Ni含量及超声振动对激光熔覆中裂纹的影响

增加熔覆粉末中N i含量可以减少熔覆层中的硬质相,使熔覆层脆性降低,韧性提高,因而提高熔覆层在冷却过程中对拉应力的承受能力,减少熔覆层裂纹;而在熔覆过程中施加超声振动,则可以打碎枝晶,细化晶粒,减少或消除拉应力产生的根源,并使熔池化学成分、温度分布趋于均匀,从而减少裂纹的产生几率。

Influence of Ni Content and Ultrasonic Vibration to Cracks in Process of Laser Cladding

Cracks on laser cladding layer are the main obstacle of the application of the laser cladding technology.Experiments show that:(1) increaseing the content of Ni in cladding powder can reduce the hard strengthening phases,lower the brittleness of the cladding layer,and raise the ability to suffer internal stress,so as to reduce cracks on cladding layer.(2)appling the ultrasonic vibration to the process of the laser cladding can smash the crystal branches,reduce or eliminate the resource of the internal stress.Thus it can also make the chemical constituents and the temperature of the cladding pool more evenly be distributed,then cracks are reduced.