Search

Semiconductors like ZnS, TiO2 and BaTiO3 were reinforced with Al-Al2O3 Metal Matrix Composites (MMCs) and were made through powder metallurgy in order to have high strength, high hardness and good thermal conductivity compared with conventional materials. Three MMC of test specimens were prepared with varying reinforcement ratio Al-Al2O3-ZnS(94-5-1), Al-Al2O3-TiO2(94-5-1), Al-Al2O3-BaTiO3(94-5-1) percentage by weight respectively. The hardness test has been made by using Brinell hardness testing instrument. Hardness test revealed that the addition of reinforcement TiO2, BaTiO3 increases the hardness value. However, the addition of ZnS to the Al-Al2O3 MMCs showed decrease in the hardness value. The crystal structure of the 3 composites were examined through X-Ray Diffraction (XRD) peaks.

In this research work the aluminium alloys including AA7075 and AA5083 are combined with friction stir welding method. This contrasts with factors such as alloy segregation, hot cracking and porosity which result from fusion welding process in the welded area. In order to generate high quality joint of aluminium alloy, friction-stir welding (FSW) an assuring welding method is followed. To achieve the determined strength, an entire control over the relevant process is needed to increase the tensile vitality. The welding factors like welding speed (WS), axial force (AF) and rotational speed (RS) are examined for optimisation. In order to measure the impact of the factors on tensile strength of FS welded joints, Taguchi L9 orthogonal array technique is employed. The amount of involvement of these factors on weld quality is determined by means of analysis of variance (ANOVA). The utmost ultimate tensile strength (UTS) attained for AA7075 and AA5083 joint is 256MPa. ANOVA results show that the quality-wise effectiveness of the weld as welding speed (5.48percent), axial force (15.18percent), then the rotational speed (79.32percent). This is due to the presence of fine equiaxed grains in the microstructures of the stir zones at different FS welding circumstances. However, a decrease in the grain size of the process zone is observed when the frictional heat flow is decreased while friction-stir welding.

The overall performance of supply chain depends on key choices with respect to demand allocation, facilities location, production strategy formulation, stock management and distribution plan. Among these the production-distribution planning has major impact on a company’s performance. Production-distribution plan integrates production, transportation, warehousing, inventory and distribution. Over the past two decades the optimization of integrated production-distribution plan has created wide interest and scope among the research and academicians dealing with supply chain management. The paper focuses on primary characteristics pertaining to production-distribution plan since it has remarkable impact on the company’s financial accountability. The present paper makes a thematic study on the collaborative production-distribution plan and solution methods with special emphasis on non traditional optimisation techniques, simulation and mathematical techniques adopted by researchers. Lastly, the paper paves the way for the future scope of research in integrated production-distribution planning.

In order to get a defect free spot weld, both the metals are desired to have the same thermal and electrical conductivity. But when welding dissimilar metals or sheets of different thickness, the fusion zone of both the metals may not experience same heat input due to the difference in material properties. This leads to weld defects such as nugget offset, voids and intergranular cracks in the fusion zone. The existence of weld defects deteriorates the mechanical performance of welded joints. A thorough metallurgical analysis must be carried out to ensure that the weld nugget is free of defects. The resistance spot welding of various dissimilar metals in the recent research publications and its practical outcomes are analyzed.

Paper recycling is the process of turning waste paper into new paper products. The main objective of the current research work is to analyze the effectiveness of stainless steel based compact paper recycling machines for small scale industries and institutions such as schools, colleges, printing media, etc. At present paper recycling technology is being implemented in large scale industries as it requires enormous space and cost involved. In the current study, an attempt is made to design a compact recycling machine that is affordable for small scale industries and institutions to possess their paper recycling units. The mechanism comprises of hydro pulper, mould box, conveyors, rollers, and driers. It is capable of recycling the used papers and produce papers, cardboards, and egg trays. The thickness of the paper is controlled by setting the distance between the two finishing rollers using a spring set up. The process of recycling is broadly divided into three main categories that include collection of waste, manufacturing of new products, and purchasing. The main advantage of the machine is waste paper be converted into a useful product and thus reduce deforestation. The cost of recycling is reduced and is affordable by small industries. The simplicity of the operation of this machine ensures that a high level of technical skill is not essential for the process. The durability of the machine is high provided if adequately maintained. Since recycling is good for the environment, and if more and more people make use of it, it will address the problem of global warming.

