Effect of milling time on the structure, micro-hardness, and thermal behavior of amorphous/nanocrystalline TiNiCu shape memory alloys developed by mechanical alloying

•Potential to produce B1′ (thermal- and stress-induced) and B2 was established.•Martensitic transformation occurred without the formation of intermediate R-phase.•Formation of unwanted intermetallics during heating was hindered by milling.•During milling, microhardness was increased, then reduced, and afterward re-increased.•By milling evolution, thermal crystallization steps changed from 3 to 2.