National Research Tomsk Polytechnic University

N. V. Martyushev, Assistant Professor, е-mail: martjushev@tpu.ru

Yu. N. Petrenko, Assistant, Department of Materials Science and Technology

Seversk Technological Institute of National Research Nuclear University “MEPhI”

S. A. Petrenko, Head of Department

In the article data about application of nanopowder on a structure of coatings of the form are submitted at a casting of lead-tin bronzes. Elimination of gas porosity on a surface bronze cast preparations of high pressure compressors piston rings was the primary goal of such application protectively-dividing coverings. For experimental works mark of multicomponent bronze has been chosen. Its structure includes tin, lead, zinc and nickel. Casting from this bronze received a method of centrifugal molding. Influence of a structure of used protective—separating coating of a foundry core on a surface smoothness was probed. Compared was an action of coatings of a following composition: anti-burning-in coating (a blend of a low dispersible powder of chromium oxide with calcinated vegetable oil); anti-burning-in material ASPF-2/RgU (on the basis a low dispersible powder of graphite and the calcinated vegetable oil); the patent № 2297300 (a blend of an ultradispersible powder of dioxide of zirconium with industrial oil). Molding without use of coverings leads porosity depth to 4–5 mm and to a marriage significant amount (to 50%). Using ASPF-2/RgU completely eliminates welding casting to a casting mold, but porosity on a surface remains. Application of coverings of a casting mold containing in quality of a filler ultradisperse powders oxide metals with low heat conductivity allows to lower roughness and to eliminate gas porosity on a cast surface from lead-tin bronze. A gas time of a surface still remains, but them becomes much less and their form changes. Depth of defects doesn't exceed 1–1,5 mm that doesn't fall outside the limits the admission.

1. Martyushev N. V., Petrenko Yu. N., Egorov Yu. P. Liteynoe proizvodstvo - Foundry Engineering. 2008. No. 8. pp. 24–25.

2. Gouldsteyn Dzh., Nyuberi D., Echlin P. and etc. Rastrovaya elektronnaya mikroskopiya i rentgenovskiy mikroanaliz. Ch. 1 : per. s angl. Pod red. V. I. Petrova (Scanning Electron Microscopy and X-ray Microanalysis. Part 1 : transl. from English. Ed. V. I. Petrov). Moscow, 1984. 303 p.
3. Baradanyants V. G. Liteynoe proizvodstvo — Foundry Engineering. 1957. No. 5. pp. 10–12.
4. Konstantinov L. S. Liteynoe proizvodstvo — Foundry Engineering. 1959. No. 6. pp. 32–35.
5. Khakhalin B. D. Raboty instituta po osvoeniyu tsentrobezhnoy otlivki chugunnykh trub. Sb. VNITOL «Tsentrobezhnoe lite chugunnykh trub» (Activities of the Institute in the sphere of development of the cast-iron pipes centrifugal casting. “Centrifugal Casting of the Cast-iron Pipes” : collection of papers of the All-Union Scientific Engineering and Technical Society of Founders). Moscow, 1951. pp. 25–44.
6. Patent 2297300 RF, MPK 7 B 22 C 3/00, B 22 D 13/00. Zashchitno-razdelitelnoe pokrytie i sposob ego naneseniya (Protective separating coating and method of its application). Martyushev N. V., Melnikov A. G., Egorov Yu. P. ; Gosudarstvennoe obrazovatelnoe uchrezhdenie vysshego professionalnogo obrazovaniya Tomskiy politekhnicheskiy universitet (State Educationsl Institution of Higher Professional Education Tomsk Politechnic University). No. 2005139121/02 ; asserted 12.14.2005 ; published 04.20.2007. Bulletin No. 11.