To the Editor: W elders are at risk of a wide range of respiratory health problems, including bronchitis, airway irritation, and lung function changes.1–5 Despite short duration of exposure, an inception cohort study of apprentice welders in Quebec documented a significant respiratory function decline, incidence of welding-related respiratory symptoms suggestive of occupational asthma and sensi...

The possibility of assembling through welding is one of the major features of thermoplastic composites and it positively contributes to their cost-effectiveness in manufacturing. This paper presents a comparative evaluation of ultrasonic, induction and resistance welding of individual CF/PPS thermoplastic composite samples that comprises an analysis of the static and dynamic mechanical behaviou...

Heating of workpieces plays an influential role in ultrasonic welding. In the present paper, an attempt was made to further understand the heating mechanism during ultrasonic welding. Three equations in this regard were derived. Firstly, based on the viscoelastic properties of the workpieces, the equation governing heat generation was derived. Secondly, a thermal equivalent circuit model was de...

To obtain satisfactory welds in positional laser beam welding, it is necessary to know how process parameters will influence the quality of welds in different welding positions. In this study, the titanium alloy Ti6Al4V sheets were laser welded in two vertical welding positions (vertical up and vertical down), and the appearance, porosity, strength, and ductility of the laser joints were evalua...

Studies in the field of environmental epidemiology indicate that for the adverse effect of inhaled particles not only particle mass is crucial but also particle size is. Ultrafine particles with diameters below 100 nm are of special interest since these particles have high surface area to mass ratio and have properties which differ from those of larger particles. In this paper, particle size di...

In the present study, the microstructure of welded zone of Hastelloy X sheets with thickness of 1 mm via pulsed Nd-YAG laser welding were studied. This welding process was done by autogenus and conductive method. Microstructure were observed by metallurgical OM and SEM. Results shown Solidification of the weld metal is dendritic. The dendrites in the central zone of the welding are fine and equ...

Automation of welding process in shipyard is ultimately necessary, since welding site is spatially enclosed by floors and girders, and therefore welding operators are exposed to hostile working conditions. To solve this problem, a welding robot that can navigate autonomously within the enclosure needs to be developed. To achieve the welding task, the robotic welding system needs a sensor system...

Arc welding is an important joining process widely used in many industrial applications including production of automobile, ships structures and metal tanks. In welding process, the moving electrode causes highly non-uniform temperature distribution that leads to residual stresses and different deviations, especially buckling distortions in thin plates. In order to control the deviations and in...

GAS TUNGSTEN ARC WELDING (GTAW) is the quality weld process. It is preferred welding process for stainless steel, low alloy steel, nickel, cobalt, titanium, aluminum, copper, and magnesium. The present work aims to evaluate the effect of Gas Tungsten Arc Welding process parameters on the quality of the weld bead. The process parameters Welding Current, Wire Diameter, Wire Feed Speed, Ratio of w...