A low-corrosivity structural timber

While densified wood emerges as a promising candidate to replace metals in structural applications, joining densified wood is critical to extend its size and shape for practical applications. Here, we investigate the roles of chemical composition and material microstructure in determining corrosion rates by studying the behavior of galvanized low-carbon steel embedded in three wood materials: natural basswood, delignified wood, and densified wood. Delignification selectively reduces acidic precursors, hemicelluloses and lignin, in wood and increases its pH value, which is also more stable at elevated temperatures. Though delignification causes densified wood to be more hydrophilic, the highly dense structure significantly reduces ion diffusion in wood. Both delignification and densification lead to exceptionally low corrosion rates for metal embedded within densified wood. This work sheds light on new approaches to corrosion resistance that can be applied to a broad range of uses for engineered wood.