Student:	Kürşat İCİN
Supervisor:	Prof. Dr. Sultan ÖZTÜRK
Department:	Metalürji ve Malzeme Mühendisliği
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University Turkey

Title of the Thesis:	PRODUCTION OF Nd-Fe-B PERMANENT MAGNET WITH MELT SPINNING METHOD AND INVESTIGATION OF THEIR STRACTURAL AND MAGNETIC PROPERTIES
Level:	M.Sc.
Acceptance Date:	7/6/2016
Number of Pages:	161
Registration Number:	i3058

Summary:

In this study, Nd15Fe77B8 hard magnetic alloy powders were produced with melt

spinning method and the produced powders were milled with high energy ball milling

method under vacuum atmosphere with addition of surface reactant material. The

morphologic, microstructural, thermal and magnetic properties of produced powders were

investigated. The Nd15Fe77B8 magnetic alloy powders were produced by the copper wheel

having different surface properties (smooth and texture) and surface temperatures (20 °C

90 to 390 minutes. The shapes of produced powders changed with wheel properties. Fiber

and flaky shaped powders were produced with smooth surface wheel and spherical shaped

powders were produced with the surface textured wheel. The cooling rates of produced

powders changed with powder size and with wheel surface temperature. The cooling rate of

5 μm thick flaky shaped powders produced with smooth surface wheel at room temperature

The microstructure of produced powders consisted with different phases such as Nd2Fe14B

hard magnetic phase, soft magnetic α-Fe phase and Nd-rich phase. The Curie temperatures

and coercivities of produced powders significantly changed with high energy ball milling

and the values increased with decreasing powder size. The maximum Curie temperature and

coercivity values were obtained as 346 °C and 4,375 kOe for smooth surface wheel with -5

Key Words: Nd15Fe77B8 hard magnetic alloy, Melt spinning method, Surfactantassistant

ball milling