Study Of Decomposition Of Thermoelastic And Non-thermoelastic Martensite In Cu-Zn-Al Alloys

Abstract
Cu based alloys are considerable traditional material with good shape memory effect. Reversal thermoelastic transformation from parent phase to martensite is necessary requirement for taking place of shape memory effect. The significant phase for taking place shape memory effect in CuZnAl alloy is ordered β phase with ideal ratio of valence electrons to atom e/a = 1.48. The alloys with ratio e/a lesser than 1.42 after quenching from single phase beta region undergo non-thermoelastic martensitic transformation and thereby don’t possess shap e memory effect. This can be obtained by quenching from dual phase α + β region in some alloys. The paper deals with comparison of decomposition at elevated temperatures of thermoelastic and non-thermoelastic martensite to more stable products. Influence of stabilization of martensite on decomposition at elevated temperatures is also studied. Depending up initial state of material and condition of decomposition it could be possible to obtain structure containing α and β or γ phase with miscellaneous morphology and it could be possible to used for modification of definitive structure or for modification of structure before another heat treatment. Study of differences between thermoelastic and non-thermoelastic martensities would be useful for intensification of shape memory properties of Cu based alloys.

Note to the reader:
On page 02035-p5, several mistakes have been corrected on September 7, 2009