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High-temperature corrosion of coal-fired boiler parts such as water walls and superheated tubes poses a serious threat to the efficiency of the thermal power plant. To overcome this, numbers of cor...

In this present work, an effort has been applied to fabricated AZ61/TiC magnesium based metal matrix composite. The effect of tool transverse speed and specimen holding time after etchant application has been studied before final design and run of experiments. A set of zig-zag holes were prepared into the 200 mm × 100 mm × 6 mm thick AZ61A plate and compacted with TiC particles. A fixed three pass Friction stir processing (FSP) was performed out employing a fixed tool rotation speed of 850 rpm and varying tool transverse speed of 25 mm/min, 100 mm/min and 170 mm/min. Optical microscopy (OM) was used to study the grain refinement. The results indicate that for tool rotational speed of 850 rpm and transverse speed of 25 mm/min better grains were formed at stir zone (SZ) and poor grains were observed once the specimen analyzed after 25 min of etching.

The comparative study of weld joints between different stainless steel grades was conducted by fabricating a weld joint between SS316 – SS304, SS316 – SS202, and SS304 – SS202 respectively with a rotary friction welding technique. The objectives of this study is to find out the best suitable combination from the above selected materials with respect to comparison of tensile strength value and Vickers micro hardness value of welded joints of prepared samples. To analyze the welding strength, tensile strength, and Vickers micro-hardness test was conducted. The observation shows that the best combination for optimum outcome is SS316 – SS304. It shows tensile value of 3920 Kgf and Vickers hardness value of 278 Hv at the weld interface. It was found that the composition of the alloying elements of the above-mentioned materials affects weld ability.

Friction stir welding (FSW) is a welding technique for the solid-state that leads to production of high quality welds. Even the results are seen in materials which are difficult to weld like brass, aluminium, copper etc. The welding institute invented this technique in 1991. This technique leads to production of a high quality weld joint without actually melting the materials. This technique is environment friendly, is easily performed and fast. Moreover components formed from FSW can be used for a lot of industry applications. The purpose of this investigation is to discuss friction stir welding process with respect to effect of the process parameters. The study provides a summary of latest research advancements in FSW of similar and dissimilar materials. The main objective is to find out the common conclusion from the compiled literature.

Purpose In recent days, friction stir processing (FSP) has emerged as a pioneering approach for the manufacture of composites with enhanced mechanical and tribological properties. The present study aims to examine the impact of process parameters such as tool rotation speed and number of FSP pass on the AZ61A/TiC magnesium metal composite for responses such as hardness and wear resistance. Design/methodology/approach To minimize number of experimental runs, design of experiment was configured according to the response surface methodology using central composite design. Analysis of variance has been conducted to develop mathematical and empirical model for studying relationship between tool rotation and number of pass for responses such as microhardness and wear resistance. Microhardness was checked on vickers microhardness testing machine, and tribological behavior were examined on pin-on-disc using tribotester. Wear morphology was analyzed via scanning electron microscopy. Findings The responses were predicted using validated mathematical model, and contour plots were generated to study the interaction and influence of process parameters. Wear observations suggest that for the base magnesium alloy adhesive wear mechanism was dominating and for the developed nanocomposites, abrasive wear mechanism is a prominent factor. It was also observed that both the selected parameters significantly influenced the responses. Originality/value To the best of the authors’ knowledge, no prior work has been conducted with this material and preparation of composites with TiC nanoparticles. Furthermore, no mathematical models have been developed to predict the response values.

The ever-increasing demand for light weighted hard materials for transportation industries encouraged researchers to develop composites with excellent mechanical properties which can transform it into more economical and eco-friendly. Reinforcing the metals with carbonaceous nanomaterials are progressively in focus due to their excellent capability to inculcate and tailor the properties of MMCs. In the present research, a hybrid nanocomposite of MWCNT-Graphene-AZ31 Mg alloy has been developed by using variable tool rotation speeds with friction stir processing (FSP). Optimized reinforcement ratio of 1.6% vol. MWCNT and 0.3% vol. of graphene have been used with variable tool rotation speeds, whereas other processing parameters are kept constant. The developed specimens were investigated using standard testing equipment for evaluating and comparing the mechanical properties on the basis of the microstructure of the processing regions and their morphological analysis, according to the ASTM standards. The obtained results revealed an improvement of 19.72% in microhardness and 77.5% of compressive strength in comparison with the base metal AZ 31 Magnesium alloy, with a tool rotational speed of 1400 rpm. The values of tensile stress and percentage area reduction were recorded as less than that of the base metal matrix, but an increasing trend has been observed in the values of both with the improvement on rotational speeds of the tool. The effectual strengthening mechanisms are analyzed on the bases of SEM images and observed that discussed and found that grain refinement strengthening is the major contributor to the strength of the nanocomposite. Keywords: MMCs (Metal Matrix composites), Friction stir processing (FSP), Multi-walled carbon nanotubes (MWCNT), Graphene Nano Particulates (GNP), Stir Zone (SZ), Thermo-mechanically affected zone (TMAZ), Heat Affected Zone (HAZ)

The premature failure of boiler tubes, especially in coal fired boilers poses serious threat to the efficiency of the Indian boilers. In coal fired thermal power plant boilers, hot corrosion and erosion is the primary reason behind downtime, which leads to huge economic losses. So the consolidated results of the various researchers working in the area of combating hot corrosion of boiler tubes, especially in context with Indian boilers (both actual and simulated environment) are presented in this article. These results help the researchers in selecting an appropriate and accurate coating material composition, coating process and parameters for a particular boiler steel to improve the life of boiler tubes. So, that, any unwanted damage of boiler tubes due to hot corrosion could be minimized.