SINGLE-CRYSTAL EMITTER SHELL AND METHOD OF ITS MANUFACTURE

摘要

FIELD: power industry.SUBSTANCE: group of inventions relates to electric generating channels (EGC) of the thermionic nuclear power plant (NPP), and can be used for development and manufacture of emitter shells of long-life EGCs for NPPs with thermal and intermediate neutrons reactors. The single-crystal emitter shell is a substrate from the strengthened Mo alloy - (3-6) wt % of Nb which has the following series applied layers: W - (1-3.5) wt % Nb 100-300 mcm thickness and W emission coating. The method of manufacture of the emitter shell includes the electron beam crucibleless zonal melting of a substrate from Mo - (3-6) wt % of Nb and application on its external surface of W layer - (1-3.5) wt % of Nb by the method of chemical transport reactions in the reactionary device by thermal decomposition of W and Nb chlorides on a heated substrate, at continuous withdrawal of exhaust gas mix from the reactionary device. The subsequent application of the emission W coating is performed without flowing of gas mix in the closed mode of the reactionary device. Thus for application of W layer - (1-3.5) wt % of Nb and the emission W coating the reactionary device is used with a possibility of switching in a single process from the flow mode to the gas mix flowless mode.EFFECT: increase of EGC service life by criterion of allowable diametrical deformation of the fuel element shell due to reduction of speed of creep of the emitter shell.3 cl, 3 dwg