Analysis of effect of tool geometry on plastic flow during friction stir spot welding using particle method

Abstract

a b s t r a c tThe effect of tool geometry on the plastic flow and material mixing during friction stir spot welding (FSSW) is investigated using the particle method approach. For spot welds made with a cylindrical pin tool with flat shoulder, the model predicts the material flow at the pin periphery to be in the upward direction and the material is pushed downward beneath the shoulder giving rise to the resultant hook geometry. Other pin geometries evaluated include tapered pin, inverse tapered pin, triangular pin, convex shoulder, and concave shoulder. With good correlation with experimental trials, this model is then used to predict the material flow for spot welds. The material flow, and thereby the resultant hook formation, is quantified using numerical methods and is expressed as standard deviation of the particle movement. A triangular pin with a concave shoulder is the preferred tool geometry from the current study that results in high strength spot welds.

Effect of tool geometry on friction stir spot welding of polypropylene sheets

“…The pin generates friction heat, deforms the material around it and stirs the heated material [19]. In FSSW of metals the diameters of the pin [20], the pin angle [21], pin thread orientation [22], pin length [23] and pin profile [24] were found important in stir zonestir zone formation. The shoulder of the tool generates heat during the welding process, forges the heated material, prevents material expulsion and assists material movement around the tool [25].…”

Effect of tool geometry and welding parameters on the microstructure and static strength of the friction-stir spot-welded DP780 dual-phase steel sheets

“…The mechanism of the material flow during the FSSW using different tool designs was fully described elsewhere. 16,31 As a result, the finergrain structure in the stir zone and thermo-mechanically affected zone of the FSSW using the triangular pin led to a higher hardness than that of the weld made with the tapered pin.…”

Efecto de la velocidad de rotación y la indentación en soldadura de punto por fricción agitación de aleaciones de aluminio disimilares

“…5 (a-b)). Este efecto estaría relacionado con que la mayor proporción del aporte térmico se produce en la zona de contacto entre el hombro de la herramienta y la chapa superior (Hirasawa et al, 2010). Por lo tanto, cuanto más cerca esté el hombro de la interface, mayor será la agitación de los materiales y más eficiente la unión metalúrgica.…”

“…Los valores obtenidos de carga de rotura han sido mejorados respecto a lo previamente reportado, teniendo en cuenta los espesores y materiales que se sueldan en el presente trabajo, y los parámetros de soldadura empleados (Hirasawa et al, 2010;Jeon et al, 2012;Bozurt y Bilici, 2013;Cox et al, 2014;Piccini y Svoboda, 2015b). No solo se han optimizado las cargas de rotura en PT, sino que, además, dichas cargas han sido obtenidas en una configuración de junta que presenta un 40% de disminución en peso a lo previamente reportado (Piccini y Svoboda, 2015b).…”