为了在304不锈钢表面上加工微小结构型腔, 一套光纤激光掩膜微细电解复合加工装置被研发, 对光纤激光掩膜微细电解复合加工的机理及影响其加工精度的因素进行研究。首先, 利用激光表面打标技术, 使光纤激光束在304不锈钢表面直写, 进行激光制掩膜, 在工件表面上生成Fe、Cr等金属氧化物层, 形成抗腐蚀性掩膜保护层。随后, 进行微细电解加工, 利用激光打标生成的掩膜层耐腐蚀特性, 依靠简单片状电极在微细电解加工中就能进行304不锈钢的定域腐蚀, 快速实现微小型腔加工。对加工电压、极间间隙、电解液浓度、脉冲电源占空比、激光功率等对加工精度有影响的因素进行分析, 选择合适的加工参数, 经过三次掩膜电解复合加工, 加工出深约为17.8 μm不锈钢方形等型腔, 该工艺在微小型腔模具加工等领域有广阔发展前景。

In order to fabricate micro-structured cavities on the surface of 304 stainless steel, a device of electrochemical micro machining(EMM)with fiber laser masking was developed. The machining mechanism of EMM with fiber laser masking technology and the influences on machining precision were investigated. First, using laser surface marking technology, the oxidation layer of Fe and Cr on 304 stainless steel surface is formed by direct laser writing, which is the protective masking layer with corrosion resistance. Subsequently, micro electrolytic processing was performed, the special layer generated by laser masking severs as protecting layer, and the micro cavity can be fabricated by using a simple sheet electrode to perform localized corrosion of the 304 stainless steel in the micro electrolytic processing. The factors that influence the machining accuracy, such as machining voltage, interelectrode gap, electrolyte concentration, pulse power duty cycle, laser power and other factors were analyzed. Then the appropriate processing parameters were selected, and a stainless steel square cavity with a depth of about 17.8 μm was fabricated by three times of mask electrolytic compound processing, which has broad prospects in the field of micro-cavity mold processing and other fields.