氧化铝陶瓷超声辅助钻削力与加工质量研究

Study on ultrasonic assisted drilling force and machining quality of Al2O3 ceramics

  • 摘要: 针对氧化铝陶瓷普通钻削时钻削力大、孔出口崩边、内壁损伤严重等问题,开展了金刚石套料钻超声辅助钻削(ultrasonic assisted drilling, UAD)与普通钻削(common drilling, CD)对比试验研究,分析了超声振动作用与工艺参数对钻削力、孔出口质量及孔内壁表面质量的影响规律。结果表明,超声辅助钻削过程中套料钻端面磨粒与试样之间的周期性“分离—接触”特性使轴向力最大降低44.6%。对于两种钻削方法,钻削力均随转速增大而减小,随进给速度增大而增大;但出口崩边面积随转速降低、进给速度增加而显著增大,并伴随大块材料脆性剥落。相比于普通钻削,超声辅助钻削促使孔出口破碎形态规则化并显著抑制切屑黏附,同时能显著提升孔壁材料的穿晶断裂比例、有效抑制沿晶断裂现象。在相同工艺参数下,超声辅助钻削孔内壁表面粗糙度最大降幅达32.4%。超声振动作用下,磨粒磨损程度得到一定降低。

     

    Abstract: To solve the problems of large drilling force, hole outlet chipping and serious inner wall damage in the ordinary drilling of alumina ceramic, a comparative experiment study on ultrasonic assisted drilling (UAD) with diamond sleeve drill and common drilling (CD) was carried out. The influence of ultrasonic vibration and process parameters on drilling force, hole outlet quality and hole inner wall surface quality was analyzed. The results show that the axial force is reduced by 44.6% in the process of ultrasound-assisted drilling because of the periodic separation and contact between the abrasive particles and the sample. Under the two drilling methods, the drilling force decreases with the increase of rotating speed and increases with the increase of feed speed. The ultrasonic vibration makes the crushing pattern at the hole outlet regular and significantly restrains the chip adhesion. However, the edge chipping area at the outlet increases significantly with the decrease of rotating speed and the increase of feed speed, and is accompanied by the brittle peeling of large materials. In addition, ultrasonic assisted drilling can significantly improve the transgranular fracture ratio of the hole wall material, and its value increases with the increase of the spindle speed and the decrease of the feed speed, at the same time, it can effectively suppress the intergranular fracture. Under the same process parameters, the maximum reduction of surface roughness of ultrasonic assisted drilling is 32.4% compared with normal drilling. Under the action of ultrasonic vibration, the degree of abrasive wear is reduced to a certain extent.

     

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