Automated monitoring and control of the weld pool surface has been one of the goals of the welding industry. This paper presents a technique which uses a calibrated charge-coupled device (CCD) sensor and structured light to extract the surface information as depth of pool from captured images. It projects a laser line from a pre-determined position onto the specular weld pool surface. A reflect...

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 new model-based approach for ultrasonic phased-array testing of dissimilar welds based on the direct measurement of the wave speeds inside the real weld by using scanning laser vibrometry is presented. With this technique the interaction of different wave modes with the weld can be studied in detail leading to important consequences for the measuring set-up. Together with the geometry of the ...

The arc welding process is widely used in industry but its automatic control is limited by the difficulty in measuring the weld bead geometry and closing the control loop on the arc, which has adverse environmental conditions. To address this problem, this work proposes a system to capture the welding variables and send stimuli to the Gas Metal Arc Welding (GMAW) conventional process with a con...

This paper presents a fully experimental study on melting, flow and weld strength development during ultrasonic welding of CF/PPS composites with integrated triangular energy directors. The main goal of this research was assessing whether the heating time to achieve maximum weld strength could be significantly reduced as compared to ultrasonic welding with flat energy directors. The main conclu...

To improve the manufacturing quality of welded structures, to prevent failures at weld joints and to predict their lifetime, measurements of the residual stresses generated by welding in the structures are extremely useful. The residual stresses may reduce the component life due to phenomena that occur at low applied stresses such as brittle fracture, fatigue and stress corrosion cracking. Weld...

Physical models for the development of microstructure have the potential of revealing new phenomena and properties. They can also help identify the controlling variables. The ability to model weld metal microstructure relies on a deep understanding of the phase transformation theory governing the changes which occur as the weld solidifies and cools to ambient temperature. Considerable progress ...

Spatially resolved measurement of creep deformation across weldments at high temperature cannot be achieved using standard extensometry approaches. In this investigation, a Digital Image Correlation (DIC) based system has been developed for long-term high-temperature creep strain measurement in order to characterise the material deformation behaviour of separate regions of a multi-pass weld. Th...

Two laser transmission welding experiments involving polyvinyl chloride are presented that aim to validate a previously presented welding model while helping to further understand the relationship between welding parameters and weld quality. While numerous previous research papers have presented the results of laser welding experiments, there exists minimal work validating models of the welding...

Monitoring systems for the laser keyhole welding process of aluminium Tailor Welded Blanks, are in many cases vital to ensure a certain weld quality. Especially process visualization with camera based systems gives a lot of insight. Although for steel it has already been demonstrated that images can be obtained in real-time from the laser welding process using these cameras based on silicon chi...