Актуальные проблемы в машиностроении №2 2015

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Актуальные проблемы в машиностроении. 2015. №2 Материаловедение
в машиностроении
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FRACTOGRAPHY OF FATIGUE FAILURE OF THE SILUMIN SURFACE SUBJECTED
TO ELECTRON-BEAM PROCESSING
Gromov V.E.1, (Physics and Mathematics), Professor, e-mail:
Alsaraeva K.V.1, Ph.D. student, e-mail:
Ivanov Yu.F.2, (Physics and Mathematics), Professor, e-mail:
Konovalov S.V.1, (Engineering), Associate Professor,
e-mail:
1 Siberian State Industrial University, 42 Kirov Street, Novokuznetsk, 654007, Russian Federation
2 Institute of High Current Electronics, Siberian Branch, Russian Academy of Sciences,
2/3 Prospect Akademicheskii, Tomsk, 634055, Russian Federation
Abstract
Aluminium –silicon alloys having high specific mechanical properties are brittle and difficult-to-
deform materials. It is necessary to essentially improve their structure and plastic properties to
expand the areas of industrial application of these alloys. Material treatment by a high-intensity
pulsed electron beam is an efficient method to modify a part surface and to increase their fatigue
life.
In this study the eutectic silumin surface was modified by a high-intensity pulsed electron beam.
Also, the regularities of the formation of the structure and phase composition of silumin subjected
to high-cycle fatigue tests up to failure were established by methods of modern physical materials
science. Analysis of the surface layer structure revealed the sources of submicrocrack nucleation. It
was also revealed that large silicon plates located on the surface and in the subsurface layer were
the most dangerous stress concentrators.
An irradiation mode increasing the silumin fatigue service life by over 3.5 times was discovered.
It was found that a significant increase in the silumin fatigue life was caused by the formation of a
multi-modal, multi-phase, submicro-and nano- sized structure.
Keywords
structure, silumin, electron beam treatment, fatigue service life, fractography of failure surface