Arc sensor is a conventional technique toward the compensation of aiming deviation which causes from the heat distortion or unevenness of work piece. But, at present, only less than 5% of arc welding robot has arc sensing function. It is hard to use in actual welding line because of occurring of miss sensing. Many studies have been performed about arc sensing, but most of them are about the performance of sensing. So, we began to reconsider over arc sensing in the meaning of reliability. We will apply theoretical equations so as to separate the signal and the noise toward unsettled arc phenomena. This report shows the research toward the behavior of arc itself at first. We developed an averaging method of arc voltage by using histogram so as to get accurate arc length. Next, we research the effect of molten pool toward the sensitivity of arc sensor. Wider weaving width leads better sensitivity. But even if the weaving width becomes small, we found the noise level does not increase.
Dissimilar materials joining of an A5052 plate and a carbon fiber reinforced thermoplastic (CFRTP), which consisted of polyamide 6 (PA6) with 20 wt% carbon fiber addition, was performed using friction lap joining (FLJ) with the Al alloy plate as a top and the CFRTP plate as a bottom. The joint characteristics were evaluated to investigate effects of the surface treatment by the silane coupling treatment for A5052 and the joining speed on the joining properties. The joint strength was increased by inducing the silane coupling treatment for the A5052 plate surface. The tensile shear fracture load of the silane coupling treated FLJ joint increased with increasing the joining speed up to 6.67mm/s, and then decreased. The maximum tensile shear fracture load of 5.0kN was obtained at the joining speed of 6.67mm/s, and the fracture occurred at the CFRTP base plate with the joint efficiency of 97%. The shear strength of the joint interface of the joint formed at the joining speed of 1.67mm/s, which fractured at the joining interface by the tensile shear test, was estimated about 19MPa. The covalent bondings between the A5052 plate and the silane coupling layer, and the silane coupling layer and the CFRTP plate were indicated by inducing the silane coupling treatment.