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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 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).

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).

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 fabrication or repairing of aircraft components made of Hastelloy X to be resolved using an arc welding technique. In this study, Hastelloy X was joint with ERNiCrCoMo-1 filler by pulsed current gas tungsten arc (PCGTA) welding. The high temperature tensile property of the weldment has been evaluated at three different temperatures such as 700 °C, 800 °C and 900 °C. The tensile properties such as yield strength (294, 259 and 205 MPa), ultimate tensile strength (475, 396 and 245 MPa) and percentage of elongation or ductility (17, 14 and 11 %) follows the similar trend with temperature at 700 °C, 800 °C and 900 °C respectively. It revealed the values of all the properties are decreased as the temperature increased. The lowest strength was evaluated for weldment at 900 °C. The high temperature tensile test also revealed that the fracture of weldments for all three conditions is found at the weld centre (WC).

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.

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.

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.

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.

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.

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.

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.