Due to their large compatibility difference, polyethylene (PE) and polyoxymethylene (POM) cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact...

PURPOSE This study evaluated the vertical misfit of implant-supported frameworks made using different techniques to obtain passive fit. MATERIALS AND METHODS Thirty three-unit fixed partial dentures were fabricated in cobalt-chromium alloy (n = 10) using three fabrication methods: one-piece casting, framework cemented on prepared abutments, and laser welding. The vertical misfit between the f...

It is not known for certain that dental stone components influence titanium welding. In this study, we investigated metallurgical problems caused by laser welding on dental stones using wrought commercial pure (CP) titanium. A pulsed Nd:YAG laser irradiated a number of specimens' surfaces which were fixed on either a dental hard stone or a titanium plate. The metallurgical properties of the wel...

A welding seam tracking visual sensor based on laser scanning is designed to solve the problems, such as indistinct image, difficulty in processing image etc., caused by serious arc light interference during welding. This visual sensor is mainly composed of a scanning motor, a linear-array CCD, a scanning rotating mirror and a semiconductor laser. Because the sensor measurement precision relies...

In this study, a three-dimensional (3D)finite elementmodel is developed to investigate thermally induced stress field during hybrid laser–gas tungsten arc welding (GTAW) process. In the hybridwelding case, we focus on the GTAWprocess sharing commonmolten poolwith laser beam and playing an augment role in thehybridweldingsystem.Anexperiment-based thermalanalysis isperformedtoobtain the temperatu...

The most common problem of welding dissimilar metals (DMWs) with respect to residual stresses is the differences in the coefficient of thermal expansion and heat conductivity of the two welded metals. In the present work, a CO2 continuous laser welding process was successfully applied and optimized for joining a dissimilar AISI 316 stainless steel and low carbon steel plates. The Taguchi approa...

Welding-induced distortion is an intrinsic problem arising due to the mismatch of thermal expansions in the weld and surrounding material. The distortion can be minimized through the pre-process, in process, or post-process methodology. In the present paper, the laser forming (LF) technology is utilized for the post correction of the welding-induced distortion. Three types of weld paths are app...

There are two laser welding mechanisms, keyhole mode and conduction mode. Keyhole welding is widely used because it produces welds with high aspect ratios and narrow heat affected zones. However keyhole welding can be unstable, as the keyhole oscillates and closes intermittently. This intermittent closure causes porosity due to gas entrapment. Conduction welding, on the other hand, is more stab...

The Nd:YAG laser welding was used to join the binary NiTi alloy wires with different compositions(Ti–50.0 at.%Ni and Ti–50.9 at.%Ni) which had the same diameter of 1 mm. The wires were welded with different parameters, including impulse width and welding current. The aim was to assess the influence of the laser-welding process on the microstructure and mechanical properties of the welded joint ...

The purpose of vision-based sensing devices in the welding industry is to electronically replicate the role of a skilled welder and emulate the human eye with a light-sensing device such as camera and the human brain with a computer algorithm that interprets the images. Just as an optical feedback from human eye guides the human welder, optical feedback in this electronic system would be used t...