In a separate paper, we reported the ability to form metallurgical joints between Nitinol components using a novel reactive eutectic brazing procedure that employs niobium as the braze filler metal. Using this joining technique together with post-braze annealing, joints with tensile strengths as high as 770 MPa were highly reproducible. Scanning electron microscopy revealed eutectic micro-constituents as the predominant microstructure in the joints. However, discontinuous Ti₂Ni-type precipitates were occasionally observed. The formation of such Ti-rich phase, which is commonly associated with the presence of oxygen, occurred despite the removal of native oxides on all Nitinol components before brazing and performing the brazing under high-vacuum. The presence of embrittling Ti₂Ni-type precipitates provides the motivation to explore ways to improve the joint mechanical and microstructural properties. Two strengthening mechanisms were explored: (1) dispersion-hardening and (2) solution-hardening. Temperature-evolution study of the joint microstructures show that the hard and brittle Ti₂Ni-type phase can be re-solutionized into the eutectic micro-constituents at elevated temperatures, suggesting the potential of dispersion hardening. Solution-hardening through micro-alloying of the joints with tungsten and zirconium were observed at the micro-level when the mechanical properties were probed by indentation techniques. Microstructural study indicated that Ti₂Ni-type phase suppression is possible with zirconium-doping. Finally, we report the potential use of vanadium as a braze filler alternative to niobium. Scanning electron microscopy also revealed the joint microstructure to be predominantly eutectic micro-constituents. Preliminary indentation studies and tensile experiments indicated that the V-based joints may have superior mechanical properties compared to the Nb counterparts.