In this work, a functionally graded Ti-Ni alloy was fabricated using directed energy deposition by depositing Ti-rich Ti-Ni alloy section on near-equiatomic TiNi substrate to demonstrate multi-sectional microstructural, thermal, and mechanical behaviors for multifunctionality. The aging effect at 400 °C with various heat treatment time durations on the graded Ti-Ni alloy was applied. Materials characterization indicated that the two sections demonstrate different responses under various aging treatments, which provided more possible combinations of functional properties in a joined component. This work shows a powerful potential application in using directed energy deposition to fabricate multifunctional smart alloys followed by aging treatment.