NIST Smooths Out "Roughness" Debate with High Tech Lasers
January 19, 2008 10:27 AM
comment(s) - last by
Testing sheet metals and stamping dies costs the automotive industry tons of cash, and it's all wrong, wrong, wrong
Sheet metal isn't high-tech stuff, but a lot of work goes into getting it right when it comes to things like the automotive industry. The surface of a stamped piece of metal is an indicator to the amount of stress it can handle and how, when and where it may fail. The standard method of measurement for surface profiling is being called into question for its accuracy after findings from a group of NIST researchers.
Traditionally, the measurements in question were done with an instrument called a profilometer. The simple device, similar to a phonograph needle, is drawn in a line over the surface of a material to measure the often microscopic terrain. After repeated tests, the data from the instrument is averaged to make a "roughness" measurement.
Unfortunately, as the NIST research shows, this method may be terribly inaccurate due to uncertainties and statistical errors when the measurements are extrapolated into a three-dimensional surface.
Rather than using a two-dimensional technique like the profilometer, Mark Stoudt, Joseph Hubbard and Stanley Janet of NIST use an instrument called a scanning laser confocal microscope to make a point-by-point image of a surface. The measured area from one image is roughly 1000 x 800 micrometers long and wide by 20 micrometers deep. The data from each point is then analyzed simultaneously using mathematical techniques to give a more accurate measurement than could be obtained by two-dimensional methods.
One discovery already made on aluminum alloy used in the study is that the generally accepted linear relationship between surface roughness and material deformation for the alloy is wrong. Data from the research suggests a more complicated relationship was hidden by the uncertainties of linear profilometers.
This and the rest of their findings have been published in a paper titled "Using Matrix Methods to Characterize Evolution of Deformation Induced Surface Roughness in Aluminum Sheet" in the journal
Materials Science and Technology
This article is over a month old, voting and posting comments is disabled
RE: A little exagerated...
1/20/2008 2:20:49 AM
If its anything like laser tomography, it should be relatively fast. The technology to read laser feedback has progressed to the point that it can go as fast as you can move the laser. I imagine, that using an instrument to swipe across the metal and measuring variance differentiation, is extremely slow. When you are measuring on a atomic level like that, any small noise or vibration can throw all the measurements off. So, take a process with lasers, that can be speed up 100 times, and the accuracy increased 100 times or more, and you have something worth implementing.
RE: A little exagerated...
1/21/2008 3:24:21 PM
Considering the things we can do with lasers these days, I was a little surprised that they weren't already used for this. Are they really using a mechanical measuring method on a single line and extrapolating that for an entire sheet?
“We do believe we have a moral responsibility to keep porn off the iPhone.” -- Steve Jobs
Latest By Levi Beckerson
Of Turbines Large And Small
May 24, 2011, 9:07 AM
Various Alcohols Shown To Make Various Improvements on Specific Superconductor
January 11, 2011, 8:32 AM
Genetics and Taste Buds; Can Science Build Better Chocolate?
December 27, 2010, 9:01 AM
New UMass Technique Seeks to Replace Petroleum for Industrial Chemicals
November 26, 2010, 7:26 AM
New MIT Nanotech Fights Cancer Naturally
September 20, 2010, 8:30 AM
Genetic Modification Turns Killers Into Saviors
September 16, 2010, 1:13 PM
New Rensselaer Nanocomposite Kills Staph
August 17, 2010, 8:10 AM
Researchers Create Nanoscale Particles For Ultrasound Applications
August 16, 2010, 3:44 PM
NCSU Study To Help Understand Nanoparticles Inside the Body
August 16, 2010, 8:38 AM
New Lithium Metal Phosphate Batteries Made With Wax and Soap
August 13, 2010, 1:10 PM
Creationists are Mad About Google Doodle Depicting Evolution
November 24, 2015, 8:48 PM
DHS and TSA: Whoops, We Missed That 73 Airport Employees May be Terrorists
November 19, 2015, 2:16 PM
Star Wars Spinoff Film "Rogue One", Theme Park Attractions Announced
August 17, 2015, 12:20 PM
SpaceX Falcon 9's Seventh Supply Mission to ISS Ends w/ Fiery Stage 1 Explosion
June 28, 2015, 1:10 PM
Cool Science Video: Glowing Millipede Prowls the Nevada Desert
May 18, 2015, 12:00 PM
Newly Discovered Costa Rican Glass Frog is Kermit's Doppelgänger
April 22, 2015, 11:26 AM
Latest Blog Posts
Sceptre Airs 27", 120 Hz. 1080p Monitor/HDTV w/ 5 ms Response Time for $220
Dec 3, 2014, 10:32 PM
Costco Gives Employees Thanksgiving Off; Wal-Mart Leads "Black Thursday" Charge
Oct 29, 2014, 9:57 PM
"Bear Selfies" Fad Could Turn Deadly, Warn Nevada Wildlife Officials
Oct 28, 2014, 12:00 PM
The Surface Mini That Was Never Released Gets "Hands On" Treatment
Sep 26, 2014, 8:22 AM
ISIS Imposes Ban on Teaching Evolution in Iraq
Sep 17, 2014, 5:22 PM
More Blog Posts
Copyright 2016 DailyTech LLC. -
Terms, Conditions & Privacy Information