Why Is Solid Solution Treatment Necessary For Nickel-based Alloys?

Almost all nickel alloys require solution treatment because solution treatment plays a crucial role in enhancing the performance of the alloys. This article will introduce the principles and functions of the solution body from various aspects.

 

From a macroscopic perspective, the solution body is the process of dissolving other metal elements (such as iron, chromium, molybdenum, etc.) into nickel metal. It is similar to the process of dissolving salt in water. However, just as its name suggests, the solution body is the dissolution of solid substances. Due to the slow movement speed of solid atoms, the general solution requires heating the metal to a certain temperature to make the atoms move more freely, thereby achieving the dissolution purpose.

 

From a microscopic perspective, the solution body is the process of other metal elements entering the nickel crystal to form a new face-centered cubic structure. The face-centered cubic crystal after solution is called austenite.

 

The solution process is shown in the following figure:

The main reasons for conducting solid solution treatment on nickel-based alloys include the following aspects:

1. Dissolving the second phase to achieve homogenization

2. Improving high-temperature performance

3. Preparing for subsequent aging treatment

4. Eliminating processing stress and improving plasticity

5. Controlling grain size