Journal of Materials Science, Vol.31, No.10, 2767-2773, 1996
Effect of NiAl Precipitation on Shape Recovery of Cuznalni Alloy
In a CuZnAl alloy containing 2.2 wt% of nickel it was found that due to alloy quenching and low temperature ageing, precipitation of NiAl disperse particles takes place resulting in raising of martensitic transformation characteristic temperatures. The ease with which this phase precipitates indicates the low thermal stability of this alloy. At the same time the process of precipitation of NiAl particles offers an opportunity for control of shape recovery temperature by varying quenching temperature, cooling rate and especially ageing time, since variations of characteristic temperatures as a function of ageing time can be expressed by the relation Delta T = At-0.5. It was also ascertained that the two way shape memory effect, as opposed to the one-way effect, is sensitive to processes associated with alloy ageing and also matrix phase transition in the bainite.
Keywords:ZN-AL ALLOYS;CU-ZN;MARTENSITIC-TRANSFORMATION;MEMORY ALLOYS;GRAIN-REFINEMENT;TEMPERATURE;PHASES