1,Why is the rebound of titanium material larger in cold stamping or cold bending? What are the influencing factors?
Titanium in the cold stamping or cold bending of the rebound is larger, because the yield limit of titanium material and the elastic modulus of the ratio of large.
Cold stamping or cold bending is a combination of plastic and elastic deformation process, when the stamped or bent workpiece is unloaded, the elastic deformation of the part of the workpiece to try to restore the original shape and rebound.
Elastic spring back to make the volume of the workpiece, the angularity and radius changes, affecting the accuracy of the workpiece.
There are many factors affecting springback, the most important of which are as follows.
a. The harder the material, the greater the amount of rebound.
b. The lower the modulus of elasticity and the higher the yield limit, the greater the springback.
c. The thicker the part, the higher the stress at the outer edge, and the higher the plastic deformation for a certain value of bending angle, the lower the springback.
d. The greater the deformation, the greater the springback.
e. The springback is greater in unidirectional bending than in polygonal bending.
f. The rebound in free bending is three times greater than that in die stamping.
g. The higher the degree of cold hardening of the metal, the higher the springback; and
h. The amount of springback decreases as the temperature of the workpiece is increased during stamping or bending.
2, titanium in the cutting process should pay attention to what matters?
Titanium material in cutting, processing should be noted that the following characteristics of titanium.
(1) Titanium has a high coefficient of friction, which makes the chips easy to generate high temperature during the cutting process and accelerates the tool wear; (2) Titanium has a high coefficient of friction, which makes the tool wear faster.
(2) The thermal conductivity of titanium is small, the chips are tough and do not curl, the heat generated by the friction with the tip of the tool is almost entirely concentrated on the cutting edge and the forward tilted surface of the tool, which will cause the cutting edge to burn out, therefore, the amount of feed should not be too small, and the cutting speed should not be too high, or it will be easy to stick to the knife and the fine titanium chips will burn and cause accidents.
(3) Due to the small modulus of elasticity of titanium, deep cutting of fine workpiece is prone to deflection, the workpiece is prone to leave the tool, so in the machining of the need to install anti-vibration frame.
(4) Titanium has high temperature activity, easy to cause surface contamination of the workpiece during processing.
(6) cutting titanium, cutting force is small, cutting processing is not easy to produce cutter marks, so it can be higher surface finish processing.
