Research On The Technology Of Thermometal Laser Welding Machine

As a new type of welding method,laser welding have many advantages than traditional welding method in a high energy density,low heat input,narrow heat affected zone, high-aspect ratio,and so on.With the advent of kw ontinuous CO2 laser, kilowatt-Nd:YAG laser,laser welding technology has been widely used in aerospace,shipbuilding,automobile manufacturing, plastics processing and other fields.In this paper, laser welding properties of high speed steel and spring sreel are researched using 500W pulsed Nd:YAG solid state laser,hoping to discover the general principles which can guide pulsed YAG laser welding of thermometel;the phase,microstructure,mechanical properties of the YAG laser welding joints are studied;the mechanism and the major defects of the laser welding process are analysed,and relevant prevention measures and solutions are put forward.Through experiment, observating process parameters which have an impact on the welding and in the subsequence by changing the different parameters and study their impact on penetration, weld width, area and other effects.Between 300W to 500W, with the laser power increases, penetration ,weld width, heat affected zone width are showing an increase.Changing defocus length ,we found under -2mm condition,we can get the greatest width.Under the premise of the penetration, gap changing from 0.1mm to 0.5mm, weld width and penetration has not changed significantly. With the increase in heat input,weld size, heat-affected area of the joint increase in a direct proportion way from a platform to another higher platform, but the area of coarse and fine grain does not increase as the line energy ever-increasing.These theories and experimental reaserch provide a basis for the laser welding machine's design, manufacture,apply.