It is a common term that we have all heard ones of times, “metrology”, just sort of rolls off the tongue… If you don’t know what metrology is, don’t feel less-than, it’s really just a fancy way of saying “the science of measurement.” Yessir, you are about to get a primer on measuring things. Jokes aside, this is a serious fundamental science that most of us take for granted. Any machinist reading this will likely have a bit of steam coming out of their ears by now.

EPARTRADE (Electronic Performance And Racing Trade), the racing industry group created to bring racing manufacturers together with racers, recently released a webinar all about the developments in nano-precision measurements and tribology in the racing industry. Hosted by Francisque Savinien, Judy Kean, and three-time NASCAR champion crew chief Jeff Hammond. This is a deep dive into the finer points of product development in the world of specialty coatings.

Understanding Material Performance Through Metrology

Material interaction is crucial in developing anything, but for race components, friction and wear must be the prime focus at both the material and surface level. What compound of tires you need, how will the brake pads react to the brake rotor surface — all of these things can rob power and performance from your race car if gotten wrong. The same is true of the internal components of your engine. But that is much harder to measure.

“I manage our optical and stylus profilometers that are used to measure the surface of the material,” explains Robert Wang of Bruker Corporation, which is a scientific measuring instrument manufacturer. “You can get a better idea of the performance of a gearing shaft or a steering rod, the properties of brakes, to analyze what you’re doing on the back end with your manufacturing, and then how that affects the front end performance of your vehicle.” Essentially, this gets down to the molecular level to determine actual performance.

Tribology studies friction and wear; this image shows the typical types of friction that the Bruker machines test.

Wang explains how the surface of your paint affects drag over the vehicle. This isn’t using yarn as a makeshift wind tunnel; this gets ultra granular. Analyzing surface parameters at a molecular level can help understand how changes to the surface will impact performance, including drag, and techniques such as polishing or changing specific properties can be used to reduce drag.

By using a profilometer (a device that measures the surface finish at a microscopic level) or tribometer (a device used to measure the friction and wear between two surfaces), you can speed up the testing process, reducing how much live testing must be done. A tribometer can help predict which combinations of materials work best, saving time and money with active vehicle testing.

Through different modules and apparatuses, the Tribolab can test pretty much any area of concern in a vehicle.

The Bruker Tribometer, which has been around for over 15 years, is a modular friction and wear tester that allows for the testing of different motions and conditions in one system, making it useful in the automotive industry, where there are many different moving parts. This flexibility allows you to test various types of motion, such as rotary, reciprocating, linear, and block-on-ring. The Tribolab model is configurable to simulate a wide range of tribology and mechanical tests in real-world conditions. It has the ability to test in oil at temperatures from 1,200 degrees-Centigrade to -40 degrees, and variable humidity, allowing you to test parts in the environment they will be in when in use.

Interferometry and Surface Analysis

Interferometry is a technique used for 3D profilometry, looking at a system at an atomic level, and analyzing the small hills and bumps on the surface, producing a 3D image of the surface. Having this level analysis of small features such as surface finish, plays a big role in determining friction and drag, even at high speeds.

Surface roughness is just one parameter that can be used to characterize a surface, and there are many other parameters that can be used to predict how a system will behave, including the use of 3D imaging to analyze surface properties.

Scanning to the atomic level, Interferometry gets down to 1 nanometer.

Applications of Surface Analysis

This system can be used in the automotive industry to look at wear scars on a bearing, the paint on a car, and other surfaces, allowing for the measurement of surface texture changes over time, such as how much a bearing has worn down or how much of a wear scar was produced on a certain part. Looking at worn-down ball bearings, corrosion, and thrust washer tests can help understand the friction and performance of a car, the same way as how tire wear affects grip and traction. Analyzing surface changes helps you to understand how friction affects performance, such as how a tire loses traction due to wear. Once you understand that, you can work to address the issues found and make it better.

When designing a car or driving, factors such as temperature, track conditions, and engine performance, and the system can help predict and analyze these parameters in a lab setting, allowing R&D teams to design better products. The system can help summarize why certain turns might be more difficult and boil it down to a number or set of numbers, allowing for more informed decisions and potentially identifying areas where the material isn’t where it should be.

Designing Better Products by Using Metrology and Tribology in Racing

The system is particularly useful for R&D teams when designing materials for a car, allowing them to make a better car by utilizing the system heavily during the design process. If a driver says they are losing traction in turn 13, you can input these parameters and develop a summary of the issue, which can lead to redesigning parts to yield maximum performance.

These methods can certainly help builders and manufacturers cut down on the extensive live testing by working out hypotheses beforehand, eliminating obvious issues, so the team can get to the solution faster. Understanding how materials behave in different conditions allows you to test before you build. And gaining that knowledge all comes thanks to advanced metrology.