Laser assisted skin wound closure offers many distinct advantages over conventional closure techniques. The objective of this in vitro experimental study, carried out at the Institute of Laser for Postgraduate Studies/Baghdad University, was to determine the effectiveness of 980 nm diode laser in welding of human skin wounds. Multiple 3-4 cm long full thickness incisions in a specimen of human ...

A robust and non-intrusive focus control system for laser welding has been developed under a collaboration between GSI Lumonics (Rugby) and Heriot-Watt University in Edinburgh, as part of the Laser Engineering for Manufacturing Applications Programme (LEMA), funded by EPSRC. It uses the light generated by the process, together with the chromatic aberrations of the focusing optics to determine t...

A three-dimensional (3D) finite element (FE) model is applied to predict the temperature evolution in the laser welding of galvanized high-strength steels in a zero-gap lap joint configuration. A rotary Gaussian volumetric heat source model is introduced to simulate the laser energy input. The temperature data measured by thermocouples are used to verify the boundary conditions of the thermal m...

Using tensile tests, this study investigated differences in the welding strength of casts of cobalt-chromium and gold alloys resulting from changes in the voltage and pulse duration in order to clarify the optimum conditions of laser irradiation for achieving favorable welding strength. Laser irradiation was performed at voltages of 150 V and 170 V with pulse durations of 4, 8, and 12 ms. For c...

Sutureless end to end ureteral anastomoses was successfully constructed in acute and chronic experiments. A photothermal sensitive hydrolyzable (PSH) albumin stent played roles as solder and intraluminal supporter to adhesion and position the anastomosed ureter by end to end fashion. The anastomosis seam was lased with 810 nm diode laser energy supplied through hand-held 600 mm noncontact optic...

The aim of this clinical study was to describe the possibility of using the Nd:YAG laser device utilized in the dental offices to weld metals intraorally. The authors, before applying this technique "in vivo" on human subjects, tested the "in vitro" metal welding efficacy of dental Nd:YAG device firstly by interferometry, SEM, and EDS and subsequently by thermal camera and thermocouples in orde...

abstract – aluminium 7075- t651 alloys are widely used in the production of light weight structures requiring a high strength to weight ratio and high corrosion resistance. the effect of processing parameters on fatigue life of 7075- t651 aluminium joints produced by friction stir welding was investigated in the present study. welding samples were made by employing rotating tool speed of 770, 9...

Both laser-arc hybrid welding and narrow gap welding have potential for the fabrication of thick sections, but their combination has been seldom studied. In this research, 40 mm thick mild steel was welded by narrow gap laser-arc hybrid welding. A weld with smooth layer transition, free of visible defects, was obtained by nine passes at a 6 mm width narrow gap. The lower part of the weld has th...

A special form of laser spot welding is introduced to overlap dissimilar welding of titanium (G2) to 3105-O aluminum alloy. A welding tactile seam tracking design using following pulses that result to a circular seam leads to spot like shape laser welding. This technique was conducted to joint overlapped grad 2 Titanium alloy (Ti G2) to 3105-O Al alloy, with 1, and 0.5 mm thicknesses respective...

The accuracy requirements of laser welding put high demands on the manipulator that is used. To use industrial six-axis robots for manipulating the laser welding optics, sensors measuring the seam trajectory close to the focal spot are required to meet the accuracy demands. When the measurements are taken while the robot is moving, it is essential that they are synchronized with the robot motio...