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Considerable weight of an automobile is constituted by the engine and there is scope for improvement in fuel efficiency and emission control through optimization of weight in the engine. In this work, AlSi10Mg alloy produced by the direct metal laser sintering (DMLS) is suggested for engine application which is a lightweight aluminum alloy. Mechanical properties like tensile strength, compressive strength, and hardness of both cast and DMLS manufactured alloy are compared followed by analysis of SEM images of tensile test fractured surfaces. Reciprocating wear test is carried out for one lakh cycles at 125°C temperature with SAE 40 grade oil as lubricant. Co-efficient of friction (COF), wear rate of the cast and DMLS manufactured samples are compared. Wear patterns are analyzed using SEM images of the wear tracks.

Duplex stainless steel (DSS) 2205 grade is welded with austenitic filler wires (ERNiCrMo-3 and ERNiCrMo-4) using gas tungsten arc welding (GTAW) process to operate at marine environments. Microstructure using optical (OM) and scanning electron microscopes (SEM) with energy dispersive spectroscope (EDS) are utilized to examine the metallurgical characterization of DSS 2205 weldments. Microhardness, impact, and tensile tests are employed to obtain the mechanical properties of weldments. Secondary precipitates such as Mo23C6 and Cr23C6 are formed in the ERNiCrMo-3 weldment which reduced the mechanical properties. In this study, ERNiCrMo-4 filler wire is provided enhanced mechanical properties for welding DSS 2205.

The main purpose of this study is to investigate additive manufactured Inconel super alloy subjected to cryogenic treatment (CT). Cryogenic treatment is mainly used in aerospace, defense and automobile application. Direct metal laser sintering is an additive manufacturing technique used for manufacturing of complex and complicated functional components. Inconel is an austenitic chromium nickel based super alloy often used in the applications which require high strength & temperature resistant. In this work, a study is carried out on microstructure and mechanical properties of additive manufactured Inconel 718 when subjected to cryogenic treatment at three different time intervals. The micro-structural evolution of IN718 super-alloy before and after CT was investigated by both optic microscope and scanning electron microscope. Surface roughness and hardness at different CT time intervals has also analyzed. Additionally, XRD technique was used to analyze the surface residual stress.

The utilization of Additive Manufacturing (AM) technology in the current manufacturing sector is growing day - by - day. This is made possible by the constant development of new materials and techniques to overcome the difficulties that are encountered while fabricating a part. In AM, parts are fabricated by laying successive layers on one another till the complete part is build. This gives AM an edge over conventional manufacturing. Even intricate or hollow parts can be fabricated with the same ease as fabricating a solid part. The key objective of this project is to evaluate and compare mechanical properties of Polyethylene Terephthalate - Glycol modified (PETG) and Carbon fiber reinforced Polyethylene Terephthalate - Glycol modified (CF - PETG), which are fabricated using Fused Deposition Modelling (FDM) process of AM. The ASTM standards D638 and D790 were followed for fabricating tensile test and Flexural test specimens respectively.

The current work investigates the hot corrosion demeanour of Hastelloy X weldment produced with autogenous mode through key-hole plasma arc welding (K-PAW). The hot corrosion test has been performed for weldment in molten salt-1 (MS-1) (75 % Na2SO4 + 25 % V2O5) and molten salt-2 (MS-2) (75 % Na2SO4 + 20 % V2O5 + 5 % NaCl) circumstance for 25 hrs (25 cycles) at 900 °C. The MS-1 substrate of both base metal and weldment provided the lowest weight gain than the MS-2 substrate. The NaCl in the MS-2 causes severe hot corrosion on the substrate, whereas the absence of NaCl in MS-1 reduces the hot corrosion effects. The highest parabolic constant is observed for K-PAW weldment in MS-2 condition. The tendency of hot corrosion rate follows the order of, Base Metal MS-1 < K-PAW MS-1 < Base Metal MS-2 < K-PAW MS-2. The occurrence of protective phases like chromium oxides (Cr2O3), spinel oxides (NiCr2O4 and NiFe2O4) Nickel oxide (NiO) on the substrate resist the further oxidation.

Today manufacturing industries have become more competitive and to survive, industries should be capable of accommodating the sudden market change. The conventional manufacturing systems like Dedicated Manufacturing Lines (DMLs) can produce high volume of product but difficult to cater to varying product types. On the other hand, Flexible Manufacturing System (FMS) is capable of handling product variety but not suited for mass production, The Reconfigurable Manufacturing System (RMS) gives the advantage of both the system, as it has the capability to adjust to both high volume requirement and product variety, and it able to upgrade to new process technology with minimal effort. In this work the reconfiguration is carried out in machine and system level. At machine level, a new inspection machine is proposed which can be used for multiple products with minimal adjustments and a special drilling and bore tool is suggested to reduce the cycle time and ramp up time when product changes.

