# Wear Properties of Sc-Bearing Zr-Based Composite BMG with Nano-CuZr\({}_{2}\) under Lubrication
## 4 Conclusions  
The original glassy (Zr\({}_{55}\)Cu\({}_{30}\)Ni\({}_{10}\)Al\({}_{5}\))\({}_{99.98}\)Sc\({}_{0.02}\)/CuZr\({}_{2}\) nanocrystal composite structure remained the same without phase transformation during the wear test under 440C disk with oil lubrication and 20 N loads. Because of the intrinsic softness of the Sc-bearing Zr-based composite BMG, (Zr\({}_{55}\)Cu\({}_{30}\)Ni\({}_{10}\)Al\({}_{5}\))\({}_{99.98}\)Sc\({}_{0.02}\)/CuZr\({}_{2}\), its wear tracks and worn surface underwent severe deformation. This deformation behaviour resulted in a higher wear coefficient and wear rate than those of the (Cu\({}_{55}\)Zr\({}_{40}\)Al\({}_{5}\))\({}_{98}\)Er\({}_{2}\) composite BMG. The worn composite BMG particles entrapped at the interface remained a constant number, leading to a constant friction coefficient of approximately 0.25 for the Sc-bearing Zr-based composite BMG; this friction coefficient was independent of the sliding velocity. CuZr\({}_{2}\) is harder than Zr-based (Zr\({}_{55}\)Cu\({}_{30}\)Al\({}_{10}\)Ni\({}_{5}\))\({}_{99.98}\)Sc\({}_{0.02}\) bulk amorphous matrix. Therefore, it is an attractive bearing and shaft material for industrial application. Conceptualization, editing and funding acquisition, S.-H.W. ; supervision and methodology, C.-C.C. ; investigation and analysis, H.-H.C.; TEM investigation, R.-T.H. ; conceptualization, H.-Y.C. ; typing and plot, C.-A.H.; review and editing, P.K.L. All authors have read and agreed to the published version of the manuscript. This research received funding support from the MOST (Ministry of Science and Technology) of Taiwan under grants MOST 108-2221-E-019-036 and MOST 109-2221-E-019-047. The authors declare no conflict of interest. * _[PERSON] et al. (2004)_ [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Wear resistance of Zr-based bulk metallic glass applied in bearing rollers. _Mater. Sci. Eng. A_**2004**, _386_, 326-330. [CrossRef]
* _[PERSON] et al. (2008)_ [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Wear behavior of a series of Zr-based bulk metallic glasses. _Mater. Sci. Eng. A_**2008**, _475_, 124-127. [CrossRef]
* _[PERSON] et al. (2001)_ [PERSON]; [PERSON]; [PERSON]; [PERSON] Sliding behavior of metallic glass: Part I. Experimental investigations. _Wear_**2001**, _250_, 409-419. [CrossRef]
* _[PERSON] et al. (2007)_ [PERSON]; [PERSON]; [PERSON]; [PERSON] Tribological behaviour of Cu\({}_{60}\)Zr\({}_{30}\)Ti\({}_{10}\) bulk metallic glass. _Mater. Sci. Eng. A_**2007**, _458_[PERSON] 290-294. [CrossRef]
* _[PERSON] et al. (1990)_ [PERSON]; [PERSON]; [PERSON] Ultrahigh tensile strengths of Al\({}_{88}\)Y\({}_{2}\)Ni\({}_{9}\)M\({}_{1}\) (M = Mn or Fe) amorphous alloys containing finely dispersed fcc-Al particles. _Mater. Trans. JIM_**1990**, _31_, [PERSON]. [CrossRef]
* _[PERSON] et al. (1991)_ [PERSON]; [PERSON]; [PERSON]; [PERSON] Mechanical properties of partially crystallized aluminum based metallic glasses. _Scr. Metall. Mater._**1991**, _25_, 1421-1424. [CrossRef]
* _[PERSON] et al. (1988)_ [PERSON] [PERSON]; [PERSON]; [PERSON] [PERSON] New Fe-based soft magnetic alloys composed of ultrafine grain structure. _J. Appl. Phys._**1988**, _64_[PERSON] 6044-6046. [CrossRef]
* _[PERSON] et al. (1990)_ [PERSON]; [PERSON] [PERSON]; [PERSON]; [PERSON]; [PERSON] High saturation magnetization and soft magnetic properties of bcc Fe-Zr-B alloys with ultrafine grain structure. _Mater. Trans. JIM_**1990**, _31_[PERSON] 743-746. [CrossRef]
* _[PERSON] et al. (1984)_ [PERSON]; [PERSON]; [PERSON]; [PERSON] Pr-Fe and Nd-Fe-based materials: A new class of high-performance permanent magnets (invited). _J. Appl. Phys._**1984**, _55_, 2078-2082. [CrossRef]
* _[PERSON] et al. (2002)_ [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] Magnetic properties and microstructural characteristics of bulk Nd-Al-Fe-Co glassy alloys. _Intermetallics_**2002**, _10_, 1215-1219. [CrossRef]
* [PERSON] (1997) [PERSON] Bulk amorphous alloys with soft and hard magnetic properties. _Mater. Sci. Eng.