Aluminum-Silicon Eutectic Morphology
The spatial distribution and fine microstructure of eutectic phases in cast alloys, which is deliberately altered from needle-like to globular. This maximizes ductility.
Physicochemical Mechanism of Action
The aluminum-silicon eutectic morphology refers to the spatial distribution and structure of eutectic phases in cast alloys. Eutectic phases form when two or more metals are simultaneously liquid and solid at a certain temperature. In aluminum-silicon alloys, an eutectic phase of aluminum-silicon (AlSi) forms, appearing as needle-like crystals in the matrix.
Metallurgical Relevance & Welding Risks
The needle-like distribution of these phases can lead to hot cracking and low ductility, as the needles act as stress raisers. Through targeted modification, this structure is transformed from needle-like to globular, increasing ductility and reducing the risk of cracking.
Shop Practice & Instructions
To achieve improved morphology, it is important to carefully perform the modification of the alloy during casting. This can be achieved by selecting the right modifier and controlling the casting process. A globular structure is achieved by slow cooling and an optimal alloy composition.