Actual Problems in Machine Building 2015 No. 2

Actual Problems in Machine Building. 2015. N 2 Materials Science in Machine Building ____________________________________________________________________ 450 APPLICATION OF CALCIUM AND MAGNESIUM CARBONATE TREATMENT TO IMPROVE PROPERTIES OF INDUSTRIAL ALUMINUM Popova M.V. , D.Sc. (Engineering), Associate Professor, e-mail: m.popova@rdtc.ru Prudnikov A.N. , D.Sc. (Engineering), Associate Professor, e-mail: a.prudnikov@mail.ru Malyuh M.A., PhD applicant Siberian State Industrial University, 42 Kirov st., Novokuznetsk, 654007, Russian Federation Abstract The results of studies of the effect of melt treatment by carbonates of calcium and magnesium as well as casting crystallization conditions on the temperature coefficient of linear expansion (TCLE) of aluminum are presented. An effect of subsequent heat treatment on the change of aluminum thermal expansion is described. It is noted that by choosing an optimal mode of melt treatment and crystallization it is possible to reduce aluminum A7 thermal expansion at low and medium test temperatures. Subsequent aging of the treated samples stabilizes TCLE. It is established that melt treatment by calcium and magnesium carbonates can significantly reduce thermal expansion of technically pure aluminum to the values characteristic of the alloys Al-11 % Si. Keywords aluminum, temperature coefficient of linear expansion, heat treatment, melt, dolomite