Resistance spot welding (RSW) of dissimilar metals is prominent in automobile industries to utilize the material properties of both the metals. RSW of dissimilar austenitic stainless steel sheets (AISI 304/316L) is investigated in this paper by varying the process parameters such as welding current and weld time at three different levels. Tensile shear test and macrostructural examinations are carried out to analyze the performance of spot welds. A three-dimensional model is also developed using commercial finite element analysis software ABAQUS FEA to predict the nugget diameter and thermal distribution profile through simultaneous structural electrothermal analysis with temperature-dependent material properties. The generated model is validated by comparing the predicted nugget diameter with experimental nugget diameter. Experimental results show good coherence with the simulation results, and the macrostructure of the spot-welded joints indicates successful welding of dissimilar sheets with defect-free fusion zone.

Cast ZK60 magnesium alloy has significant beneficial properties including high strength-to-weight ratio. Poor surface properties such as low friction and wear resistance restrict the use of this alloy in structural applications. Therefore, it is very much essential to adopt surface engineering to enhance this alloy’s surface properties. Friction stir processing is one of the potential thermo-mechanical processing techniques that alters the microstructural and tribological properties of the material. In the present study, ZK60/SiCp was fabricated by means of FSP. Tool tilt angle is a critical process parameter which influences the material flow, and particle breakup and distribution in the processed zone. In this work, an attempt has been made to understand the effects of tool tilt angle (ranges 0°–4°) on the grain refinement of matrix and the distribution of SiC particles. It is shown that the FSPed materials zone produced using the tilt angle 2° exhibited higher hardness (125 Hv); this was attributed to the optimization of heat generation, material flow, grain boundary strengthening, and homogeneous particle distribution.

In traditional joining process, copper alloys are hard to weld owing to its thermal and electrical properties. Owing to the high melting temperature and large thermal conductivity, excessive heat is needed for the joining operation of copper alloys. With Increased heat input, the heat affected region of the welded part increases, the mechanical and thermal properties of the component deteriorate. The objectives of this research are to discover the ideal mechanical performance of FSW of copper alloys. Two main factors such as tool speed and traversing speed has been investigated. A cylindrical profile of tool pin is used for all the experiments. A total of four experiments were conducted with two rotational as well as traversing speed for this investigation. The response such as tensile strength was analysed for accessing the integrity of the welded joints. At a steady load, the joints manufactured are found to have a highest tensile strength of 262 Mpa. Thus the 93.57 percentage of joint efficiency is achieved.

A Cast ZK60 magnesium alloy plays a tremendous role in the fabrication of lightweight structural materials. However, the low surface properties, like low friction and wear resistance, restricts the magnesium alloy during the structural application. Conventionally, the surface properties of magnesium alloys were improved using various processing methods like high-energy electron beam irradiation, plasma-transferred arc surfacing, and high-energy laser melt treatment. However, the above processes are involved in melting the magnesium material, which results in defects and detrimental metallurgical phase formation. Friction Stir Processing (FSP) can overcome this problem since the processing is done in the solid state. However, FSP often appears to be a significant applicant on the magnesium plate to attain successful fabrication of surface metal matrix composites. In this investigation, an attempt at FSP zone formation in magnesium alloy has been made in order to understand the influences of rotational speeds ranging from 700 to 1,100 r/min. From this investigation, it is found that the FSP made by using the high tool rotational speed of 900 r/min and 10 mm/min exhibited higher hardness and uniform particle distribution. This may be attributed to the grain boundary and dispersion strengthening.

This paper deals with electricity from photovoltaic system for cascaded multilevel inverter. The general function of multilevel inverter is to synthesis desired voltage from solar source. This inverter has advantageous of industrial applications. The use of converters will increase losses and cost in conventional methods. The proposed nine level multilevel inverter with solar energy using Pulse Width Modulation Technique (PWM) of providing high switching frequency will highly reduce harmonics.