Resistance spot welding is one of the most widely used processes in sheet metal fabrication. Improvements in quality assurance are important to increase welding productivity. Until now, quality estimation was performed using dynamic resistance at the secondary circuit, which is easily measured. However, this method has many problems when applied to in-process real-time systems. In this study, w...

This thesis presents a process planning methodology for a rapid injection mold tool manufacturing system that involves additive and subtractive techniques, whereby slabs are sequentially bonded and milled using layered tool paths. Mold tools are grown in a bottom up fashion, eliminating the need for multi-axis machining operations (beyond three axes) and allowing small features in deep cavities...

In this paper a novel laser impact spot welding (LISW) method is described, in which a hump was formed on the flyer plate on the intended welding spot location by local pre-forming. When the flyer and base plates were placed together to perform welding, the two plates kept in contact over their entire surfaces except at the hump, where a local air gap was enough to guarantee the impact velocity...

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...

Health monitoring of structural joints is a major concern of the engineering community. Among joining techniques, spotwelding play a major role. Spot welding is the traditional method of assembly for steel-based automotive structures, while spot-welding of aluminum is being considered for future vehicular structures. Though spot welding of steel is well researched and understood, the spot-weldi...

The performance of laser welding of Ti and two dental precious alloys (Ag-Pd-Au, Au-Pt-Ag) was investigated by mechanical testing and microscopic observation, using butt joint as design. The laser irradiation was done using a commercial Nd:YAG dental laser-welding device in a single pulse mode with output currents 150, 200, 250, 300A, spot diameters 0.6, 0.9, 1.2mm, and pulse duration 10ms. The...

Objective: The welding process involves metal ions capable of causing cell lysis. In view of this fact, the aim of this study was to test the hypothesis that cytotoxicity is present in different types of alloys (CrNi, TMA, NiTi) commonly used in orthodontic practice when these alloys are subjected to electric spot welding. Methods: Three types of alloys were evaluated in this study. Thirty-six ...

The health monitoring of structural joints is a major concern of the engineering community and needs to be addressed with the proper consideration. Among joining techniques, the spot welding and weld-bonding (spot weld + adhesive bonding) methods are of great interest in a number of industries. Spot welding is the traditional assembly method for steel-based automotive structures, while weld-bon...