Effect of beam oscillation on porosity and intermetallics of electron beam welded DP600-steel to Al 5754-alloy

Formation of porosity and intermetallic compounds (IMCs) were studied in electron beam welded (EBW) DP-600 steel to Al-5754 dissimilar alloy joints at three different weld conditions such as without beam oscillation, with beam oscillation and with varying beam oscillation diameter. X-ray Diffraction (XRD), scanning electron microscopy (SEM), microhardness, three-dimensional X-ray computed tomography (XCT) were used to characterize porosity and IMCs distribution in these weld joints. Beam oscillation with optimum oscillation diameter (1 mm diameter) improved the weld quality by reducing the amount, maximum size and percentage of pores in weld zone significantly. For IMCs, average size increased little bit but maximum size, percentage of formation and amount reduced. By increasing oscillation diameter (2 mm diameter) beyond optimum value (1 mm diameter), quality of joints was found to deteriorate with accompanying higher pore density, average pore size, average IMCs size etc. Raman spectroscopy and Leco gas analyzer were also used to identify and quantify the entrapped gases in the weld joint

Effect of weld parameters on porosity formation in electron beam welded Zircaloy-4 joints : X-ray tomography study

Zircaloy-4 to Zircaloy-4 (Zr-4) similar butt joints were prepared using Electron Beam Welding (EBW) technique under different weld conditions such as with beam oscillation, without beam oscillation and at different welding speeds. Three-dimensional (3D) visualisation of porosity in weld joints was carried out using X-ray computed tomography (XCT) technique. Quantification of porosity such as the average size, number and shape of the pores were evaluated and compared among weld joints produced under different conditions. XCT results show that the porosity of the welds increased substantially with the increase in the weld speed. More interestingly, the results also show that there is a significant decrease in porosity of the joint produced with beam oscillation condition. An increase in weld speed from 700 mm/min to 1000 mm/min resulted in a significant increase in pore density (from 16 to 313 per mm3) and it was observed that the average size of the macro pores increased from 96.4 μm to 121.5 μm. The joints prepared with beam oscillation produced least number of pores with minimum percentage of macro pores and maximum percentage of spherical pores in it. Raman spectroscopy results confirmed the presence of hydrogen gas in pores of all the weld joints

X-ray tomography study on porosity in electron beam welded dissimilar copper–304SS joints

Dissimilar joining of copper (C10300) to AISI–304 Stainless Steel (SS) sheets was performed using Electron Beam Welding (EBW) process. EBW was performed for two weld conditions such as with beam oscillation and without beam oscillation. X-ray Computed Tomography (XCT) technique was used for three-Dimensional (3D) visualization and quantification of porosity in the weld region. It was observed that the application of beam oscillation resulted in less porosity and the average pore size was found to be smaller as compared to without beam oscillation condition. Also, pores were found to be uniformly distributed in the weld incase of with beam oscillation as compared to without beam osicllaition condition. Further, it was observed that there exists an optimum beam oscillation diameter beyond which there is no positive effect of beam oscillation in controlling the porosity formation in the weld joint

Unplanned Construction of a 210 Ft High Temple

A 210′ high temple site was located on a hillock made up of filled up soil. Taking the advantage of site topography terraced construction consisting of the main temple in the centre and rooms on the three sides were planned. The construction progressed without any soil investigations. The paper highlights the problems faced at the stage when the construction had already progressed up to +50 ft. Soil investigations were carried out at this stage. Then, the performance of structures was predicted and possible modifications in the future construction are presented

Filozofia Sankhja, głęboka ekologia i zrównoważony rozwój

Samkhya philosophy is one of the oldest philosophies in the Indian philosophical system. This philosophy is independent in origin and mainly known for its evolution theory.  Samkhya philosophy has accepted the two ultimate and independent realities, Nature and pure Consciousness. This paper is an attempt to comprehend the notion of deep ecology from the Samkhya’s evolution theory perspective. In this paper, firstly, we have elucidated the Samkhya philosophy of suffering and the solution to the problem. In the second part of the article, we have argued that how Samkhya’s philosophical notion of Nature demonstrates our embeddedness in Nature.  Therefore, the idea of deep ecology is always there in one or another form in Samkhya philosophy. It has also connections to the idea of sustainable development. Filozofia Sankhja jest jedną z najstarszych filozofii indyjskiego systemu filozoficznego. Ma niezależne pochodzenie i znana jest głównie z teorii ewolucji. Filozofia sankhji zaakceptowała dwie ostateczne i niezależne rzeczywistości: Naturę i czystą Świadomość. Niniejszy artykuł jest próbą zrozumienia pojęcia głębokiej ekologii z perspektywy teorii ewolucji Sankhji. Po pierwsze, wyjaśniamy filozofię cierpienia Sankhji i pokazujemy rozwiązanie problemu. W drugiej części artykułu dowodzimy, że filozoficzne pojęcie Natury stosowane przez Sankhję ukazuje nasze zakorzenienie w Naturze. Dlatego idea głębokiej ekologii jest zawsze obecna w tej czy innej formie w filozofii sankhji. Ma ona także powiązania z ideą rozwoju zrównoważonego