OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 4 2022 Ta b l e 2 Volumetric changes of the sintered compacts with recycled steel 45 chips, % No. Composition ΔV/V0, % 1 Steel 45 chip powder 6.5 2 Ti + chips (steel 45) –2.7 3 Ti + Al + chips (steel 45) –26.7 appear at once that allow not only increasing the titanium lattice volume, but also affect the dimensional parameters of iron. For comparison, Table 2 shows the volumetric changes after sintering in compacts made from the treated chip without the addition of other components (aluminum and titanium), which demonstrate the standard shrinkage for this case. Conclusions After simple available additional operations of oxidation and grinding, metalworking wastes from steel 45 can be used in powder technologies not only as sources of iron, but also of its oxides. An acceptable powder component-adding can be obtained for further use in multicomponent mixtures for the synthesis of metal-matrix composites based on titanium and aluminum using a simple method of steel chip preparing (treatment). The steel chip is well grinded after additional oxidation in water and actively interacts with the titanium and aluminum base during the vacuum sintering at 1,000 °C. In the case of a mixture with aluminum (Al + chips (steel 45)), the sintering actually is running in the thermal explosion mode, and the results of interaction can be in the form of a multiphase powder product with the synthesized Al2O3 oxide phase. At the selected ratio of components (Ti + chips (steel 45)), interaction with titanium does not lead to any change in the phase composition, although there is a potential to increase the fraction of oxygen due to the greater oxidation of the chip. When using titanium and aluminum as a matrix material with the addition of the grinded chip (Ti + Al + chips (steel 45)), in-situ synthesis of the Al2O3 phase is not excluded if the ratio of components and the level of oxidation of the used steel chip are selected. In this case, there is the development prospect of a new composite material with a fine oxide phase in a metal matrix. Preliminary results of the features analysis of the metal-matrix composites structure formation with the participation of the steel chip under vacuum sintering conditions showed that metalworking waste can be used as an interacting component of the powder mixture after appropriate technological preparation. Further studies will make it possible to determine the working range of the component concentrations, its optimal ratio, which can ensure the certain structural-phase state formation that predetermines the corresponding properties. References 1. D’yakonovO.M. Kompleksnaya pererabotka struzhki i metallosoderzhashchikh shlamov [Integrated processing of chips and metal-containing sludge]. Minsk, Tekhnologiya Publ., 2012. 262 p. 2. D’yakonov O.M. Issledovanie fiziko-khimicheskikh i mekhanicheskikh svoistv stal’noi i chugunnoi struzhki [Investigation of physicochemical and mechanical characteristics of steel and cast iron chips]. Lit’e i metallurgiya = Foundry Production and Metallurgy, 2009, no. 4 (53), pp. 161–173. 3. D’yakonov O.M. Poluchenie metallurgicheskikh briketov na osnove struzhko-poroshkovykh kompozitsii goryachim pressovaniem [Production of metallurgical briquettes on the basis of chips-powder compositions by hot press molding]. Lit’e i metallurgiya = Foundry Production and Metallurgy, 2011, no. 4 (63), pp. 129–137. 4. Rovin S.L., Rovin L.E., Zayac T.M., Valickaya O.M. Pererabotka struzhki chernykh metallov [Processing of ferrous metal shavings]. Lit’e i metallurgiya = Foundry Production and Metallurgy, 2017, no. 4 (89), pp. 94–101. 5. Rovin S.L., Kalinichenko A.S., Rovin L.E. Vozvrashchenie dispersnykh metallootkhodov v proizvodstvo [The return of the dispersed metal waste into production]. Lit’e i metallurgiya = Foundry Production and Metallurgy, 2019, no. 1, pp. 45–48.
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