Influence of Gas Tungsten Arc Welding Parameters in Aluminium 5083 Alloy
The present work deals with the identification of the best combination of welding parameters, in TIG welding of Aluminium alloy 5083. In this study two level full factorial experimental design is considered which consists of two factors and two levels. Inorder to avoid experimental errors two replications are performed for each experimental combination. The working ranges of welding parameters for conducting experiments are initially obtained by trial and from literature survey. After the experiment, various tests like Tensile test; Microhardness, Macrostructure and Microstructure study are conducted to the welded specimens. The analysis of the test results is conducted and the combination of welding parameter ranges that gives best result is found. This combination can be considered as good working ranges for TIG welding of Aluminium alloy 5083.
Microstructure, Mechanical And Wear Properties Of Aluminum 5083 Alloy Processed By Equal Channel Angular Extrusion
In this study, commercially available aluminum magnesium (Al 5083) alloy was subjected to equal channel angular extrusion (ECAE) up to two passes using route-Bc at room temperature. Microstructure, mechanical and wear properties of the alloy before and after ECAE were investigated to examine the effect of ECAE on Al 5083 alloy. Microstructural investigations were carried out along the flow and transverse planes of the extruded alloy using optical microscope and it revealed that the coarse microstructure of the alloy was refined to a considerable amount. The micro hardness and tensile strength of the alloy increased with increase in pass number. The wear properties of the alloy after ECAE were improved considerably along with improvement in hardness and tensile strength. It is clear from the results that the mechanical properties of the alloy were improved to a particular extent due to the highly refined grains imparted by ECAE process and it makes the alloy to be used in various engineering applications requiring high strength.
Traceability strategy for gear-pitch-measuring instruments: development and calibration of a multiball artifact
There is a strong demand to ensure the traceability of gear-measuring instruments (GMIs). We propose a multiball artifact (MBA) for the evaluation of pitch-measuring accuracy. The aim of the MBA is to transfer the minimum uncertainty from a calibrated value at the National Metrology Institute of Japan (NMIJ) to a measured value of GMIs at a shop floor. The MBA is composed of equally spaced high-accuracy balls around an axis. The pitch-measuring accuracy of GMIs is evaluated by measuring the angular pitch deviation of the balls instead of the angular pitch deviation of a gear. We calibrated the angular pitch deviation using a coordinate measuring instrument (CMM) at the NMIJ and adapting a multiple-orientation technique. We proposed a calibration strategy of the angular pitch deviation. The calibration value of the pitch deviation for the MBA at the NMIJ was obtained with a measurement uncertainty (U95) of 0.2 µm. We evaluated the pitch-measuring accuracy of a GMI using the calibrated MBA. Each value of U95 for the cumulative and single pitch deviations for the left and right flanks was less than or equal to 0.5 µm. The small uncertainty was transferred from the NMIJ to the GMI.