Structural and mechanical evolution of reactively and non-reactively sputtered Zr-Al-N thin films during annealing

SURFACE & COATINGS TECHNOLOGY

卷:244

Article

Mayrhofer, P. H.¹  Sonnleitner, D.²  Bartosik, M.¹  Holec, D.² 

[1] Vienna Univ Technol, Inst Mat Sci & Technol, A-1040 Vienna, Austria

[2] Univ Leoben, Dept Phys Met & Mat Testing, A-8700 Leoben, Austria

关键词: ZrAlN;    Non-reactive sputtering;    Decomposition;    Age-hardening;    DSC;   

DOI  :  10.1016/j.surfcoat.2014.01.049

来源: Elsevier

【 摘 要 】

The influence of reactive and non-reactive sputtering on structure, mechanical properties, and thermal stability of Zr1 -xAlxN thin films during annealing to 1500 degrees C is investigated in detail. Reactive sputtering of a Zr0.6Al0.4 target leads to the formation of Zr0.66Al0.34N thin films, mainly composed of supersaturated cubic (c) Zr1-xAlxN with small fractions of (semi-)coherent wurtzite (w) AIN domains. Upon annealing, the formation of cubic Zr-rich domains and growth of the (semi-)coherent w-AlN domains indicate spinodal-like decomposition. Loss of coherency can only be observed for annealing temperatures above 1150 C. Following these decomposition processes, the hardness remains at the as-deposited value of similar to 29 GPa with annealing up to 1100 degrees C. Using a ceramic (ZrN)(0.6)(AlN)(0.4) target and sputtering in Ar atmosphere allows preparing c-Zr0.68Al0.32N coatings with a well-defined crystalline single-phase cubic structure combined with higher hardnesses of similar to 31 GPa. Due to the absence of (semi-)coherent w-AlN domains in the as-deposited state, which could act as nucleation sites, the decomposition process of c-Zr1-xAlxN is retarded. Only after annealing at 1270 degrees C, the formation of incoherent w-AlN can be detected. Hence, their hardness remains very high with similar to 33 GPa even after annealing at 1200 degrees C. The study highlights the importance of controlling the deposition process to prepare well-defined coatings with high mechanical properties and thermal stability. (c) 2014 The Authors. Published by Elsevier B.V. All rights reserved.

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