Evaluation of the thermal stability of a Cu60Hf25Ti15 metallic glass

Abstract

The present letter shows how a continuous heating transformation diagram for a Cu60Hf25Ti15 metallic glass can be obtained by applying an extension of the Kissinger analysis. According to the calculation this glass is completely stable in the Earth’s climate for its lifetime. This extension of the Kissinger analysis method can be applied to any other metallic glass.

Origin of nondetectable x-ray diffraction peaks in nanocomposite CuTiZr alloys

“…The DSC curve for the as-cast rod is in good agreement with data reported in the literature. [5][6][7][8][9][10][11][12] With increasing annealing time, the enthalpy of the first exothermic peak monotonically decreases from 25 J/g for the as-cast rod to about 5 J/g for the sample annealed for 7.8 ks, while the second exothermic peak remains almost unchanged within experimental uncertainty. With further increasing annealing time, the second exothermic peak starts to decrease and its position shifts to low temperatures.…”

“…It is concluded that the as-prepared ternary samples are classified as a nanocomposite: nanocrystals embedded in an amorphous matrix. However, one experimental fact reported in the literature [5][6][7][8][9][10][11][12] still remains a puzzle for the community, i.e., no diffraction peaks from the nanocrystalline component were detected in the XRD patterns recorded for the as-cast or as-spun Cu 60 Ti 10 Zr 30 samples. In this letter, we uncover the origin of the puzzle by performing TEM, XRD and differential scanning calorimeter ͑DSC͒ measurements of asprepared and annealed Cu 60 Ti 10 20 Zr 20 samples were prepared by the meltspinning method.…”

“…However, only the x-ray diffraction ͑XRD͒ technique was applied to characterize the samples. Louzguine and Inoue 7,8 further studied the microstructures of the samples annealed at various stages using transmission electron microscopy ͑TEM͒. Formation of nanocrystals in annealed samples was observed.…”

“…[2][3][4] Very recently, the report of ternary Cu 60 Ti 10 Zr 30 and Cu 60 Ti 15 Hf 25 systems, 5,6 exhibiting excellent mechanical properties, has triggered considerable research activity in this area, especially in the microstructure of the ternary systems. [5][6][7][8][9][10][11][12] Inoue et al, 5,6 reported that bulk glassy alloys with a rod diameter of 4 mm can be formed in the ternary Cu 60 Ti 10 Zr 30 and Cu 60 Ti 15 Hf 25 systems. However, only the x-ray diffraction ͑XRD͒ technique was applied to characterize the samples.…”

Investigation of Solidification Behaviour in Cu-based Cu-Hf-Ti alloy system

“…Examinations however, focused mainly on their thermodynamical parameters, such as liquidus temperature, solidus temperature, crystallisation temperature, and the calculated data (T g , T rg , T x , ΔT x ), which are thought to represent glass forming ability (GFA) of an alloy [1][2][3][4][5][6]. Some isothermal treatments were performed by DSC at different temperatures to examine crystallization behaviour of the best glass forming composition, Cu 60 Hf 25 Ti 15 [7][8][9]. Phases that crystallized from the amorphous state were identified as binary Cu-Hf phases such as Cu 8 Hf 3 and Cu 51 Hf 14 .…”