Moisés de Mattos Dias

Influence of Milling Time During the Mechanical Alloying Process on the Properties of Fe-3Si-0.75P Alloy

In this study the soft magnetic alloy Fe-3Si-0.75P (wt%) was obtained by mechanical alloying through powder metallurgy. The processing included the formulation of metallic powder, wet milling for 1 h, 3 h, 6h and 9 h, in an attritor mill using alcohol P.A. as a lubricant. Cold compaction was then performed in a floating die under 600 MPa pressure and, finally the ring-shaped test specimens were sintered at 1150 °C for 1h. The electrical, physical and magnetic properties were then analyzed using the following assays: Laser granulometry, density, metallography, hysteresis curve and AC permeability, resistivity and XRD. The results showed a strong influence of milling time on magnetic properties of the alloy. There was a decrease in grain size with the milling time, which is likely the cause of increased in magnetic properties.

Desenvolvimento de ímãs para sensor de velocidade para motor de arranque de avião

The aim of this work is develop ferrite magnets used in speed sensor for outburst motor of an airplane, manufactured by the company Aeromot (Canoas – RS). Two magnets types were requested by the company, in the cylinder form and in the ring form. For the magnets manufacturing a raw material was used with known magnetic properties, however, the obtained pieces were appraised starting from the hysteresis curve. Finally the magnets was mounted in the speed sensor prototypes, and submitted the acting tests for the Aeromot company.