Salt Water Immersion Corrosion Testing
In a previous corrosion properties post we began a salt water immersion test – explaining results for the first and second month would be coming soon.
A simple salt water immersion corrosion test was set up to get a general idea of the corrosion properties of Liquidmetal alloys. Here are the specimens we tested:
- LM-001 cast plate
- LM-001B cast plate
- LM-105 cast plate
- LM-106 cast plate
- LM-601 cast plate
- LM-601ZB (LM601 + stainless steel unpolished thin sheet
- Titanium grade 3 unpolished thin sheet
All specimens were placed in a tank of slightly agitated salt water at room temperature. All specimens were weighed and micrographed before the test began and after each month.
The micrographs can be seen below. (Note: All micrographs were taken at different locations so we can’t do an exact side-by-side comparison. Instead, these are representative micrographs meant to give a general picture of the surfaces.)
There are no significant signs of corrosion.
In general, there are no significant signs of corrosion or overall uniform attack on the Liquidmetal alloy specimens. We did observe some rounding of previously more pronounced/sharp topography and we could also see some pitting, though sparse.
No visible signs of corrosion could be seen on the stainless steel or titanium specimens either. We may exchange these specimens for thin polished plates instead since we would prefer to have comparable specimen geometries and surface finishes.
The cumulative mass loss after two months was insignificant for all specimens, except for LM-601 and LM601-ZB which had measurable quantities of mass loss, 0.03% & 0.02%, respectively.
Based on these results, we decided to stop the test and set-up a more controlled corrosion test (according to ASTM G31).
Therefore, coming soon…immersion corrosion tests of Liquidmetal alloys in chemical solutions! We’re working on an in-house set-up to test the alloys in more corrosive environments. For now, we are planning on seawater, hydrochloric acid, sulfuric acid, nitric acid, and sodium hydroxide at room and elevated temperatures.