Mechanical property evaluation of infrastructure and heavy machinery overlay and repair coatings enabled via additive processing

Structural reclamation of stressed components represents a critical focus for enabling low-cost, sustainable manufacturing and recovery of degraded structural metals and alloys. In addition to additive manufacturing processes such as laser cladding and welding, high-velocity impact deposition processes like thermal and cold spray are expanding their usage for restoration of heavy machinery components, military assets, and power generation equipment. These structures often approach their intended design limits and suffer from the combined effects of in-field degradation and corrosion over their service lives, ultimately necessitating potentially costly repair and replacement.

Localized restoration, enabled by thermal or cold spray, has allowed for near full-density repairs and, in some cases, recovery of mechanical properties. However, appropriate property assessment is critical, as simple metallographic analysis of coating density does not always correlate with expected mechanical behavior trends, especially as related to internal cohesion/bonding and substrate adhesion. An integrated mechanical assessment approach is used here to compare the behavior of additive spray deposited materials under load and when constrained by an underlying substrate. These techniques can be used to assess and compare the composite strength, interfacial load transfer, and strain-to-failure of several different thermal and cold spray coating and substrate systems, reflecting "real-world" operation.