Indian Welding Journal

M. S. Gopalakrishna ¹, K. S. Raman ¹, B. S. Vaideswaran ², M. R. Seshadri ²

Affiliations
1 Dept. of Metallurgy, I.I.Sc., Bangalore-560012, IN
2 Dept. of Mech. Engg., I.I.Sc., Bangalore-560012, IN

Abstract

Feasibility test on calcium oxide-silica-calcium fluoride system with other consumables as the flux on spheroidal graphite (S.G.) core wire for multi-pass manual metal arc welding of S.G. iron base metal and malleable iron (M.I.) base metal has been carried out with a constant pre-heat of 500°C. Under similar conditions of welding, the same flux system on high carbon steel core wire has also been tried on M.I. base metal alone. Structure compatibility between the weldment and the base metal in as-welded condition was aimed at, by welding in a groove design used by Schaeffler and Schumbacker. The metallurgical factors involved in the welding process have been studied. The results obtained are promising and favourable. The structures obtained in the weldment are amenable to post weld heat-treatment and resulted in completely favourable microstructures.

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S. Srinivasa Murthy ¹, A. H. Yegneswaran ¹, K. S. Raman ¹

Affiliations
1 Department of Metallurgy, Indian Institute of Science, Bangalore-560 012, IN

Abstract

Nickel and its alloys can be successfully soldered using tin-lead solders. For several engineering and electronic applications, either nickel and its alloys or other metallic materials coated with nickel are to be soldered. Even though the soldering practice for nickel has been in use for some years, data concerning systematic fundamental studies on the solderability of nickel with different solders and fluxes under different conditions of soldering are scarce in literature. In this work, an attempt has been made to study the effect of solder composition, nature of flux and soldering temperature on the efficiency of soldering and on the joint strength of butt and lap soldered joints of pure nickel.

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K. S. Raman ¹

Affiliations
1 Materials Research Group, Department of Metallurgy, Indian Institute of Science, Bangalore, IN

Abstract

Spreading characteristics of Sn, Pb and nine Sn-Pb alloys on cast iron (3.2% C) have been evaluated by employing zinc ammonium chloride flux (79 parts of zinc chloride and 21 parts of ammonium chloride) at the liquidus temperatures of the solders. The solder, flux and specimen preparation procedures have been reported elsewhere. The solder-flux interfacial tension has been determined by the method of Chalmers and Wadie and contact angles were measured by an optical method. The spreading coefficients have been computed by using contact angle and interfacial tension values.

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