Cold spray coatings form only when particles clear a critical impact velocity, a threshold set by material properties, particle size and morphology, and native oxide condition. This article looks at what powder-side QC can flag before a spray trial, and where it stops short of predicting deposition efficiency.

Triboelectric separation turns contact electrification from a handling hazard into a deliberate sorting mechanism. This article covers how material pairs are selected by charge polarity, what feed moisture and particle size do to separation efficiency, and where the technique sits relative to density and optical sorting.

Pairing laser diffraction with dynamic image analysis adds per-particle shape descriptors, aspect ratio, circularity, convexity, that help explain an anomalous D50 or D90 and show where the combined result still cannot replace a dedicated particle morphology study.

FDA's proposed hub-and-spoke registration rule treats geographically separate manufacturing units as one establishment. The registration paperwork is new; proving that blend uniformity, granulation endpoints, and moisture behavior actually match between sites is the older, harder problem.