Fractography of Fatigue Fracture Surface in Silumin Subjected to Electron-Beam Processing

7th International Scientific Practical Conference "Innovative Technologies in Engineering"

Konovalov, S.V.^1 ; Aksenova, K.V.^1 ; Gromov, V.E.^1 ; Ivanov, Yu F.^2,3 ; Semina, O.A.^1

Siberian State Industrial University, Novokuznetsk, Russia^1

Institute of High Current Electronics, Siberian Branch, Russian Academy of Science, Tomsk, Russia^2

National Research Tomsk Polytechnic University, Tomsk, Russia^3

关键词: Electron beam processing;    Fatigue fracture surfaces;    Intense pulsed electron beam;    Modification process;    Pulsed electron beams;    Safety coefficient;    Subgrain structures;    Surface irradiation;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/142/1/012080/pdf
DOI  :  10.1088/1757-899X/142/1/012080

来源: IOP

【 摘 要 】

The surface modification of the eutectic silumin with high-intensity pulsed electron beam has been carried out. Multi-cycle fatigue tests were performed and irradiation mode made possible the increase in the silumin fatigue life more than 3.5 times was determined. Studies of the structure of the surface irradiation and surface fatigue fracture of silumin in the initial (unirradiated) state and after modification with intense pulsed electron beam were carried out by methods of scanning electron microscopy. It has been shown, that in mode of partial melting of the irradiation surface the modification process of silicon plates is accompanied by the formation of numerous large micropores along the boundary plate/matrix and microcracks located in the silicon plates. A multi-modal structure (grain size within 30-50 μm with silicon particles up to 10 μm located on the boundaries) is formed in stable melting mode, as well as subgrain structure in the form of crystallization cells from 100 to 250 μm in size). Formation of a multi-modal, multi-phase, submicro- and nanosize structure assisting to a significant increase in the critical length of the crack, the safety coefficient and decrease in step of cracks for loading cycle was the main cause for the increase in silumin fatigue life.