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...

Expertise of packaging for optoelectronic components requires the solution of optical, mechanical and electrical problems in the same way. The purpose of this study is to present three-dimensional simulations using finite element method (FEM) of thermomechanical stresses and strains in transmitter Laser modules induced by Nd:YAG crystal Laser welds on main sub-assembly Laser submount. Non-linea...

Laser beam welding of dissimilar sheet metal combinations such as Ti/Al, SS/Al and Cu/Al are increasingly demanded due to high energy densities with less fusion and heat affected zones. A good weld joint strength involves combinations of dissimilar metals and the formation of solid solution in the weld pool. Many metal pairs suffer from significant intermetallic phase formation during welding w...

The paper presents the analysis of thermo-mechanical fatigue cracking of die casting die during industrial use. An innovative, production friendly approach to monitor the surface crack dimensions was introduced, which is based on measuring defect-fi n on the casting part. A new four moulds die casting die was monitored 40 000 cycles in order to complete the production series. The production was...

Laser beam welding produces good quality welds with minimum shrinkage for sheet metal joints. The quality of welded joint depends upon surface morphology, hardness, mixing of liquid phases and metallurgical non-homogeneity induced by gradients of temperatures and cooling rate at the weld interface. In the present investigation, Titanium Grade5 (Ti) and AA2024 (Al) alloy dissimilar sheet metals ...

The need for the control of the depth of weld penetration has been and remains of a long term interest in the automated welding process. In this study, the relationship between the depth of weld penetration and the acoustic signal acquired during the laser welding process of high strength steels is investigated. The acoustic signals are first preprocessed by the spectral subtraction noise reduc...

Observation of the weld pool provides an effective path to understand and control the welding process. Observation data also attribute to the validation of numerical models, which helps researchers to analyze and evaluate the welding process. Extensive research has been conducted to provide in situ monitoring of the weld pool. The arc sensor was one of the first few sensors that was adopted for...

To address the need for robust and fast representation, we introduce deep learning neural networks and parallel programming techniques for laser welding. In order to deal with high-dimensional data within real-time constraints, we use a deep autoencoder to extract robust, meaningful and low dimensional features. The implementation is then optimized, using parallel programming techniques and sho...

This paper presents a communication framework for integrating sensors in a robotic laser welding system. The framework was originally developed for the application of sensorguided robotic laser welding, but the principles are generic, making it useful in other application areas as well. To use the sensor measurements during the robot motion, a synchronisation mechanism is presented for an image...