Elimination of Negative Effect of Fe in Secondary Alloys AlSi6Cu4 (En Ac 45 000, A 319) by Nickel

Abstract

ELIMINATION OF NEGATIVE EFFECT OF Fe IN SECONDARY ALLOYS AlSi6Cu4 (EN AC 45 000, A 319) BY NICKEL ROLA Ni W ELIMINOWANIU SZKODLIWEGO WPŁYWU FAZ ZAWIERAJĄCYCH Fe W STOPACH WTÓRNYCH AlSi6Cu4(EN AC 45 000, A 319)Submitted article deals with influence of iron based phases segregation by nickel, which is in literature known as iron based phases corrector. Iron is one of the most common impurities that can be found in Al-Si alloys. It is impossible to remove iron from melt by standard operations, but it is possible to eliminate iron negative effects by addition of other elements, that enables segregation of iron in form of intermetallics with less harmful effect. For melt treatment was selected an exact alloy with requested iron content -master alloy AlNi20. Influence of nickel was evaluated quantitatively by chemical analysis (solubility), thermal analysis and microstructure evaluation. Experimental results analysis shows a new view on solubility of iron based phases during melt preparation and treatment with higher iron content and also nickel effect as iron corrector of iron based phases. It can be concluded that nickel did not influenced iron based phases (β-phases), it does not change their type into more favorable form. As an initial impulse for starting this work was insufficient theoretical knowledge of usage secondary alloys Al-Si-Cu with higher iron content and its appropriate elimination in process of castings production for automotive industry. Increased iron content in alloys causes segregation of iron phases in various shapes and types during solidification, which subsequently affects quality, soundness and lifetime of castings. Because of increased demands for casting quality, final mechanical properties and effort to reduce costs, it is necessary to look for compromises in casting production from secondary alloys with occurrence of various impurities.Keywords: Iron based phases, thermal analysis, iron based phases correctors, nickelArtykuł opisuje wpływ dodatku niklu do stopów wtórnych Al-Si-Cu na segregację faz zawierających żelazo, które jest jednym z najpowszechniej występujących zanieczyszczeń w tych stopach. Powszechnie wiadomo, iż nie jest możliwe usunięcie żelaza z kąpieli metalowej, natomiast można ograniczać negatywny jego wpływ poprzez związanie żelaza w fazach między-metalicznych mniej szkodliwych niż fazy β Fe, np. w następstwie dodatku innych pierwiastków. W badaniach do obróbki kąpieli zastosowano zaprawę AlNi20 z dokładnie określoną zawartością żelaza. Oddziaływanie niklu na skład i morfologię faz żelazowych określano na drodze analizy chemicznej (badania rozpuszczalności), analizy termicznej i oceny struktury. Na podstawie wyników badań stwierdzono, iż w badanych stopach nikiel nie wywiera wpływu na zmianę składu fazy β Fe, nie zmienia również kształtu jej wydzieleń do postaci bardziej korzystnej z punktu widzenia wpływu na właściwości.

Iron Intermetallic Phases in the Alloy Based on Al-Si-Mg by Applying Manganese

“…This is due to its high melting point, high specific gravity and hardness which causes the increasing wear of melting devices and deteriorating of the alloy machinability. Except of this, once the sludge phase is formed, it cannot be removed from alloy by further re-melting or re-melting process [1,5].…”

“…It is well known that the Mn and Fe content can influence the type, the size and the ratio of different Fe intermetallic compounds. Furthermore, a Mn/Fe ratio of 0.5 is recommended even though the amount of Mn needed to neutralize Fe has not been well established [4,5].…”

Self-Hardening AlZn10Si8Mg Aluminium Alloy as an Alternative Replacement for AlSi7Mg0.3 Aluminium Alloy

“…The alloy is based on aluminum, zinc and silicon and further additives and supporting elements, wherein the zinc content is between 1 -10 mass %. Despite of high zinc content, this alloy belongs to the typical Al-Si alloys, because it has similar structure than hypoeutectic Al-Si alloys [7,8]. The experimental material has been casted into a sand mold.…”

Heat flow and heat transfer coefficient during crystallization under the pressure

“…The change rate of the thermal content of the solid, the rate of isotherm process and temperature equalization is directly proportional to his thermal conductivity λ and inversely proportional thermal-capacity cabability c.ρ. [1,2,5,6].…”