Direct Metal Deposition (DMD) is a rapid prototyping technique used to fabricate and repair metallic prototypes. It can be used in the production of complex geometries and unique parts. In functional automotive applications wear characteristics hold key importance. In the present study, an analysis on the influence of various parameters (coating thickness, load and temperature) on the wear characteristics of Direct Metal Deposited (DMD) Inconel 625 coating has been carried out using a Design of Experiments (DOE). ANOVA calculations were performed to find out which of these parameters showed significant influence on the wear properties. It was found that load was the most significant parameter influencing the wear characteristics .Similarly load was found to be most influencing parameter for co efficient of friction. The trend was found to follow when verified at 30 second, 3 minutes, 60 minutes and 120 minutes.

This research work describes the effect of microsegregation, microstructure and tensile strength of the Hastelloy X weldment produced by keyhole plasma arc welding (K-PAW). Weld joint was obtained in a single pass without the addition of filler wire. The significant results obtained in this research work are (i) fine equiaxed dendrite was detected in the weld centre due to lesser heat input (HI) along with the faster solidification attained in K-PAW (ii) The existence of secondary precipitates in the interdendritic boundary was identified by the scanning electron microscope (SEM) analysis (iii) Energy dispersive X-ray spectroscope (EDS) revealed the Cr and Mo microsegregation in interdendritic boundary of the weld zone (iv) X-ray diffraction (XRD) analysis confirmed the Mo-rich P phase and Cr-rich M23C6 phase. The observed tensile strength of weldment is 6.14 % inferior to base metal.

This research is an attempt to investigate the possibility of enhancing wear and corrosion behaviour of aluminium alloy and composites for high-temperature applications. The 319 alloys with minor additions of Ni, Ti and Fe elements using the liquid metallurgy technique, Al-Si-Cu-Mg matrix alloy (Al alloy) was obtained and it was used as a base alloy and it is reinforced with Silicon carbide (SiC), Magnesium oxide (MgO) under the following composites, namely Al alloy/3wt % MgO (AA-SRM), Al alloy/ 3wt % SiC (AA-SRS) and Al alloy/3wt %SiC-3wt % MgO (AAHRSM) using a stir casting route. The wear test was investigated under the following factors, namely constant sliding velocity 3.21 m/s, sliding distance up to 10000 m under different loadings (4.9, 9.8, 14.7, 19.62, and 24.5 N) using wear test by a pin on the disc test rig. The wear rate was calculated using the tested samples under different loadings, sliding distance, and weight concentration conditions.

In the current work the metallurgical and tensile properties of the weld joints of alloy C-2000 were investigated. Welding technique employed in this study is Tungsten Inert Gas Welding (TIG) and Pulsed Current Tungsten Inert Gas (PC-TIG) welding with autogenous mode and Ni-Cr-Mo rich ERNiCrMo-10 filler wire. The results show that PC-TIG weldment obtained the refined microstructure compared to the TIG weldment. Energy dispersive spectroscopy (EDS) showed the extent of Cr segregation was observed in all the weldments. PC-TIG welding shows reduced segregation compared to the corresponding TIG. X-ray diffraction (XRD) corroborated the existence of Ni3Cr2 phases in the weld fusion zone. Tensile test results show the PC-TIG weldment obtained marginally higher tensile properties comparing over the corresponding TIG weldment. The strength of the weldments is inferior in all cases in comparison to base metal.

The objective of the study is to investigate the effect of current pulsation frequency on the weld bead microstructure, segregation and hardness of Hastelloy C-2000 weldments. Bead on Plate (BoP) welds were made by using Pulsed Current Gas Tungsten Arc Welding method (PCGTAW) at eleven different frequencies. The weld bead width and depth of penetration was measured with the help of Dinolite macro analyzer. The microstructure of weldments are further examined through optical microscope and Scanning Electron Microscopy (SEM) to identify the type of grain, grain coarsening and extent of the Heat Affected Zone (HAZ). The grain structure turn into finer and equiaxed in all cases and there was an optimum frequency range over which the significant grain refinement was observed. Microsegregation of alloying elements were computed with the aid of Energy Dispersive X-ray Spectroscopy (EDS). Vickers Hardness Tester was used to measure the hardness of the weld samples at ambient conditions.

Experimental investigations were carried out on the machinable wax filament using the fused deposition modelling (FDM) rapid prototyping process. The printer used for conducting the experiments was Flash Forge guider 2. The filament material used for this study was machinable wax filament of 1.75 mm diameter. Experimental trials were carried out as per Taguchi L9 orthogonal array to determine the optimum process parameter combination. The dimensional analysis of test samples were carried out in terms of change in volume of samples which is result of combine effect of deviations in all the dimensions of test sample. Four factors each at three levels was used to obtain the optimum printing parameters for better dimensional accuracy and proper printing. The four important printing parameters were taken as factor and set to analyse the significant factor affecting on printing. The complexity in printing of wax filament is taken in to consideration during the experimental study.

