If you work with precision surfaces, you’ve most likely encountered callouts for surface roughness/surface texture. At first glance, roughness may seem straightforward…you run a roughness gage over a surface, it reports a number, and you make sure that the number is within spec. But there’s a LOT more to texture specification and measurement, and it … Read more
Don Cohen decribes Michigan Metrology’s contract measurement services, measurement consulting, and surface roughness/wear/tribology training classes. Learn how Michigan Metrology can help you solve issues related to leaks, squeaks, friction, wear, fit and finish! Download the Michigan Metrology Introduction Presentation (PDF)
3D optical profilers provide high-resolution measurement of surface roughness and shape. Earlier optical profilers were limited by the size of their measurement areas (Field-of-view, or FOV), typically less than 1mm x 1mm. “Stitching” techniques were developed to overcome this limitation by merging many measurements into one single, high-resolution measurement. But long acquisition times and large file … Read more
Thursday, March 28th, 7:30am–1:00pm EST Michigan Metrology, Bruker, and ASM-Detroit are sponsoring a complementary Metal Forming Tribology/Surface Metrology workshop on March 28, 2024, 730am–1pm. The morning session will include a light breakfast and presentations from Martinrea International, General Motors, American Steel Partnership, EQS, Michigan Metrology, and Bruker. Following a complimentary lunch, an open house will … Read more
For a medical device to function over a long lifespan, we need to accurately specify, measure, and control its surface finishes. Yet, most surface finish specifications rely on parameters that give little information about the aspects of texture that will actually impact how the device will function. In this post we’ll look at the kinds … Read more
On November 28, Surface Ventures will be hosting their first Mini-Symposium, gathering renowned experts in the fields of tribology, surface engineering and metrology for a series of presentations on tribological coatings and surfaces. Michigan Metrology’s Don Cohen will be presenting, “Coatings and surface texture spatial wavelengths.” Other speakers will include Prof. Martin Dienwiebel (Karlsruhe Institute … Read more
In this 3-part series we look at the case of dry, sliding friction and discuss how surface roughness and materials impact the surface as a bearing. PART 3 Plasticity Last week we introduced the “plasticity index”1: The higher the plasticity, the more likely the surface will be to deform plastically. From the equation, we can … Read more
In this 3-part series we look at the case of dry, sliding friction and discuss how surface roughness and materials impact the surface as a bearing. PART 1. Real area of contact As a general rule, for a bearing surface that will undergo dry sliding, we want to achieve the lowest possible friction. Several factors … Read more
In my office I have dozens of books that I consider primary engineering texts. But there are a few that I consider essential. Anton van Beek’s Advanced Engineering Design is one such resource. I’ve spent all of this past summer working through it—it seems to cover every topic I’ve come across in my career, including many aspects of tribology and surface metrology. Van Beek gets right to the fundamental knowledge and practical applications.
Key concepts in tribology have often been discovered by trial and error…then made more broadly useful through rigorous work that uncovers the broader understanding. Such is the case of material compatibility. Ernest Rabinowicz went to great lengths to understand the relationship between material properties and wear, to determine the characteristics that work best in sliding … Read more