Showing 4 results for Melt Spinning
S. Mirzaei , A. Jazayeri Gharehbagh,
Volume 31, Issue 1 (6-2012)
Abstract
The soft magnetic nanocrystalline Fe73.5Si13.5B9Cu1Nb3 alloy (FINEMET®) is produced by heat treatment of amorphous precursor. Determining kinetic parameters of amorphous structure transformation to nanocrystalline allows the control of microstructure (e.g. size and volume fraction of nanocrystalline grains) in order to achieve desired soft magnetic properties by optimizing the heat treatment conditions. In this research, the nanocrystallization kinetics of amorphous FINEMET alloy were studied using isoconversional and isokinetic methods under non-isothermal conditions of various heating rates ranging from 5 to 20˚C/min. The changes in the microstructure and magnetic properties of amorphous ribbon during nanocrystallization process were studied using X-ray diffractometry and hysteresisgraph, respectively.
B. Binesh, A. Jazayerigharehbagh, A. R. Foroghi,
Volume 35, Issue 3 (12-2016)
Abstract
In this research, the TLP bonding of IN-738LC superalloy was investigated using MBF-20 amorphous foil produced by melt spinning process. The bonding process was carried out at 1035-1080°C for 30-60 min under the vacuum atmosphere. Microstructural investigations showed that the eutectic phases formed in non-isothermal solidified zone (ASZ) are consised of secondary phase borieds rich in nickel, chromium and nickel silicides. Nickel silicide fine precipitates are formed within γ solid solution via solid state precipitation during cooling. The centerline eutectic phases decreased with increase of the bonding time and decrease of amorphous foil thickness. It was found that isothermal solidification was completed when bonding was done at 1055°C for 30 min. However, the isothermal solidification rate decreased with increasing of the bonding temperature up to 1080°C. Unexpectedly, isothermal solidification rate decreased by increasing the tempretarure to 1080°C. The shear strength increased by completing isothermal solidification stage and eliminating brittle secondary phase particles in the centerline of bonding zone.
M. Hosseinzadeh, M. Bozorgmehr, M. Askari,
Volume 36, Issue 1 (6-2017)
Abstract
Cobalt-based amorphous alloys attracted the attention of many researchers to carry out fundamental research for their application in electronics, sensors and magnetic memory due to their special magnetic properties including close to zero Magnetostriction, magnetic permeability and high saturation magnetization. The purpose of this study is the formation and evaluation of microstructure and magnetic properties of cobalt-based amorphous alloy produced by melt spinning and mechanical alloying. The final compositions produced by both methods were studied by scanning electron microscopy, X-ray diffraction and vibrating magnetoresistance. The results showed that compound produced by chill block melt spinning has a better magnetic properties.
S. Sarafrazian, M. Tavoosi, A. Ghasemi ,
Volume 40, Issue 2 (9-2021)
Abstract
The aim of this study was optimization of the annealing process in melt spun Nd2Fe14B intermetallic magnetic alloy. In this regard, the melt spinning process was done at wheel speed of 40 m.s-1. In order to achieving the desired microstructure, the as-spun ribbons were subsequently annealed at temperature range of 500 to 700 ºC for different periods of time. Structural and magnetic characterization of produced samples were performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The results showed that the structure of as-spun ribbons at wheel speed of 40m.s-1 was composed of Fe-α, Nd2Fe14B and amorphous phases with the coercivity and saturation of magnetization in the range of 0.14 kOe and 120 emu/g, respectively. By annealing the produced ribbons and crystallization of the amorphous phase, the percentage of Fe-α and Nd2Fe14B was decreased and increased, respectively. The optimum annealing conditions for achieving the highest value of coercivity (about 9.2 kOe) was 600°C for 6h.
