Elastocaloric effect in a rapidly quenched Ti$_2$NiCu alloy at a periodic action of a stretching force at frequencies to 50 Hz

The elastocaloric effect (ECE) is studied in samples of rapidly quenched ribbons of a Ti$_2$NiCu alloy at a periodic action by a mechanical stress to 300 MPa at a frequency to 50 Hz. ECE is maximal near the temperatures of a first-order thermoelastic martensitic phase transition. The ECE maximum is observed in a point corresponding to the completion of the reverse martensitic transition ($T$ = 67.5$^{\circ}$C) and is 21 and 6 K at cyclic mechanical loads of 300 and 100 MPa, respectively. The ECE value is shown to be independent of the frequency of the external loads in the range from 0 to 50 Hz. The specific power of a rapidly quenched ribbon as a thermal energy transformer is estimated at the external mechanical stress of 100 MPa; its value is 150 W/g at a frequency of 50 Hz and ECE is 6 K.