0.21-0.37 cm(3) g(-1) pore volume and having an average particle size of 3 mm were obtained. Aging in CoCl2 solutions decreased the surface area of silica gels from 540 cm(2) g(-1) to 392-430 m2 g-l and pore volume from 0.27 to 0.21-0.23 cm(3) g(-1) for CoCl2 concentration smaller than 0.28 mol dm(-3) in silica gel. Adsorbed water desorbed from the gels absorbing 1917-2555 i g(-1) energy as determined by differential scanning calorimetry. The CoCl2-containing gels were successfully used in dynamic column experiments, with linear relation between velocities of inlet air and movement of blue to pink boundary. The colour change also makes the detection of the defects in column filling which causes air channelling. (C) 1998 Elsevier Science B.V. All rights reserved