Analysis of hot extrusion process characteristics of titanium rod and titanium alloy rod

The hot extrusion process of titanium and titanium rods is more complex than that of aluminum, copper and even steel. This complexity is mainly due to the special physical and chemical properties of titanium and titanium alloys. The study of metal flow dynamics of industrial titanium alloys shows that the metal flow behavior will change significantly in different phase temperature ranges. Therefore, the heating temperature of the billet, which is a key factor to determine the phase transition state of the metal, has an important influence on the extrusion flow characteristics of titanium and titanium alloy rods. Extrusion at α or α+β phase region temperature results in more uniform metal flow than extrusion at β phase region temperature. However, to obtain high surface quality extruded products for titanium alloy rods is a difficult task. Until now, the extrusion process of titanium alloy rods had to rely on the use of lubricants. This is mainly because titanium at high temperatures of 980 degrees and 1030 degrees will form fusible eutectic crystals with iron - or nickel-based alloy mold materials, resulting in strong wear of the mold.

In the extrusion process, the main factors affecting the metal flow include:

1. The metal flow is more uniform in the reverse extrusion compared with the forward extrusion; Compared with hot extrusion, the metal flow is more uniform. The metal flow is also more uniform in lubricated extrusion than in non-lubricated extrusion. These effects are mainly achieved by changing the friction conditions.

2. Extrusion speed: With the increase of extrusion speed, the non-uniformity of metal flow will be intensified.

3. Extrusion temperature: As the extrusion temperature increases, the deformation resistance of the billet decreases, but the uneven flow of the metal will also be intensified. If the heating temperature of the extrusion cylinder and the mold is too low, the temperature difference between the outer layer and the center layer of the metal increases, and the non-uniformity of the metal flow will also increase.

The better the thermal conductivity of the metal, the more uniform the temperature distribution on the end face of the billet. 4. Metal strength Under the same conditions, the higher the metal strength, the more uniform the metal flow. 5. Die Angle: The greater the die Angle (that is, the Angle between the die end face and the central axis), the more uneven the metal flow. However, when the perforated die is used and the die holes are arranged reasonably, the metal flow tends to be uniform. 6. Degree of deformation Too large or too small will lead to uneven metal flow. In summary, the hot extrusion process characteristics of titanium rods and titanium alloy rods are complex and changeable, and a variety of factors need to be considered comprehensively to ensure the quality and performance of extruded products.

BaoJi DingDing Titanium Products Co.,Ltd.titanium and titanium rods