Mechanical properties study of W/TiN/Ta system multilayers

• Published in: Journal of alloys and compounds 2017-11, Vol.725, p.283-290
• Main Authors: Zhang, Ying, Xu, Gaoyong, Wang, Yan, Zhang, Cheng, Feng, Shuaijie, Suo, Jinping
• Format: Article
• Language: English
• Subjects: Crack propagation; Cracks; DBTT; Deformation effects; Ductility; Ductility tests; Fracture mechanics; High temperature; Layered toughening; Mechanical properties; Microcracks; Multilayers; Oxidation; Plastic deformation; Protective coatings; Tensile strength; Tensile tests; W/TiN/Ta multilayers
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2017.07.115

In the present work, W/TiN/Ta system multilayers are developed and compared with W/Ta multilayers through three point bending and tensile tests. W/TiN/Ta, especially W/TiN(Ti)/Ta multilayers have much higher strength than that of W/Ta multilayers due to the intrinsic high strength of TiN and the increased layered interfaces, while with less ductility. W/TiN/Ta and W/TiN(Ti)/Ta with tTa/W = 1 also exhibit multiple cracks propagation characteristic as W/Ta, while the fracture characteristics are similar to that of W/Ta multilayers with smaller tTa/W due to lower interface strength. The plastic deformation and bridging effect of Ta layer are smaller; the interface cracking is much more intense; and more micro-cracks generated under load in these two multilayers. Their DBTT by tensile test is all about 300 °C, the ductility of W/Ta is better than W/TiN/Ta and W/TiN(Ti)/Ta above 300 °C, and reaches 37% at 400 °C, while the ductility of W/Ta decreases dramatically during 400–700 °C due to oxidation. At the whole temperature range, the ductility of W/TiN/Ta and W/TiN(Ti)/Ta is close, and keeps highest during 400–600 °C, which is about 12%. The interface of W/TiN/Ta system multilayers can be protected from serious oxidation by TiN coating at high temperature. •W/TiN/Ta system multilayers have high strength and ductility.•Comparisons were made between W/TiN/Ta and W/Ta.•Layered interface has a great effect on mechanical property.•DBTT of W/Ta and W/TiN/Ta, W/TiN(Ti)/Ta is about 300 °C.