皮秒激光切向修整青铜结合剂金刚石砂轮的影响因素研究

The Influencing Factors of Tangential Dressing of Bronze-bond Diamond Grinding Wheel by Picosecond Pulsed Laser

青铜结合剂金刚石砂轮因为其优异的磨削性能和较强的耐磨性被广泛应用于硬脆材料的磨削。为改善砂轮的磨削性能,本研究提出了青铜结合剂金刚石砂轮的皮秒激光修整研究,对粗粒度(100#)的青铜结合剂金刚石砂轮进行了激光切向整形。通过理论计算获得了脉宽为10 ps的激光烧蚀去除青铜结合剂及金刚石磨粒的功率密度阈值。研究了激光功率密度、激光扫描速度、砂轮转速和偏置距离对激光修整质量的影响,通过修整后砂轮表面粗糙度、磨粒突出高度和磨粒后角角度评价砂轮修整效果。结果表明当激光功率密度I_(40W)=2.60×10^(11)W/cm^(2)、激光扫描速度v=360 mm/min、砂轮转速n=9 000 r/min、激光偏置距离a=0.5 mm时,可以获得表面粗糙度较低、磨粒形态更好的金刚石砂轮表面。本研究采用的超快脉冲激光具有极高的峰值功率和极短的脉冲宽度,几乎可以对任何材料进行加工,且具有热效应小和加工精度高等独特优势,有望实现更高精度的砂轮修整。

Bronze-bonded diamond grinding wheel is widely used in the grinding of hard and brittle materials because of its excellent grinding performance and strong wear resistance.In order to improve the grinding performance,this study proposes a picosecond laser dressing study of the bronze-bonded diamond grinding wheel,and laser tangential profiling of the coarse-grained(100#)bronze-bonded diamond grinding wheel.The power density threshold of laser removing bronze binder and diamond with pulse width of 10 ps is obtained by theoretical calculation.The influences of laser power density,laser scanning speed,grinding wheel speed and offset distance on laser dressing quality are studied,the dressing results of the grinding wheel is evaluated by the surface roughness,relief angle of abrasive grain and the protrusion height of the abrasive grain after dressing.The results show that when the laser power density I_(40W)=2.60×10^(11)W/cm^(2),laser scanning speed v=360 mm/min,grinding wheel speed n=9000 r/min,laser offset distance a=0.5 mm,the diamond grinding wheel surface with higher contour accuracy and better abrasive morphology are obtained.The ultrafast pulsed laser used in this study has extremely high peak power and extremely short pulse width.It can process almost any material,and has the unique advantages of small thermal effect and high machining accuracy.It is expected to achieve higher precision grinding wheel dressing.