TiAlN涂层错齿BTA钻头钻削性能与磨损机理研究

Machinability and wear mechanisms of TiAIN coated staggered teeth BTA drill

为提高错齿BTA钻头的钻削寿命与钻削孔的质量,采用TiAlN涂层与未涂层错齿BTA钻头对核电管板进行深孔钻削试验。通过扫描电子显微镜观察钻头的磨损形貌、能谱仪分析失效钻头刀齿表面物质的结构,揭示错齿BTA钻头的磨损形式与机理。研究TiAlN涂层对钻削核电管板错齿BTA钻头的钻削性能、钻削力、加工孔表面粗糙度、孔径偏差的影响。结果表明:错齿BTA钻头磨损最严重的是外齿与第1导向条,钻头的磨损主要以黏结磨损、扩散磨损和磨粒磨损为主,刀齿切削刃的磨损影响钻削力,外齿定径刃的磨损影响加工孔径,导向条的磨损影响加工孔壁的表面粗糙度;TiAlN涂层使错齿BTA钻头的钻削能力提高2.8倍,减小钻削扭矩和扭矩值的波动,提高钻削孔的质量。

In order to enhance the life of staggered teeth BTA drill and the quality of drilled holes,both the TiAlN coated and uncoated staggered BTA drills were used to conduct deep hole drilling test on the nuclear tube sheet.The wear morphology of BTA drills was observed by scanning electron microscope（SEM）,and energy spectrum analysis（EDS）was applied to acquire the quality percentage of chemical elements in wear area.The effects of TiAlN coating on the performance of drilling,drilling force,surface roughness and diameter deviation of drilled hole were studied.The results indicate that the serious wear sections of staggered teeth BTA drill are external teeth and first guide pad.The main wear forms of drill are adhesion wear,diffusion wear and abrasive wear.To be specific,the abrasion of cutting edge of cutter tooth affects drilling force,and the wear of the external tooth edge influences the machining aperture.In addition,the wear of the guide pads affects the surface roughness of the machined hole wall.The TiAlN coating improves the drilling ability of the staggered BTA by 2.8 times.Meanwhile,drilling torque and fluctuation of torque are decreased,which improves the quality of the drilling hole.