The issue of strength analysis as well as foreknowledge of component and structure life is of interest at this time for new composite materials. New composite materials and alloys elastic response is often unknown, and standard methods for their determining can not be applied to, e.g. materials featuring surface gradient properties. Elasticity modulus method of examination is based on stepwise removal of part of the material from the rod sample surface or application of a coating onto the sample surface. Each step is accompanied by measurement of the sample lateral dimensions, and density. To determine Young´s modulus, resonance frequencies of the sample subjected to forced longitudinal vibrations are measured using an ultrasonic device. The device principle of operation is based on excitation and tracking of the sample forced mechanical oscillations close to its own frequencies, measurement of resonance peak parameters followed by calculations of the Young´s modulus. To induce and track the forced oscillations in the sample, use is made of piezoelectric transducers attached to damped acoustic transmission rods, while the sample is fixed between pointed rod ends. This arrangement makes it possible to examine also Young´s modulus temperature dependences. Young´s modulus measurement results for case-hardened hard alloy are provided. It is shown that Young´s modulus of surface layers is lower than that of the base material, which is explained by formation of new compounds in the surface layers owing to chemical and diffusion reactions between an alloying element and alloy components. The doped layer extends to 0.45 mm. The results obtained can be used for strength calculations of case-hardened materials, estimation of cohesive and adhesive strength of individual layers of coatings, structure and other physical and mechanical properties of materials.
technical condition, multilayer element, aircraft construction, border of the defect, temperature contrast
1. Barvinok V. A., Bogdanovich V. I., Vasil´eva V. G. i dr. Sposob opredeleniya modulya uprugosti materialov / Avt. svid. SSSR № 1078315. 1984.
2. Shiryaev A. M., Pashkin V. A. i dr. K metodike izmereniya moduley uprugosti tonkikh plenok i pokrytiy. - Zavodskaya laboratoriya. 1991. № 7. S. 45-47.
3. Kompozitsionnye materialy / Pod red. L. Brautmana, R. Kroka. T. 4. Kompozitsionnye materialy s metallicheskoy matritsey / Red. K. Kreyder; per. s angl. pod red K. I. Portnogo. - Moskva: Mashinostroenie, 1978. - 502 s.
4. Metallovedenie i termicheskaya obrabotka stali / Sprav. izd. v 3-kh t.// Pod red. M. L. Bernshteyna, A. G. Rakhshtada. T.1. Metody ispytaniy i issledovaniy. - M.; Metallurgiya, 1991. - 462 s.
5. Samsonov G. V., Verkhoturov A. D., Bovkun G. A., Sychev V. S. Elektroiskrovoe legirovanie metallicheskikh poverkhnostey. - Kiev: Naukova dumka, 1976. - 219 s.
6. Vlasov V. M. Rabotosposobnost´ uprochnennykh trushchikhsya poverkhnostey. - M.: Mashinostroenie, 1987. - 304 s.
7. Vereshchaka A. S. Rabotosposobnost´ rezhushchego instrumenta s iznosostoykimi pokrytiyami. - M.: Mashinostroenie, 1993. - 336 s.
8. Baranov V. M., Kudryavtsev E. M., Martynenko S. P. Akusticheskaya metodika opredeleniya kharakteristik uprugosti i vnutrennego treniya materialov v shirokom intervale temperatur. - Problemy prochnosti. 1989. № 6. S. 116-119.
9. Lanovenko E. V. Issledovanie akusticheskikh svoystv metallov i splavov v oblasti fazovykh perekhodov / Avtoref. diss. k. t. n.: Komsomol´sk-na-Amure: KnAGTU, 2000. - 23 s.
10. Fizicheskaya akustika / Pod red. U. Mezon - M.: Mir, 1968.
11. Chigrin Yu. L. Issledovanie, razrabotka i poluchenie gradientnykh instrumental´nykh materialov na osnove tugoplavkikh metallov i ikh soedineniy / Dis. k. t. n. - Blagoveshchensk, 1999. - 159 s.
12. Konakov A. V., Emel´yanov E. N. Sposob opredeleniya fiziko-mekhanicheskikh svoystv mnogosloynykh i poverkhnostno-uprochnennykh materialov. Patent RF № 2219518. Zayavl. 12.08.2002; opubl. 20.12.2003.
13. Konakov A. V., Emel´yanov E. N. Sposob opredeleniya fiziko-mekhanicheskikh svoystv mnogosloynykh i poverkhnostno-uprochnennykh materialov. Patent RF № 2227281. Zayavl. 12.08.2002; opubl. 20.04.2004.
14. Konakov A.V., Emel´yanov E.N.Sposob opredeleniya fiziko-mekhanicheskikh svoystv materiala s pokrytiem. Patent RF № 2219519. Zayavl. 12.08.2002; opubl. 20.12.2003.
15. Konakov A. V., Emel´yanov E. N. Sposob opredeleniya fiziko-mekhanicheskikh svoystv materiala s pokrytiem. Patent RF № 2220412. Zayavl. 12.08.2002; opubl. 27.12.2003.
16. Fadeev V. S., Verkhoturov A. D., Emel´yanov E. N. Razrabotka i issledovanie materiala instrumental´nogo naznacheniya s poverkhnostnym gradientom uprugikh svoystv. - Perspektivnye materialy. 2003. № 1. S. 73-80..
