I frequently describe learning to weld as one of the most empowering breakthroughs in my growth as a designer. All new fabrication skills open new opportunities to dream a little (or a lot) bigger, and welding suddenly let me see much more of the sorts of things around me as achievable by my own hand.
In general, I like to work on a principle that if I can find a way to enjoy the practice, the result will be both better and more authentic. (This is key not only to welding, but any skill). So I set out to find fun little excercises to practice welding on.
One of these excercises was making rings from square and round tubing. If you have a saw that can cut accurate angles repeatably, it’s easy to turn out a set of parts that will fit into a nice ring, with lots of seams to practice welding together. Below are the first such rings I undertook, when practicing TIG-brazing mild steel rings with silicon bronze filler metal. Along the way, I realized with delight that here was a great excuse to destructively test something, too. Thus, the video at the bottom, which shows one frame per hydraulic-pump-stroke, as I crushed the first ring and observed its failure modes.
I’ve been playing with a new process in which I remove the silvering of mirrors in detailed patterns, leaving optically clear glass.
My first experiment was to make a Zone Plate, but my current process didn’t have enough resolution to make fine enough lines for a zone plate of short focal length at normal visible wavelengths around 600nm:
However, the process is fantastic for barrier grid a.k.a. moiré a.k.a. ‘strip’ animations, and for an afternoon project this has borne incredible fruit: only about a dozen promising directions to go from here! I decided to focus first on making an animated cautionary text and moving image safety sign for vehicles, especially bicycles, especially helpful for night-time visibility.
Grey Iron and Ductile Iron Pipe are the dominant conveyances of water and sewage in American infrastructure. These types of iron have carbon and iron constituents whose relative distribution and crystal sizes determine their mechanical properties. Over time, this material are susceptible to ‘graphitization corrosion’ in which either graphite particles migrate and aggregate (typically at temperatures above 800F) or in which local electrochemical corrosion at room temperature results in preferential loss of the iron / ferrite constituent of the matrix. When this happens, the pipe becomes brittle, and mechanical insults like vibration or thermal stresses can exceed the flexibility of this now brittle material, leading to brittle failure and cracks. However, this corrosion can be invisible, because the remainder graphite particles are cohesive and the pipe appears physically unchanged.
During road work, construction, and maintenance operations, these pipes are visually inspected, but because pipes experiencing graphitization corrosion often look physically unchanged – the graphite material remains in the same contour as the original material, a method of detecting the change in properties of the pipe was needed which did not depend on visual changes, or subjective “bang on it with a hammer” subjective methodology, as was the state of the art previously. We needed a non-destructive method of detecting the changing properties of the pipe.
The insight of this patent is that the changing microstructure of the graphitized material has reduced magnetic properties due to the loss of iron. This could be sensed by measuring the magnetic permeability of the pipe, or it’s consequential magnetic measurements like inductance or the force developed within a fixed magnetic field. At the urging of my mentor Dr. Mehrooz Zamanzadeh, President and Principal Scientist of Matco Services, and with my assistant Sam, I developed a prototype sensor and confirmed that magnetic flux concentration, magnetic force, and inductance measurements are all viable methods of non-destructive detection of changed microstructure and ferrite loss in grey iron and ductile iron pipe. US Patent 8154279 was issued on April 10th 2012 for “Non-destructive testing apparatus for the detection of graphitization of iron”