Bending properties of additively manufactured commercially pure titanium (CPTi) limited contact dynamic compression plate (LC-DCP) constructs: Effect of surface treatment.

Additive manufacturing of metallic materials, a layer-wise manufacturing method, is currently gaining attention in the biomedical industry because of its capability to fabricate complex geometries including customized parts fitting to patient requirements. However, one of the major challenges hindering the full implementation of additively manufactured parts in safety-critical applications is their poor mechanical performance under cyclic loading. This study investigated both quasi-static bending properties (bending stiffness, bending structural stiffness, and bending strength) and bending fatigue properties of additively manufactured (AM) commercially pure titanium (CPTi) limited contact dynamic compression plate (LC-DCP) constructs based on ASTM International standard for metallic bone plates (ASTM F382). In addition, the effect of post surface treatment methods including single shot-peened (SP), dual shot-peened (DP), and chemically assisted surface enhancement (CASE) on bending fatigue performance was also evaluated. Results indicated that bending stiffness and bending structural stiffness of AM CPTi LC-DCPs are comparable to conventionally manufactured (CM) counterparts; however, the bending strength of AM CPTi LC-DCPs is lower than CM counterparts. While the fatigue strength of as-built AM CPTi LC-DCPs is lower compared to the CM counterparts, AM CPTi LC-DCPs after post surface treatments (SP, DP, and CASE) exhibit statistically comparable fatigue strength to the CM CPTi LC-DCPs.