Chen Li, Holec David, Du Yong, Mayrhofer Paul H
Department of Physical Metallurgy and Materials Testing, Montanuniversität Leoben, Leoben, 8700, Austria.
Thin Solid Films. 2011 Jun 1;519(16):5503-5510. doi: 10.1016/j.tsf.2011.03.139.
Multinary Ti-Al-N thin films are used for various applications where hard, wear and oxidation resistant materials are needed. Here, we study the effect of Zr addition on structure, mechanical and thermal properties of Ti(1-x)Al(x)N based coatings under the guidance of ab initio calculations. The preparation of Ti(1-x-z)Al(x)Zr(z)N by magnetron sputtering verifies the suggested cubic (NaCl-type) structure for x below 0.6-0.7 and z ≤ 0.4. Increasing the Zr content from z = 0 to 0.17, while keeping x at ~ 0.5, results in a hardness increase from ~ 33 to 37 GPa, and a lattice parameter increase from 4.18 to 4.29 Å. The latter are in excellent agreement with ab initio data. Alloying with Zr also promotes the formation of cubic domains but retards the formation of stable wurtzite AlN during thermal annealing. This leads to high hardness values of ~ 40 GPa over a broad temperature range of 700-1100 °C for Ti(0.40)Al(0.55)Zr(0.05)N. Furthermore, Zr assists the formation of a dense oxide scale. After 20 h exposure in air at 950 °C, where Ti(0.48)Al(0.52)N is already completely oxidized, only a ~ 1 μm thin oxide scale is formed on top of the otherwise still intact ~ 2.5 μm thin film Ti(0.40)Al(0.55)Zr(0.05)N.
多元Ti-Al-N薄膜用于需要坚硬、耐磨和抗氧化材料的各种应用中。在此，我们在从头算计算的指导下，研究了添加Zr对Ti(1-x)Al(x)N基涂层的结构、力学和热性能的影响。通过磁控溅射制备Ti(1-x-z)Al(x)Zr(z)N，验证了对于x低于0.6 - 0.7且z≤0.4时所建议的立方（NaCl型）结构。在保持x约为0.5的情况下，将Zr含量从z = 0增加到0.17，导致硬度从约33 GPa增加到37 GPa，晶格参数从4.18 Å增加到4.29 Å。后者与从头算数据非常吻合。与Zr合金化还促进了立方畴的形成，但在热退火过程中阻碍了稳定纤锌矿AlN的形成。这使得Ti(0.40)Al(0.55)Zr(0.05)N在700 - 1100 °C的宽温度范围内具有约40 GPa的高硬度值。此外，Zr有助于形成致密的氧化膜。在950 °C空气中暴露20小时后，Ti(0.48)Al(0.52)N已经完全氧化，而在原本仍完好无损的约2.5 μm薄膜Ti(0.40)Al(0.55)Zr(0.05)N顶部仅形成了约1 μm厚的氧化膜。
