Glass Formation of Null-Matrix Cu-Hf-(Zr, Ti) Alloys
Por:
Lozada-Flores, Octavio, FIGUEROA, IGNACIO ALEJANDRO
Publicada:
1 ene 2019
Resumen:
An approach following the null-matrix, Ti/Zr ratio of 2.08, for neutron
diffraction was used to calculate the glass formation in Cu-Ti-(Hf,Zr)
alloys. The Cu55Zr14.6Ti30.4, CU61.48Hf18.52Zr6.48Ti13.52, Cu-58(.1)
Hf(16.9)Zr(8.1)Ti(1)(.)(69)( )and Cu52.46Hf14.2Zr10.8Ti22.54
compositions (at. %), were calculated and prepared by argon arc
melting. Copper die suction casting was employed to produce conical
shaped samples with diameters decreasing from 8 mm to 1 mm. X-ray
diffraction and Neutron Diffraction were used to characterize the alloys
with the aim of obtaining the critical glassy diameter, dc, of the
alloys. The results showed the composition with the biggest d(c) was the
CU(61)(.48)Hf(18.52)Zr(6.)(48)Til(3.)(52) 352 alloy, with dc = 6 mm.
Thermal parameters were obtained by differential scanning calorimetry
and the maximum values for glass transition temperature, T-g, (747 K),
crystallization temperature, T-x, (772 K), solidus temperature, T-m,
(1152 K) and liquidus temperature, T-1, (1230 K) corresponded to the
CU(61)(.48)Hf(18.52)Zr(6.)(48)Til(3.)(52 )composition. The results also
showed that the parameters obtained from thermal analysis did not
correlate with the GFA obtained. However, a good correlation of GFA and
d was found by means of the topological model, where the highest %
packing efficiency (53.57 %) was found for the
CU61.48Hf18.52Zr6.48Ti3.52 alloy, which also showed the highest d value
with 6 mm.
Filiaciones:
Lozada-Flores, Octavio:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Coyoacan, Ciudad De Mexic, Mexico
FIGUEROA, IGNACIO ALEJANDRO:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Coyoacan, Ciudad De Mexic, Mexico
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