International Journal of Additive and Subtractive Materials Manufacturing (6 papers in press)
Mechanical and Microstructural Characterization on Direct Metal Laser Sintered Inconel 718
by Jinoop A.N., Kanmani Subbu S., R. Arockia Kumar
Abstract: Direct metal laser sintering (DMLS) is one of the additive manufacturing technologies which al-lows the fabrication of complex components in layer by layer technique with melting and solidifica-tion of powder raw material by laser heat source. This paper investigates about the mechanical and microstructural characteristics such as bulk density, porosity, micro hardness and surface roughness on Inconel 718, a nickel super alloy made by using DMLS. Bulk density and porosity finds good agreement with the components fabricated by casting. Micro hardness and surface roughness along the surface of the component was investigated and also surface roughness along the build direction was inspected. The phases present in the processed Inconel 718 was found by using X- ray diffrac-tometer. Optical microscopy and scanning electron microscopy was used to examine and understand the microstructure of as-built Inconel 718 without post-processing effects.
Keywords: Laser; DMLS; Inconel 718; characterization; mechanical; microstructure;additive man-ufacturing.
Effect of heat treatment on mechanical properties and microstructure of Ti/Al sheet metal joint using laser beam welding
by Kuppusamy Kalaiselvan, A. Elango, N.M. Nagarajan, N. Mathiazhagan
Abstract: Industry demands new materials to meet its requirements for that dvanced technics are adopted to find solution through research. One such attempt is use of laser beam welding to join Ti/Al dissimilar alloy for aerospace and other applications. It is still a challenge to achieve satisfactory joint between these dissimilar alloys. In the present work, Ti6Al4V and AA2024 alloys thin sheet combinations are welded using Nd: YAG pulsed laser welding unit. Subsequently the welded joints are subjected to age hardening and the results are compared with weld joints prior to aging. Test results reveal that aging treatment brings strength for the structure more than 60% and laser beam welding is suitable for dissimilar metal joining.
Keywords: Nd: YAG welding; Heat treatment; Microstructure; Mechanical properties.
Integrated approach for Product Optimization in a Rolling Mill using Fuzzy MCDM Tools
by SenthilKannan N, Parameshwaran R
Abstract: An integrated optimisation of process input attributes for improved
output quality in a steel rolling mill has been proposed in this study. The
intention is to control the process attributes within the specified limits to
improve the quality of the output and therefore control the other implications
involved. An evaluation model based on failure mode and effect analysis
(FMEA) using fuzzy analytic hierarchy process (FAHP) and fuzzy technique
for order preference by similarity to ideal solution (TOPSIS) is used in
assessing the risk priority of the critical process in the rolling industry. A fuzzy
methodology consenting experts to use linguistic variables for defining severity
(S), occurrence (O) and detection (D) is considered for FMEA by applying
fuzzy TOPSIS integrated with FAHP. The interface using fuzzy FMEA and
fuzzy quality function deployment (FQFD) is performed for the enhancement
of the process and the product development.
Keywords: multi-criteria decision making; MCDM; fuzzy AHP; fuzzy
TOPSIS; fuzzy QFD; fuzzy Delphi method; cause and effect analysis.
AMALGAMATION OF ALUMINUM-Mg2Si ALLOYS IN VARIOUS WEIGHT PERCENTAGE AND STUDY OF THEIR TENSILE AND WEAR BEHAVIORS
by SUNDARAMOORTHY R, RAVINDRAN R
Abstract: Within the most recent years there has been a fast increase in the use of aluminum-magnesium silicide alloys, mostly in the automobile industries, owing to their elevated strength to weight ratio, prominent wear resistance, little density and stumpy coefficient of thermal expansion. The development in the field of application makes the study of their wear and tensile behavior of greatest significance. In this present research, Aluminum based alloys containing 4%, 8% and 12% weight of magnesium silicide were manufactured using stir casting method. Compositional analysis and tensile tests of various samples of same composition have exposed near uniform distribution of Mg2Si in the manufactured alloys. Investigation of microstructure has illustrated the presence of primary magnesium silicide. Tensile tests were performed with universal testing machine. Yield strength and ultimate tensile strength has improved with increase in magnesium silicide percentage. Wear performance was studied by using computerized pin on disc wear testing machine. Opposition to wear has improved with increase in magnesium silicide amount.
Keywords: Stir Casting; Optical Spectrometer; SEM -Microstructure; Tensile; Hardness & Wear.
Investigations on Electric Discharge Machining of Copper-Al2O3-Gr Powder metallurgy Composites
by Gnanasekaran R, Bensam Raj J, Anandakrishnan Veeramani
Abstract: Copper composites with 5 weight percentage of alumina and graphite weight percentage of 0, 2.5, and 5 were produced by powder metallurgy process. To examine the presence and distribution of reinforcements in the produced copper composites, metallurgical characterization such as X-ray diffraction analysis and scanning electron microscopic analysis was performed. Further to analyze the machining behavior of the produced composites, electrical discharge machining was performed using Taguchis L27 orthogonal design by considering Pulse on time, Pulse off time and Current as the machining parameters. To ascertain the behavior of electric discharge machining of produced composites, statistical analysis was performed and the optimal levels of parameters was obtained through the main effect plot. Through the response table and ANOVA analysis, the significant factors was identified and finally, the test results was validated with a confirmation test.
Keywords: Composites; Copper; Graphite; Hybrid; Electric Discharge Machining; Taguchi approach.
Metrology for Additive Manufacturing (3D Printing) Technologies
by Tyler Musgraves, Hitesh Vora, Subrata Sanyal
Abstract: The findings presented in this paper are based on the survey of unclassified literature on additive manufacturing (AM)/3D printing technologies and their metrology. AM technologies allow engineers to design and build parts more freely than ever before, in addition to making production more distributed and eliminating obsolescence. This paper introduces different types of additive manufacturing as well as metrology challenges that need to be addressed by the Naval Surface Warfare Center, Corona Division (NSWC Corona) - the leading agency for Navys Metrology and Calibration (METCAL) program. It discusses potential uses, process limitations, and metrology related to three popular categories of AM: material extrusion (e.g., Fused Deposition Modeling), powder bed fusion (e.g., Selective Laser Melting), and directed energy deposition (e.g., Laser-Engineered Net Shaping). Powder bed fusion and directed energy deposition are proven to be capable of firearm- and aerospace-grade manufacturing. AM technologies demonstrate huge promise and may revolutionize design, manufacturing, logistics, maintenance, and acquisition in the Navy. There are still multiple hurdles to overcome before AM becomes an effective component in the military toolset. As AM continues to advance, the only way to ensure that these new technologies are reliable pieces of the warfighter arsenal is to prioritize development of measurement techniques and calibration schedules.
Keywords: Metrology; Additive Manufacturing (AM); 3D Printing.