PHYSICO-CHEMICAL METHODS OF INCREASING THE CRACK RESIS- TANCE OF ALLOY AM4.5KD (VAL10). NOTICE 4: COMPARISON OF THE EFFICIENCY OF PHYSICO-CHEMICAL INFLUENCES ON MELTS

Procesi littâ, 2024, Vol 1 (155), 29-38

Abstract

The purpose of the article is to study the effectiveness of ways to increase the crack resistance of AM4.5Kd alloy (VAL10), including modification with rapidly cooled (V_охол.≥103 ^оС/s) ligatures, vibration in the process of solidification of the casting, treatment of the melt with hydrogen and a rotating cooling rotor.To achieve this goal, a special test was developed. Its design makes it possible to assess the susceptibility of the alloy to crack formation by the size and configuration of the hot crack in the casting, to make samples for mechanical tests, which contributes to the determination of productive methods of increasing its crack resistance and properties under various physical and chemical influences on the liquid state.The set of methods used in the work made it possible to obtain data on the effectiveness of the investigated methods of influence, which was calculated by the ratio of the number of castings that solidified without a crack to the total number of castings obtained using one or another action on the melt aimed at preventing the formation of a crack. The ability of the alloy to form cracks, its strength and plasticity after liquid-phase treatment were compared with each other, as well as with control samples obtained in this sample under conditions that exclude the formation of hot cracks and in a mold that provides good feeding of the casting. The obtained results can be used in the practice of foundry production for a reasoned choice of a method of increasing resistance to cracks depending on the technological capabilities of the enterprise and the features of the casting technology at this enterprise. In particular, 100 percent efficiency was shown by modification with a rapidly crystallized aluminum-titanium ligature based on the introduction of 0.15% titanium into the melt, as well as processing of the melt with a rotor. At the same time, in the first case, the strength and plasticity of the cast metal is significantly higher than in the second, and higher than when using other investigated methods.