Machine Talk Blog

In friction welding, we always strive toward repeatability—even when there are differences in the length of incoming parts.  This is especially true in the automotive and aerospace industry where finished parts are held to rigid standards.  Using Torque Modulation with Dynamic Profile Modification, we’re able to ensure our first welded part is the same length as our last welded part. 

Our customers—especially those in the automotive industry—rely on repeatable upset in order to meet tight part tolerances.  Remember, upset is the amount of shortening of the two parts as a result of friction welding.

 When it comes to friction welding, we want to work towards repeatability, even when there are incoming part variations.  But how can we do that?  One way is through pressure modulation.

Over the course of this series on upset control, we’ve discussed the repeatability of upset control and part variation in rotary friction welding. Remember, upset is the amount of shortening you get in the part as a result of friction welding.  Upset is different than overall length, which is the total length of the part after welding.

In Part One of this series, we talked about how upset is the amount of shortening of a part resulting from friction welding. Remember, if we had perfect incoming parts then we could fix the amount of energy used to make that weld, and get very repeatable upset. However, incoming parts variations such as area differences, surface conditions, material differences, or even interface “squareness” can cause subtle variations in upset.

In previous Whiteboard Wednesday videos, we discussed the various types and benefits of rotary friction welding. The two most common types that have been discussed are Inertia and Direct Drive Friction. In this post, we’re going to look at an important aspect of these friction welding types: upset control.