In this present work, laser welding experiments were carried out on 1 mm thin Ti6Al4V sheets using a low power Nd-YAG laser machine without using any filler wire and without edge preparation of welding specimens. The influence of different major process control parameters such as welding speed and power on the yield parameters like temperature field, weld bead geometry, microstructure, and mechanical properties are critically investigated. Experimental results are compared in detail with the simulated results obtained using a commercial 3D finite element model. In the simulation model, temperature-dependent thermal and mechanical properties of plates were considered. The temperature readings were recorded with the aid of K type thermocouples. Forced convection has been assumed near weld zone region because of the movement of the shielding gas. Appreciable agreement is found between the experimental and the simulated temperature fields in most of the cases with few exceptions. These deviations on few occasions may be due to the presence of uncertainties inherently present in the experimental domain and uncertainties in the subsequent temperature sensing techniques by the thermocouples. In addition, annealing has been done at 950 °C, 980 °C, and 1010 °C for one selected parameter (192 W, 6 mm/s). The tensile strength of the samples annealed at 980 °C has been found to be 1048 MPa and it is 3% to 4% higher than that of the usual welded samples.

Nd: YAG laser welding is an important joining technique for titanium alloys in aerospace industries, aircraft industries, biomedical instrument and various other fusion welding industries. Titanium alloy (Ti-6Al-4V) is used during the research, because it has high strength and oxidation resistance in a wide range of temperatures. It is used in combustion cans, and transition liners in both aircraft and land-based gas turbines and medical engineering. In the present research work, an experimental and numerical analysis of Nd-YAG laser welded titanium alloy thin sheet for temperature distribution has been done. A three dimensional heat conduction equation has been used for the numerical simulation. The influence of different welding conditions like welding speed, welding power on the heat affected zone (HAZ) morphology, metallurgy and mechanical properties was discussed in detail. Microstructures were assessed by optical microscopy and by field emission scanning electron microscope (FE-SEM), while the mechanical behavior was analyzed in terms of Vickers micro-hardness is compared with different welding conditions. The temperature field of the welding process for the different parameters were studied. It was found that the simulated results are in good agreement with the experimental result.

The influence of different welding parameters like welding speed and laser power on microstructure and the mechanical properties of low power pulsed Nd: Yag laser welded Nickel based super alloy inconel 617 sheets of thickness 1.5 mm has been investigated. In the present study, the welding of the specimens was done in a single pass aimed to full depth penetration. The microstructure of the various samples at fusion zone and at heat affected zone was characterized by field effect scanning electron microscope (FESEM) while the weld size of the welded metal at different parameters were measured using optical microscope (OM). The microhardness in the various zones for the welded sample has also been investigated. The microhardness of the welded samples was compared with base metal after experimental observations. The XRD technique was used to analyze the crystallography of the material at (2θ degree). The material has been used for the present study because of its exceptional properties of heat resistant and corrosion resistant. The Nd: YAG pulsed laser has been used because of its overlapping factor during welding that reduces porosity in the weld zone.

Dissimilar welding of Inconel 718 and SS-316 was carried out using TIG welding with SS304 filler, followed by post-weld heat treatment (PWHT) at 900 °C, 950 °C, and 1000 °C under air cooling (normalizing) and furnace cooling (annealing). Microstructural analysis revealed a defect-free fusion zone with dendritic solidification, along with unmixed zones and Nb-rich Laves phases concentrated in the Inconel heat-affected zone (HAZ). The maximum hardness measured on the Inconel side reached 418 HV, while the fusion zone exhibited an average hardness of 184 HV, and the SS-316 side showed ~ 163 HV, confirming a progressive hardness increase from SS toward Inconel. Tensile testing showed that all samples fractured in the SS-316 parent metal, establishing that the welds possessed higher strength than both base metals. The average tensile strength of the as-welded joints was ~ 600 MPa, which decreased to ~ 573 MPa after PWHT at ≥ 950 °C due to Laves phase coarsening and microstructural changes. Annealed samples at 950 °C and 1000 °C exhibited the highest ductility with a maximum strain of 0.32 mm. The results confirm that TIG welding produced a sound dissimilar joint and that PWHT significantly influenced microstructure, hardness, and tensile performance, with moderate-temperature annealing improving hardness without severely compromising strength.

Pack carburizing is an old method of case hardening of steel, mainly low carbon steel. In this, the sample is placed inside the solid environment of carbon/char Pack carburizing is an old method of case hardening of steel, mainly low carbon steel. In this, the sample is placed inside the solid environment of carbon/char