IDEA #7MLA36 Metallic Materials With Elements Of Self-Organization For Operation In Extreme Conditions

APPLIED RESEARCH • NEWMATERIALS RESEARCH METALLIC MATERIALS WITH ELEMENTS OOFF SELF(cid:2)(cid:2)ORGANIZATION FOR OPERATION IINN EXTREME CONDITIONS Description Areas ooff Application High(cid:2)loaded mechanisms working in conditions of dry or semi(cid:2) dry friction at multicyclic loads. Space mechanisms: gearings and sliding bearings used in the control systems of supervision devices over the Earth and planets, and also solar batteries and Planetokhods. Pic.1 The lower bush of the steering connection. Stage ooff Development It is accessible to demonstration. The material specimens and inserts for trolley(cid:2)bus steering rod are made and tested. Contact Details Frantsevich Institute for Problems of Materials Science of the National Academy of Science of Ukraine (IPMS of NASU) Contact persons: Kostornov Anatoly Frolov Gennady 3, Krzhizhanovski Street, Kiev(cid:2)142, 03680, Ukraine. Tel.: +380(44) 424(cid:2)0492 Fax: +380(44) 424(cid:2)2131 E(cid:2)mail:g_frolov@i(cid:2)c.com.ua; g_frolov@nbi.com.ua YUZHNOYE State Design Office Contact person: Tykhyy Viktor 3, Krivorozhskaia Street, Dnipropetrovsk, 49008. Ukraine. Telephone: +380(562) 92(cid:2)5027 Fax: +380(562) 770(cid:2)0125, E(cid:2)mail: info@yuzhnoye.com Under the conditions of space vacuum, the mechanisms that ensure wear resistance of materials under friction do not take place, because of absence of the gas environment. At dry fric(cid:2) tion in vacuum the plastic strain accumulates and rapid seiz(cid:2) ing processes occur. For gearings used in control systems of space mechanisms are offered wear(cid:2)resistant materials with elements of self(cid:2) organization of structure during friction for gearings. Introduction of МехSey chalcogenid compounds in a iron or, for example, titanic alloy is a necessary condition of self(cid:2) organizing of a material during which are formed the dissipa(cid:2) tive structures disseminating external energy streams. As for(cid:2) mation of the dissipative structures with dynamic character of stability basically occurs in zones of the material’s structure defects, arising at friction it is possible to explain significant decrease of its deterioration by curing of these defects. Innovative Aspect and Main Advantages Substantial increase of wear resistance of materials with ele(cid:2) ments of self(cid:2)organiation is explained by formation of dissipa(cid:2) tive structures under influence of the energy streams exceed(cid:2) ing some critical value. At triboactivation, dispersion of energy occurs owing to topochemical reactions between the entered additives (for example, chalcogenides) and a material basis. The chalcogenides are not stable compounds at the elevated temperature and could be decomposed during friction of the heterogeneous material. The product of the decomposition provides a self(cid:2)sustained oscillation chemical reaction with components of the base. The existence of such reactions was confirmed by thermokinetic method using local control of ther(cid:2) mo(cid:2)EMF through thermocouples and by mass(cid:2)spectrometry. Comparative tests of materials with self(cid:2)organization ele(cid:2) ments and of their equilibrium analogs have revealed that addition of 1 vol. % of chalcohenide that allows realization of the self(cid:2)organization processes in composite materials, results in a decrease wear rate of high(cid:2)strength titanium alloy by a few times with increase in sliding velocity and load. Thus, dependence of friction factor and wear on sliding velocity essentially varies. These materials can be used not only in a vacuum but in air also. For example, inserts have been manufactured from the iron(cid:2)based material with self(cid:2)organization elements for trolley(cid:2) bus steering rod with exploitation capacity of up to 4 t load and 107 work cycles. These inserts have been tested and a con(cid:2) siderable increase in service life by a factor of 10 compared with their analogs have been established. These composite materials represent so(cid:2)called “smart” mate(cid:2) rials, i.e. those materials the properties of which change in relation to the work conditions and are able to adapt to the specific conditions. Such materials have complex composition and can be manufactured only by powder metallurgy technol(cid:2) ogy. YUZHNOYE State Design Office, which is a collaborator of this work, created a special test bench for accelerated definition of a friction coefficient and a wear at large loading. It can be used for testing a broad spectrum of loaded friction units of trans(cid:2) port machines. 20