Study On Laser Polishing Machanism And Technology Of The SLM Plate Of Ti6Al4V

Laser polishing is a kind of widely used special processing technology.It is especially suitable for parts with high hardness and small size that are difficult to process with traditional methods.The selected material Ti6Al4V(hereinafter abbreviated as TC4)is an ?+? dual phase titanium alloy with good organizational stability,plastic toughness and other comprehensive performance.It has been widely used in aviation,automobiles,aircrafts and other fields.After experimental research,laser processing technology can be more efficient and environmentally friendly polishing TC4 alloy.Firstly,using a carbon dioxide laser with a wavelength of 10.6 ?m polished the alloy of the TC4 surface.The surface roughness of the material was measured with a three-dimensional profile instrument.The influences on the surface roughness such as laser power,defocus amount,scanning speed,and scanning pitch were analyzed in combination with the micro-morphology of the material surface before and after polishing.Having obtained the ideal process parameters,when the laser power was 500 W,the defocus amount was 30 mm,the scanning speed was 450mm/min and the scanning pitch was 0.3mm,the TC4 alloy titanium surface roughness was minimum 117.62 nm,a drop of above 90%.However,carbon dioxide laser polishing caused serious heat accumulation and obvious surface cracks.Secondly,using a fiber laser having a wavelength of 1080 nm polished the alloy of TC4 alloy.The effects on the surface roughness such as surface morphology,defocus amount,and scanning path were analyzed.Innovative use of multiple shifting scanning finished for optimal polishing.When the defocus amount was 9mm above the focusing surface,the power was 90 W,the scanning speed was 80mm/s,and the scanning pitch was 0.3mm,The polishing surface had the lowest roughness.The number of Ra dropped to 148.91 nm,about 93% reduction.The experimental results show that the use of fiber lasers for multiple moving scans can more quickly and effectively polish the TC4 titanium alloy.And due to the lower energy density,and there is no deformation and few of obvious surface cracks.At the same time,if the pre-polishing excimer laser is used,the original roughness of the alloy material can be reduce further.