The efficiency of electromagnetic treatment for the production of heterogeneous endogenous and exogenous aluminum composites

Processy litʹâ, 2021, Tom 143, №1, p.3-10

Abstract

UDK 621.7.044.7:669.716

The paper considers variants of realization of the complex magnetic-dynamic-vibration in-fluence on metallic melts and hardening of cast aluminum alloys Al7Si, Al7Si, Al12Si2Cu1Mg1Ni for production of cast composite materials strengthened with different types of particles. Their efficiency of four technologies was tested for particles introduction into the melt, and assessment of the  technologies has been made prospects for usage depending on the mode of processing, the type of reinforcing particles, and the aluminum matrix alloy. The ad-vantages and disadvantages of each method of 
particle introduction are highlighted and recom-mendations for their usage are formulated. By the 
methods of metallography and tribological studies were evaluated the uniformity of distribution of reinforcing particles in the metal matrix, the presence of interfacial zone and defects of wetting particles by aluminum melt, the reinforc-ing effect on tribological properties of samples and their contribution to friction surfaces and third body formation. There were shown the reduction of wear of composite materials in comparison with Al7Si alloy in 1,3-1,4 times at approximately identical coefficient of friction. Increasing the duration of electromagnetic treatment with vibration increases the wear resistance of the composite mate-rials. There shown advantages of the technology, where high-modulus amplifier particles (160-200) μm are introduced in the form of a composite ligature, the technology can be used for the production of parts for tribological purposes. The optimal mode of complex processing is deter-mined by induction of alternating magnetic field of MHD processing 0.07-0.09 T; vibration am-plitude 0.4-0.5 mm, frequency 100 Hz; processing time not less than 6 minutes was stated. How-ever, with this technology, the size of the hardener can not be less than 
100 μm, which can in-crease the mechanical properties due to the effect of modifying the cast microstructure of the aluminum matrix of composite castings. In order to obtain composite materials with high struc-tural properties, it is additionally necessary to apply high-energy influence that can effectively grind the hardener directly in the melt without its oxidation or degradation, for example by the action of plasma on the melt.