Експериментальне дослідження впливу на показники якості виливків одночасної обробки розплаву різними струмами

• Дата: 2023
• Автори: Цуркін, В.М., Іванов, А.В., Жданов, О.О., Честних, М.В., Дьогтєв, Ю.Н., Харитонова, Т.Г.
• Формат: Стаття
• Мова: Англійська
• Опубліковано: Physico-technological Institute of Metals and Alloys 2023
• Теми: Розплав; фізичний експеримент; електричні струми; кристалізаційна здатність; механічні властивості; структурно-фазовий склад; успішність обробки
• Онлайн доступ: https://www.metalsandcasting.com/index.php/mcu/article/view/230
• Назва журналу: Metal and Casting of Ukraine

The purpose of the work is to obtain results that would confirm the effectiveness and perspective of using the methodof simultaneous treatment of a liquid alloy based on Al with different types of currents in foundry technologies.As it is known the different types of current passing through the melt (alternating, constant, pulsed) are differ from eachother by their different functional capabilities. The each types of currents generate electromagnetic fields with differentamplitude-frequency characteristics and distribution, which determine the sphere of influence. The work proposedto use an innovative principle of simultaneous passing of at least two currents with different electrical characteristicsthrough the melt and with different variants of electrode systems. This method made it possible to affect more effectivelyon the structure and properties of the melt and, in turn, improve the service characteristics of the casting.In the work, two series of experiments were performed with the application of melt treatment with three typesof currents and three types of electrode systems in different combinations. Ingot alloys of the Al-Si system wastreated: AK7 (GOST 1583-93), chemical composition: Si (7.3 %); Fe (0.5 %); Cu (0.5 %); Mn (0.07 %); Mg (0.07 %);Zn (0.2 %); Pb (0.01 %), Al base; and non-standard pre-eutectic silumin additionally doped with certain components(Si (8 %); Fe (0.79 %); Cu (1.98 %); Mn (0.1 %); Mg (0.27 %); Zn (0.44 %), Al base). In contrast to the treatment of onetype of current, an increase the mechanical properties of castings and an effective modification of the elements of thesolid state structure were achieved. Thus, for the first grade of alloy, σВ was increased by 13 %, and δ — by 1.5 times.Also after simultaneous treatment with different types of currents with defined modes, the value of Ψ was recorded at thelevel of 4.4 %. For the AK7 alloy, this indicator is not even specified by the standard. For the second grade of alloy, aftersimultaneous treatment with different types of currents, significant grinding of intermetallics to sizes from 8 μm to 11 μmwas observed, while compared to the original sample, there is practically no segregation of the intermetallic componentby size. The structure of the treated samples is distinguished by the grinding of silicon particles in the eutectic. The totalenergy consumption, under certain conditions, for both brands of alloys was reduced by 3 times. The main mechanismof a positive change in the crystallization ability of the melt is formation of electromagnetic fields superposition with morepowerful thermoforce effect in the treatment object by passing different types of currents simultaneously than whenusing one type of current.