Application and Prospect of Laser Quenching Technology in Mould Surface Treatment
The work aims to analyze factors affecting the service life of mould and summerize main forms of mould failure based on illustrating advantages of producing parts by utilizing a mould and its status in industrial production.Major techniques used to modify metallic surface previously were summarized.The advantages of laser quenching were pointed out by comparing laser quenching technology with traditional heat treatment process.The development history of laser quenching technology and the mechanism of laser quench hardening were introduced generally.Parameters influencing the laser quenching process and test methods for determing sizes of three major factors were put forward.In addition,formation and various properties of structure at different depths of workpieces subject to the laser quenching process were also anlyzed with detailed instruction on atomic diffusion organism during the formation of the first layer of phase-change hardening layer.Moreover,effective methods and advantages of pretreatment were discussed to improve laser absorptivity of material surface.It was indicated that CO2 laser and YAG laser were commonly used in the laser quenching,their corresponding purposes were briefly discussed.Microstructure and corresponding micro hardness of hardened layers in hot working dies,cold working dies and plastic moulds steel subject to quenching under different laser quenching parameters were listed.The main purpose of applying laser quenching to the three kinds of die steel was pointed out.Finally,the advantages and disadvantages of the laser quenching technology as well as prospect of laser modification on mold surface were summarized.