硬质合金刀具表面微结构的激光加工研究
2018-11-12
作者:任长春1,2,何宁2,郝秀清2,王琛2 ,李亮2 单位:1南京信息职业技术学院;2南京航空航天大学
摘要:硬质合金刀具常用来加工难加工材料,通过刀具表面织构化技术可以提高硬质合金刀具的耐磨性和加工性能。激光加工技术作为一种快速非接触自动化加工技术,可以在硬质合金刀具表面上加工出微结构。本文主要研究平均功率、扫描速度、脉冲频率、离焦量、扫描次数这五个工艺参数对硬质合金刀具微结构尺寸及形貌的影响,从而选定最优的激光加工工艺参数。实验结果表明:随着平均功率的增大,微沟槽的深度和宽度都在增加,但功率过大导致严重烧蚀使底侧面形貌不平整;扫描速度和脉冲频率的增加都会使得微沟槽的深度和宽度呈现减小的趋势,过大的扫描速度使得底面形貌不连续,随着脉冲频率和扫描次数的增加,沟槽底面形貌变得平整;离焦量从0mm变化到-1.2mm时,微沟槽的宽度缓慢增大,深度则先增大后减小,底面形貌由连续变成稀疏的孔洞。通过优选出的激光加工硬质合金刀具工艺参数,制备出了良好的刀具表面单一型和混合型微结构。
关键词:激光加工;硬质合金刀具;微结构;工艺参数
中图分类号:TG506;TH162;TN249文献标志码:A
 Research on Laser Machining Microstructure of Carbide Cutting Tools 
Ren Changchun,He Ning,Hao Xiuqing,Wang Chen,Li Liang 
Abstract:Carbide tools are commonly used to process difficulttomachine materials,whose wearresistance and processability can be improved through the tool surface texturing technology.Laser processing technology is a fast,noncontact and automated technology which can be used to prepare microstructure on the surface of carbide tools.The paper studies the effects including average power,scanning speed,pulse repetition rate,defocusing distance and scanning counts on the microstructure size and morphology of the carbide tool in order to select the optimal parameters.The experimental results show that with the increase of average power,the depth and width of the microgrooves also increase,but serious ablation causes the bottom surface to be uneven due to the excessive power.The increase of the scanning speed and the pulse frequency will lead the depth and width of the microgrooves to decrease and the large scanning speed makes the shape of the bottom surface discontinuous.The shape of the bottom surface of the microgroove become smooth with the increase of the pulse frequency and scanning counts.The defocus distance changed from 0mm to -1.2mm,the width of the microgrooves slowly increases,while the depth increases first and then decreases,and the shape of the bottom surface continuously changes into sparse holes.A single and mixedtype microstructure on carbide tool surface is machined using parametric optimization of laser processing.
Keywords: laser processing;carbide tool;microstructure;processing parameters