Study On Welding Performances Of Vibration Damping Sheet With Resinic Layer

In this paper, influences of welding parameters on in-between resinous layer duringCO2 arc and spot welding of Vibration Damping Sheet (VDS) are investigated. Quantitative formula of relation between main technologic parameters andin-between resinous layer separate width (W) during CO2 arc welding is obtained by useof multi-linearity regressive orthogonal design experimental means. The result showsthat relations between main technologic parameters such as welding current, weldingtime, diameter of welding thread and W are linear. Distribution of hardness and hardened area width(B) of different position, changeof tissue and component, relations between meltingdepth, melting width of welding lineand W are studied. The results show that W, B and hardness of the area near in-betweenresinous layer increase with elevation of welding current and delay of welding time. W,B and hardness of the area near in-between resinous layer decreasewith aggrandizementof the diameter of welding thread. Tissues of the hardened area near resinous layer areFerrite and Troostite, tissue of the base are Ferrite. There is not obvious differenceconcerning chemic component between resinous layer and base. Accessorial electric structure is designed, distribution of current and change ofresistance are analyzed in VDS spot welding. Influences of spot welding parameters onsize, performance, rupture of welding point and tissues in fusion area are studied bymeans of ordinal spot welding. The results show that except abruption capability of thefirst welding spot is worse, there is not difference with regard to that of the secondwelding spot and subsequent welding spots; abruption position and tissues in fusionarea are similar in first and second welding points. During spot welding, length(L), position, range of under-fusion area of resinouslayer and change of tissues, component near resinous layer are researched. The resultsshow that L of under-fusion decreases and hardened range of under-fusion areaincreases with aggrandizement of welding heat, delay of welding time and decrease ofelectrode press. Positions of under-fusion area are far from center of welding spot anddistributions of under-fusion area are more symmetrical to center of welding spot withaggrandizement of welding heat, electrode press and delay of welding time. At the sametime, under a certain electrode press, VDS of same position of the second welding spotnot only joints more closely, but also the hardened area disappears withaggrandizementof welding heat, delay of welding time.