The use of thermoplastics in various fields like aerospace, automotive, medical and packaging industries is growing day by day, due to their light weight and compactness. In some instances, the plastic components are required to be welded. In this research study, process parameters used for the ultrasonic welding of thermoplastics which produces highest weld strength for complex use in the above said applications is carried out. Also, the possibilities of welding dissimilar plastics are also tested. Tensile testing of above welded samples fabricated through injection moulding was carried out for all possible welds and the ultimate tensile strength was calculated in each case. Of all the welded specimens, at given parameters like weld time, weld pressure and energy director, it is observed that ultimate tensile strength of ABS (8.89 N/mm2) is highest.

Fiber-reinforced polymer composites propose exceptional directional mechanical properties, and combining their advantages with the potential of 3D printing has resulted in many novel research fronts. Industries have started using 3D printed components which are rapidly replacing conventional material components in most of the industries. Carbon fiber reinforced Polylactic Acid (PLA) often finds its application in reasonably high loading conditions working at lesser speed like lightweight gears, spanners, nuts, and bolts. Wear reduction is an important factor that plays an important role in prolonging the component's life. Hence, it is crucial to optimize 3D printing parameters to get desired strength according to the application. The aim of this paper is to conduct the wear rate test on the Fused Deposition Modelled (FDM) printed carbon fiber reinforced PLA parts, to identify the optimum printing parameters which are crucial for wear reduction.

The developed model analysis is built in matrix runs to optimise the friction stir welding parameters of rotational speed, welding speed, shoulder diameter and tilt angle in this research. The aim of any design is to maximise the welded properties, either to surpass the base metal properties. The model that is created is the product of a number of regression methods that have been tested for adequacy. In this model we have taken three levels of varying parameters shoulder diameters, rotational speed, welding speed. Mathematical model is developed for the effect of three process parameter at three levels using response surface methodology (RSM).

The current research work scrutinized the influence of plasma arc in the metallurgical and mechanical behavior of Nimonic 80A weldment. Defect free weld bead of 6 mm thickness was achieved in a single pass through plasma arc welding. The microstructure of weldment is decorated with cellular dendritic structure at the center and at the weld interface region columnar dendritic structure was observed. Metallurgical analysis showed the Cr and Ti secondary precipitates in the interdendritic region of the WZ. The existence of M23C6 and Cr2Ti were observed through the X-ray diffraction analysis. Both tensile test and microhardness test were conducted to study the mechanical properties of weldment. The result concluded that both the strength and ductility inferior than base metal and the hardness of the weld bead is similar to that of BMl.

This work inspects the metallurgical and tensile demeanor of pulsed current gas tungsten arc welded ERNiCrCoMo-1 filler wire on alloy 80A weldment. Defect free weldment was achieved in a four pass through PCGTA welding. The center of the weld microstructure is decorated with equiaxed dendritic structure and columnar dendritic structure. SEM analysis showed the existence of Mo, Fe and Ti secondary phase precipitation in the grain boundary region of the weld zone. Tensile testing was conducted to analysis the strength and ductility of weldment. The result showed that the tensile strength and ductility were lower than that of base metal (BM).

In additive manufacturing, lasercusing is the selective laser melting technique. Finely pulverized metal is melted using a high-energy fibre laser, by Island principle strategy produces mechanically and thermally stable metallic components with reduced thermal gradients, stresses & at high precision. Maraging steel 300 (18Ni-300) is an iron-nickel steel alloy often used in applications requires high fracture toughness and strength. It maintains dimensional changes at a minimal level, e.g. aircraft and aerospace industries for rocket motor castings and landing gear or tooling applications. Current research attempts to analyze the effect of laser shock peening on lasercused material. Surface roughness of the material was found to be increased by 8%, due to effect of laser shock pulse & ablative nature. Also 8% increase in macro hardness on the surface.

In Additive manufacturing, Direct Metal Laser Sintering (DMLS) is a rapid manufacturing technique used for manufacturing of functional component. Finely powered metal is melted by using high-energy fiber laser, by Island principle strategy that produces mechanically and thermally stable metallic component with reduced stresses, thermal gradients and at high precision. Inconel is an austenitic chromium nickel-based superalloy often used in the applications which require high strength and temperature resistant. It can retain its properties at high temperature. An attempt is made to examine the effect of laser shot peening (LSP) on DMLS Inconel 718 sample. Microstructure shows elliptical shaped structure and formation of new grain boundaries. The surface roughness of the material has been increased due to the effect of laser shock pulse and ablative nature. Macro hardness increased to 13% on the surface.

This study examines the influence of cryogenic treatment on the microstructure and on the physical properties of the rapid prototype SLS material. The wear properties of the rapid prototype SLS material both before and after cryogenic treatment are studied in three phases. Phase I deals with the sample preparation through the SLS technique; Phase II involves the preliminary tests like roughness test, hardness test, SEM and wear test. Phase III is the cryogenic treatment of the sample in the setup designed. The cryogenic coolant used is Nitrogen, having a boiling point of 77 K, and the whole treatment process takes about 2 to 3 days. Phase IV deals with the testing of the cryogenically treated samples in which similar tests to that in Phase I are carried out. These results are tabulated and graphs are plotted. Furthermore, the percentage change in the hardness and wear properties of the samples are found.