SINTERED METALS AND ALLOYS/DEFORMATION OF POROUS FIBROUS TiNi MATERIALS

摘要

The paper examines the strain of porous fibrous TiNi materials resulting from the shape memory effect. The most intensive growth of green compacts in heating is observed at 35 to 50 deg C and stops at 90 deg C. It is shown that the strain reaches 250 percent for fibrous TiNi compacts; the porosity thus increases by a factor of 1.4 to 1.8. It is established that flexible-rigid particulate bonds and shape memory effect in combination cause a manifold increase in the strain as compared with powder TiNi or fibrous tungsten. Sintered materials showed mainly the effect of super elasticity. The total shape recovery is close to 100 percent at a strain of 10 to 20 percent and sharply decreases at a strain greater than 30 percent. The most probable cause is the Ti_4Ni_2O_x phase.