Dilatometry and X-ray measurements have been used for more detailed phase analysis of intermetallic alloys (Ni2Cu)(0.775)Sn-0.225 and Ni2CuSn. In the first alloy there exist two transformation processes (alpha + 2H)<---->(alpha + 2H + DO3)<---->(alpha + DO3) with the transformation temperature 505 degrees C and 595 degrees C. In Ni2CuSn alloy the transfomations (alpha + DO3 + 2H)<---->(alpha + DO3)<----> DO3 take place at 520 degrees C and 785 degrees C.