Use of Nanoindentation and Silviscan to Determine the Mechanical Properties of 10 Hardwood Species

The objectives of this study were to investigate the properties of bulk wood and cell walls of 10 hardwoods, Alder Birch (Betula spp.), Asian White Birch (Betula platyphylla spp.), Manchurian Ash (Fraxinus mandshurica spp.), Mongolian Oak (Quercus spp.), Poplar (Populus spp.), Red Oak (Quercus spp), White Oak (Quercus spp.), Iroko (Chlorophora excelsa spp.), Keranji (Dialium spp.), and Kwila (Intsia spp.). The relationship between wood species and mechanical properties as well as the relativity of wood species and microfibril angle to the hardness and elastic modulus were investigated. It showed that lower density hardwoods had higher microfibril angle than higher density hardwoods. The elastic moduli of bulk wood and cell walls of wood were both significantly different, whereas the hardness of the cell wall was not significantly different among the 10 species. The SilviScan elastic modulus increased with wood density and decreased with microfibril angle. At the cell wall level, the elastic modulus and hardness obtained by nanoindentation were more related to the properties of natural libriform fibers. However, there was no significant trend found for the hardness of the cell wall as affected by either wood bulk density or microfibril angle