Actual Problems in Machine Building 2018 Vol. 5 No. 1-2

Актуальные проблемы в машиностроении. Том 5. № 1-2. 2018 Материаловедение в машиностроении ____________________________________________________________________ 131 PRODUCTION OF PRESSED BILLETS FROM HYPEREUTECTIC SILUMIN AND THEIR PROPERTIES Prudnikov A.N ., D.Sc. (Engineering), Professor, e-mail: a.prudnikov@mail.ru Prudnikov V.A., Ph.D. student, e-mail: vladpr88@gmail.com Siberian State Industrial University, 42 Kirov st., Novokuznetsk, 654007, Russian Federation Abstract Results of preliminary thermocycling effect draft on the microstructure and mechanical properties of semi-continuous casting of ingots piston hypereutectic silumin based Al-20 % Si. Ingots used for draft vertical type hydraulic press force of 90 MN. Technological parameters of thermocyclic draft: the heating temperature in the cycle was 480-500 ° C, the reduction rate in the first cycle is no more than 15 %, the number of cycles is 4-5. The possibility of pressing of billets after draft from the doped hypereutectic silumin is shown by using the rational thermokinetic parameters of deformation. The parameters of the pressing process are calculated: pressing temperature – 440÷450 ºС; holding time before deformation – 4 h; pressing speed – 0.05÷1 m / mm; the design drawing ratio is 9; the size of the press-residue is 40 mm. The structure and mechanical properties of ingots, billets after draft and pressed rods from piston silumin are studied. It has been established that plastic deformation of doped hypereutectic silumins leads to the crushing of primary silicon crystals in the structure of the billets. The eutectic component (Al + Si) in the deformed silumin becomes a globular form. Changes in the structure of the hypereutectic silumin after deformation provide an increase in the strength and plastic characteristics (σ ts , δ) of the billets. The strength (σ ts ) of the pressed billets from the hypereutectic silumin is 40 % higher than that of the ingot, and the elongation (δ) is more than 2 times higher. Keywords silumin, draft, pressing, deformation thermo-cyclic treatment, structure, mechanical properties.