This indeed does not look like any sintering MLS or otherwise surface I’ve seen which looks like this https://assets.newatlas.com/dims4/default/0c9b8ea/2147483647...

Edit closed surface finish I’ve seen is indeed of a Laser Assisted DED here is a research published this year https://www.sciencedirect.com/science/article/pii/S221486042...

Good reference right here.

Just because Apple is using space-grade titanium (likely Ti-6Al-4V) for the new Watch case doesn’t necessarily mean the same material or process is being used for the USB-C housing. As mentioned in the video, the scratch resistance of the watch case appears to be higher than that of the USB housing. This could be due to differences in surface finishing, post-processing, microstructure, or even different base materials. Scratch resistance generally correlates with hardness, which in turn scales with yield strength of the material.

Regarding the manufacturing method, based on the sectioned images and visible layer patterns, the USB housing does appear to be additively manufactured, likely SLM or DED, not binder jetting. However, those optical images alone don’t provide enough evidence to pin the exact AM process used. The visible "fish scale" surface texture could result from either Directed Energy Deposition (DED) or Powder Bed Fusion (PBF/SLM) since fish scale morphology is a result of remelting of the previous deposited tracks. Without cross-sectional images showing the interface between the housing and the substructure, it's hard to tell whether the part was printed directly onto the assembly (DED-fashion), or printed separately (SLMEd) and then soldered on. Even some additional simple SEM images that reveals the microstructure at 50 micron scale would give more information since DED and SLM have inherently different cooling rate that gives different grain morphology and pattern in sub-micron scale.

Worth noting that while DED has advanced enough to achieve relatively fine resolution today, DED Titanium typically exhibit higher ductility and lower strength/hardness compared to PBF, due to its beta-phase dominated microstructure as opposed to the alpha dominated structure + martensitic phase in PBF. A scale bar on the optical images would’ve helped estimate melt pool size or hatch spacing, giving more insight into the process used. As it stands, we can speculate, but more detailed characterization is needed to be 100 % sure. Cheers

Could it be post processed by milling?