Studies at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington, are being conducted to evaluate nondestructive examinations (NDE) coupled with mechanical testing of butt fusion joints in high-density polyethylene (HDPE) pipe for assessing lack of fusion. The work provides information to the Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection te...

In the present research, friction stir welding (FSW) process was used for butt joining of pure copper plate to 316L stainless steel plate. Mechanical properties and microstructural characteristics of the joint were evaluated by microhardness and tensile tests as well as optical and scanning electron microscope (SEM). It was found that microstructure of the weld nugget (WN) has fine grains where...

Welding is an area in which technological developments out match the developments in its science base, which is primarily driven by the phenomenal industrial demand for welded structure. Reliability, Reproducibility and Viability requirements are forcing Technologists to look at weld defects such as distortion, hot cracking, in a systematic and logical approach than on adhoc basis. Distortion i...

Laser-based ultrasonic (LBU) measurement shows great promise for on-line monitoring of weld quality in tailor-welded blanks. Tailor-welded blanks are steel blanks made from plates of differing thickness and/or properties butt-welded together; they are used in automobile manufacturing to produce body, frame, and closure panels. LBU uses a pulsed laser to generate the ultrasound and a continuous ...

In this paper, the stress intensity factor (SIF) expression for defected butt welds containing undercut and inclined lack of penetration (LOP) subject to far-field tensile stress is derived. Some of the standards such as ISO 5817 and BS EN 25817 have specified allowable limits for the length of the undercut and LOP defects and for the height of the weld. In addition, EN 29692 standard has deter...

Three-dimensional residual stress mapping of an aluminum 2024-T3 arcan specimen, butt-welded by the friction stir technique, was performed by neutron diffraction. Results indicate that the residual stress distribution profiles across the weld region are asymmetric with respect to the weld centerline, with the largest gradients in the measured residual stress components occurring on the advancin...

The paper presents results of the investigation of structure relaxation and thermal properties of PE-80 and PE-100 polyethylene hot-tool butt welds. It was found that a weld with the re-crystallized crystalline structure is formed during the welding of dissimilar types of polyethylene. It is shown that within a long period (1 year) the relaxation occurs not only in amorphous but also in the cry...

Considerable research has been carried out to study the laser welding of magnesium alloys. However, studies are mainly devoted butt welding, and there limited information in published literature concerning bead-on-plate AZ91D, even though is required for repair cast AZ91D parts with surface defects. In present investigation, cracking weld metal was observed when an alloy welded using method. Th...

Polymer-based nanocomposites due to their advantages such as corrosion resistance,adequate mechanical properties and low cost are widely used in modern technologies. The increasing application of these nanocomposites, and hence their welding seems unavoidable. In this paper, a novel hottool in friction stir welding process is used for butt welding nanocomposite plates of 5 mm thick containing p...

Suture repair of a severed peripheral nerve is cumbersome, presents a focus for infection and neuroma formation, and does not always produce adequate stump alignment. An alternative form of repair is laser nerve welding, which is attractive because it does not introduce foreign material into the anastomotic site, it forms a circumferential seal, and it can be performed in difficult-to-reach are...