EFFECT OF REPEATED MANDRELLING AND SUBSEQUENT HEATING ON THE CHARACTERISTICS OF SLEEVES FROM TITANIUM NICKELIDE

Alloys possessing the shape memory effect are widely used in various f ields of science, engineering, and medicine. For example, they are use d in thermomechanical couplings of pipes. As distinct from conventiona l welded or soldered joints, such joints are characterized by good rel iability and corrosion resistance, a high density of assembly, the pos sibility of connecting pipes of different materials and thicknesses, a nd absence of harmful thermal and electric effects. In Russian industr y connecting sleeves are mainly produced from alloys based on titanium nickelides TNl and TNlK. Phase transformations occur in the region of positive temperatures in the TNl alloy and in the region of negative temperatures in the TNlK alloy. In order to determine whether the slee ves can be used repeatedly, we should know how repeated mandrelling (c alibration of the openings) affects the temperature of phase transform ations in titanium nickelides and the quality of the internal surfaces of these parts. These data cannot be found in the literature. The pre sent work is devoted to this problem.