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Hot wire Gas Tungsten Arc Welding (GTAW) process is selected for the fabrication of thick section modified 9Cr 1Mo steel components of Steam Generators (SGs) for 500MWe Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, India. During the welding procedure qualification for fabrication of SGs, the 30 mm and 62 mm thick modified 9Cr 1Mo steel welds were subjected to chemical analysis, visual examination, liquid penetrant examination, radiography examination, micro-hardness tests, longitudinal and transverse tensile tests (at ambient temperature and 525 °C), bend tests, drop weight tests and impact tests (at 0 °C and +18 °C). Literature reveals both positive and negative view on the welding of thick-section steel components. Limited information is available in the open literature on the effect of thickness on material properties of modified 9Cr 1Mo steel welds made by the hot wire GTAW method. In view of the above, authors attempted to systematically investigate the influence of thickness on the mechanical properties of modified 9Cr 1Mo steel welds made by the hot wire GTAW process. In this paper, the chemical compositions, hardness, tensile strength, bending strength and impact properties of 30 mm and 62 mm thick welds produced by narrow gap hot wire GTAW process are characterized and compared. It is found that the mechanical properties of 30 mm and 62 mm thick welds are comparable except the impact properties at 0 °C. The impact strength at 0 °C for a 62 mm thick weld was found inferior in comparison with a 30 mm thick weld. [ABSTRACT FROM AUTHOR]

The present work is concentrated on the erosive behaviour of NiCrAlY/B4C/Cenosphere composite coating at high temperatures. The coating was deposited on MDN 321 steel used in turbine blades by plasma spray coating technique. The erosion tests were carried out at impingement angles of 60° and 90° with temperature at 600°C in both cases. The coatings and worn samples were characterised by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Al2O3 particles of 150 microns were used as the erodents with a velocity of 30 m s−1. The erosive wear resistance for the impingement angle of 60° was found to be higher compared to 90°. The major failure of the material is shown by the brittle nature of the material removal. This is also reflected by the higher particles size found around the eroded area and higher surface roughness values of Ra and Rz. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dry sliding wear characteristics of glass-epoxy (G-E), graphite-filled G-E and functionally graded graphite-filled G-E composites were investigated using pin-on-disc test rig. The specific wear rate was determined as a function of applied load, sliding velocity and sliding distance. The results revealed that the specific wear rate increases in all the tested composites with increasing wear parameter. But, the admirable wear resistance was obtained with functionally graded graphite-filled G-E composite. The scanning electron microscope studies of worn-out surfaces support the involved wear mechanisms and are well indicated in the worn-out surface features such as matrix wear, fibre exposure, fibre breakage, fibre and matrix deboning, microcracking, debris formation, fibre cracking and removal of fibres. [ABSTRACT FROM PUBLISHER]

In this work the moisture absorption capability, compressive properties, collapse modes of various types of composite sandwich structures are reported. The tested sandwich structures were constructed with varieties of hybridized skin materials and different compositions of the core materials. The moisture absorption, Flatwise compression and Edgewise compression tests are conducted for core as well as sandwich structures. Comparisons of results have been between the hybridized and non-hybridized sandwich structures. Two modes of collapse were noticed in the Edgewise compressive test, one of which being progressive end-crushing of the sandwich structure featured by significant crash energy absorption. This feature was highly desired for the parts of transportation vehicles. Microscopic analysis has been carried out to know the nature of failure under compressive loads. It has been observed that with increasing the debonding strength of the core–face interface, the failure mode changes from unstable collapse mode stable progressive crushing. [ABSTRACT FROM PUBLISHER]

This experimental investigation deals with the evaluation of abrasive wear behavior of Glass Epoxy (G-E) composites on pin-on-disc test rig. A plan of experiments, based on the Taguchi Design of Experiments, was performed to acquire data in controlled way. An orthogonal array and the analysis of variance were employed to investigate the percentage of contribution of various process parameters like sliding speed, applied load, sliding distance and their interactions affecting the abrasive wear volume loss of composites. The correlations between the various factors affecting the abrasive wear behavior of composites were obtained by using multiple linear regression equations. The obtained results indicate that applied load and sliding distance were the wear factors that have the highest physical as well as statistical influence on the abrasive wear behavior of both filled and unfilled G-E composites. A good agreement between the predicted and actual wear resistance was observed within ± 12%. [ABSTRACT FROM AUTHOR]

The results of the experimental analysis carried out on the Glass-Epoxy composites with secondary fillers in particular emphasis on critical stress intensity factor have been reported. The silicon carbide particles and Graphite have been used as the secondary fillers. The experiments were carried out according to ASTM E 1922 standards. The results have revealed that the addition of graphite as the secondary filler has increased the critical stress intensity factor in comparison with the SiCp. The influence of applied tensile stress and the induced bending stress during eccentric loading have been evaluated separately. From the macroscopic analysis it has been identified that the induced bending stress plays a vital role in the failure mechanism of these filled composites. [ABSTRACT FROM AUTHOR]

Effect of filler material on three-body abrasive wear behaviour of Glass - Epoxy composites has been investigated. The abrading distance, applied load and sliding speed are the parameters used for the study. A L9 orthogonal array and ANOVA were used to identify the contribution of individual parameters. The result shows that the weight loss increases with increase in load, sliding speed and abrading distance. The abrading distance has more effect on the wear compared to other parameters. The filler material (SiC) contributes a significant wear resistance of the G-E composites. [ABSTRACT FROM AUTHOR]

This study presents an experimental investigation on tool wear in machining Al 2219/15SiCp and Al 2219/15SiCp-3Gr (hybrid) composites at different cutting conditions with carbide, coated carbide, and polycrystalline diamond (PCD) tools. An attempt is made in the present investigation to study the effect of graphite incorporation in Al 2219/15SiCp composite on tool wear. The results reveal that the incorporation of graphite in Al 2219/15SiCp composite reduces tool wear at all cutting conditions. This is due to graphite, which reduces the coefficient of friction between tool and workpiece and between tool and chip interface. PCD tool performs better than carbide and coated carbide tools. [ABSTRACT FROM AUTHOR]