Method for manufacturing damage-healable resettable alloys through multi-step resetting process and resettable alloys manufactured thereby

A method for manufacturing a resettable alloy including a BCT-FCC microstructure capable of metastable reversible phase transformation, the method comprising sequentially performing the steps of:

• (a) melting alloying elements to obtain an alloy having a composition of Fe100-a-b-c-d—MnaCrbWcCd (3≤a≤15, 0<b≤11.87, 0<c≤3, and 0<d≤2.01 wt %);
• (b) heat-treating and then quenching the alloy to form a homogenized body-centered tetragonal (BCT) martensite phase;
• (c) heat-treating the alloy at a minimum temperature (T1,min(° C.)=−18×wt % (Mn)+640) or higher and a maximum temperature (T1,max(° C.)=−18×wt % (Mn)+820) or lower depending on the Mn composition of the alloy, and then quenching the alloy to form Mn segregation and a face-centered cubic (FCC) austenite precipitation phase;
• (d) heat-treating the alloy at a minimum temperature (T2,min(° C.)=−18×wt % (Mn)+820) or higher and a maximum temperature (T2,max(° C.)=0.8×Tm) or lower depending on the Mn composition of the alloy, and then quenching the alloy to eliminate the FCC austenite precipitation phase and to form a homogenized BCT martensite phase;
• and
• (e) heat-treating the alloy at a minimum temperature (T1,min(° C.)=−18×wt % (Mn)+640) or higher and a maximum temperature (T1,max(° C.)=−18×wt % (Mn)+820) or lower depending on the Mn composition of the alloy, and then quenching the alloy to reform the FCC austenite precipitation phase.