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The aluminium alloys have enormous potentional of weight saving that are drastically gaining importance in the production of transport systems, for example, automobiles, aircraft and aerospace vehicles as well as in production of machines. Owing to the lack of sufficient abrasive wear resistance of aluminium components their application has, so far, been restricted. However, the application range of aluminium components will be extensible through the improvement of the abrasive wear resistance. The main objective of this work is the development of high wear resistant composite coatings on aluminium components by plasma transferred arc (PPA) welding. In this paper the development of the fused tungsten carbide and TiC based composite coatings with a thickness range of a few millimetres is presented. Aluminium alloys are used as matrix material and fused tungsten carbide and TiC are used as hard particles. The weldability of the powder systems with varying welding parameters is examined. The developed coating systems are tested with regard to their specific properties and their wear resistance. Finally, their application potential is presented.

Present day metal cutting industry has to meet the challenges of productivity and the quality of the machined parts during the turning processes economically. In the present work, an attempt has been made to develop a model and predict the tool wear and nodal temperature of hard turned AISI D3 hardened steel using Response Surface Methodology (RSM). The combined effects of cutting speed, feed rate and depth of cut are investigated using contour plots. RSM based Central Composite Design (CCD) is applied as an experimental design. Al2O3/TiC mixed ceramic tool with a corner radius of 0.8 mm is employed to accomplish 20 tests with six centre points. The adequacy of the developed models is checked using Analysis of Variance (ANOVA). Main and interaction plots are drawn to study the effect of process parameters on output responses.

Nickel alloys have gathered wide acceptance in the fabrication of components, which require high temperature resistance and corrosion resistance, such as metal bellows used in expansion joints in aircraft, aerospace and petroleum industry. In case of single pass welding of thinner sections of this alloy, Pulsed Current Micro Plasma Arc Welding (PCMPAW) was found beneficial due to its advantages over the conventional continuous current process. The quality of welded joint depends on the grain size, hardness and ultimate tensile strength, which have to be properly controlled and optimized to ensure better economy and desirable mechanical characteristics of the weld. This paper highlights the development of empirical mathematical equations using multiple regression analysis, correlating various process parameters to grain size, grain size and ultimate tensile strength in PCMPAW of Inconel 625 sheets. The experiments were conducted based on a five factor, five level central composite rotatable design matrix. A Genetic Algorithm (GA) was developed to optimize the process parameters for achieving the desired grain size, hardness and ultimate tensile strength.

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