Results from a computational model of arc welding, in which the arc plasma, workpiece and electrode are treated self-consistently, are presented. It is demonstrated through three examples (the effect of shielding gas composition, metal vapour and electrode shape on the weld pool) that reliable prediction of weld pool depth and geometry requires that the arc plasma is included in the computation...

A remarkable number of complex aerosols are generated from welding processes. The objective of this study was to compare DNA damage and lipid peroxidation in plasma and in lung and in liver tissue of rats exposed to welding fumes in an exposure chamber with those of control animals. Three air samples from the chamber were also collected to assess the exposure dose for each exposure (total sampl...

In this paper, a low cost, high performance and full PC-based sensor system for the pulsed gas metal arc welding (PGMAW) is described. It allows the visual online observation of all states of the welding process, including the material transition, and all welding situations without an additional lighting unit. Additionally, the synchronized measurement of the welding current and welding voltage...

The plasma optical radiation emitted during CO2 laser welding of stainless steel samples has been detected with a Si-PIN photodiode and analyzed under different process conditions. The discrete wavelet transform (DWT) has been used to decompose the optical signal into various discrete series of sequences over different frequency bands. The results show that changes of the process settings may y...

The relationships between the acoustic signal and the modes of the welding pool such as no-keyhole (melt-in), keyhole and cutting in variable polarity plasma arc welding (VPPAW) are investigated. Welch power spectral density (PSD) estimate is used for preprocessing the sound data. A neural network (NN) is used to distinguish the keyhole mode from the cutting mode. The results show that the keyh...

Metals in particulate matter (PM) are considered a driving factor for many pathologies. Despite the hazards associated with particulate metals, personal exposures for at-risk workers are rarely assessed due to the cost and effort associated with monitoring. As a result, routine exposure assessments are performed for only a small fraction of the exposed workforce. The objective of this research ...

This paper presents a solid freeform fabrication (SFF) technique based on micro-plasma powder deposition (MPPD). The relationship between the geometric features of the deposited layers and the welding parameters is investigated. The arc length is controlled through the monitoring of the arc voltage. The result of building parts with functionally graded components by the MPPD process is shown as...

In this paper several approaches for the detection of the melt pool circle (i.e. its position and radius) in laser welding applications are described. Instead of indirectly examining the evolution of the melt pool via the radiation of plasma that is generated during the welding process, we use a direct view onto the melt pool that is possible in a narrow wavelength band with a coaxial aligned h...