Research And Design Of The Process Parameters Measuring System For The FSW Experiment Machine

Friction Stir Welding(FSW)is a new type of solid phase connection technology that invented and patented by The Welding Institute(TWI)in 1991.FSW is the most revolutionary welding technology since the invention of laser welding technology and is now by more and more attention all over the world.The development of this technology is of great significance for the improvement of modern manufacturing especially the aviation manufacturing technology.FSW has become a welding technology that traditional fusion welding technology cannot compared with completely by reason of its series of advantages.It has rapidly replaced the traditional fusion welding in some ways and is playing the effect that cannot be replaced in each of its application field.FSW is a very complicated process and vertical force and plunge depth of the tool shoulder are two of the very important process parameters.Some researches show us that the two parameters present a certain positive correlation relationship when other process parameters unaltered and even a kind of constant function relationship during stable welding conditions.This subject undertakes some necessary researches about the measurements of vertical force and plunge depth of the tool shoulder during the process of welding based on a gantry type FSW experiment machine that designed and manufactured by the School of Materials Science and Engineer of Northeastern University.It comes up with the measuring methods of the two process parameters during welding and conducts some relevant researches about the structure of the machine.Research contents of this subject mainly include:(1)Builds the 3D model of the whole FSW experiment machine,and makes mechanical analysis about some large forced parts in it to check the strength during welding.(2)Comes up with the design idea of wireless force measuring shank combining with the technology characteristics of FSW after making a analysis for the force condition of the FSW tool according to the welding process,and finishes the dynamic calibration experiment of the wireless force measuring shank.(3)Finishes the static loading experiment of the weighing sensor inside of the shank and gets the output signal changing characteristics of the sensor in the situations of different loaded.(4)Comes up with the design idea of the plunge depth measuring device after analyzing the motion course of the FSW tool.Makes use of a linear scale to translate the displacement signal of the tool into the digital impulse signal and passes it to the PLC by the serial port.