激光诱导氧化辅助微细铣削TiB2基陶瓷复合材料试验研究

Experimental Study on Laser-induced Oxidation Assist Micro-milling of TiB2-based Ceramic Composite

陶瓷复合材料具有高硬度、高弹性模量、耐磨、抗化学腐蚀等诸多优异性能,在航空航天、微电子、汽车、切削刀具和生物医学等领域具有广泛应用前景,但其微细铣削加工中存在铣削力高、刀具磨损严重等问题。本文提出了一种激光诱导氧化辅助微细铣削的复合加工方法,并用该方法制备了TiB2基陶瓷复合材料微结构。在激光辐照下,TiB2基陶瓷复合材料氧化生成具有一定厚度的、疏松易去除的氧化层;在此基础上,利用微细铣削工艺依次去除氧化层、热影响层和少量基体材料,以获得高加工效率和加工质量。主要研究了铣削深度和每齿进给量对铣削力和表面粗糙度的影响规律,结果表明,随着铣削深度和每齿进给量的增大,铣削力逐渐增大;在铣削深度为2μm、每齿进给量为0.3μm/z时,已加工表面粗糙度最小,Sa为0.06μm;随着铣削深度和每齿进给量的增大,材料去除方式先后经历弹性滑动摩擦、延性模式和脆性模式三个阶段。

Ceramic composites are widely used in aerospace,microelectronics,automotive,cutting tools and biomedical fields because of their high hardness,high strength,low density,low expansion coefficient,good resistance properties to wear and abrasion.However,the machining of ceramic composites is intricate due to high machining force and severe tool wear.A novel process of using laser-induced oxidation to assist micro-milling of the TiB 2-based ceramic composites is proposed,and the microstructures are prepared by the process.Under the laser irradiation,the TiB 2-based ceramic composite is oxidized to form a loose and easy-to-remove oxide layer.On this basis,the oxide layer,the heat-affected layer and a small amount of substrate material are sequentially removed by the micro-milling process to get high processing quality and processing efficiency.The influences of milling depth and feed per tooth on milling force and roughness are investigated.The results show that as the milling depth and the feed per tooth increase,the milling force increases.When the milling depth is 2μm and the feed per tooth is 0.3μm/z,the roughness of the machined surface is the smallest, S a is 0.06μm.As the milling depth and the feed per tooth increase,the material removal mode experiences three stages of elastic sliding friction,ductile-mode and brittle-mode.