6

For big constructions, there is a survey plan and a few bench marks marked and cemented by the surveyor. Then at the time of excavation there are auto rotating laser levels that cast a level moving beam which is easy to see and follow. there are reflecting mirrors and elevation readers. Excavation is done in stages, from rough to fine contours using ...


5

Chuck is right that there could be some galvanic action contributing to your issue. One other possibility is that your aluminum has been contaminated with steel particles at some point. Your second picture does seem to clearly show rust, which wouldn't be happening if the metal was all aluminum. It's less clear what the issue is in the first picture, but it ...


4

The condensation mechanism of water vapor onto a chilled surface requires not only a chilled surface but also the presence of nucleation seed sites in the surface to kickstart the condensation kinetics. Those nucleation seeds are sites on the surface (usually microscopic pores, crevices or specks of dust) which have a little water already trapped in them. ...


3

Shot peening improves the fatigue life , mostly used for steel springs. It does not change the bulk strength much . Shot peening is also used for aluminum. A very smooth ,polished surface can also improve "strength" in VERY highly stressed high strength steels ( this is likely of little use in ordinary applications ; I measured the effect in hydrogen stress ...


3

Regarding Kamran's citation of laser leveling, note that this technique is also used to produce rice fields covering tens to hundreds of acres with very precise drainage slopes. In this case, the earth moving machine receives the light flashes from the rotating laser mirror and lifts or lowers the grading blade in response. The machine operator then simply ...


3

You say you have, "some metal parts which are aluminum" - would any of the other parts happen to be stainless steel? Your parts could be experiencing galvanic corrosion, where two dissimilar metals essentially form a battery in the presence of an electrolyte. The electrolyte could be moisture from condensation mixing with chemicals/salt in the air or ...


2

Both materials you have selected are not good candidates for electroplating because they both protect themselves already with an oxide coating. "anodized" is referring to an intentional increased amount of surface oxide to protect the metal. This oxide must be removed, so you really want to ask "how to gold plate aluminum" not anodized aluminum. In order to ...


1

Finishing operations on steel will not affect the hardness significantly. Roughing or forging operations on steel, however, do increase its hardness (by work hardening). Generally, the more a machining process deforms the surface of steel, the harder it becomes. Here is a research article on, Effects of Milling Condition on the Surface Integrity of Hot ...


1

1nm layer is not much: let me remind you that this is roughly 10 atoms thickness... But the good news is that we can easily create very thin films with a process of atomic layer deposition (ALD) The isolating layer could be the classically grown $SiO_2$ (usually grown 0.5-2nm) You could also use $TiO_2$ or $TiO_2/SiN_x$ stack which are also great for ...


1

The most economic thing to do is to use raw material that already has the finish you want. Stainless is most commonly available in a 'Brushed' #4 finish, or a 'mirror' #8 finish, or a number of bead blasted options, although there are a number of other choices like swirl patterns. These will be readily available in both 304 and 316, less common for the more ...


1

The vocabulary word you are looking for is "Color Buffing"; which is the final buffing process of polishing in a single direction. https://www.youtube.com/watch?v=gyOodLNI4BQ http://www.pjtool.com/buffing-polishing-terms.aspx http://expha.com/articles/13/


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