Technical Talk

RSS

The study of heat treatment and the metallurgy of metals is perhaps the oldest science known to man-kind. If one thinks about that statement, you realize that there was a time that humans used only stone for weapons and digging. Then came the age that carried man into the world of metals.

Looking closely at an object and noticing its features and details is a good way to increase our creative powers. Following up on our curiosity is a good way to build a solid foundation of knowledge. Studying natural objects in this way is an excellent entrance to the world of scientific facts.

When visiting a brazing job-shop recently, I was told that one of the shop’s clients insisted that some of their components be re-brazed because the braze fillets were not large enough, according to that client. When I examined the component myself, the braze fillet was actually perfectly OK, but the shop’s client thought that all fillets – welded or brazed – needed to be large.

As every heat treater – captive or commercial – knows, distortion will occur. The heat treater must recognize the many reasons why distortion occurs. This applies to both ferrous and nonferrous materials.

Last month, my right rear-lower molar broke. As shown in Figure 1, the fracture event resulted in a chipped condition.

Most heat treaters have been told by in-house customers, as well as external customers, that we need to have the component “heat treated without distortion.” That is an impossibility.

Spectacular structural collapses sometimes happen due to inadequate strength of the material used to make the structure. But machinery components, subject to stresses from rotational motion and/or vibrations, usually break due to fatigue.

Welcome to my part of “Technical Talk,” where we will discuss brazing, a very important metal-joining technique that continues to grow in usage each year in many industries around the world. Most people are familiar with welding and soldering, but many are not familiar with where brazing might fit into the overall metals-joining landscape.

This column will discuss a brief comparison between low- to high-temperature-deposition methods of surface-modification treatments in relation to thermal-diffusion treatments.

Tooling failure analysis can be very challenging. Frequently, we have to deal with complex loading and multiple simultaneous damage processes. Because the tools are so hard, fracture surface features are often very faint.