Skuibida O. Improving of processes of refining, modification and heat treatment of hypoeutectic silumins made from secondary materials.

The object of research - processes and mechanisms of structure formation, phase transformations, as well as forming of mechanical and service properties of hypoeutectic silumins under the influence of refining, modification and heat treatment. The subject of research - structural state, phase transformations, mechanical and service properties of alloys АК5М2, АК6М2, АК8М3 and АК9М2, produced from secondary raw materials. The purpose of the work is improvement of structure, mechanical and service properties of hypoeutectic silumins, produced from secondary raw materials by means of improvement of refining, modification and heat treatment technology. Research methods are spectral analysis, optical and electron microscopy, static tensile and compression tests; mathematical processing of experimental data with the use of personal computer; regression and correlation analysis. The particularity of changes in the structure of alloys AK5M2, AK6M2 and AK9M2 made from scrap and waste upon the influence of refining-modifying treatment is established. Heat treatment of Al-Si alloys with high iron content is optimized. It is shown that significant improvement of quality of secondary silumins can be achieved by using a complex processing technology, including the refining, modification and heat treatment. Implemented at JSC "Motor Sich". Area of application - metallurgy and machinery.