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It was proposed in the work to use the method of furnace surfacing to produce double-layer macroheterogeneous compositions. It consists in successive impregnation of hard filler-alloy particles by two metal binder-alloys having different melting points. As a filler the Cr-TiC alloy is used, as binders the dispersion-hardening alloy of grade MNMts20-20 and hypoeutectic Fe-B-C alloy are used. As a result of impregnation a double-layer composition is produced, the layers of which are hardened by particles of the same filler, but having different composition of binder-alloy. It is shown that after furnace impregnation almost defect-free structure of double-layer compositions is formed, the porosity of which does not exceed 5-7 %. The comparison of dissolution rate of primary and peritectic phase of filler-alloy in melts based on copper and iron was made. Determined were the mechanical properties of layers of surfacing composition intended for hardening the parts operating under the conditions of non-uniform distribution of temperatures, stresses and deformations. 5 Ref. 3 Tables, 6 Figures.

Structure and properties of macro-heterogeneous composite layers produced using method of furnace surfacing were investigated. As the fillers the quasi-crystalline alloys Al-Cu-Fe, Al-Co-Cu and Al-Co-Ni were used. As the bonds the alloys based on aluminium and copper were used. It was shown that the method of furnace surfacing allows obtaining the content of quasi-crystalline icosahedral ψ-phase of not less than 30 vol.% in the structure of composite layers strengthened by Al-Cu-Fe alloy-filler, and the content of quasi-crystalline decagonal D-phase of up to 55 vol.% in the structure of composite layers with alloys-fillers Al-Co-Cu and Al-Co-Ni. The regularities of formation of interfaces between filler and bond during surfacing are explained by realization of solution-diffusive mechanism of processes of contact interaction. The primary dissolution of crystalline phases of alloys-fillers was established, which leads to penetration of molten bonds inside the filler along the boundaries of crystals of the quasi-crystalline phase. The increase in intensity of processes of dissolution of filler crystalline phases in use for surfacing of Cu-based bonds results in their complete recrystallization in the process of cooling at retaining not-dissolved inclusions of quasi-crystalline phase in the structure of composite layers. To produce the surfaced layers operating under the conditions of dry friction, the composite material based on tin bronze Br.Ots 10-2 armored by the Al-Co-Ni alloy-filler was recommended. The composite material with bond of brass L62 and alloy-filler Al-Co-Cu has the maximum resistance in oxide media. 11 Ref., 1 Table, 4 Figures.

When looking at the various manifestations of syphilis in its primary and secondary periods, the old syphilidologists noted that in individual patients they proceed differently: while in some patients the secondary period, for example, is characterized by a profuse roseless, papular or pustular rash, which is often preceded by a vigorous prodromal period of fever, in others it proceeds very sluggishly, The secondary period is characterized by an abundant rosellar, papular or pustular rash, which is often preceded by a violent prodromal period with fever, while in others it runs very sluggish, the rash is barely noticed or absent at all (so called lues sine exantheniate). Comparing then the manifestations of the secondary period with the further course of lues, many syphilidologists have come to the conclusion that a more or less violent manifestation of the primary and secondary periods of the disease exempts the patient from lesions of the nervous system, and vice versa, having mild skin manifestations during these periods are candidates for tabes and progressive paralysis.