Ioan TĂUT


20-56 ASPECTE MORFOLOGICE ŞI STRUCTURALE ALE AMESTECULUI PULVERULENT Fe50Ni50 SUPUS ALIERII MECANICE

MORPHOLOGICAL AND STRUCTURAL ASPECTS
OF Fe50Ni50 POWDER MIXTURE SUBJECTED TO
MECHANICAL ALLOYING
The mechanical alloying experiment was performed inti a planetary
ball mill using elemental Fe and Ni powders mixed together at 50 wt. % ratio.
Powder samples were taken out after 1, 2, 4, 8, 16, 32, 48, and 64 hours of
milling. These samples were subjected to X-ray diffraction, sieving analysis,
and optical microscopy inspection. The results allow us to conclude that Ni
presents a ductile behaviour meanwhile Fe acts as a brittle component which
conducts to the forming of mixed particles of Ni embedding smaller Fe one. The
particle structure is more refined progressive with the milling time. Finally, the
solid solution of Fe in Ni FCC is completely formed at 64 hours of milling.
Keywords: Fe-Ni, alloy mechanical, planetary mill
Cuvinte cheie: Fe-Ni, aliere mecanică, moară planetară

56 ASPECTE MORFOLOGICE ŞI STRUCTURALE


24-15 EXTINDEREA SOLUBILITĂŢII ÎN STARE SOLIDĂ A SISTEMULUI Fe-Ni PRIN ALIERE MECANICĂ

SOLID STATE SOLUBILITY EXTINCTION OF Fe-Ni SISTEM
BY MECHANICAL ALLOYING
Experiments took place in a high energy ball planetary mill, with four
villas. There were used 46 balls having 15 mm diameter to mill 100 g powder
mixtures of Fe80Ni20, Fe70Ni30, Fe60Ni40, Fe50Ni50, Fe40Ni60, Fe30Ni70,
Fe20Ni80 (figures in mass %) in each vial. Milling space of each vial was filled
a half with balls and powder and the balls/powder mass ratio was of 8: 1. There
were taken samples (5 g of mixture powder) at 0, 1, 2, 4, 8, 16, 32, 48, and 64
hours of milling. The appeared identified phases are solid solutions of Fe(VCC)
and Ni(FCC) in the milled mixtures subjected to a minimum 2 hours of milling.
Iron is imposing its crystallizing system between 70 – 100 mass % of Fe and
nickel between 40 – 100 mass % of Ni.
Cuvinte cheie: aliere mecanică, pulberi Fe – Ni, moară planetară
Keywords: mechanical alloying, Fe-Ni powders, planetary mill

15 EXTINDEREA SOLUBILITĂŢII ÎN STARE SOLIDĂ


22-34 ASPECTE STRUCTURALE ALE AMESTECURILOR PULVERULENTE Fe60Ni40, Fe50Ni50, Fe40Ni60 SUPUSE ALIERII MECANICE

The mechanical alloying experiments were performed on a high
energy planetary ball mill. Four vials were used for powder mixtures milling.
The milling charge contains 46 steel balls having 15 mm average diameter and
100 g powder mixture. It corresponds to a charge level of ½ of the vial volume
and represents a 8:1 ball/powder ratio. The powder mixtures: Fe60Ni40, Fe50Ni50,
Fe40Ni60, were milled for 1, 2, 4, 8, 16, 32, 48 şi 64 hours. At each milling time
were taken samples for analysis (5 grams). The X-ray diffraction analysis
reveals that after 8 hours of milling the Fe peaks disappear and the Ni phase is
featured in all powder mass. The calculated crystal parameters prove that the
mechanical alloying process induces Ni structure for all powder mixtures after 8
hours of milling resulting a substitution solid solution where some Ni atoms
were replaced with Fe ones.
Cuvinte cheie: aliere mecanică, pulberi Fe Ni, moara planetară
Keywords: mechanical alloying, powder Fe Ni, planetary mill

34 ASPECTE STRUCTURALE ALE AMESTECURILOR