The Research Of Red Copper Laser Welding Technology

Red copper is one of the most commonly used metal materials in industrial application.In recent years,red copper sheet is much more widely used in the field of the instrument and meter,aerospace,nuclear industry and so on.Therefore,ultra-thin copper plate welding and encapsulation is becoming more and more important.Red copper welding has some defects such as burned through easily,deformation,porosity and crack because of its good heat transference and easy to be oxidated.Laser welding is suitable for sheet materials for large energy density,high efficiency,small heat affected zone,high degree of automation features.Firstly,this paper theoretically analyzes the mechanism of interaction between laser and material which obtains the main parameters that affecting the welding quality.Secondly,this article mainly focuses on the pretreatment of copper surface because of the high reflectivity of red copper for laser,and a 532 nm nanosecond laser was chosen for the surface blacken of red copper,which find out the red copper optimum blacken parameters: laser output power 40 w,coke amount 0 mm,scanning speed 800 mm/s,filling width 2 microns.Through the study,84.5% absorption rate on blackening copper on wavelength of 1064 nm laser is found.Then,on the basis of theoretical analysis,0.3 ? thick copper plate lap welding experiment is carried on,and the influence of welding line molding,welding line surface hardness,tensile strength of laser power,welding speed,defocusing amount is also researched.This research finds the best weld surface morphology,the maximum weld hardness,the biggest tensile strength when the laser power 500 w,the welding speed 4 mm/s,defocusing amount 0 mm.Finally,this paper studies the effect of laser welding of red copper sheet which using surface blackening and coated graphite these two kinds of surface treatment,and finds that black surface treatment of red copper is more stable for laser welding process,much high weld hardness and tensile strength..At the same time,this article also developed a multi-functional fiber laser processing system.The system mainly includes fiber laser,six axis robot,multi-function processing head,three dimensional flexible welding jig,CCD(graphic sensor)positioning system,air system,computer off-line programming system andservo system,etc.The system is mainly applied to the space motion of the robot and the characteristics of optical fiber laser flexible transmission to realizing complex components of the three-dimensional processing,which greatly reducing the laser energy loss by adopting the method of adjusting light path by CCD.This paper has proved the feasibility of laser welding copper sheet,through experiment,found the superiority of black surface before welding.In the rapid development of laser welding technology,the laser welding of red copper sheet will be more and more mature,and the high performance red copper will be used more and more widely in the future.