Microstructure, mechanical and anti-corrosion property evaluation of iron-based thin ﬁlm metallic glasses Li-Ting Chen a , Jyh-Wei Lee b,c, ⁎, Yung-Chin Yang a , Bih-Show Lou d , Chia-Lin Li e , Jinn P. Chu f a Institute of Materials Science and Engineering, National Taipei University of Technology, Taipei, Taiwan, ROC b Department of Materials Engineering, Ming Chi University of Technology, New Taipei, Taiwan, ROC c Center for Thin Film Technologies and Applications, Ming Chi University of Technology, New Taipei, Taiwan, ROC d Chemistry Division, Center for General Education, Chang Gung University, Taoyuan, Taiwan, ROC e Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei, Taiwan, ROC f Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, ROC abstract article info Available online xxxx Keywords: Fe–Zr–Ti Thin ﬁlm metal glass Supercooled liquid region Nanoindentation HRC-DB test Potentiodynamic polarization test Thin ﬁlm metallic glasses (TFMGs) represent a class of promising engineering materials for structural applications. Despite the effort that has been made in the development of TFMG materials, the iron-based thin ﬁlm metallic glasses fabricated by sputtering have gained limited attention. In this work, ﬁve iron-based Fe–Zr–Ti thin ﬁlm metallic glasses with different Fe contents ranging from 37.6 to 49.8 at.% were prepared by magnetron co-sputtering system using pure Fe, Zr and Ti targets. Through XRD and TEM analyses, the amorphous phase was conﬁrmed for each coating. The glass transition temperature (T g ) and crystallization temperature (T x ) of TFMG increased with increasing Fe content and reached 963 K and 989 K, respectively, when Fe content was 49.8 at.%. The supercooled liquid region was around 26.3 to 51.6 °C, which was shown to be unrelated to Fe concentration. The hardness, elastic modulus, and H/E ratio of TFMGs increased with increasing Fe concentration. Based on the HRC-DB test, adequate adhesion quality was obtained for all TFMGs. The corrosion resistance of TFMGs also increased with increasing Fe content and spontaneous passivation behavior was discovered due to the large content of Zr and Ti valve metals. Nevertheless, the corrosion resistance of Fe–Zr–Ti TFMGs was strongly inﬂuenced by surface defects. A series of high hardness Fe–Zr–Ti thin ﬁlm metallic glasses with good adhesion property and adequate corrosion resistance was reported in this study. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The research and development of amorphous bulk metallic glass (BMG) materials have been highlighted by researchers and industries due to their unique properties, such as high hardness, good wear and corrosion resistance [1,2] for the last few decades. Among a number of BMG alloy systems, the Fe-based BMGs have attracted great interest since 1995 [3] due to their high mechanical properties, excellent wear resistance, good corrosion resistance, and relatively cheap material cost [3–7]. For example, rather high hardness and elastic modulus, around Hv900 and 150 GPa and Hv1200–1300 and 170 GPa, were re- ported for Fe-P and Fe-B BMGs, respectively [1]. The micro hardness for Fe 40 Ni 38 Mo 4 B 18 and Fe 77 Cr 2 B 16 Si 5 BMG ribbons are Hv885 and Hv858, respectively [8]. On the other hand, the hardness and elastic modulus for Fe 74 Ni 4 Mo 3 B 17 Si 2 and Fe 77 Cr 2 B 16 Si 5 BMG are Hv990 and higher than 60 GPa, Hv860 and 58 GPa, respectively [9]. Extremely high elastic moduli of approximately 180–200 GPa and microhardness of approximately 13 GPa have been reported [10]. Meanwhile, excellent anti-corrosion behavior of Fe 41 Co 7 Cr 15 Mo 14 C 15 B 6 Y 2 BMG [11] and Fe 71.4 - x C 7.1 Si 4.4 B 6.5 P 8.6 Cr x Al 2.0 BMG [12]was investigated and showed that the addition of Cr played a critical role for the enhancement of corrosion resistance for Fe-based BMGs. In addition, an excellent anti-corrosion Fe-based Fe 41 Ce 15 Co 7 Mo 14 C 12 B 9 Y 2 BMG with large glass forming ability has been developed recently [13]. The brittleness of Fe-based BMGs below the glass transition temper- ature (Tg) restricts their applications in industries [14]. The Fe-based metallic glass coatings fabricated by thermal spraying process [15–17] or by sputtering [18,19], however, provide applicable routes to overcome its brittle problem. High hardness and excellent corrosion resistance have also been reported for the thermal sprayed Fe-based coatings [19–22]. In this work, the newly developed Fe–Zr–Ti thin ﬁlm metallic glasses with different Fe contents were prepared by magnetron co-sputtering system using pure Fe, Zr and Ti targets. Reasons for selection of Zr and Ti elements are due to their biocompatibility and frequent use as main constituents of TFMG and BMG materials. The aim of this study is to in- crease the understanding of the new Fe–Zr–Ti thin ﬁlm metallic glass Surface & Coatings Technology xxx (2014) xxx–xxx ⁎ Corresponding author at: #84 Gungjuan Rd., Taishan, New Taipei City 24301, Taiwan. E-mail address: jefﬂee@mail.mcut.edu.tw (J.-W. Lee). SCT-19575; No of Pages 10 http://dx.doi.org/10.1016/j.surfcoat.2014.07.039 0257-8972/© 2014 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Surface & Coatings Technology journal homepage: www.elsevier.com/locate/surfcoat Please cite this article as: L.-T. Chen, et al., Surf. Coat. Technol. (2014), http://dx.doi.org/10.1016/j.surfcoat.2014.07.039