Cracking is a major concern in welding aluminum alloys. Although weld solidification cracks can be eliminated through the addition of filler metal, the additives modify the alloy or base metal constituents and may not always be desirable. High-energy beam processes, such as electron beam welding, that result in minimal heat input reduce crack sensitivity, but their high cost limits their applic...

Gas tungsten arc welding (GTAW) is the primary process for precision joining of metals due to its capability for accurate control of heat input. As a close relative and modification of GTAW, plasma arc welding (PAW) has higher energy density and can penetrate thicker workpieces while maintaining the desired capability for accurate control of heat input. In order to produce quality welds consist...

This paper presents an evaluation of an infrared sensor for monitoring the welding pool temperature in a Gas Tungsten Arc Welding (GTAW) process. The purpose of the study is to develop a real time system control. It is known that the arc welding pool temperature is related to the weld penetration depth; therefore, by monitoring the temperature, the arc pool temperature and penetration depth are...

Abstract The gas tungsten arc welding process is an uncertain nonlinear multivariable system. In order to control the welding process, the nonlinear dynamic relationship between the weld pool geometry reflecting the weld quality and the welding parameters must be developed. A three-dimensional numerical model is developed to investigate the dynamic characteristics of the weld pool geometry when...

To assess the exposure of welders to thorium-232 (232Th) during tungsten inert gas arc (TIG) welding, airborne concentrations of 232Th in the breathing zone of the welder and background levels were measured. The radioactive concentrations were 1.11 x 10(-2) Bq/m3 during TIG welding of aluminum (TIG/Al), 1.78 x 10(-4) Bq/m3 during TIG welding of stainless steel (TIG/SS), and 1.93 x 10(-1) Bq/m3 ...

Power input to the arc in gas metal arc welding controls both the metal transfer process and the base-plate heating process. It would be advantageous to decouple these processes. Methods to achieve this decoupling are discussed. Pulsed-power welding is widely used, but only decoupling can be achieved. More complete decoupling may be obtained by using independent power inputs to the system. Seve...

This paper analyses the arc interference in an a.c. combined (both the pilot arc and the plasma arc exist in the welding process) plasma arc welding of aluminium alloys. This phenomenon results in an unstable welding process and weld formation. To maintain the pilot arc during the period when the electrode is positive, a cathode region must be formed in front of the tungsten electrode tip. Howe...

In this investigation, an attempt is made to study the tensile and microstructural impact of different gas tungsten arc (GTA) welding processes pulsed current, constant magnetic oscillation welded AZ31B magnesium metal joints. These techniques were chosen because they have potential produce welds with high strength excellent integrity. Five joints produced using each approach, one employing a u...

The present paper describes fuzzy logic simulation of shielded metal arc welding (SMAW) process to predict the Quality of weld joint. It describe the quality of weld joint & effect of welding current, voltage and welding speed on tensile strength of shielded metal arc pipe welded mild steel joints. An ERW Mild steel pipe I S 1239 of 6 mm thickness and 150 mm diameter were used as the base mater...