The shrinkage behavior of the titanium tube in the casting process is similar to other metals. It will go through three stages of liquid shrinkage, solidification shrinkage, and solid shrinkage. According to the difference in shrinkage manifestation, titanium tube casting shrinkage is usually divided into two categories: volume shrinkage and linear shrinkage. Among them, volume shrinkage, as a key process parameter, directly affects the formation characteristics of internal defects of castings. Specifically, the sum of the volumes of concentrated shrinkage cavities and dispersed shrinkage is equal to the total shrinkage. Studying the solidification shrinkage law of titanium alloy is of great significance for controlling the quality of castings and predicting shrinkage defects.
The main factors affecting the solidification shrinkage of titanium tubes include:
1. Alloy composition: Alloy elements directly affect the solidification characteristics by changing the crystallization temperature range. Eutectic titanium alloys in narrow crystallization temperature zones have good fluidity, which is conducive to the formation of concentrated shrinkage cavities; while alloys in wide crystallization temperature zones are prone to shrinkage defects, which is consistent with the trend of alloy fluidity changes.
2. Casting characteristics: The thermal conductivity of the casting material affects the solidification gradient, and the rigid titanium tube casting shrinkage can effectively compensate for shrinkage deformation.
3. Structural design: Structural factors such as differences in pipe wall thickness and geometric shape will change the local cooling rate, thus forming different shrinkage modes.
As an important structural material, titanium tubes are widely used in chemical equipment, aerospace, marine engineering, and other fields due to their excellent strength-to-weight ratio, corrosion resistance, and thermal stability. By reasonably controlling the titanium tube casting shrinkage process parameters, the technical advantages of titanium tubes can be fully utilized, while improving the reliability and service life of equipment, and achieving the simultaneous optimization of production efficiency and economic benefits.
