Friction stir welding and tungsten inert gas welding techniques were employed to weld armor grade aluminum alloy to investigate the effect of welding processes on tensile behavior of weld joints. Tensile tests, Vicker microhardness tests and optical microscopy were performed on developed weld joints and base metal. Welding process influenced tensile behavior and microstructure of weld joints. F...

An attempt has been made to determine the strength and impact properties of Cr-Mo steel weld and base materials by varying the current during manual metal arc welding. Toughness over a temperature range from -32 to 100°C of base, heat affected zone (HAZ) and weld zones at three current settings are made. It is observed that the deterioration in notch toughness at any zone with the temperature d...

Oxides in steel weld metals can initiate fracture or can improve toughness by influencing the development of beneficial microstructures. In this work, the authors conducted experiments in which the oxygen concentration was varied from 20 to 560 ppmw (parts per million by weight) in weld metals with tensile strength in the range 580–780 MPa. It is demonstrated that low and medium strength weld m...

Theoretical and experimental investigations have been carried out to examine the in uence of laser power and on time on the weld thermal cycle and weld metal microstructure and hardness during laser spot welding of low alloy steel. A transient heat transfer model that takes into account the temperature dependence of material properties and latent heat of phase transformation is employed to sim...

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 ...

During the last several years we have been investigating ultrasonic techniques for evaluating the quality of solid state weld interfaces [1 ,2]. Promising results have been obtained on a variety of different solid state welds by extracting features from the ultrasonic waveforms and applying pattern recognition algorithms to separate acceptable from unacceptable welds. In general, the primary di...

A simple thermal-mechanical model for friction stir spot welding (FSSW) was developed to obtain similar weld performance for different weld tools. Use of the thermal-mechanical model and a combined approach enabled the design of weld tools for various sizes but similar qualities. Three weld tools for weld radii of 4, 5, and 6 mm were made to join 6061-T6 aluminum sheets. Performance evaluations...

The present work has been carried out to study the sensitization behavior of AISI 304L austenitic stainless steel weld, fabricated using GTAW (gas tungsten arc welding process). This weld was subjected to post weld thermal aging (PWTA) treatments lying in the sensitization range, viz. 700 ?C for 30 minutes, 500 minutes and 1000 minutes for studying the influence of carbide precipitation on thei...