METHOD for producing thermosensitive element GRADIENT by concentration on the basis of alloys with shape memory

摘要

The invention relates to the field of metallurgy, in particular to a method for producing thermosensitive element gradient by concentration on the basis of alloys with shape memory and can be widely used in power engineering. The method involves the following operations: the first is melting of the shape memory alloy at a melting temperature Tm under the volume pressure Pv, giving to the billet of the prescribed working form at the temperature of Tf = (0,6 0,9)Tm, tempering theref from - region, deformation thereof in changing the shape of the element during cooling from temperatures in the range between beginning point (Mb) to the end point (Me) direct martensitic transformation (Mb - Me), a fixation of this form after deformation = 0.01 - 10% at temperatures Tmin = Mbmin - Memin and Tmax = Mbmax - Memax, holding at this temperature for v = 1.0 - 10.0 min., eliminating of form fixation in the temperature range Tmin = Mbmin - Memin, at that after the giving of the specified form to the working billet form on its surface alloying material(s) is/are rigidly fixed with variable weight (m) along the billet length (Lb), the billet is heated with alloying material(s) to a temperature Tb= (1.1 - 1.7) Tm. in the gas composition medium on the basis of neutral gas under the interior volume pressure Pv = 0.5 100 MPa, and the melting zone is hold fixed in a liquid state at a temperature Tls = (1.1 1.7) Tm during ls = 0.1 - 10.0 min, the billet is cooled in the range of minimum temperatures of the direct martensitic transformation Tmin = Mnmin Mkmin with the rate of V= 0,1 1,5 ° C / sec., the billet is melted the third time by moving melting zone (Lmz) along the billet at a rate of Vmz = 0,1 5,0 mm/min. at that the temperature Tmz = (1,2 1,5) Tm, melting zone is cooled from the temperature Tm with the crystallization rate Vcr = 0.01 3.0 mm/min. at the temperature gradient Tgrad = (0.1 0.9) Tm, and after the above mentioned - tempering, fixation, holding and removal of fixation, the billet is additionally load with tensile or compressing force in the temperature range Tmin = Mbmin - Memin and it is thermocycled under load of 3-50 cycles through the intervals of operating temperatures Tmin÷Tmax. The invention provides a wide and continuous range of operating temperatures, saturated degree of plastic and intense deformation.