Non-Isothermal Crystallization Kinetics of a Rapidly Solidified as-Cast TiZrHfNiCu High Entropy Bulk Metallic Glass

Abstract

This paper aims to investigate the thermal behavior and crystallization kinetics of TiZrHfNiCu high entropy bulk metallic glass (HE-BMG) alloy using the standard procedure of Differential Scanning Calorimetric (DSC) annealing technique. The alloy was produced using an arc melting machine with a critical diameter of 1.5 mm. The crystallization kinetics and phase transformation mechanism of TiZrHfNiCu HE-BMG was investigated under the isochronal condition at a single heating run based on the Johnson-Mehl-Avrami (JMA) theory. In isochronal heating, the apparent activation energy for glass transition and crystallization events was analyzed by Kissinger and Ozawa methods. The average activation energy value for crystallization of TiZrHfNiCu amorphous alloys in isochronal modes was 226.41 kJ/mol for the first crystallization and 297.72 kJ/mol for second crystallization stages. The crystallization mechanism of the first step was dominated by twoand three-dimensional growth with increasing nucleation rate, while the crystallization mechanism in the second stage was dominated by two-dimensional crystallization growth with a constant nucleation rate. The diffusion mechanism result proved the theory of sluggish atomic diffusion of HEA at elevated temperature.

Study of Surface Roughness of Cutting Isothermally Hardened Ductile Iron in Tosa Knife Forging Technique Based on Intelligent Calculation

“…In addition, foreign studies have been done to some extent on the Achang and their knife craftsmanship, but most of these studies were conducted on the history of the late Qing Dynasty and the World War I and II period when the British and French were stationed in Burma, and there are very few studies specifically on the Achang, and it is difficult to guarantee the quality of these studies because of the language barrier [9,10]. is study starts from the technological craft of Tosa knife, mainly using documentary research method, ephemeral and cotemporal research methods, field survey method, and application of comprehensive analysis to analyze the value of the craft, to understand the historical changes of ethnic minorities, to find out many urgent problems behind the craft, and to focus on the bloodline between ethnic groups, especially how, in the social environment of extremely flooded cultural industrialization, traditional handicrafts of ethnic minorities are more in need of inheritance and protection by today's society [11,12].…”

Carbides Formation in MarM247 Directional Solidified during Stress-Rupture Test at High Temperature

“…Recently, Nordin et al [19] used the Differential Scanning Calorimetric (DSC) technic to characterize the crystallization kinetic of a high entropy bulk samples and the average activation energy value. The DSC technic could be used to confirm the process and formation kinetics of the carbide formation presented in this paper as a future study.…”