Selective single pulse femtosecond laser removal of alumina (Al₂O₃) from a bilayered Al₂O₃/TiAlN/steel coating

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• 作者：B. Gakovi? ; B. Radak ; C. Radu ; M. Zamfirescu ; M. Trtica ; S. Petrovi? ; J. Sta?i? ; P. Panjan ; I.N. Mihailescu
• 关键词：Hard coatings ; Alumina (Al2O3) ; Titanium aluminum nitride (TiAlN) ; Femtosecond laser ablation ; Selective layer removal
• 刊名：Surface and Coatings Technology
• 出版年：2012
• 出版时间：15 August, 2012
• 年：2012
• 卷：206
• 期：24
• 页码：5080-5084
• 全文大小：986 K

文摘

We studied surface modification of a double layer protective coating on steel induced by single fs laser pulse irradiation in ambient air. The outer alumina (Al₂O₃) layer, which protects against aggressive environments, was 1.7 ¦Ìm thick and the titanium aluminum nitride (TiAlN) layer in contact with the steel surface had a thickness of 1.9 ¦Ìm. The pulses (¦Ë = 775 nm, ¦Ó = 200 fs) were generated by a Ti:sapphire laser source. The pulse energy was varied from 0.32 ¦ÌJ to 50 ¦ÌJ, corresponding to an incident laser fluence of 0.11 J cm^? 2 to 16.47 J cm^? 2. The surface damage threshold was found to be 0.20 J cm^? 2 and the alumina layer removal was initiated at 0.56 J cm^? 2. This selective ablation of alumina was possible in a wide range of fluences, up to the maximum applied, without ablating the TiAlN layer beneath.