Introduction To Common Alloy Phases

Alloys typically contain multiple atomic arrangement structures. These different structures are called alloy phases. Different alloy phases have different effects on the properties of the alloy. The phases that are beneficial to the performance of the alloy are called strengthening phases, while the phases that are not beneficial to the alloy's performance are called harmful phases. The following table shows the common phases in high-temperature alloys and their effects:

The alloy phase is usually formed during the cooling process of the alloy. During the melting process, the alloy is initially in a liquid state. At this time, the atoms in the alloy are arranged randomly. When the liquid alloy cools down, the alloy gradually turns into a solid. During this process, the atoms in the alloy start to gather and form certain arrangement rules. This process is called crystallization. In the crystallization process of superalloys, crystals with different structures are often produced simultaneously. These different structures are called different phases. The process of generating these phases is called liquid phase transformation.

In addition, alloys will also form new phases during the heat treatment process. During the heat treatment process, the alloy is heated to a higher temperature and cooled at a certain rate. During the cooling process, the structure of the alloy will undergo reorganization. This process is called recrystallization. During recrystallization, sometimes new phases are generated. This phenomenon is called solid phase transformation. The type and quantity of the phase finally precipitated during the recrystallization process are closely related to the heat treatment temperature and cooling rate.