Optimization of layered microstructure and mechanical properties of Ni-Al alloy based on FRSIP

To address the application requirements for hard-to-deform Ni-Al alloy thin-walled components prepared by forming and reaction synthesis integrated process (FRSIP), this study investigates the preparation process and performance optimization of alloy sheets based on laminated foils. The alloy with an alternating layered structure of Ni/Ni₃Al and Ni₃Al was designed and prepared. The alloy demonstrated tensile strengths of 824.0 MPa at room-temperature (RT) and 116.8 MPa at 1000 °C, with corresponding elongations of 18.0% and 18.5%, respectively. By analyzing the microstructural evolution within the individual layers of the Ni–Al alloy, the transformation mechanism of Ni₃Al from granular grains to large lamellar precipitates was revealed, and its correlation with mechanical properties was established. Furthermore, the performance was optimized by replacing pure Al foil with Al(B) alloy foil and the results showed that boron (B) segregated at the Ni₃Al interlayer interfaces. Compared with the Ni-Al alloy, the RT strength of Ni-Al-B alloy was increased by approximately 9% and the elongation was also increased by 26.7%, while enhancing the high-temperature (1000 °C) strength by 22.7%. In addition, the strengthening and plasticizing mechanism resulting from B addition was thoroughly discussed.