电化学抛光对选区激光熔化成形Ti6Al4V牙冠表面质量及耐蚀性能的影响

Effect of electrochemical polishing on surface quality and corrosionresistance of Ti6Al4V crowns fabricated by selective laser melting

研究了电化学抛光过程中电解液比例、电压、电解时间等参数对选区激光熔化成形Ti6Al4V牙冠表面质量及耐蚀性能的影响。结果表明,选区激光熔化成形的Ti6Al4V牙冠表面粗糙度较大,有明显的熔池边界及台阶,试样表面粘结大量粉末颗粒,初始粗糙度高达30μm。在体积比1:8的高氯酸和醋酸电解液中进行电化学抛光,当电压较小(10 V)时,只能去除表面粘附的粉末颗粒,抛光效果不明显;当抛光电压较高(50 V)或高氯酸和醋酸比例较大时,表面抛光过度,导致局部凹凸不平,粗糙度明显上升。在30 V电压下抛光30 min后,表面质量较好,表面粗糙度约为1μm,达到使用要求。经抛光处理后的Ti6Al4V牙冠表面的耐蚀性能大大提升,相比于未进行表面处理的牙冠,其耐蚀性能提高近一个数量级。

The effects of electrolyte ratio,voltage,and polishing time on the surface quality and corrosion resistance of the Ti6Al4V crowns fabricated by selective laser melting were analyzed in this paper.The results show that,the surface roughness of the Ti6Al4V crowns is large,and there are a large number of powder particles on the sample surface.At the same time,the undulating molten pool boundary and steps can be observed and the initial roughness is about 30μm.For the electrochemical polishing performed with the volume ratio of perchloric acid and acetic acid as 1:8,when the voltage is low(10 V),the adhered powder particles are removed,the surface roughness changes little,the polishing effect is not obvious.Meanwhile,when the voltage is high(50 V)or the volume ratio of perchloric acid and acetic acid is high,the surface is locally uneven,the surface roughness increases,the polishing effect is excessive.The surface quality of the Ti6Al4V crowns is significantly optimized by polishing in the electrolyte with the volume ratio of perchloric acid and acetic acid as 1:8 at 30 V for 30 min,the surface roughness is about 1μm after polishing,satisfying the requirements for application.The corrosion resistance of the Ti6Al4V crowns after electrochemical polishing is greatly improved,which is nearly an order of magnitude compared with the crowns without the surface treatment.