High coercivity, anisotropic, heavy rare earth-free Nd-Fe-B by Flash Spark Plasma Sintering

Flash (Ultra-Rapid) Spark-Plasma Sintering of Silicon Carbide

A new ultra-rapid process of flash spark plasma sintering is developed. The idea of flash spark plasma sintering (or flash hot pressing - FHP) stems from the conducted theoretical analysis of the role of thermal runaway phenomena for material processing by flash sintering. The major purpose of the present study is to theoretically analyze the thermal runaway nature of flash sintering and to exp...

High coercivity rare earth–cobalt films

COERCIVITY AND THERMAL REMAGNETIZATION OF SINTERED Nd-Fe-B

Statistical methods are used to estimate coercivity J Hc and thermal remagnetization of uniaxially nucleationcontrolled permanent magnetic materials. Sintered Nd-Fe-B consists of the tetragonal magnetic Nd2FelrB phase with a volume fraction w = 80 % and of nonmagnetic phases. At temperatures above T, rz 150 K the tetragonal axis is the easy direction of magnetization [I]. It is well known [2] t...

Fabrication of Nanostructured Cu matrix Nanocomposites by High Energy Mechanical Milling and Spark Plasma Sintering

Spark plasma sintering (SPS) is a sintering process that is capable of sintering hard worked powders in short times. This technique was used to fabricate bulk Cu and Cu-SiC nanocomposites. Pure Cu and mixed powders of Cu including 4 vol% of SiC nanoparticles were mechanically alloyed for 25 h and sintered at 750˚C under vacuum condition by SPS method. Microstructures of the materials were chara...

Analysis Technique for Improving Coercivity of Nd-Fe-B Magnets and Development of Dy-free Magnet

Hiroyuki Yamamoto, Dr. Eng. Isao Kitagawa, Dr. Sc. Teruo Kohashi, Dr. Sc. Akira Sugawara, Dr. Eng. Takeshi Nishiuchi, Dr. Eng. OVERVIEW: Hitachi is working to improve the performance of the NdFe-B magnets that help make people’s way of life more energy efficient and reduce the load it places on the environment. To study the factors that govern coercivity, an important parameter of magnet perfor...