Incomplete penetration is a type of welding defect that severely impacts the quality weldments. In order to identify levels in pulsed laser and plasma transferred arc (laser-PTA) hybrid welding, this paper uses structure-borne acoustic sensors detect signals. Their characteristics are then analyzed with respect time frequency domains. Acoustic signals characteristic incomplete-penetration defec...

Electron beam welding (EBW) shows certain problems with the control of focus regime. The electron beam focus can be controlled in electron-beam welding based on the parameters of a secondary signal. In this case, the parameters like secondary emissions and focus coil current have extreme relationships. There are two values of focus coil current which provide equal value signal parameters. There...

To address control difficulties in laser welding, we propose the idea of a self-learning and self-improving laser welding system that combines three modern machine learning techniques. We first show the ability of a deep neural network to extract meaningful, low-dimensional features from high-dimensional laser-welding camera data. These features are then used by a temporal-difference learning a...

Repair welding (RW) with wire cladding is a common procedure to extend the in-service life of heavily loaded tool parts for die and mould industries 1-5 . The main advantages of repair welding are short downtime and cost efficiency compared to production of new tool part. Repair welding in general lowers the tool cost in the final part and enables higher added value to the die casting and injec...

Laser welding with CO2, fiber and various types of solidstate lasers is a well established process currently utilized in a wide range of industries and applications. However, recent technological developments in high power diode laser technology have expanded the capabilities of laser welding, as well as changed its cost characteristics. As a result, diode lasers are poised to replace tradition...

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...

Development of techniques for joining and welding materials on a micrometer scale is of great importance in a number of applications, including life science, sensing, optoelectronics and MEMS packaging. In this paper, methods of welding and sealing optically transparent materials using a femtosecond fiber laser (1 MHz & 1 μm) were demonstrated which overcome the limit of small area welding of o...

Laser welding has been considered as a promising method to join sintered NdFeB permanent magnets thanks to its high precision and productivity. However, the influences of laser welding on the magnetic property of NdFeB are still not clear. In the present paper, the effects of laser power on the remanence (Br) were experimentally investigated in laser spot welding of a NdFeB magnet (N48H). Resul...