Cylinders of TiNi shape-memory alloy were synthesized from mixtures of equiatomic fine irregular titanium and nickel powders by explosive-wave compression with a detonation velocity of about 6500 m s(-1). B2 type parent phase, R phase, B19’ type martensite, Ti2Ni, Ti3Ni4 and Ti2Ni3 phases were observed in this as-synthesized material. In the B2 matrix high density dislocations existed. The Burgers vectors of many dislocations were determined to be parallel to [111] directions. The R phase variants formed (001) B2 twinning structure. The substructure of the B19’ martensite was (001) B19’ type I twin and stacking faults on the (001) B19’ plane. When increasing the temperature of the as-synthesized material in a differential scanning calorimeter, no B19’ --> R --> B2 transitions were observed on the temperature range -50 to 100 degrees C. However, B2 --> B49’(R) transitions occurred during the cooling cycle. After heat treating the specimen at 800 degrees C for 1 h and then ageing at 400 degrees C for 10 min, both B2 --> R --> B19’ and B19’(R) --> B2 phase transitions were observed.