A calorimetric study of alloys along the section TiZn3-TiAl3 is carried out to determine their heat of formation (Δf H{ring operator}) at 300 K using a high temperature direct drop calorimeter. The target compositions of the alloys lie in the range of 10-65 at.% Al. The structure and composition of the reacted samples are characterized by X-ray diffraction and electron probe microanalysis. The following values of Δf H{ring operator} (in kJ/mol-atom) at 300 K are obtained (by interpolation) for L 12- Ti(Zn,Al)3 solid solution: -27±1 (at Ti25Zn65Al10), -30±1 (at Ti25Zn55Al20), -32±1 (at Ti25Zn45Al30), -34±1 (at Ti25Zn35Al40), -35±1 (at Ti25Zn25Al50) and -36±1 (at Ti25Zn15Al60). Calorimetric data are compared with the formation energy of L 12- Ti(Zn,Al)3 alloys calculated from first-principles and sublattice cluster expansion, showing a very good agreement. Stabilization of L 12- Al3Ti, by substituting Zn for Al, offers a potential to introduce it as strengthening precipitates in Al alloys.

A calorimetric study of alloys along the Ti(Zn,Al)3 section

DELSANTE, SIMONA;BORZONE, GABRIELLA
2009

Abstract

A calorimetric study of alloys along the section TiZn3-TiAl3 is carried out to determine their heat of formation (Δf H{ring operator}) at 300 K using a high temperature direct drop calorimeter. The target compositions of the alloys lie in the range of 10-65 at.% Al. The structure and composition of the reacted samples are characterized by X-ray diffraction and electron probe microanalysis. The following values of Δf H{ring operator} (in kJ/mol-atom) at 300 K are obtained (by interpolation) for L 12- Ti(Zn,Al)3 solid solution: -27±1 (at Ti25Zn65Al10), -30±1 (at Ti25Zn55Al20), -32±1 (at Ti25Zn45Al30), -34±1 (at Ti25Zn35Al40), -35±1 (at Ti25Zn25Al50) and -36±1 (at Ti25Zn15Al60). Calorimetric data are compared with the formation energy of L 12- Ti(Zn,Al)3 alloys calculated from first-principles and sublattice cluster expansion, showing a very good agreement. Stabilization of L 12- Al3Ti, by substituting Zn for Al, offers a potential to introduce it as strengthening precipitates in Al alloys.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11567/218232
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 11
  • ???jsp.display-item.citation.isi??? 8
social impact