Introductory course in "new materials related to energy utilization". 2. Metal : magnetic materials, "materials for permanent magnet".

Permanent Magnet Materials

Rare-earth Permanent Magnets: New Magnet Materials and Applications

The introduction of rare-earth permanent magnets based on samarium-cobalt in about 1970, and neodymium-iron-boron magnets in the mid-nineteen eighties, has ushered in a new era in hard magnetic materials. This has resulted in a dramatic improvement in permanent magnet performance, with neodymium-iron-boron (Nd2Fe14B) magnets having a magnetic energy product up to an order of magnitude greater t...

The Introductory Materials Science and Engineering Course

The introductory materials science and engineering course offered at the college/university level is, for many instructors, very difficult to design and to teach. This presentation discusses challenges for the course, as well as several problematic issues to include: course content, course organization, and course mechanics. The results of two surveys of engineering faculty are presented and di...

Reversal mechanism in permanent magnetic materials

The phenomenon of magnetization reversal in a hard magnet is studied analytically within a framework of a simplified energy minimization model for a two grain system. The transition region ~a domain wall-like moment structure! is found to play a crucial role in nucleating a reversed domain and in the subsequent formation of a domain wall near the grain boundary. This is shown to result in a con...

NEW REFRACTORY MATERIALS FOR THE COPPER INDUSTRY

Wear of various basic refractory materials to substitute to currently used magnesia chrome bricks has been studied, measuring matte and slag penetration and dissolution, through different cup and rotary slag tests. High magnesia with and without impregnation, magnesia graphite, magnesia-alumina spinel with and without impregnation, olivine-magnesia and olivine magnesia- graphite bricks, as well...