PECULIARITIES OF THE STRUCTURE FORMATION AND PROPERTIES OF SILUMIN AlSi7 UNDER THE INFLUENCE OF THE NANOFILLER TiC-Al₂O₃

KOMAROV Alexander I., Ph. D. in Eng., Head of the Laboratory of Modification Technologies of Engineering Materials, Joint Institute of Mechanical Engineering of the NAS of Belarus, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

ORDA Dmitriy V., Junior Researcher of the Laboratory of Modification Technologies of Engineering Materials, Joint Institute of Mechanical Engineering of the NAS of Belarus, Minsk, Republic of Belarus

ISKANDAROVA Donata O., Junior Researcher of the Laboratory of Modification Technologies of Engineering Materials, Joint Institute of Mechanical Engineering of the NAS of Belarus, Minsk, Republic of Belarus

The article deals with the structural-phase transformations of the pre-eutectic alloy AlSi7, occurring during its modification by nanoscale composition TiC–α-Al₂O₃, introduced together with micro powders of aluminum or copper. It is shown that the use of micro powders of different nature and morphology has a direct impact on the degree of transformation of the alloy structure. In this case, the introduction of a nanofiller is most effective together with copper powder, the particles of which are represented by dendrites with a developed surface. It is shown that the modification of the alloy by small fractions (0.5 wt.%) of nanofiller leads to dispersion of the structure (reduction of aluminum solid solution dendrites and iron-containing inclusions by 2 and 3 times, respectively), as well as changes in the morphology of intermetallic inclusions. The formation of the modified structure reduces the friction coefficient, increases wear resistance and extends the range of loads. It is shown that the introduction of nanoscale composition TiC–α-Al₂O₃ in the amount of 0.5 wt.% together with the micro powder of copper or aluminum leads to a decrease in the coefficient of friction in 1.8–2 times at loads up to 20 MPa, and the additional introduction of CNT provides an intensive reduction in the coefficient of friction at 30 MPa to values 0.016–0.018. It was found that the use of aluminum micro powders with the introduction of the modifier provides an increase in wear resistance by 1.4–1.6 times, and the use of copper or copper with CNT provides a multiple increase in wear resistance (weight loss on the samples is not fixed), whereas for the initial alloy it is 8.73∙10^–5 mg/m.

nanofiller, titanium carbide, corundum, structure formation, alloy AlSi7, friction coefficient, wear resistance

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