Development of metallic wood with enhanced physical, mechanical, and thermal conduction properties based on a self-driven penetration mechanism

Abstract

High-performance wood composite materials have attracted an increasing interest in recent years due to their excellent mechanical and thermal properties obtained by wood metallization. However, the existing methods for wood metallization generally result in structural damage to wood cell walls and large amounts of energy consumption caused by high-pressure treatment. Herein, a high-efficiency, energy-saving, self-driven wood metallization method was proposed for the fabrication of metallic wood based on high-low temperature alternating cycle treatment and the control of the moisture content in wood. The results show that a high weight percent gain of 544.65% was reached for the metallic wood with the dimensions of 20 mm × 20 mm × 20 mm. The density of the metallic wood was about 5.85 times higher than that of the unmodified wood. In addition, the compression strength and thermal conductivity of the metallic wood could be up to 3 times and 10 times higher than those of the unmodified wood, respectively. Interestingly, the penetration effect was immune to the wood sample dimensions applied here. The further mechanism analysis of the penetration of the low melting point alloy into the wood suggest that the vacuum effect in the wood channels caused by the change of water in the wood channels with the temperature difference contributed to providing the driving force and reducing the internal resistance, thus achieving rapid penetration. The modified metallic wood with enhanced physical, mechanical, and thermal properties can be potentially utilized in construction and heat-conductive flooring.