微磨料水射流三维加工的实验研究

Experimental Study on Three Dimensional Machining Using Micro Abrasive Water Jet

对微磨料水射流技术三维加工进行了实验研究。实验采用特殊设计的微磨料水射流切割头,水喷嘴内径为127μm,聚焦管内径为300μm,碳化硅固体磨料粒子平均直径25μm。微磨料水射流切割头利用螺杆泵送原理直接将微细磨料主动送入切割头混合腔,通过水射流对磨料粒子加速、混合并经聚焦管喷出形成微磨料水射流。螺杆由步进电机驱动,通过控制步进电机转速来精确控制磨料流量。将切割头置于高精度四轴联动数控平台的刀架上,实现对工件的加工。研究表明,通过改变磨料流量可较好地控制微磨料水射流的能量密度。对特定材料,首先设定走刀速度,改变磨料流量就能获得不同的切割深度,实现微磨料水射流车削、磨削、铣削、雕刻等三维加工。微磨料水射流在半导体材料加工、微型电子机械制造以及光学器件生产上具有广阔应用前景。

Three dimensional machining using micro abrasive water jet was experimentally studied. A specially designed cutting head for micro abrasive water jet, in which the inside diameter of orifice and focusing tube is 127p, m and 300μm respectively, while the average diameter of silicon carbide solid abrasives is 25μm, was used during experiments. An auger mechanism was used to feed the micro abrasives to mixing chamber of cutting head directly. Then the micro abrasives were mixed with water and accelerated by water jet in focusing tube, thereafter the micro abrasive water jet was generated. The auger mechanism was driven by an electrical step motor. Therefore the flow rate of abrasives can be precisely controlled by regulating the rotating speed of the electrical step motor. The cutting head was then mounted on a numeric controlled machine tool with four axes. Thus the three dimensional machining can be experimented. It was shown that the cutting energy of micro abrasive water jet could be well controlled by regulating the flow rate of micro abrasives. For a given material, if the feed rate of micro abrasive water jet was kept unchanged, then the cutting depth of the material varied with the flow rate of micro abrasives. Consequently, three dimensional machining was realized. Micro abrasive water jet has a wide application in fabrication of semiconductor, manufacturing of micro mechatronic system as well as optic devices etc.