PROCESS AND MACHINE FOR DEFORMING TAPER-SHAPED ACTIVE ELEMENTS MADE OF SHAPE-MEMORY MATERIALS BY TWISTING UPON HIGH PRESSURE

摘要

The invention relates to a process for severe plastic deformation by twisting upon high pressure and high rotary speed of active elements made of shape-memory alloys of FeMnSiCr type, of tapered shape having an internal diameter of 10 mm, an external diameter of 30 mm, a thickness of 0.5 mm, an angle of 10° and to a twisting machine with high rotary speed of the upper punch. The claimed process consists in the severe plastic deformation of the active element to the final shape and size, by twisting with high rotary speed of 900 rpm under high pressure, starting from an annular half-finished product of shape-memory material in order to obtain nanometric structures to confer special properties on the material. The claimed machine comprises an electric motor () with a power of 18 kW, a hydraulic system () with cylinder-piston () in order to generate a high pressure on the half-finished product (), a fixing-guiding system consisting of a housing () in which there is guided the support of a die () as well as a key shaft punch holder () by means of radial bearings (), the components of the machine being mounted on a frame consisting of an upper plate (), a lower plate (), some guide columns () and a mobile plate (), and the entire deformation process is controlled by a system consisting of a resistive strain gauge (), a data acquisition board () and an electronic computer ().